fix: generate seed if empty on register (fresh install), add JNI debug logging

SignalManager (NEW):
- Dedicated Rust struct with its own QUIC connection to _signal
- Separate JNI handle (nativeSignalConnect/GetState/PlaceCall/etc)
- Kotlin wrapper polls state every 500ms via getState() JSON
- Lives independently of WzpEngine — survives across calls
- connect() blocks briefly on 8MB thread, then recv loop runs on dedicated thread

WzpEngine (CLEANED):
- Back to pure media-only role (audio, codec, FEC, jitter)
- Removed start_signaling/place_call/answer_call methods
- Removed signal_transport/signal_fingerprint from EngineState

CallViewModel:
- Two separate managers: signalManager (persistent) + engine (per-call)
- Two separate polling loops: signalPollJob + statsJob
- Auto-connect to media room when signal polling detects "setup" state
- hangupDirectCall() ends media but keeps signal alive

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.agents/skills/caveman/SKILL.md

@@ -0,0 +1,72 @@
+---
+name: caveman
+description: >
+  Ultra-compressed communication mode. Slash token usage ~75% by speaking like caveman
+  while keeping full technical accuracy. Use when user says "caveman mode", "talk like caveman",
+  "use caveman", "less tokens", "be brief", or invokes /caveman. Also auto-triggers
+  when token efficiency is requested.
+---
+
+# Caveman Mode
+
+## Core Rule
+
+Respond like smart caveman. Cut articles, filler, pleasantries. Keep all technical substance.
+
+## Grammar
+
+- Drop articles (a, an, the)
+- Drop filler (just, really, basically, actually, simply)
+- Drop pleasantries (sure, certainly, of course, happy to)
+- Short synonyms (big not extensive, fix not "implement a solution for")
+- No hedging (skip "it might be worth considering")
+- Fragments fine. No need full sentence
+- Technical terms stay exact. "Polymorphism" stays "polymorphism"
+- Code blocks unchanged. Caveman speak around code, not in code
+- Error messages quoted exact. Caveman only for explanation
+
+## Pattern
+
+```
+[thing] [action] [reason]. [next step].
+```
+
+Not:
+> Sure! I'd be happy to help you with that. The issue you're experiencing is likely caused by...
+
+Yes:
+> Bug in auth middleware. Token expiry check use `<` not `<=`. Fix:
+
+## Examples
+
+**User:** Why is my React component re-rendering?
+
+**Normal (69 tokens):** "The reason your React component is re-rendering is likely because you're creating a new object reference on each render cycle. When you pass an inline object as a prop, React's shallow comparison sees it as a different object every time, which triggers a re-render. I'd recommend using useMemo to memoize the object."
+
+**Caveman (19 tokens):** "New object ref each render. Inline object prop = new ref = re-render. Wrap in `useMemo`."
+
+---
+
+**User:** How do I set up a PostgreSQL connection pool?
+
+**Caveman:**
+```
+Use `pg` pool:
+```
+```js
+const pool = new Pool({
+  max: 20,
+  idleTimeoutMillis: 30000,
+  connectionTimeoutMillis: 2000,
+})
+```
+```
+max = concurrent connections. Keep under DB limit. idleTimeout kill stale conn.
+```
+
+## Boundaries
+
+- Code: write normal. Caveman English only
+- Git commits: normal
+- PR descriptions: normal
+- User say "stop caveman" or "normal mode": revert immediately

.cargo/config.toml

@@ -0,0 +1,5 @@
+[target.aarch64-linux-android]
+linker = "aarch64-linux-android26-clang"
+
+[target.armv7-linux-androideabi]
+linker = "armv7a-linux-androideabi26-clang"

.gitea/workflows/build.yml

@@ -2,187 +2,57 @@ name: Build Release Binaries
 
 on:
   push:
+    branches:
+      - main
+      - 'feat/*'
     tags:
       - 'v*'
+    paths-ignore:
+      - '.gitea/**'
   workflow_dispatch:
-    inputs:
-      targets:
-        description: 'Targets to build (comma-separated: amd64,arm64,armv7,mac-arm64)'
-        required: false
-        default: 'amd64'
 
 env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  # Always builds on push tags. On manual dispatch, reads inputs.
   build-amd64:
-    if: >-
-      github.event_name == 'push' ||
-      contains(github.event.inputs.targets, 'amd64')
     runs-on: ubuntu-latest
     container:
-      image: rust:1-bookworm
+      image: catthehacker/ubuntu:act-latest
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install dependencies
+      - name: Init submodules
-        run: apt-get update && apt-get install -y cmake pkg-config libasound2-dev
-
-      - name: Cache cargo
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: cargo-amd64-${{ hashFiles('Cargo.lock') }}
-          restore-keys: cargo-amd64-
-
-      - name: Build headless binaries
-        run: cargo build --release --bin wzp-relay --bin wzp-client --bin wzp-bench --bin wzp-web
-
-      - name: Build audio client
         run: |
-          cargo build --release --bin wzp-client --features audio
+          git config --global url."https://git.manko.yoga/".insteadOf "ssh://git@git.manko.yoga:222/"
-          cp target/release/wzp-client target/release/wzp-client-audio
+          git submodule update --init --recursive
-          cargo build --release --bin wzp-client
+
+      - name: Install Rust + dependencies
+        run: |
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+          source "$HOME/.cargo/env"
+          apt-get update && apt-get install -y cmake pkg-config libasound2-dev ninja-build
+          rustc --version
+
+      - name: Build relay + tools
+        run: |
+          source "$HOME/.cargo/env"
+          cargo build --release --bin wzp-relay --bin wzp-client --bin wzp-bench --bin wzp-web
 
       - name: Run tests
-        run: cargo test --workspace --lib
-
-      - name: Package
         run: |
-          mkdir -p dist/wzp-linux-amd64
+          source "$HOME/.cargo/env"
-          cp target/release/wzp-relay dist/wzp-linux-amd64/
+          cargo test --workspace --lib
-          cp target/release/wzp-client dist/wzp-linux-amd64/
-          cp target/release/wzp-client-audio dist/wzp-linux-amd64/
-          cp target/release/wzp-web dist/wzp-linux-amd64/
-          cp target/release/wzp-bench dist/wzp-linux-amd64/
-          cp -r crates/wzp-web/static dist/wzp-linux-amd64/
-          cd dist && tar czf wzp-linux-amd64.tar.gz wzp-linux-amd64/
 
-      - name: Upload artifact
+      - name: Upload to rustypaste
-        uses: actions/upload-artifact@v4
-        with:
-          name: wzp-linux-amd64
-          path: dist/wzp-linux-amd64.tar.gz
-
-  build-arm64:
-    if: >-
-      github.event_name == 'push' ||
-      contains(github.event.inputs.targets, 'arm64')
-    runs-on: ubuntu-latest
-    container:
-      image: rust:1-bookworm
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Install cross-compilation tools
-        run: |
-          dpkg --add-architecture arm64
-          apt-get update
-          apt-get install -y cmake pkg-config gcc-aarch64-linux-gnu libc6-dev-arm64-cross
-          rustup target add aarch64-unknown-linux-gnu
-
-      - name: Cache cargo
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: cargo-arm64-${{ hashFiles('Cargo.lock') }}
-          restore-keys: cargo-arm64-
-
-      - name: Build
         env:
-          CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
+          PASTE_AUTH: ${{ secrets.PASTE_AUTH }}
-          CC_aarch64_unknown_linux_gnu: aarch64-linux-gnu-gcc
+          PASTE_URL: ${{ secrets.PASTE_URL }}
         run: |
-          cargo build --release --target aarch64-unknown-linux-gnu \
+          tar czf /tmp/wzp-linux-amd64.tar.gz \
-            --bin wzp-relay --bin wzp-client --bin wzp-bench --bin wzp-web
+            -C target/release wzp-relay wzp-client wzp-web wzp-bench
-
+          ls -lh /tmp/wzp-linux-amd64.tar.gz
-      - name: Package
+          LINK=$(curl -sF "file=@/tmp/wzp-linux-amd64.tar.gz" \
-        run: |
+            -H "Authorization: ${PASTE_AUTH}" \
-          mkdir -p dist/wzp-linux-arm64
+            "https://${PASTE_URL}")
-          cp target/aarch64-unknown-linux-gnu/release/wzp-relay dist/wzp-linux-arm64/
+          echo "Download: ${LINK}"
-          cp target/aarch64-unknown-linux-gnu/release/wzp-client dist/wzp-linux-arm64/
-          cp target/aarch64-unknown-linux-gnu/release/wzp-web dist/wzp-linux-arm64/
-          cp target/aarch64-unknown-linux-gnu/release/wzp-bench dist/wzp-linux-arm64/
-          cp -r crates/wzp-web/static dist/wzp-linux-arm64/
-          cd dist && tar czf wzp-linux-arm64.tar.gz wzp-linux-arm64/
-
-      - name: Upload artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: wzp-linux-arm64
-          path: dist/wzp-linux-arm64.tar.gz
-
-  build-armv7:
-    if: >-
-      github.event_name == 'push' ||
-      contains(github.event.inputs.targets, 'armv7')
-    runs-on: ubuntu-latest
-    container:
-      image: rust:1-bookworm
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Install cross-compilation tools
-        run: |
-          dpkg --add-architecture armhf
-          apt-get update
-          apt-get install -y cmake pkg-config gcc-arm-linux-gnueabihf libc6-dev-armhf-cross
-          rustup target add armv7-unknown-linux-gnueabihf
-
-      - name: Cache cargo
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: cargo-armv7-${{ hashFiles('Cargo.lock') }}
-          restore-keys: cargo-armv7-
-
-      - name: Build
-        env:
-          CARGO_TARGET_ARMV7_UNKNOWN_LINUX_GNUEABIHF_LINKER: arm-linux-gnueabihf-gcc
-          CC_armv7_unknown_linux_gnueabihf: arm-linux-gnueabihf-gcc
-        run: |
-          cargo build --release --target armv7-unknown-linux-gnueabihf \
-            --bin wzp-relay --bin wzp-client --bin wzp-bench --bin wzp-web
-
-      - name: Package
-        run: |
-          mkdir -p dist/wzp-linux-armv7
-          cp target/armv7-unknown-linux-gnueabihf/release/wzp-relay dist/wzp-linux-armv7/
-          cp target/armv7-unknown-linux-gnueabihf/release/wzp-client dist/wzp-linux-armv7/
-          cp target/armv7-unknown-linux-gnueabihf/release/wzp-web dist/wzp-linux-armv7/
-          cp target/armv7-unknown-linux-gnueabihf/release/wzp-bench dist/wzp-linux-armv7/
-          cp -r crates/wzp-web/static dist/wzp-linux-armv7/
-          cd dist && tar czf wzp-linux-armv7.tar.gz wzp-linux-armv7/
-
-      - name: Upload artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: wzp-linux-armv7
-          path: dist/wzp-linux-armv7.tar.gz
-
-  # Release job — creates a release with all artifacts when a tag is pushed
-  release:
-    if: startsWith(github.ref, 'refs/tags/v')
-    needs: [build-amd64]
-    runs-on: ubuntu-latest
-    steps:
-      - name: Download all artifacts
-        uses: actions/download-artifact@v4
-        with:
-          path: artifacts
-
-      - name: Create release
-        uses: softprops/action-gh-release@v2
-        with:
-          files: artifacts/**/*.tar.gz
-          generate_release_notes: true

.gitea/workflows/mirror-github.yml

@@ -0,0 +1,43 @@
+name: Mirror to GitHub
+
+on:
+  push:
+    branches:
+      - main
+      - 'feat/*'
+      - 'feature/*'
+    tags:
+      - '*'
+
+jobs:
+  mirror:
+    runs-on: ubuntu-latest
+    container:
+      image: catthehacker/ubuntu:act-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Push to GitHub
+        env:
+          GH_SSH_KEY: ${{ secrets.GH_SSH_KEY }}
+        run: |
+          mkdir -p ~/.ssh
+          echo "${GH_SSH_KEY}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          ssh-keyscan github.com >> ~/.ssh/known_hosts 2>/dev/null
+
+          git remote add github git@github.com:manawenuz/wzp.git
+
+          # Push the current branch
+          BRANCH="${GITHUB_REF#refs/heads/}"
+          TAG="${GITHUB_REF#refs/tags/}"
+
+          if [ "${GITHUB_REF}" != "${GITHUB_REF#refs/tags/}" ]; then
+            echo "Pushing tag: ${TAG}"
+            git push github "refs/tags/${TAG}" --force
+          else
+            echo "Pushing branch: ${BRANCH}"
+            git push github "HEAD:refs/heads/${BRANCH}" --force
+          fi

.gitignore

@@ -4,3 +4,28 @@
 *.swp
 *.swo
 *~
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+dev-debug.log
+# Dependency directories
+node_modules/
+# Environment variables
+.env
+# Editor directories and files
+.idea
+.vscode
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
+# OS specific
+
+# Taskmaster (local workflow tool)
+.taskmaster/
+.env.example

Cargo.lock

@@ -43,6 +43,12 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "android_log-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85965b6739a430150bdd138e2374a98af0c3ee0d030b3bb7fc3bddff58d0102e"
+
 [[package]]
 name = "android_system_properties"
 version = "0.1.5"
@@ -841,6 +847,27 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "dirs"
+version = "6.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3e8aa94d75141228480295a7d0e7feb620b1a5ad9f12bc40be62411e38cce4e"
+dependencies = [
+ "dirs-sys",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e01a3366d27ee9890022452ee61b2b63a67e6f13f58900b651ff5665f0bb1fab"
+dependencies = [
+ "libc",
+ "option-ext",
+ "redox_users",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "displaydoc"
 version = "0.2.5"
@@ -1754,6 +1781,15 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6d2cec3eae94f9f509c767b45932f1ada8350c4bdb85af2fcab4a3c14807981"
 
+[[package]]
+name = "libredox"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ddbf48fd451246b1f8c2610bd3b4ac0cc6e149d89832867093ab69a17194f08"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.12.1"
@@ -1796,6 +1832,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "matchers"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d1525a2a28c7f4fa0fc98bb91ae755d1e2d1505079e05539e35bc876b5d65ae9"
+dependencies = [
+ "regex-automata",
+]
+
 [[package]]
 name = "matchit"
 version = "0.7.3"
@@ -2074,6 +2119,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "option-ext"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
+
 [[package]]
 name = "os_str_bytes"
 version = "6.6.1"
@@ -2414,6 +2465,17 @@ dependencies = [
  "bitflags 2.11.0",
 ]
 
+[[package]]
+name = "redox_users"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4e608c6638b9c18977b00b475ac1f28d14e84b27d8d42f70e0bf1e3dec127ac"
+dependencies = [
+ "getrandom 0.2.17",
+ "libredox",
+ "thiserror 2.0.18",
+]
+
 [[package]]
 name = "regex"
 version = "1.12.3"
@@ -3325,6 +3387,17 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-android"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12612be8f868a09c0ceae7113ff26afe79d81a24473a393cb9120ece162e86c0"
+dependencies = [
+ "android_log-sys",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-attributes"
 version = "0.1.31"
@@ -3363,10 +3436,14 @@ version = "0.3.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb7f578e5945fb242538965c2d0b04418d38ec25c79d160cd279bf0731c8d319"
 dependencies = [
+ "matchers",
  "nu-ansi-term",
+ "once_cell",
+ "regex-automata",
  "sharded-slab",
  "smallvec",
  "thread_local",
+ "tracing",
  "tracing-core",
  "tracing-log",
 ]
@@ -4179,6 +4256,32 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9edde0db4769d2dc68579893f2306b26c6ecfbe0ef499b013d731b7b9247e0b9"
 
+[[package]]
+name = "wzp-android"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "async-trait",
+ "bytes",
+ "cc",
+ "jni",
+ "libc",
+ "rand 0.8.5",
+ "rustls",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.18",
+ "tokio",
+ "tracing",
+ "tracing-android",
+ "tracing-subscriber",
+ "wzp-codec",
+ "wzp-crypto",
+ "wzp-fec",
+ "wzp-proto",
+ "wzp-transport",
+]
+
 [[package]]
 name = "wzp-client"
 version = "0.1.0"
@@ -4267,6 +4370,8 @@ dependencies = [
  "async-trait",
  "axum 0.7.9",
  "bytes",
+ "chrono",
+ "dirs",
  "futures-util",
  "prometheus",
  "quinn",
@@ -4274,6 +4379,7 @@ dependencies = [
  "rustls",
  "serde",
  "serde_json",
+ "sha2",
  "tokio",
  "toml",
  "tower-http",
@@ -4293,30 +4399,18 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "bytes",
+ "ed25519-dalek",
+ "hkdf",
  "quinn",
  "rcgen",
  "rustls",
  "serde_json",
+ "sha2",
  "tokio",
  "tracing",
  "wzp-proto",
 ]
 
-[[package]]
-name = "wzp-wasm"
-version = "0.1.0"
-dependencies = [
- "chacha20poly1305",
- "getrandom 0.2.17",
- "hkdf",
- "js-sys",
- "rand 0.8.5",
- "raptorq",
- "sha2",
- "wasm-bindgen",
- "x25519-dalek",
-]
-
 [[package]]
 name = "wzp-web"
 version = "0.1.0"

Cargo.toml

@@ -9,7 +9,7 @@ members = [
     "crates/wzp-relay",
     "crates/wzp-client",
     "crates/wzp-web",
-    "crates/wzp-wasm",
+    "crates/wzp-android",
 ]
 
 [workspace.package]
@@ -40,7 +40,7 @@ codec2 = "0.3"
 
 # Crypto
 x25519-dalek = { version = "2", features = ["static_secrets"] }
-ed25519-dalek = { version = "2", features = ["rand_core"] }
+ed25519-dalek = { version = "2", features = ["rand_core", "pkcs8"] }
 chacha20poly1305 = "0.10"
 hkdf = "0.12"
 sha2 = "0.10"

android/.gitignore

@@ -0,0 +1,6 @@
+.gradle/
+build/
+app/build/
+app/src/main/jniLibs/
+local.properties
+keystore/*.jks

android/app/build.gradle.kts

@@ -0,0 +1,85 @@
+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+}
+
+android {
+    namespace = "com.wzp.phone"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.wzp.phone"
+        minSdk = 26  // AAudio requires API 26
+        targetSdk = 34
+        versionCode = 1
+        versionName = "0.1.0"
+        ndk { abiFilters += listOf("arm64-v8a") }
+    }
+
+    signingConfigs {
+        create("release") {
+            storeFile = file("${project.rootDir}/keystore/wzp-release.jks")
+            storePassword = "wzphone2024"
+            keyAlias = "wzp-release"
+            keyPassword = "wzphone2024"
+        }
+        getByName("debug") {
+            storeFile = file("${project.rootDir}/keystore/wzp-debug.jks")
+            storePassword = "android"
+            keyAlias = "wzp-debug"
+            keyPassword = "android"
+        }
+    }
+
+    buildTypes {
+        debug {
+            signingConfig = signingConfigs.getByName("debug")
+            isDebuggable = true
+        }
+        release {
+            signingConfig = signingConfigs.getByName("release")
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+
+    buildFeatures { compose = true }
+    composeOptions { kotlinCompilerExtensionVersion = "1.5.8" }
+
+    ndkVersion = "26.1.10909125"
+}
+
+// cargo-ndk integration: build the Rust native library for Android targets
+tasks.register<Exec>("cargoNdkBuild") {
+    workingDir = file("${project.rootDir}/..")
+    commandLine(
+        "cargo", "ndk",
+        "-t", "arm64-v8a",
+        "-o", "${project.projectDir}/src/main/jniLibs",
+        "build", "--release", "-p", "wzp-android"
+    )
+}
+
+// Skip cargo-ndk in CI/Docker — .so is pre-built into jniLibs
+// tasks.named("preBuild") { dependsOn("cargoNdkBuild") }
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.12.0")
+    implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.7.0")
+    implementation("androidx.activity:activity-compose:1.8.2")
+    implementation(platform("androidx.compose:compose-bom:2024.01.00"))
+    implementation("androidx.compose.ui:ui")
+    implementation("androidx.compose.material3:material3")
+}

android/app/proguard-rules.pro

@@ -0,0 +1,9 @@
+# WZPhone ProGuard rules
+
+# Keep JNI native methods
+-keepclasseswithmembernames class * {
+    native <methods>;
+}
+
+# Keep the WZP engine bridge class
+-keep class com.wzp.phone.engine.** { *; }

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MICROPHONE" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
+
+    <application
+        android:name="com.wzp.WzpApplication"
+        android:label="WZ Phone"
+        android:supportsRtl="true"
+        android:theme="@android:style/Theme.Material.Light.NoActionBar">
+
+        <activity
+            android:name="com.wzp.ui.call.CallActivity"
+            android:exported="true"
+            android:launchMode="singleTask">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <service
+            android:name="com.wzp.service.CallService"
+            android:foregroundServiceType="microphone"
+            android:exported="false" />
+
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
+    </application>
+</manifest>

android/app/src/main/java/com/wzp/WzpApplication.kt

@@ -0,0 +1,38 @@
+package com.wzp
+
+import android.app.Application
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.os.Build
+
+/**
+ * Application entry point for WarzonePhone.
+ *
+ * Creates the notification channel required for the foreground [com.wzp.service.CallService].
+ */
+class WzpApplication : Application() {
+
+    override fun onCreate() {
+        super.onCreate()
+        createNotificationChannel()
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel = NotificationChannel(
+                CHANNEL_ID,
+                "Active Call",
+                NotificationManager.IMPORTANCE_LOW
+            ).apply {
+                description = "Shown while a VoIP call is in progress"
+                setShowBadge(false)
+            }
+            val nm = getSystemService(NotificationManager::class.java)
+            nm.createNotificationChannel(channel)
+        }
+    }
+
+    companion object {
+        const val CHANNEL_ID = "wzp_call_channel"
+    }
+}

android/app/src/main/java/com/wzp/audio/AudioPipeline.kt

@@ -0,0 +1,359 @@
+package com.wzp.audio
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.media.AudioAttributes
+import android.media.AudioFormat
+import android.media.AudioRecord
+import android.media.AudioTrack
+import android.media.MediaRecorder
+import android.media.audiofx.AcousticEchoCanceler
+import android.media.audiofx.NoiseSuppressor
+import android.util.Log
+import androidx.core.content.ContextCompat
+import com.wzp.engine.WzpEngine
+import java.io.BufferedOutputStream
+import java.io.File
+import java.io.FileOutputStream
+import java.io.OutputStreamWriter
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import kotlin.math.pow
+import kotlin.math.sqrt
+
+/**
+ * Audio pipeline that captures mic audio and plays received audio using
+ * Android AudioRecord/AudioTrack APIs running on JVM threads.
+ *
+ * PCM samples are shuttled to/from the Rust engine via JNI ring buffers:
+ * - Capture: AudioRecord → WzpEngine.writeAudio() → Rust encoder → network
+ * - Playout: network → Rust decoder → WzpEngine.readAudio() → AudioTrack
+ *
+ * All audio is 48kHz, mono, 16-bit PCM (matching Opus codec requirements).
+ */
+class AudioPipeline(private val context: Context) {
+
+    companion object {
+        private const val TAG = "AudioPipeline"
+        private const val SAMPLE_RATE = 48000
+        private const val CHANNEL_IN = AudioFormat.CHANNEL_IN_MONO
+        private const val CHANNEL_OUT = AudioFormat.CHANNEL_OUT_MONO
+        private const val ENCODING = AudioFormat.ENCODING_PCM_16BIT
+        /** 20ms frame at 48kHz = 960 samples */
+        private const val FRAME_SAMPLES = 960
+    }
+
+    @Volatile
+    private var running = false
+    /** Playout (incoming voice) gain in dB. 0 = unity. */
+    @Volatile
+    var playoutGainDb: Float = 0f
+    /** Capture (mic) gain in dB. 0 = unity. */
+    @Volatile
+    var captureGainDb: Float = 0f
+    /** Whether to attach hardware AEC. Must be set before start(). */
+    var aecEnabled: Boolean = true
+    /** Enable debug recording of PCM + RMS histogram to cache dir. */
+    var debugRecording: Boolean = false
+    private var captureThread: Thread? = null
+    private var playoutThread: Thread? = null
+
+    // DirectByteBuffers for zero-copy JNI audio transfer.
+    // Allocated as class fields (NOT locals) because ART's JIT OSR
+    // can null local variables when it replaces the stack frame mid-loop.
+    // These survive OSR because they're on the heap.
+    private val captureDirectBuf: ByteBuffer =
+        ByteBuffer.allocateDirect(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
+    private val playoutDirectBuf: ByteBuffer =
+        ByteBuffer.allocateDirect(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
+
+    /** Latch counted down by each audio thread after exiting its loop.
+     *  stop() does NOT wait on this — teardown waits via awaitDrain(). */
+    private var drainLatch: CountDownLatch? = null
+
+    private val debugDir: File by lazy {
+        File(context.cacheDir, "wzp_debug").also { it.mkdirs() }
+    }
+
+    fun start(engine: WzpEngine) {
+        if (running) return
+        running = true
+        drainLatch = CountDownLatch(2) // one for capture, one for playout
+
+        captureThread = Thread({
+            runCapture(engine)
+            drainLatch?.countDown() // signal: capture loop exited, no more JNI calls
+            // Park thread forever — exiting triggers a libcrypto TLS destructor
+            // crash (SIGSEGV in OPENSSL_free) on Android when a JNI-calling thread exits.
+            parkThread()
+        }, "wzp-capture").apply {
+            isDaemon = true
+            priority = Thread.MAX_PRIORITY
+            start()
+        }
+
+        playoutThread = Thread({
+            runPlayout(engine)
+            drainLatch?.countDown() // signal: playout loop exited
+            parkThread()
+        }, "wzp-playout").apply {
+            isDaemon = true
+            priority = Thread.MAX_PRIORITY
+            start()
+        }
+
+        Log.i(TAG, "audio pipeline started")
+    }
+
+    fun stop() {
+        running = false
+        // Don't join threads — they are parked as daemons to avoid native TLS crash.
+        // Don't null thread refs or drainLatch — teardown() needs awaitDrain().
+        Log.i(TAG, "audio pipeline stopped (running=false)")
+    }
+
+    /** Block until both audio threads have exited their loops (max 200ms).
+     *  After this returns, no more JNI calls to the engine will be made. */
+    fun awaitDrain(): Boolean {
+        val ok = drainLatch?.await(200, TimeUnit.MILLISECONDS) ?: true
+        if (!ok) Log.w(TAG, "awaitDrain: audio threads did not drain in 200ms")
+        captureThread = null
+        playoutThread = null
+        drainLatch = null
+        return ok
+    }
+
+    private fun applyGain(pcm: ShortArray, count: Int, db: Float) {
+        if (db == 0f) return
+        val linear = 10f.pow(db / 20f)
+        for (i in 0 until count) {
+            pcm[i] = (pcm[i] * linear).toInt().coerceIn(-32000, 32000).toShort()
+        }
+    }
+
+    private fun computeRms(pcm: ShortArray, count: Int): Int {
+        var sumSq = 0.0
+        for (i in 0 until count) {
+            val s = pcm[i].toDouble()
+            sumSq += s * s
+        }
+        return sqrt(sumSq / count).toInt()
+    }
+
+    private fun parkThread() {
+        try {
+            Thread.sleep(Long.MAX_VALUE)
+        } catch (_: InterruptedException) {
+            // process exiting
+        }
+    }
+
+    private fun runCapture(engine: WzpEngine) {
+        if (ContextCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO)
+            != PackageManager.PERMISSION_GRANTED
+        ) {
+            Log.e(TAG, "RECORD_AUDIO permission not granted, capture disabled")
+            return
+        }
+
+        val minBuf = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_IN, ENCODING)
+        val bufSize = maxOf(minBuf, FRAME_SAMPLES * 2 * 4) // at least 4 frames
+
+        val recorder = try {
+            AudioRecord(
+                MediaRecorder.AudioSource.VOICE_COMMUNICATION,
+                SAMPLE_RATE,
+                CHANNEL_IN,
+                ENCODING,
+                bufSize
+            )
+        } catch (e: SecurityException) {
+            Log.e(TAG, "AudioRecord SecurityException: ${e.message}")
+            return
+        }
+
+        if (recorder.state != AudioRecord.STATE_INITIALIZED) {
+            Log.e(TAG, "AudioRecord failed to initialize")
+            recorder.release()
+            return
+        }
+
+        // Attach hardware AEC if available and enabled in settings
+        var aec: AcousticEchoCanceler? = null
+        var ns: NoiseSuppressor? = null
+        if (aecEnabled) {
+            if (AcousticEchoCanceler.isAvailable()) {
+                try {
+                    aec = AcousticEchoCanceler.create(recorder.audioSessionId)
+                    aec?.enabled = true
+                    Log.i(TAG, "AEC enabled (session=${recorder.audioSessionId})")
+                } catch (e: Exception) {
+                    Log.w(TAG, "AEC init failed: ${e.message}")
+                }
+            } else {
+                Log.w(TAG, "AEC not available on this device")
+            }
+
+            // Attach hardware noise suppressor if available
+            if (NoiseSuppressor.isAvailable()) {
+                try {
+                    ns = NoiseSuppressor.create(recorder.audioSessionId)
+                    ns?.enabled = true
+                    Log.i(TAG, "NoiseSuppressor enabled")
+                } catch (e: Exception) {
+                    Log.w(TAG, "NoiseSuppressor init failed: ${e.message}")
+                }
+            }
+        } else {
+            Log.i(TAG, "AEC disabled by user setting")
+        }
+
+        recorder.startRecording()
+        Log.i(TAG, "capture started: ${SAMPLE_RATE}Hz mono, buf=$bufSize, aec=${aec?.enabled}, ns=${ns?.enabled}")
+
+        val pcm = ShortArray(FRAME_SAMPLES)
+        // Debug: PCM file + RMS CSV
+        var pcmOut: BufferedOutputStream? = null
+        var rmsCsv: OutputStreamWriter? = null
+        val byteConv = ByteBuffer.allocate(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
+        var frameIdx = 0L
+        if (debugRecording) {
+            try {
+                pcmOut = BufferedOutputStream(FileOutputStream(File(debugDir, "capture.pcm")), 65536)
+                rmsCsv = OutputStreamWriter(FileOutputStream(File(debugDir, "capture_rms.csv")))
+                rmsCsv.write("frame,time_ms,rms\n")
+            } catch (e: Exception) {
+                Log.w(TAG, "debug recording init failed: ${e.message}")
+            }
+        }
+        try {
+            while (running) {
+                val read = recorder.read(pcm, 0, FRAME_SAMPLES)
+                if (read > 0) {
+                    applyGain(pcm, read, captureGainDb)
+                    // Zero-copy write via DirectByteBuffer (class field, survives JIT OSR)
+                    captureDirectBuf.clear()
+                    captureDirectBuf.asShortBuffer().put(pcm, 0, read)
+                    engine.writeAudioDirect(captureDirectBuf, read)
+
+                    // Debug: write raw PCM + RMS
+                    if (pcmOut != null) {
+                        byteConv.clear()
+                        for (i in 0 until read) byteConv.putShort(pcm[i])
+                        pcmOut.write(byteConv.array(), 0, read * 2)
+                    }
+                    if (rmsCsv != null) {
+                        val rms = computeRms(pcm, read)
+                        val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
+                        rmsCsv.write("$frameIdx,$timeMs,$rms\n")
+                    }
+                    frameIdx++
+                } else if (read < 0) {
+                    Log.e(TAG, "AudioRecord.read error: $read")
+                    break
+                }
+            }
+        } finally {
+            pcmOut?.close()
+            rmsCsv?.close()
+            recorder.stop()
+            aec?.release()
+            ns?.release()
+            recorder.release()
+            Log.i(TAG, "capture stopped (frames=$frameIdx)")
+        }
+    }
+
+    private fun runPlayout(engine: WzpEngine) {
+        val minBuf = AudioTrack.getMinBufferSize(SAMPLE_RATE, CHANNEL_OUT, ENCODING)
+        val bufSize = maxOf(minBuf, FRAME_SAMPLES * 2 * 4)
+
+        val track = AudioTrack.Builder()
+            .setAudioAttributes(
+                AudioAttributes.Builder()
+                    .setUsage(AudioAttributes.USAGE_VOICE_COMMUNICATION)
+                    .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
+                    .build()
+            )
+            .setAudioFormat(
+                AudioFormat.Builder()
+                    .setSampleRate(SAMPLE_RATE)
+                    .setChannelMask(CHANNEL_OUT)
+                    .setEncoding(ENCODING)
+                    .build()
+            )
+            .setBufferSizeInBytes(bufSize)
+            .setTransferMode(AudioTrack.MODE_STREAM)
+            .build()
+
+        if (track.state != AudioTrack.STATE_INITIALIZED) {
+            Log.e(TAG, "AudioTrack failed to initialize")
+            track.release()
+            return
+        }
+
+        track.play()
+        Log.i(TAG, "playout started: ${SAMPLE_RATE}Hz mono, buf=$bufSize")
+
+        val pcm = ShortArray(FRAME_SAMPLES)
+        val silence = ShortArray(FRAME_SAMPLES)
+        // Debug: PCM file + RMS CSV for playout
+        var pcmOut: BufferedOutputStream? = null
+        var rmsCsv: OutputStreamWriter? = null
+        val byteConv = ByteBuffer.allocate(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
+        var frameIdx = 0L
+        if (debugRecording) {
+            try {
+                pcmOut = BufferedOutputStream(FileOutputStream(File(debugDir, "playout.pcm")), 65536)
+                rmsCsv = OutputStreamWriter(FileOutputStream(File(debugDir, "playout_rms.csv")))
+                rmsCsv.write("frame,time_ms,rms\n")
+            } catch (e: Exception) {
+                Log.w(TAG, "debug playout recording init failed: ${e.message}")
+            }
+        }
+        try {
+            while (running) {
+                // Zero-copy read via DirectByteBuffer (class field, survives JIT OSR)
+                playoutDirectBuf.clear()
+                val read = engine.readAudioDirect(playoutDirectBuf, FRAME_SAMPLES)
+                if (read >= FRAME_SAMPLES) {
+                    playoutDirectBuf.rewind()
+                    playoutDirectBuf.asShortBuffer().get(pcm, 0, read)
+                    applyGain(pcm, read, playoutGainDb)
+                    track.write(pcm, 0, read)
+
+                    // Debug: write raw PCM + RMS
+                    if (pcmOut != null) {
+                        byteConv.clear()
+                        for (i in 0 until read) byteConv.putShort(pcm[i])
+                        pcmOut.write(byteConv.array(), 0, read * 2)
+                    }
+                    if (rmsCsv != null) {
+                        val rms = computeRms(pcm, read)
+                        val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
+                        rmsCsv.write("$frameIdx,$timeMs,$rms\n")
+                    }
+                    frameIdx++
+                } else {
+                    track.write(silence, 0, FRAME_SAMPLES)
+                    // Log silence frames to RMS as 0
+                    if (rmsCsv != null) {
+                        val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
+                        rmsCsv.write("$frameIdx,$timeMs,0\n")
+                    }
+                    frameIdx++
+                    Thread.sleep(5)
+                }
+            }
+        } finally {
+            pcmOut?.close()
+            rmsCsv?.close()
+            track.stop()
+            track.release()
+            Log.i(TAG, "playout stopped (frames=$frameIdx)")
+        }
+    }
+}

android/app/src/main/java/com/wzp/audio/AudioRouteManager.kt

@@ -0,0 +1,142 @@
+package com.wzp.audio
+
+import android.content.Context
+import android.media.AudioDeviceCallback
+import android.media.AudioDeviceInfo
+import android.media.AudioManager
+import android.os.Handler
+import android.os.Looper
+
+/**
+ * Manages audio routing between earpiece, speaker, and Bluetooth devices.
+ *
+ * Wraps [AudioManager] operations and listens for device connection changes
+ * via [AudioDeviceCallback] (API 23+).
+ *
+ * Usage:
+ * 1. Call [register] when the call starts
+ * 2. Use [setSpeaker] and [setBluetoothSco] to switch routes
+ * 3. Call [unregister] when the call ends
+ */
+class AudioRouteManager(context: Context) {
+
+    private val audioManager = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
+    private val mainHandler = Handler(Looper.getMainLooper())
+
+    /** Listener for audio route changes. */
+    var onRouteChanged: ((AudioRoute) -> Unit)? = null
+
+    /** Current active route. */
+    var currentRoute: AudioRoute = AudioRoute.EARPIECE
+        private set
+
+    // -- Device callback (API 23+) -------------------------------------------
+
+    private val deviceCallback = object : AudioDeviceCallback() {
+        override fun onAudioDevicesAdded(addedDevices: Array<out AudioDeviceInfo>) {
+            for (device in addedDevices) {
+                if (device.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO) {
+                    // A Bluetooth headset was connected — optionally auto-switch
+                    onRouteChanged?.invoke(AudioRoute.BLUETOOTH)
+                }
+            }
+        }
+
+        override fun onAudioDevicesRemoved(removedDevices: Array<out AudioDeviceInfo>) {
+            for (device in removedDevices) {
+                if (device.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO) {
+                    // Bluetooth disconnected — fall back to earpiece or speaker
+                    val fallback = if (audioManager.isSpeakerphoneOn) {
+                        AudioRoute.SPEAKER
+                    } else {
+                        AudioRoute.EARPIECE
+                    }
+                    currentRoute = fallback
+                    onRouteChanged?.invoke(fallback)
+                }
+            }
+        }
+    }
+
+    // -- Public API -----------------------------------------------------------
+
+    /** Register the device callback. Call when a call starts. */
+    fun register() {
+        audioManager.registerAudioDeviceCallback(deviceCallback, mainHandler)
+    }
+
+    /** Unregister the device callback and release Bluetooth SCO. Call when the call ends. */
+    fun unregister() {
+        audioManager.unregisterAudioDeviceCallback(deviceCallback)
+        stopBluetoothSco()
+    }
+
+    /**
+     * Enable or disable the loudspeaker.
+     *
+     * When enabling speaker, Bluetooth SCO is disconnected.
+     */
+    @Suppress("DEPRECATION")
+    fun setSpeaker(enabled: Boolean) {
+        if (enabled) {
+            stopBluetoothSco()
+        }
+        audioManager.isSpeakerphoneOn = enabled
+        currentRoute = if (enabled) AudioRoute.SPEAKER else AudioRoute.EARPIECE
+        onRouteChanged?.invoke(currentRoute)
+    }
+
+    /**
+     * Enable or disable Bluetooth SCO (Synchronous Connection Oriented) audio.
+     *
+     * When enabling Bluetooth, the speaker is turned off.
+     */
+    @Suppress("DEPRECATION")
+    fun setBluetoothSco(enabled: Boolean) {
+        if (enabled) {
+            audioManager.isSpeakerphoneOn = false
+            audioManager.startBluetoothSco()
+            audioManager.isBluetoothScoOn = true
+            currentRoute = AudioRoute.BLUETOOTH
+        } else {
+            stopBluetoothSco()
+            currentRoute = AudioRoute.EARPIECE
+        }
+        onRouteChanged?.invoke(currentRoute)
+    }
+
+    /** Check whether a Bluetooth SCO device is currently connected. */
+    fun isBluetoothAvailable(): Boolean {
+        val devices = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS)
+        return devices.any { it.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO }
+    }
+
+    /** List available output audio routes. */
+    fun availableRoutes(): List<AudioRoute> {
+        val routes = mutableListOf(AudioRoute.EARPIECE, AudioRoute.SPEAKER)
+        if (isBluetoothAvailable()) {
+            routes.add(AudioRoute.BLUETOOTH)
+        }
+        return routes
+    }
+
+    // -- Internal -------------------------------------------------------------
+
+    @Suppress("DEPRECATION")
+    private fun stopBluetoothSco() {
+        if (audioManager.isBluetoothScoOn) {
+            audioManager.isBluetoothScoOn = false
+            audioManager.stopBluetoothSco()
+        }
+    }
+}
+
+/** Audio output route. */
+enum class AudioRoute {
+    /** Phone earpiece (default for calls). */
+    EARPIECE,
+    /** Built-in loudspeaker. */
+    SPEAKER,
+    /** Bluetooth SCO headset/headphones. */
+    BLUETOOTH
+}

android/app/src/main/java/com/wzp/data/SettingsRepository.kt

@@ -0,0 +1,203 @@
+package com.wzp.data
+
+import android.content.Context
+import android.content.SharedPreferences
+import com.wzp.ui.call.ServerEntry
+import org.json.JSONArray
+import org.json.JSONObject
+import java.security.SecureRandom
+
+/**
+ * Persists user settings via SharedPreferences.
+ *
+ * Stores: servers, default server index, room name, alias, gain values,
+ * IPv6 preference, and the identity seed (hex-encoded 32 bytes).
+ */
+class SettingsRepository(context: Context) {
+
+    private val prefs: SharedPreferences =
+        context.applicationContext.getSharedPreferences("wzp_settings", Context.MODE_PRIVATE)
+
+    companion object {
+        private const val KEY_SERVERS = "servers_json"
+        private const val KEY_SELECTED_SERVER = "selected_server"
+        private const val KEY_ROOM = "room_name"
+        private const val KEY_ALIAS = "alias"
+        private const val KEY_PLAYOUT_GAIN = "playout_gain_db"
+        private const val KEY_CAPTURE_GAIN = "capture_gain_db"
+        private const val KEY_PREFER_IPV6 = "prefer_ipv6"
+        private const val KEY_IDENTITY_SEED = "identity_seed_hex"
+        private const val KEY_AEC_ENABLED = "aec_enabled"
+        private const val KEY_DEBUG_RECORDING = "debug_recording"
+        private const val KEY_RECENT_ROOMS = "recent_rooms"
+        private const val TOFU_PREFIX = "tofu_"
+    }
+
+    // --- Servers ---
+
+    fun saveServers(servers: List<ServerEntry>) {
+        val arr = JSONArray()
+        servers.forEach { entry ->
+            arr.put(JSONObject().apply {
+                put("address", entry.address)
+                put("label", entry.label)
+            })
+        }
+        prefs.edit().putString(KEY_SERVERS, arr.toString()).apply()
+    }
+
+    fun loadServers(): List<ServerEntry>? {
+        val json = prefs.getString(KEY_SERVERS, null) ?: return null
+        return try {
+            val arr = JSONArray(json)
+            (0 until arr.length()).map { i ->
+                val obj = arr.getJSONObject(i)
+                ServerEntry(obj.getString("address"), obj.getString("label"))
+            }
+        } catch (_: Exception) { null }
+    }
+
+    fun saveSelectedServer(index: Int) {
+        prefs.edit().putInt(KEY_SELECTED_SERVER, index).apply()
+    }
+
+    fun loadSelectedServer(): Int = prefs.getInt(KEY_SELECTED_SERVER, 0)
+
+    // --- Room ---
+
+    fun saveRoom(name: String) { prefs.edit().putString(KEY_ROOM, name).apply() }
+    fun loadRoom(): String = prefs.getString(KEY_ROOM, "android") ?: "android"
+
+    // --- Alias ---
+
+    fun saveAlias(alias: String) { prefs.edit().putString(KEY_ALIAS, alias).apply() }
+
+    /**
+     * Load alias, generating a random name on first launch.
+     */
+    fun getOrCreateAlias(): String {
+        val existing = prefs.getString(KEY_ALIAS, null)
+        if (!existing.isNullOrEmpty()) return existing
+        val name = generateRandomName()
+        prefs.edit().putString(KEY_ALIAS, name).apply()
+        return name
+    }
+
+    private fun generateRandomName(): String {
+        val adjectives = listOf(
+            "Swift", "Silent", "Brave", "Calm", "Dark", "Fierce", "Ghost",
+            "Iron", "Lucky", "Noble", "Quick", "Sharp", "Storm", "Wild",
+            "Cold", "Bright", "Lone", "Red", "Grey", "Frosty", "Dusty",
+            "Rusty", "Neon", "Void", "Solar", "Lunar", "Cyber", "Pixel",
+            "Sonic", "Hyper", "Turbo", "Nano", "Mega", "Ultra", "Zinc"
+        )
+        val nouns = listOf(
+            "Wolf", "Hawk", "Fox", "Bear", "Lynx", "Crow", "Viper",
+            "Cobra", "Tiger", "Eagle", "Shark", "Raven", "Falcon", "Otter",
+            "Mantis", "Panda", "Jackal", "Badger", "Heron", "Bison",
+            "Condor", "Coyote", "Gecko", "Hornet", "Marten", "Osprey",
+            "Parrot", "Puma", "Raptor", "Stork", "Toucan", "Walrus"
+        )
+        val adj = adjectives.random()
+        val noun = nouns.random()
+        return "$adj $noun"
+    }
+
+    // --- Gain ---
+
+    fun savePlayoutGain(db: Float) { prefs.edit().putFloat(KEY_PLAYOUT_GAIN, db).apply() }
+    fun loadPlayoutGain(): Float = prefs.getFloat(KEY_PLAYOUT_GAIN, 0f)
+
+    fun saveCaptureGain(db: Float) { prefs.edit().putFloat(KEY_CAPTURE_GAIN, db).apply() }
+    fun loadCaptureGain(): Float = prefs.getFloat(KEY_CAPTURE_GAIN, 0f)
+
+    // --- IPv6 ---
+
+    fun savePreferIPv6(prefer: Boolean) { prefs.edit().putBoolean(KEY_PREFER_IPV6, prefer).apply() }
+    fun loadPreferIPv6(): Boolean = prefs.getBoolean(KEY_PREFER_IPV6, false)
+
+    // --- AEC ---
+
+    fun saveAecEnabled(enabled: Boolean) { prefs.edit().putBoolean(KEY_AEC_ENABLED, enabled).apply() }
+    fun loadAecEnabled(): Boolean = prefs.getBoolean(KEY_AEC_ENABLED, true)
+
+    // --- Debug recording ---
+
+    fun saveDebugRecording(enabled: Boolean) { prefs.edit().putBoolean(KEY_DEBUG_RECORDING, enabled).apply() }
+    fun loadDebugRecording(): Boolean = prefs.getBoolean(KEY_DEBUG_RECORDING, false)
+
+    // --- Codec choice ---
+    // 0 = Opus (GOOD), 1 = Opus Low (DEGRADED), 2 = Codec2 (CATASTROPHIC)
+    fun saveCodecChoice(choice: Int) { prefs.edit().putInt("codec_choice", choice).apply() }
+    fun loadCodecChoice(): Int = prefs.getInt("codec_choice", 0)
+
+    // --- Identity seed ---
+
+    /**
+     * Get or generate the identity seed. On first call, generates a random
+     * 32-byte seed and persists it. Subsequent calls return the same seed.
+     */
+    fun getOrCreateSeedHex(): String {
+        val existing = prefs.getString(KEY_IDENTITY_SEED, null)
+        if (!existing.isNullOrEmpty()) return existing
+        val seed = ByteArray(32).also { SecureRandom().nextBytes(it) }
+        val hex = seed.joinToString("") { "%02x".format(it) }
+        prefs.edit().putString(KEY_IDENTITY_SEED, hex).apply()
+        return hex
+    }
+
+    fun loadSeedHex(): String = prefs.getString(KEY_IDENTITY_SEED, "") ?: ""
+
+    fun saveSeedHex(hex: String) {
+        prefs.edit().putString(KEY_IDENTITY_SEED, hex).apply()
+    }
+
+    // --- Recent rooms ---
+
+    data class RecentRoom(val relay: String, val room: String)
+
+    fun addRecentRoom(relay: String, room: String) {
+        val rooms = loadRecentRooms().toMutableList()
+        rooms.removeAll { it.relay == relay && it.room == room }
+        rooms.add(0, RecentRoom(relay, room))
+        if (rooms.size > 5) rooms.subList(5, rooms.size).clear()
+        val arr = JSONArray()
+        rooms.forEach { arr.put(JSONObject().apply { put("relay", it.relay); put("room", it.room) }) }
+        prefs.edit().putString(KEY_RECENT_ROOMS, arr.toString()).apply()
+    }
+
+    fun loadRecentRooms(): List<RecentRoom> {
+        val json = prefs.getString(KEY_RECENT_ROOMS, null) ?: return emptyList()
+        return try {
+            val arr = JSONArray(json)
+            (0 until arr.length()).map { i ->
+                val o = arr.getJSONObject(i)
+                RecentRoom(o.getString("relay"), o.getString("room"))
+            }
+        } catch (_: Exception) { emptyList() }
+    }
+
+    fun clearRecentRooms() {
+        prefs.edit().remove(KEY_RECENT_ROOMS).apply()
+    }
+
+    // --- Server fingerprint TOFU ---
+
+    fun saveServerFingerprint(address: String, fingerprint: String) {
+        prefs.edit().putString("$TOFU_PREFIX$address", fingerprint).apply()
+    }
+
+    fun loadServerFingerprint(address: String): String? {
+        return prefs.getString("$TOFU_PREFIX$address", null)
+    }
+
+    // --- Ping RTT cache ---
+
+    fun savePingRtt(address: String, rttMs: Int) {
+        prefs.edit().putInt("ping_rtt_$address", rttMs).apply()
+    }
+
+    fun loadPingRtt(address: String): Int {
+        return prefs.getInt("ping_rtt_$address", -1)
+    }
+}

android/app/src/main/java/com/wzp/debug/DebugReporter.kt

@@ -0,0 +1,198 @@
+package com.wzp.debug
+
+import android.content.Context
+import android.util.Log
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.BufferedOutputStream
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.zip.ZipEntry
+import java.util.zip.ZipOutputStream
+
+/**
+ * Collects call debug data (audio recordings, logs, histograms, stats)
+ * into a zip file for email sharing.
+ */
+class DebugReporter(private val context: Context) {
+
+    companion object {
+        private const val TAG = "DebugReporter"
+        private const val SAMPLE_RATE = 48000
+    }
+
+    /**
+     * Build a zip with all debug data.
+     * Returns the zip File on success, or null on failure.
+     */
+    suspend fun collectZip(
+        callDurationSecs: Double,
+        finalStatsJson: String,
+        aecEnabled: Boolean,
+        alias: String,
+        server: String,
+        room: String
+    ): File? = withContext(Dispatchers.IO) {
+        try {
+            val debugDir = File(context.cacheDir, "wzp_debug")
+            val timestamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(Date())
+            val zipFile = File(context.cacheDir, "wzp_debug_${timestamp}.zip")
+
+            ZipOutputStream(BufferedOutputStream(FileOutputStream(zipFile))).use { zos ->
+                // 1. Call metadata
+                val meta = buildString {
+                    appendLine("=== WZ Phone Debug Report ===")
+                    appendLine("Timestamp: $timestamp")
+                    appendLine("Alias: $alias")
+                    appendLine("Server: $server")
+                    appendLine("Room: $room")
+                    appendLine("Duration: ${"%.1f".format(callDurationSecs)}s")
+                    appendLine("AEC: ${if (aecEnabled) "ON" else "OFF"}")
+                    appendLine("Device: ${android.os.Build.MANUFACTURER} ${android.os.Build.MODEL}")
+                    appendLine("Android: ${android.os.Build.VERSION.RELEASE} (API ${android.os.Build.VERSION.SDK_INT})")
+                    appendLine()
+                    appendLine("=== Final Stats ===")
+                    appendLine(finalStatsJson)
+                }
+                addTextEntry(zos, "meta.txt", meta)
+
+                // 2. Logcat — WZP-related tags
+                val logcat = collectLogcat()
+                addTextEntry(zos, "logcat.txt", logcat)
+
+                // 3. Capture audio (mic) → WAV
+                val captureRaw = File(debugDir, "capture.pcm")
+                if (captureRaw.exists() && captureRaw.length() > 0) {
+                    addWavEntry(zos, "capture.wav", captureRaw)
+                    Log.i(TAG, "capture.pcm: ${captureRaw.length()} bytes -> WAV")
+                }
+
+                // 4. Playout audio (speaker) → WAV
+                val playoutRaw = File(debugDir, "playout.pcm")
+                if (playoutRaw.exists() && playoutRaw.length() > 0) {
+                    addWavEntry(zos, "playout.wav", playoutRaw)
+                    Log.i(TAG, "playout.pcm: ${playoutRaw.length()} bytes -> WAV")
+                }
+
+                // 5. RMS histogram CSV
+                val captureHist = File(debugDir, "capture_rms.csv")
+                if (captureHist.exists()) addFileEntry(zos, "capture_rms.csv", captureHist)
+                val playoutHist = File(debugDir, "playout_rms.csv")
+                if (playoutHist.exists()) addFileEntry(zos, "playout_rms.csv", playoutHist)
+            }
+
+            Log.i(TAG, "zip created: ${zipFile.length()} bytes (${zipFile.length() / 1024}KB)")
+
+            // Clean up raw debug files (keep zip)
+            debugDir.listFiles()?.forEach { it.delete() }
+
+            zipFile
+        } catch (e: Exception) {
+            Log.e(TAG, "debug report failed", e)
+            null
+        }
+    }
+
+    /** Clean up any leftover debug files from a previous session. */
+    fun prepareForCall() {
+        val debugDir = File(context.cacheDir, "wzp_debug")
+        if (debugDir.exists()) {
+            debugDir.listFiles()?.forEach { it.delete() }
+        }
+        debugDir.mkdirs()
+        // Also clean up old zip files
+        context.cacheDir.listFiles()?.filter { it.name.startsWith("wzp_debug_") }?.forEach { it.delete() }
+    }
+
+    private fun collectLogcat(): String {
+        return try {
+            val process = Runtime.getRuntime().exec(
+                arrayOf(
+                    "logcat", "-d",
+                    "-t", "5000",
+                    "--format", "threadtime"
+                )
+            )
+            val output = process.inputStream.bufferedReader().readText()
+            process.waitFor()
+            output.lines()
+                .filter { line ->
+                    line.contains("wzp", ignoreCase = true) ||
+                    line.contains("WzpEngine") ||
+                    line.contains("AudioPipeline") ||
+                    line.contains("WzpCall") ||
+                    line.contains("CallService") ||
+                    line.contains("AudioTrack") ||
+                    line.contains("AudioRecord") ||
+                    line.contains("AcousticEchoCanceler") ||
+                    line.contains("NoiseSuppressor") ||
+                    line.contains("FATAL") ||
+                    line.contains("ANR") ||
+                    line.contains("AudioFlinger") ||
+                    line.contains("DebugReporter") ||
+                    line.contains("QUIC") ||
+                    line.contains("quinn") ||
+                    line.contains("send task") ||
+                    line.contains("recv task") ||
+                    line.contains("send stats") ||
+                    line.contains("recv stats") ||
+                    line.contains("send_media") ||
+                    line.contains("FEC block") ||
+                    line.contains("recv gap") ||
+                    line.contains("frames_dropped") ||
+                    line.contains("opus")
+                }
+                .joinToString("\n")
+        } catch (e: Exception) {
+            "Failed to collect logcat: ${e.message}"
+        }
+    }
+
+    private fun addWavEntry(zos: ZipOutputStream, name: String, pcmFile: File) {
+        val dataSize = pcmFile.length().toInt()
+        val byteRate = SAMPLE_RATE * 1 * 16 / 8
+        val blockAlign = 1 * 16 / 8
+
+        zos.putNextEntry(ZipEntry(name))
+
+        // Write WAV header (44 bytes)
+        val header = ByteBuffer.allocate(44).order(ByteOrder.LITTLE_ENDIAN)
+        header.put("RIFF".toByteArray())
+        header.putInt(36 + dataSize)
+        header.put("WAVE".toByteArray())
+        header.put("fmt ".toByteArray())
+        header.putInt(16)
+        header.putShort(1)   // PCM
+        header.putShort(1)   // mono
+        header.putInt(SAMPLE_RATE)
+        header.putInt(byteRate)
+        header.putShort(blockAlign.toShort())
+        header.putShort(16)  // bits per sample
+        header.put("data".toByteArray())
+        header.putInt(dataSize)
+        zos.write(header.array())
+
+        // Stream PCM data directly (avoids loading entire file into memory)
+        FileInputStream(pcmFile).use { it.copyTo(zos) }
+        zos.closeEntry()
+    }
+
+    private fun addTextEntry(zos: ZipOutputStream, name: String, content: String) {
+        zos.putNextEntry(ZipEntry(name))
+        zos.write(content.toByteArray())
+        zos.closeEntry()
+    }
+
+    private fun addFileEntry(zos: ZipOutputStream, name: String, file: File) {
+        zos.putNextEntry(ZipEntry(name))
+        FileInputStream(file).use { it.copyTo(zos) }
+        zos.closeEntry()
+    }
+}

android/app/src/main/java/com/wzp/engine/CallStats.kt

@@ -0,0 +1,120 @@
+package com.wzp.engine
+
+import org.json.JSONArray
+import org.json.JSONObject
+
+/**
+ * Snapshot of call statistics, mirroring the Rust `CallStats` struct.
+ *
+ * Constructed from the JSON string returned by [WzpEngine.getStats].
+ */
+data class CallStats(
+    /** Current call state ordinal (see [CallStateConstants]). */
+    val state: Int = 0,
+    /** Call duration in seconds. */
+    val durationSecs: Double = 0.0,
+    /** Quality tier: 0 = Good, 1 = Degraded, 2 = Catastrophic. */
+    val qualityTier: Int = 0,
+    /** Observed packet loss percentage (0..100). */
+    val lossPct: Float = 0f,
+    /** Smoothed round-trip time in milliseconds. */
+    val rttMs: Int = 0,
+    /** Jitter in milliseconds. */
+    val jitterMs: Int = 0,
+    /** Current jitter buffer depth in packets. */
+    val jitterBufferDepth: Int = 0,
+    /** Total frames encoded since call start. */
+    val framesEncoded: Long = 0,
+    /** Total frames decoded since call start. */
+    val framesDecoded: Long = 0,
+    /** Number of playout underruns (buffer empty when audio was needed). */
+    val underruns: Long = 0,
+    /** Frames recovered by FEC. */
+    val fecRecovered: Long = 0,
+    /** Current mic audio level (RMS, 0-32767). */
+    val audioLevel: Int = 0,
+    /** Our current outgoing codec (e.g. "Opus24k"). */
+    val currentCodec: String = "",
+    /** Last seen incoming codec from peers. */
+    val peerCodec: String = "",
+    /** Whether auto quality mode is active. */
+    val autoMode: Boolean = false,
+    /** Number of participants in the room. */
+    val roomParticipantCount: Int = 0,
+    /** Participants in the room (fingerprint + optional alias). */
+    val roomParticipants: List<RoomMember> = emptyList(),
+    /** SAS verification code (4-digit, null if not in a call). */
+    val sasCode: Int? = null,
+    /** Incoming call ID (or "relay|room" for CallSetup). */
+    val incomingCallId: String? = null,
+    /** Incoming caller's fingerprint. */
+    val incomingCallerFp: String? = null,
+    /** Incoming caller's alias. */
+    val incomingCallerAlias: String? = null,
+) {
+    /** Human-readable quality label. */
+    val qualityLabel: String
+        get() = when (qualityTier) {
+            0 -> "Good"
+            1 -> "Degraded"
+            2 -> "Catastrophic"
+            else -> "Unknown"
+        }
+
+    companion object {
+        private fun parseParticipants(arr: JSONArray?): List<RoomMember> {
+            if (arr == null) return emptyList()
+            return (0 until arr.length()).map { i ->
+                val o = arr.getJSONObject(i)
+                RoomMember(
+                    fingerprint = o.optString("fingerprint", ""),
+                    alias = if (o.isNull("alias")) null else o.optString("alias", null),
+                    relayLabel = if (o.isNull("relay_label")) null else o.optString("relay_label", null)
+                )
+            }
+        }
+
+        /** Deserialise from the JSON string produced by the native engine. */
+        fun fromJson(json: String): CallStats {
+            return try {
+                val obj = JSONObject(json)
+                CallStats(
+                    state = obj.optInt("state", 0),
+                    durationSecs = obj.optDouble("duration_secs", 0.0),
+                    qualityTier = obj.optInt("quality_tier", 0),
+                    lossPct = obj.optDouble("loss_pct", 0.0).toFloat(),
+                    rttMs = obj.optInt("rtt_ms", 0),
+                    jitterMs = obj.optInt("jitter_ms", 0),
+                    jitterBufferDepth = obj.optInt("jitter_buffer_depth", 0),
+                    framesEncoded = obj.optLong("frames_encoded", 0),
+                    framesDecoded = obj.optLong("frames_decoded", 0),
+                    underruns = obj.optLong("underruns", 0),
+                    fecRecovered = obj.optLong("fec_recovered", 0),
+                    audioLevel = obj.optInt("audio_level", 0),
+                    currentCodec = obj.optString("current_codec", ""),
+                    peerCodec = obj.optString("peer_codec", ""),
+                    autoMode = obj.optBoolean("auto_mode", false),
+                    roomParticipantCount = obj.optInt("room_participant_count", 0),
+                    roomParticipants = parseParticipants(obj.optJSONArray("room_participants")),
+                    sasCode = if (obj.has("sas_code")) obj.optInt("sas_code") else null,
+                    incomingCallId = if (obj.isNull("incoming_call_id")) null else obj.optString("incoming_call_id", null),
+                    incomingCallerFp = if (obj.isNull("incoming_caller_fp")) null else obj.optString("incoming_caller_fp", null),
+                    incomingCallerAlias = if (obj.isNull("incoming_caller_alias")) null else obj.optString("incoming_caller_alias", null),
+                )
+            } catch (e: Exception) {
+                CallStats()
+            }
+        }
+    }
+}
+
+data class RoomMember(
+    val fingerprint: String,
+    val alias: String? = null,
+    val relayLabel: String? = null
+) {
+    /** Short display name: alias if set, otherwise first 8 chars of fingerprint. */
+    val displayName: String
+        get() = alias?.takeIf { it.isNotBlank() }
+            ?: fingerprint.take(8).ifEmpty { "unknown" }
+}

android/app/src/main/java/com/wzp/engine/SignalManager.kt

@@ -0,0 +1,97 @@
+package com.wzp.engine
+
+import org.json.JSONObject
+
+/**
+ * Persistent signal connection for direct 1:1 calls.
+ * Separate from WzpEngine — survives across calls.
+ *
+ * Lifecycle: connect() → [placeCall/answerCall] → destroy()
+ */
+class SignalManager {
+
+    private var handle: Long = 0L
+
+    val isConnected: Boolean get() = handle != 0L
+
+    /**
+     * Connect to relay and register for direct calls.
+     * MUST be called from a thread with sufficient stack (8MB).
+     * Blocks briefly during QUIC connect + register, then returns.
+     */
+    fun connect(relay: String, seedHex: String): Boolean {
+        if (handle != 0L) return true // already connected
+        handle = nativeSignalConnect(relay, seedHex)
+        return handle != 0L
+    }
+
+    /** Get current signal state as parsed object. Non-blocking. */
+    fun getState(): SignalState {
+        if (handle == 0L) return SignalState()
+        val json = nativeSignalGetState(handle) ?: return SignalState()
+        return try {
+            val obj = JSONObject(json)
+            SignalState(
+                status = obj.optString("status", "idle"),
+                fingerprint = obj.optString("fingerprint", ""),
+                incomingCallId = if (obj.isNull("incoming_call_id")) null else obj.optString("incoming_call_id"),
+                incomingCallerFp = if (obj.isNull("incoming_caller_fp")) null else obj.optString("incoming_caller_fp"),
+                incomingCallerAlias = if (obj.isNull("incoming_caller_alias")) null else obj.optString("incoming_caller_alias"),
+                callSetupRelay = if (obj.isNull("call_setup_relay")) null else obj.optString("call_setup_relay"),
+                callSetupRoom = if (obj.isNull("call_setup_room")) null else obj.optString("call_setup_room"),
+                callSetupId = if (obj.isNull("call_setup_id")) null else obj.optString("call_setup_id"),
+            )
+        } catch (e: Exception) {
+            SignalState()
+        }
+    }
+
+    /** Place a direct call to a target fingerprint. */
+    fun placeCall(targetFp: String): Int {
+        if (handle == 0L) return -1
+        return nativeSignalPlaceCall(handle, targetFp)
+    }
+
+    /** Answer an incoming call. mode: 0=Reject, 1=AcceptTrusted, 2=AcceptGeneric */
+    fun answerCall(callId: String, mode: Int = 2): Int {
+        if (handle == 0L) return -1
+        return nativeSignalAnswerCall(handle, callId, mode)
+    }
+
+    /** Send hangup signal. */
+    fun hangup() {
+        if (handle != 0L) nativeSignalHangup(handle)
+    }
+
+    /** Destroy the signal manager. */
+    fun destroy() {
+        if (handle != 0L) {
+            nativeSignalDestroy(handle)
+            handle = 0L
+        }
+    }
+
+    // JNI native methods
+    private external fun nativeSignalConnect(relay: String, seed: String): Long
+    private external fun nativeSignalGetState(handle: Long): String?
+    private external fun nativeSignalPlaceCall(handle: Long, targetFp: String): Int
+    private external fun nativeSignalAnswerCall(handle: Long, callId: String, mode: Int): Int
+    private external fun nativeSignalHangup(handle: Long)
+    private external fun nativeSignalDestroy(handle: Long)
+
+    companion object {
+        init { System.loadLibrary("wzp_android") }
+    }
+}
+
+/** Signal connection state. */
+data class SignalState(
+    val status: String = "idle",
+    val fingerprint: String = "",
+    val incomingCallId: String? = null,
+    val incomingCallerFp: String? = null,
+    val incomingCallerAlias: String? = null,
+    val callSetupRelay: String? = null,
+    val callSetupRoom: String? = null,
+    val callSetupId: String? = null,
+)

android/app/src/main/java/com/wzp/engine/WzpCallback.kt

@@ -0,0 +1,32 @@
+package com.wzp.engine
+
+/**
+ * Callback interface for VoIP engine events.
+ *
+ * All callbacks are invoked on the main/UI thread.
+ */
+interface WzpCallback {
+
+    /**
+     * Called when the call state changes.
+     *
+     * @param state one of [CallStateConstants]: IDLE(0), CONNECTING(1), ACTIVE(2),
+     *              RECONNECTING(3), CLOSED(4)
+     */
+    fun onCallStateChanged(state: Int)
+
+    /**
+     * Called when the network quality tier changes.
+     *
+     * @param tier 0 = Good, 1 = Degraded, 2 = Catastrophic
+     */
+    fun onQualityTierChanged(tier: Int)
+
+    /**
+     * Called when an error occurs in the native engine.
+     *
+     * @param code    numeric error code (negative)
+     * @param message human-readable description
+     */
+    fun onError(code: Int, message: String)
+}

android/app/src/main/java/com/wzp/engine/WzpEngine.kt

@@ -0,0 +1,232 @@
+package com.wzp.engine
+
+/**
+ * Native VoIP engine wrapper. Delegates all work to libwzp_android.so via JNI.
+ *
+ * Lifecycle:
+ * 1. Construct with a [WzpCallback]
+ * 2. Call [init] to create the native engine
+ * 3. Call [startCall] to begin a VoIP session
+ * 4. Use [setMute], [setSpeaker], [getStats], [forceProfile] during the call
+ * 5. Call [stopCall] to end the session
+ * 6. Call [destroy] when the engine is no longer needed
+ *
+ * Thread safety: all methods must be called from the same thread (typically main).
+ */
+class WzpEngine(private val callback: WzpCallback) {
+
+    /** Opaque pointer to the native EngineHandle. 0 means not initialised. */
+    private var nativeHandle: Long = 0L
+
+    /** Whether the engine has been initialised. */
+    val isInitialized: Boolean get() = nativeHandle != 0L
+
+    /** Create the native engine. Must be called before any other method. */
+    fun init() {
+        check(nativeHandle == 0L) { "Engine already initialized" }
+        nativeHandle = nativeInit()
+        check(nativeHandle != 0L) { "Native engine creation failed" }
+    }
+
+    /**
+     * Start a call.
+     *
+     * @param relayAddr relay server address (host:port)
+     * @param room      room identifier (used as QUIC SNI)
+     * @param seedHex   64-char hex-encoded 32-byte identity seed (empty = random)
+     * @param token     authentication token (empty = no auth)
+     * @param alias     display name sent to relay for room participant list
+     * @return 0 on success, negative error code on failure
+     */
+    /**
+     * @param profile 0 = Opus GOOD, 1 = Opus DEGRADED, 2 = Codec2 CATASTROPHIC
+     */
+    fun startCall(relayAddr: String, room: String, seedHex: String = "", token: String = "", alias: String = "", profile: Int = 0): Int {
+        check(nativeHandle != 0L) { "Engine not initialized" }
+        val result = nativeStartCall(nativeHandle, relayAddr, room, seedHex, token, alias, profile)
+        if (result == 0) {
+            callback.onCallStateChanged(CallStateConstants.CONNECTING)
+        } else {
+            callback.onError(result, "Failed to start call")
+        }
+        return result
+    }
+
+    /** Stop the active call. Safe to call when no call is active. */
+    @Synchronized
+    fun stopCall() {
+        if (nativeHandle != 0L) {
+            nativeStopCall(nativeHandle)
+            callback.onCallStateChanged(CallStateConstants.CLOSED)
+        }
+    }
+
+    /** Mute or unmute the microphone. */
+    fun setMute(muted: Boolean) {
+        if (nativeHandle != 0L) nativeSetMute(nativeHandle, muted)
+    }
+
+    /** Enable or disable loudspeaker mode. */
+    fun setSpeaker(speaker: Boolean) {
+        if (nativeHandle != 0L) nativeSetSpeaker(nativeHandle, speaker)
+    }
+
+
+    /**
+     * Get current call statistics as a JSON string.
+     *
+     * @return JSON-serialised [CallStats], or `"{}"` if the engine is not initialised.
+     */
+    @Synchronized
+    fun getStats(): String {
+        if (nativeHandle == 0L) return "{}"
+        return try {
+            nativeGetStats(nativeHandle) ?: "{}"
+        } catch (_: Exception) {
+            "{}"
+        }
+    }
+
+    /**
+     * Force a quality profile, overriding adaptive selection.
+     *
+     * @param profile 0 = GOOD, 1 = DEGRADED, 2 = CATASTROPHIC
+     */
+    fun forceProfile(profile: Int) {
+        if (nativeHandle != 0L) nativeForceProfile(nativeHandle, profile)
+    }
+
+    /** Destroy the native engine and free all resources. The instance must not be reused. */
+    @Synchronized
+    fun destroy() {
+        if (nativeHandle != 0L) {
+            nativeDestroy(nativeHandle)
+            nativeHandle = 0L
+        }
+    }
+
+    /**
+     * Write captured PCM samples into the engine's capture ring buffer.
+     * Called from the AudioRecord capture thread.
+     */
+    fun writeAudio(pcm: ShortArray): Int {
+        if (nativeHandle == 0L) return 0
+        return nativeWriteAudio(nativeHandle, pcm)
+    }
+
+    /**
+     * Read decoded PCM samples from the engine's playout ring buffer.
+     * Called from the AudioTrack playout thread.
+     */
+    fun readAudio(pcm: ShortArray): Int {
+        if (nativeHandle == 0L) return 0
+        return nativeReadAudio(nativeHandle, pcm)
+    }
+
+    /**
+     * Write captured PCM from a DirectByteBuffer — zero JNI array copy.
+     * The buffer must be a direct ByteBuffer with native byte order containing i16 samples.
+     * Called from the AudioRecord capture thread.
+     */
+    fun writeAudioDirect(buffer: java.nio.ByteBuffer, sampleCount: Int): Int {
+        if (nativeHandle == 0L) return 0
+        return nativeWriteAudioDirect(nativeHandle, buffer, sampleCount)
+    }
+
+    /**
+     * Read decoded PCM into a DirectByteBuffer — zero JNI array copy.
+     * The buffer must be a direct ByteBuffer with native byte order.
+     * Called from the AudioTrack playout thread.
+     */
+    fun readAudioDirect(buffer: java.nio.ByteBuffer, maxSamples: Int): Int {
+        if (nativeHandle == 0L) return 0
+        return nativeReadAudioDirect(nativeHandle, buffer, maxSamples)
+    }
+
+    // -- JNI native methods --------------------------------------------------
+
+    private external fun nativeInit(): Long
+    private external fun nativeStartCall(
+        handle: Long, relay: String, room: String, seed: String, token: String, alias: String, profile: Int
+    ): Int
+    private external fun nativeStopCall(handle: Long)
+    private external fun nativeSetMute(handle: Long, muted: Boolean)
+    private external fun nativeSetSpeaker(handle: Long, speaker: Boolean)
+    private external fun nativeGetStats(handle: Long): String?
+    private external fun nativeForceProfile(handle: Long, profile: Int)
+    private external fun nativeWriteAudio(handle: Long, pcm: ShortArray): Int
+    private external fun nativeReadAudio(handle: Long, pcm: ShortArray): Int
+    private external fun nativeWriteAudioDirect(handle: Long, buffer: java.nio.ByteBuffer, sampleCount: Int): Int
+    private external fun nativeReadAudioDirect(handle: Long, buffer: java.nio.ByteBuffer, maxSamples: Int): Int
+    private external fun nativeDestroy(handle: Long)
+
+    companion object {
+        init { System.loadLibrary("wzp_android") }
+
+        /** Get the identity fingerprint for a seed hex. No engine needed. */
+        @JvmStatic
+        private external fun nativeGetFingerprint(seedHex: String): String?
+
+        /** Compute the full identity fingerprint (xxxx:xxxx:...) from a seed hex string. */
+        @JvmStatic
+        fun getFingerprint(seedHex: String): String = nativeGetFingerprint(seedHex) ?: ""
+    }
+    private external fun nativePingRelay(handle: Long, relay: String): String?
+    private external fun nativeStartSignaling(handle: Long, relay: String, seed: String, token: String, alias: String): Int
+    private external fun nativePlaceCall(handle: Long, targetFp: String): Int
+    private external fun nativeAnswerCall(handle: Long, callId: String, mode: Int): Int
+
+    /**
+     * Ping a relay server. Requires engine to be initialized.
+     * Returns JSON `{"rtt_ms":N,"server_fingerprint":"hex"}` or null.
+     */
+    fun pingRelay(address: String): String? {
+        if (nativeHandle == 0L) return null
+        return nativePingRelay(nativeHandle, address)
+    }
+
+    /**
+     * Start persistent signaling connection for direct 1:1 calls.
+     * The engine registers on the relay and listens for incoming calls.
+     * Call state updates are available via [getStats].
+     *
+     * @return 0 on success, -1 on error
+     */
+    fun startSignaling(relay: String, seed: String = "", token: String = "", alias: String = ""): Int {
+        check(nativeHandle != 0L) { "Engine not initialized" }
+        return nativeStartSignaling(nativeHandle, relay, seed, token, alias)
+    }
+
+    /**
+     * Place a direct call to a peer by fingerprint.
+     * Requires [startSignaling] to have been called first.
+     *
+     * @return 0 on success, -1 on error
+     */
+    fun placeCall(targetFingerprint: String): Int {
+        check(nativeHandle != 0L) { "Engine not initialized" }
+        return nativePlaceCall(nativeHandle, targetFingerprint)
+    }
+
+    /**
+     * Answer an incoming direct call.
+     *
+     * @param callId The call ID from the incoming call (available in stats.incoming_call_id)
+     * @param mode 0=Reject, 1=AcceptTrusted (P2P in Phase 2), 2=AcceptGeneric (relay-mediated)
+     * @return 0 on success, -1 on error
+     */
+    fun answerCall(callId: String, mode: Int = 2): Int {
+        check(nativeHandle != 0L) { "Engine not initialized" }
+        return nativeAnswerCall(nativeHandle, callId, mode)
+    }
+
+}
+
+/** Integer constants matching the Rust [CallState] enum ordinals. */
+object CallStateConstants {
+    const val IDLE = 0
+    const val CONNECTING = 1
+    const val ACTIVE = 2
+    const val RECONNECTING = 3
+    const val CLOSED = 4
+}

android/app/src/main/java/com/wzp/net/RelayPinger.kt

@@ -0,0 +1,12 @@
+package com.wzp.net
+
+// Relay pinging is now done via WzpEngine.pingRelay() (instance method).
+// This file kept for the data class only.
+
+object RelayPinger {
+    data class PingResult(
+        val rttMs: Int,
+        val reachable: Boolean,
+        val serverFingerprint: String = "",
+    )
+}

android/app/src/main/java/com/wzp/service/CallService.kt

@@ -0,0 +1,172 @@
+package com.wzp.service
+
+import android.app.Notification
+import android.app.PendingIntent
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.media.AudioManager
+import android.net.wifi.WifiManager
+import android.os.IBinder
+import android.os.PowerManager
+import androidx.core.app.NotificationCompat
+import com.wzp.WzpApplication
+import com.wzp.ui.call.CallActivity
+
+/**
+ * Foreground service that keeps the VoIP call alive when the app is backgrounded.
+ *
+ * Responsibilities:
+ * - Shows a persistent notification during the call
+ * - Acquires a partial wake lock so the CPU stays on
+ * - Acquires a Wi-Fi lock to prevent Wi-Fi from going to sleep
+ * - Sets [AudioManager] mode to [AudioManager.MODE_IN_COMMUNICATION]
+ * - Releases all resources when the call ends
+ */
+class CallService : Service() {
+
+    private var wakeLock: PowerManager.WakeLock? = null
+    private var wifiLock: WifiManager.WifiLock? = null
+    private var previousAudioMode: Int = AudioManager.MODE_NORMAL
+
+    // -- Lifecycle ------------------------------------------------------------
+
+    override fun onCreate() {
+        super.onCreate()
+        acquireWakeLock()
+        acquireWifiLock()
+        setAudioMode()
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        when (intent?.action) {
+            ACTION_STOP -> {
+                onStopFromNotification?.invoke()
+                stopSelf()
+                return START_NOT_STICKY
+            }
+        }
+
+        startForeground(NOTIFICATION_ID, buildNotification())
+        return START_STICKY
+    }
+
+    override fun onDestroy() {
+        restoreAudioMode()
+        releaseWifiLock()
+        releaseWakeLock()
+        super.onDestroy()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    // -- Notification ---------------------------------------------------------
+
+    private fun buildNotification(): Notification {
+        // Tapping the notification returns to the call screen
+        val contentIntent = PendingIntent.getActivity(
+            this,
+            0,
+            Intent(this, CallActivity::class.java).apply {
+                flags = Intent.FLAG_ACTIVITY_SINGLE_TOP
+            },
+            PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
+        )
+
+        // "End call" action button
+        val stopIntent = PendingIntent.getService(
+            this,
+            1,
+            Intent(this, CallService::class.java).apply { action = ACTION_STOP },
+            PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
+        )
+
+        return NotificationCompat.Builder(this, WzpApplication.CHANNEL_ID)
+            .setContentTitle("WZ Phone")
+            .setContentText("Call in progress")
+            .setSmallIcon(android.R.drawable.ic_menu_call)
+            .setOngoing(true)
+            .setContentIntent(contentIntent)
+            .addAction(android.R.drawable.ic_menu_close_clear_cancel, "End Call", stopIntent)
+            .setCategory(NotificationCompat.CATEGORY_CALL)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .build()
+    }
+
+    // -- Wake lock ------------------------------------------------------------
+
+    private fun acquireWakeLock() {
+        val pm = getSystemService(Context.POWER_SERVICE) as PowerManager
+        wakeLock = pm.newWakeLock(
+            PowerManager.PARTIAL_WAKE_LOCK,
+            "wzp:call_wake_lock"
+        ).apply {
+            acquire(MAX_CALL_DURATION_MS)
+        }
+    }
+
+    private fun releaseWakeLock() {
+        wakeLock?.let {
+            if (it.isHeld) it.release()
+        }
+        wakeLock = null
+    }
+
+    // -- Wi-Fi lock -----------------------------------------------------------
+
+    @Suppress("DEPRECATION")
+    private fun acquireWifiLock() {
+        val wm = applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager
+        wifiLock = wm.createWifiLock(
+            WifiManager.WIFI_MODE_FULL_HIGH_PERF,
+            "wzp:call_wifi_lock"
+        ).apply {
+            acquire()
+        }
+    }
+
+    private fun releaseWifiLock() {
+        wifiLock?.let {
+            if (it.isHeld) it.release()
+        }
+        wifiLock = null
+    }
+
+    // -- Audio mode -----------------------------------------------------------
+
+    private fun setAudioMode() {
+        val am = getSystemService(Context.AUDIO_SERVICE) as AudioManager
+        previousAudioMode = am.mode
+        am.mode = AudioManager.MODE_IN_COMMUNICATION
+    }
+
+    private fun restoreAudioMode() {
+        val am = getSystemService(Context.AUDIO_SERVICE) as AudioManager
+        am.mode = previousAudioMode
+    }
+
+    // -- Static helpers -------------------------------------------------------
+
+    companion object {
+        private const val NOTIFICATION_ID = 1001
+        private const val ACTION_STOP = "com.wzp.service.STOP"
+        private const val MAX_CALL_DURATION_MS = 4L * 60 * 60 * 1000 // 4 hours
+
+        /** Called when the user taps "End Call" in the notification. */
+        var onStopFromNotification: (() -> Unit)? = null
+
+        /** Start the foreground call service. */
+        fun start(context: Context) {
+            val intent = Intent(context, CallService::class.java)
+            context.startForegroundService(intent)
+        }
+
+        /** Stop the foreground call service. */
+        fun stop(context: Context) {
+            val intent = Intent(context, CallService::class.java).apply {
+                action = ACTION_STOP
+            }
+            context.startService(intent)
+        }
+    }
+}

android/app/src/main/java/com/wzp/ui/call/CallActivity.kt

@@ -0,0 +1,149 @@
+package com.wzp.ui.call
+
+import android.Manifest
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Bundle
+import android.util.Log
+import android.widget.Toast
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.activity.viewModels
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.platform.LocalContext
+import androidx.core.content.ContextCompat
+import androidx.core.content.FileProvider
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
+import com.wzp.ui.settings.SettingsScreen
+import kotlinx.coroutines.launch
+
+/**
+ * Main activity hosting the in-call Compose UI.
+ *
+ * Call lifecycle (wake lock, Wi-Fi lock, audio mode, notification)
+ * is managed by [com.wzp.service.CallService] foreground service.
+ */
+class CallActivity : ComponentActivity() {
+
+    companion object {
+        private const val TAG = "CallActivity"
+    }
+
+    private val viewModel: CallViewModel by viewModels()
+
+    private val audioPermissionLauncher = registerForActivityResult(
+        ActivityResultContracts.RequestPermission()
+    ) { granted ->
+        if (!granted) {
+            Toast.makeText(this, "Microphone permission is required for calls", Toast.LENGTH_LONG).show()
+        }
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        viewModel.setContext(this)
+
+        setContent {
+            WzpTheme {
+                var showSettings by remember { mutableStateOf(false) }
+                if (showSettings) {
+                    SettingsScreen(
+                        viewModel = viewModel,
+                        onBack = { showSettings = false }
+                    )
+                } else {
+                    InCallScreen(
+                        viewModel = viewModel,
+                        onHangUp = { viewModel.stopCall() },
+                        onOpenSettings = { showSettings = true }
+                    )
+                }
+            }
+        }
+
+        if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO)
+            != PackageManager.PERMISSION_GRANTED
+        ) {
+            audioPermissionLauncher.launch(Manifest.permission.RECORD_AUDIO)
+        }
+
+        // Watch for debug zip ready → launch email intent
+        lifecycleScope.launch {
+            repeatOnLifecycle(Lifecycle.State.STARTED) {
+                viewModel.debugZipReady.collect { zipFile ->
+                    if (zipFile != null && zipFile.exists()) {
+                        Log.i(TAG, "debug zip ready: ${zipFile.absolutePath} (${zipFile.length()} bytes)")
+                        launchEmailIntent(zipFile)
+                        viewModel.onDebugReportSent()
+                    }
+                }
+            }
+        }
+    }
+
+    private fun launchEmailIntent(zipFile: java.io.File) {
+        try {
+            val authority = "${applicationContext.packageName}.fileprovider"
+            Log.i(TAG, "FileProvider authority: $authority, file: ${zipFile.absolutePath}")
+            val uri = FileProvider.getUriForFile(this, authority, zipFile)
+            Log.i(TAG, "FileProvider URI: $uri")
+
+            val intent = Intent(Intent.ACTION_SEND).apply {
+                type = "message/rfc822"
+                putExtra(Intent.EXTRA_EMAIL, arrayOf("manwefarm@gmail.com"))
+                putExtra(Intent.EXTRA_SUBJECT, "WZ Phone Debug Report - ${zipFile.name}")
+                putExtra(
+                    Intent.EXTRA_TEXT,
+                    "Debug report attached.\n\nContains: call recordings (WAV), RMS histograms (CSV), logcat, stats."
+                )
+                putExtra(Intent.EXTRA_STREAM, uri)
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            }
+            startActivity(Intent.createChooser(intent, "Send debug report"))
+            Log.i(TAG, "email intent launched")
+        } catch (e: Exception) {
+            Log.e(TAG, "email intent failed", e)
+            Toast.makeText(this, "Failed to launch email: ${e.message}", Toast.LENGTH_LONG).show()
+        }
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        if (isFinishing) {
+            viewModel.stopCall()
+        }
+    }
+}
+
+@Composable
+fun WzpTheme(content: @Composable () -> Unit) {
+    val darkTheme = isSystemInDarkTheme()
+    val context = LocalContext.current
+
+    val colorScheme = when {
+        android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S -> {
+            if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
+        }
+        darkTheme -> darkColorScheme()
+        else -> lightColorScheme()
+    }
+
+    MaterialTheme(
+        colorScheme = colorScheme,
+        content = content
+    )
+}

android/app/src/main/java/com/wzp/ui/call/CallViewModel.kt

@@ -0,0 +1,764 @@
+package com.wzp.ui.call
+
+import android.content.Context
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.wzp.audio.AudioPipeline
+import com.wzp.audio.AudioRouteManager
+import com.wzp.data.SettingsRepository
+import com.wzp.debug.DebugReporter
+import com.wzp.engine.CallStats
+import com.wzp.service.CallService
+import com.wzp.engine.WzpCallback
+import com.wzp.engine.WzpEngine
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import org.json.JSONObject
+import java.io.File
+import java.net.Inet4Address
+import java.net.Inet6Address
+import java.net.InetAddress
+
+data class ServerEntry(val address: String, val label: String)
+
+data class PingResult(
+    val rttMs: Int,
+    val serverFingerprint: String = "",
+    val reachable: Boolean = rttMs > 0,
+)
+
+enum class LockStatus { UNKNOWN, OFFLINE, NEW, VERIFIED, CHANGED }
+
+class CallViewModel : ViewModel(), WzpCallback {
+
+    private var engine: WzpEngine? = null
+    private var engineInitialized = false
+    private var audioPipeline: AudioPipeline? = null
+    private var audioRouteManager: AudioRouteManager? = null
+    private var audioStarted = false
+    private var appContext: Context? = null
+    private var settings: SettingsRepository? = null
+    private var debugReporter: DebugReporter? = null
+    private var lastStatsJson: String = "{}"
+    private var lastCallDuration: Double = 0.0
+    private var lastCallServer: String = ""
+
+    private val _callState = MutableStateFlow(0)
+    val callState: StateFlow<Int> get() = _callState.asStateFlow()
+
+    private val _isMuted = MutableStateFlow(false)
+    val isMuted: StateFlow<Boolean> = _isMuted.asStateFlow()
+
+    private val _isSpeaker = MutableStateFlow(false)
+    val isSpeaker: StateFlow<Boolean> = _isSpeaker.asStateFlow()
+
+    private val _stats = MutableStateFlow(CallStats())
+    val stats: StateFlow<CallStats> = _stats.asStateFlow()
+
+    private val _qualityTier = MutableStateFlow(0)
+    val qualityTier: StateFlow<Int> = _qualityTier.asStateFlow()
+
+    private val _errorMessage = MutableStateFlow<String?>(null)
+    val errorMessage: StateFlow<String?> = _errorMessage.asStateFlow()
+
+    private val _roomName = MutableStateFlow(DEFAULT_ROOM)
+    val roomName: StateFlow<String> = _roomName.asStateFlow()
+
+    private val _selectedServer = MutableStateFlow(0)
+    val selectedServer: StateFlow<Int> = _selectedServer.asStateFlow()
+
+    private val _servers = MutableStateFlow(DEFAULT_SERVERS.toList())
+    val servers: StateFlow<List<ServerEntry>> = _servers.asStateFlow()
+
+    private val _preferIPv6 = MutableStateFlow(false)
+    val preferIPv6: StateFlow<Boolean> = _preferIPv6.asStateFlow()
+
+    private val _recentRooms = MutableStateFlow<List<com.wzp.data.SettingsRepository.RecentRoom>>(emptyList())
+    val recentRooms: StateFlow<List<com.wzp.data.SettingsRepository.RecentRoom>> = _recentRooms.asStateFlow()
+
+    /** Ping results keyed by server address. */
+    private val _pingResults = MutableStateFlow<Map<String, PingResult>>(emptyMap())
+    val pingResults: StateFlow<Map<String, PingResult>> = _pingResults.asStateFlow()
+
+    /** Known server fingerprints (TOFU). */
+    private val _knownFingerprints = MutableStateFlow<Map<String, String>>(emptyMap())
+
+    private val _playoutGainDb = MutableStateFlow(0f)
+    val playoutGainDb: StateFlow<Float> = _playoutGainDb.asStateFlow()
+
+    private val _captureGainDb = MutableStateFlow(0f)
+    val captureGainDb: StateFlow<Float> = _captureGainDb.asStateFlow()
+
+    private val _alias = MutableStateFlow("")
+    val alias: StateFlow<String> = _alias.asStateFlow()
+
+    private val _seedHex = MutableStateFlow("")
+    val seedHex: StateFlow<String> = _seedHex.asStateFlow()
+
+    private val _aecEnabled = MutableStateFlow(true)
+    val aecEnabled: StateFlow<Boolean> = _aecEnabled.asStateFlow()
+
+    private val _debugRecording = MutableStateFlow(false)
+    val debugRecording: StateFlow<Boolean> = _debugRecording.asStateFlow()
+
+    // Quality profile index (matches JNI bridge profile_from_int)
+    private val _codecChoice = MutableStateFlow(0)
+    val codecChoice: StateFlow<Int> = _codecChoice.asStateFlow()
+
+    /** Key-change warning dialog state. */
+    data class KeyWarningInfo(val address: String, val oldFp: String, val newFp: String)
+    private val _keyWarning = MutableStateFlow<KeyWarningInfo?>(null)
+    val keyWarning: StateFlow<KeyWarningInfo?> = _keyWarning.asStateFlow()
+
+    /** True when a call just ended and debug report can be sent. */
+    private val _debugReportAvailable = MutableStateFlow(false)
+    val debugReportAvailable: StateFlow<Boolean> = _debugReportAvailable.asStateFlow()
+
+    /** Status: null=idle, "Preparing..."=in progress, "ready"=zip ready, "Error:..."=failed */
+    private val _debugReportStatus = MutableStateFlow<String?>(null)
+    val debugReportStatus: StateFlow<String?> = _debugReportStatus.asStateFlow()
+
+    /** The zip file ready to be emailed. Set by sendDebugReport, consumed by Activity. */
+    private val _debugZipReady = MutableStateFlow<File?>(null)
+    val debugZipReady: StateFlow<File?> = _debugZipReady.asStateFlow()
+
+    private var statsJob: Job? = null
+
+    // ── Direct calling state ──
+    /** 0=room mode, 1=direct call mode */
+    private val _callMode = MutableStateFlow(0)
+    val callMode: StateFlow<Int> = _callMode.asStateFlow()
+
+    /** Target fingerprint for direct call */
+    private val _targetFingerprint = MutableStateFlow("")
+    val targetFingerprint: StateFlow<String> = _targetFingerprint.asStateFlow()
+
+    /** Signal state string: "idle", "registered", "ringing", "incoming", "setup" */
+    private val _signalState = MutableStateFlow("idle")
+    val signalState: StateFlow<String> = _signalState.asStateFlow()
+
+    /** Incoming call info */
+    private val _incomingCallId = MutableStateFlow<String?>(null)
+    val incomingCallId: StateFlow<String?> = _incomingCallId.asStateFlow()
+
+    private val _incomingCallerFp = MutableStateFlow<String?>(null)
+    val incomingCallerFp: StateFlow<String?> = _incomingCallerFp.asStateFlow()
+
+    private val _incomingCallerAlias = MutableStateFlow<String?>(null)
+    val incomingCallerAlias: StateFlow<String?> = _incomingCallerAlias.asStateFlow()
+
+    /** Separate signal manager (persistent, survives calls) */
+    private var signalManager: com.wzp.engine.SignalManager? = null
+    private var signalPollJob: Job? = null
+
+    fun setCallMode(mode: Int) { _callMode.value = mode }
+    fun setTargetFingerprint(fp: String) { _targetFingerprint.value = fp }
+
+    /** Register on relay for direct calls */
+    fun registerForCalls() {
+        val serverIdx = _selectedServer.value
+        val serverList = _servers.value
+        if (serverIdx >= serverList.size) return
+
+        val relay = serverList[serverIdx].address
+        var seed = _seedHex.value
+        // Generate seed if empty (fresh install or cleared storage)
+        if (seed.isEmpty()) {
+            val newSeed = ByteArray(32).also { java.security.SecureRandom().nextBytes(it) }
+            seed = newSeed.joinToString("") { "%02x".format(it) }
+            _seedHex.value = seed
+            settings?.saveSeedHex(seed)
+            Log.i(TAG, "generated new identity seed")
+        }
+        val resolvedRelay = resolveToIp(relay) ?: relay
+
+        // nativeSignalConnect has JNI overhead — must be on a thread with enough stack.
+        // Dispatchers.IO threads overflow. Use explicit Java Thread.
+        Thread(null, {
+            try {
+                val mgr = com.wzp.engine.SignalManager()
+                val ok = mgr.connect(resolvedRelay, seed)
+                viewModelScope.launch {
+                    if (ok) {
+                        signalManager = mgr
+                        startSignalPolling()
+                    } else {
+                        _errorMessage.value = "Failed to register on relay"
+                    }
+                }
+            } catch (e: Exception) {
+                viewModelScope.launch {
+                    _errorMessage.value = "Register error: ${e.message}"
+                }
+            }
+        }, "wzp-signal-init", 8 * 1024 * 1024).start()
+    }
+
+    /** Poll signal manager state every 500ms */
+    private fun startSignalPolling() {
+        signalPollJob?.cancel()
+        signalPollJob = viewModelScope.launch {
+            while (isActive) {
+                val mgr = signalManager
+                if (mgr != null && mgr.isConnected) {
+                    val state = mgr.getState()
+                    _signalState.value = state.status
+                    _incomingCallId.value = state.incomingCallId
+                    _incomingCallerFp.value = state.incomingCallerFp
+                    _incomingCallerAlias.value = state.incomingCallerAlias
+
+                    // Auto-connect to media room when call is set up
+                    if (state.status == "setup" && state.callSetupRelay != null && state.callSetupRoom != null) {
+                        Log.i(TAG, "CallSetup: connecting to ${state.callSetupRelay} room ${state.callSetupRoom}")
+                        startCallInternal(state.callSetupRelay, state.callSetupRoom)
+                    }
+                }
+                delay(500L)
+            }
+        }
+    }
+
+    private fun stopSignalPolling() {
+        signalPollJob?.cancel()
+        signalPollJob = null
+    }
+
+    /** Place a direct call to the target fingerprint */
+    fun placeDirectCall() {
+        val target = _targetFingerprint.value.trim()
+        if (target.isEmpty()) {
+            _errorMessage.value = "Enter a fingerprint to call"
+            return
+        }
+        signalManager?.placeCall(target)
+    }
+
+    /** Answer an incoming direct call */
+    fun answerIncomingCall(mode: Int = 2) {
+        val callId = _incomingCallId.value ?: return
+        signalManager?.answerCall(callId, mode)
+    }
+
+    /** Reject an incoming direct call */
+    fun rejectIncomingCall() {
+        val callId = _incomingCallId.value ?: return
+        signalManager?.answerCall(callId, 0)
+    }
+
+    /** Hang up direct call — media ends, signal stays alive */
+    fun hangupDirectCall() {
+        signalManager?.hangup()
+        engine?.stopCall()
+        engine?.destroy()
+        engine = null
+        engineInitialized = false
+    }
+
+    companion object {
+        private const val TAG = "WzpCall"
+        val DEFAULT_SERVERS = listOf(
+            ServerEntry("172.16.81.175:4433", "LAN (172.16.81.175)"),
+            ServerEntry("193.180.213.68:4433", "Pangolin (IP)"),
+        )
+        const val DEFAULT_ROOM = "general"
+    }
+
+    fun setContext(context: Context) {
+        val appCtx = context.applicationContext
+        appContext = appCtx
+        if (audioPipeline == null) {
+            audioPipeline = AudioPipeline(appCtx)
+        }
+        if (audioRouteManager == null) {
+            audioRouteManager = AudioRouteManager(appCtx)
+        }
+        if (debugReporter == null) {
+            debugReporter = DebugReporter(appCtx)
+        }
+        if (settings == null) {
+            settings = SettingsRepository(appCtx)
+            loadSettings()
+        }
+    }
+
+    private fun loadSettings() {
+        val s = settings ?: return
+        s.loadServers()?.let { saved ->
+            if (saved.isNotEmpty()) _servers.value = saved
+        }
+        _selectedServer.value = s.loadSelectedServer().coerceIn(0, _servers.value.lastIndex)
+        _roomName.value = s.loadRoom()
+        _alias.value = s.getOrCreateAlias()
+        _preferIPv6.value = s.loadPreferIPv6()
+        _playoutGainDb.value = s.loadPlayoutGain()
+        _captureGainDb.value = s.loadCaptureGain()
+        _seedHex.value = s.getOrCreateSeedHex()
+        _aecEnabled.value = s.loadAecEnabled()
+        _debugRecording.value = s.loadDebugRecording()
+        _codecChoice.value = s.loadCodecChoice()
+        _recentRooms.value = s.loadRecentRooms()
+    }
+
+    fun selectServer(index: Int) {
+        if (index in _servers.value.indices) {
+            _selectedServer.value = index
+            settings?.saveSelectedServer(index)
+        }
+    }
+
+    fun setPreferIPv6(prefer: Boolean) {
+        _preferIPv6.value = prefer
+        settings?.savePreferIPv6(prefer)
+    }
+
+    fun addServer(hostPort: String, label: String) {
+        val current = _servers.value.toMutableList()
+        current.add(ServerEntry(hostPort, label))
+        _servers.value = current
+        settings?.saveServers(current)
+    }
+
+    fun removeServer(index: Int) {
+        if (index < DEFAULT_SERVERS.size) return // don't remove built-in servers
+        val current = _servers.value.toMutableList()
+        if (index in current.indices) {
+            current.removeAt(index)
+            _servers.value = current
+            if (_selectedServer.value >= current.size) {
+                _selectedServer.value = 0
+            }
+            settings?.saveServers(current)
+            settings?.saveSelectedServer(_selectedServer.value)
+        }
+    }
+
+    /** Batch-apply servers and selection from Settings draft state. */
+    fun applyServers(servers: List<ServerEntry>, selected: Int) {
+        _servers.value = servers
+        _selectedServer.value = selected.coerceIn(0, servers.lastIndex)
+        settings?.saveServers(servers)
+        settings?.saveSelectedServer(_selectedServer.value)
+    }
+
+    /**
+     * Ping all servers via native QUIC. Requires engine to be initialized.
+     * Creates engine if needed, pings, keeps engine alive for subsequent Connect.
+     */
+    fun pingAllServers() {
+        viewModelScope.launch {
+            // Ensure engine exists
+            if (engine == null || engine?.isInitialized != true) {
+                try {
+                    engine = WzpEngine(this@CallViewModel).also { it.init() }
+                    engineInitialized = true
+                } catch (e: Exception) {
+                    Log.w(TAG, "engine init for ping failed: $e")
+                    return@launch
+                }
+            }
+            val eng = engine ?: return@launch
+
+            val results = mutableMapOf<String, PingResult>()
+            val known = mutableMapOf<String, String>()
+            _servers.value.forEach { server ->
+                val json = withContext(Dispatchers.IO) {
+                    eng.pingRelay(server.address)
+                }
+                if (json != null) {
+                    try {
+                        val obj = JSONObject(json)
+                        val rtt = obj.getInt("rtt_ms")
+                        val fp = obj.optString("server_fingerprint", "")
+                        results[server.address] = PingResult(rttMs = rtt, serverFingerprint = fp)
+                        // TOFU
+                        if (fp.isNotEmpty()) {
+                            val saved = settings?.loadServerFingerprint(server.address)
+                            if (saved == null) settings?.saveServerFingerprint(server.address, fp)
+                            known[server.address] = saved ?: fp
+                        }
+                    } catch (_: Exception) {}
+                }
+            }
+            _pingResults.value = results
+            _knownFingerprints.value = known
+        }
+    }
+
+    /** Load saved TOFU fingerprints. */
+    fun loadSavedFingerprints() {
+        val known = mutableMapOf<String, String>()
+        _servers.value.forEach { server ->
+            settings?.loadServerFingerprint(server.address)?.let {
+                known[server.address] = it
+            }
+        }
+        _knownFingerprints.value = known
+    }
+
+    /** Get lock status for a server. */
+    fun lockStatus(address: String): LockStatus {
+        val pr = _pingResults.value[address] ?: return LockStatus.UNKNOWN
+        if (!pr.reachable) return LockStatus.OFFLINE
+        val known = _knownFingerprints.value[address] ?: return LockStatus.NEW
+        if (pr.serverFingerprint.isEmpty()) return LockStatus.NEW
+        return if (pr.serverFingerprint == known) LockStatus.VERIFIED else LockStatus.CHANGED
+    }
+
+    fun setRoomName(name: String) {
+        _roomName.value = name
+        settings?.saveRoom(name)
+    }
+
+    fun setPlayoutGainDb(db: Float) {
+        _playoutGainDb.value = db
+        audioPipeline?.playoutGainDb = db
+        settings?.savePlayoutGain(db)
+    }
+
+    fun setCaptureGainDb(db: Float) {
+        _captureGainDb.value = db
+        audioPipeline?.captureGainDb = db
+        settings?.saveCaptureGain(db)
+    }
+
+    fun setAlias(alias: String) {
+        _alias.value = alias
+        settings?.saveAlias(alias)
+    }
+
+    fun restoreSeed(hex: String) {
+        _seedHex.value = hex
+        settings?.saveSeedHex(hex)
+    }
+
+    fun setAecEnabled(enabled: Boolean) {
+        _aecEnabled.value = enabled
+        settings?.saveAecEnabled(enabled)
+    }
+
+    fun setDebugRecording(enabled: Boolean) {
+        _debugRecording.value = enabled
+        settings?.saveDebugRecording(enabled)
+    }
+
+    fun setCodecChoice(choice: Int) {
+        _codecChoice.value = choice
+        settings?.saveCodecChoice(choice)
+    }
+
+    /**
+     * Resolve DNS hostname to IP address on the Kotlin/Android side,
+     * since Rust's DNS resolution may not work on Android.
+     * Returns "ip:port" string.
+     */
+    private fun resolveToIp(hostPort: String): String {
+        val parts = hostPort.split(":")
+        if (parts.size != 2) return hostPort
+        val host = parts[0]
+        val port = parts[1]
+
+        // Already an IP address — return as-is
+        if (host.matches(Regex("""\d+\.\d+\.\d+\.\d+"""))) return hostPort
+        if (host.contains(":")) return hostPort // IPv6 literal
+
+        return try {
+            val addresses = InetAddress.getAllByName(host)
+            val preferV6 = _preferIPv6.value
+            val picked = if (preferV6) {
+                addresses.firstOrNull { it is Inet6Address } ?: addresses.firstOrNull { it is Inet4Address }
+            } else {
+                addresses.firstOrNull { it is Inet4Address } ?: addresses.firstOrNull { it is Inet6Address }
+            }
+            if (picked != null) {
+                val ip = picked.hostAddress ?: host
+                val formatted = if (picked is Inet6Address) "[$ip]:$port" else "$ip:$port"
+                formatted
+            } else {
+                hostPort
+            }
+        } catch (_: Exception) {
+            hostPort // resolution failed — pass through and let Rust try
+        }
+    }
+
+    /** Tear down engine and audio. Pass stopService=true to also stop the foreground service. */
+    private fun teardown(stopService: Boolean = true) {
+        Log.i(TAG, "teardown: stopping audio, stopService=$stopService")
+        val hadCall = audioStarted
+        CallService.onStopFromNotification = null
+        stopAudio()             // sets running=false (non-blocking)
+        stopStatsPolling()
+
+        // Wait for audio threads to exit their loops before destroying the engine.
+        // This guarantees no in-flight JNI calls to writeAudio/readAudio.
+        val drained = audioPipeline?.awaitDrain() ?: true
+        if (!drained) {
+            Log.w(TAG, "teardown: audio threads did not drain in time")
+        }
+        audioPipeline = null
+
+        Log.i(TAG, "teardown: stopping engine")
+        try { engine?.stopCall() } catch (e: Exception) { Log.w(TAG, "stopCall err: $e") }
+        try { engine?.destroy() } catch (e: Exception) { Log.w(TAG, "destroy err: $e") }
+        engine = null
+        engineInitialized = false
+        _callState.value = 0
+        if (hadCall) {
+            _debugReportAvailable.value = true
+        }
+        if (stopService) {
+            try { appContext?.let { CallService.stop(it) } } catch (_: Exception) {}
+        }
+        Log.i(TAG, "teardown: done")
+    }
+
+    /** Accept the new server key and proceed with the call. */
+    fun acceptNewFingerprint() {
+        val info = _keyWarning.value ?: return
+        _knownFingerprints.value = _knownFingerprints.value.toMutableMap().also {
+            it[info.address] = info.newFp
+        }
+        settings?.saveServerFingerprint(info.address, info.newFp)
+        _keyWarning.value = null
+        startCallInternal()
+    }
+
+    fun dismissKeyWarning() {
+        _keyWarning.value = null
+    }
+
+    fun startCall() {
+        val serverEntry = _servers.value[_selectedServer.value]
+        // Check for key change before connecting
+        val ls = lockStatus(serverEntry.address)
+        if (ls == LockStatus.CHANGED) {
+            val known = _knownFingerprints.value[serverEntry.address] ?: ""
+            val current = _pingResults.value[serverEntry.address]?.serverFingerprint ?: ""
+            _keyWarning.value = KeyWarningInfo(serverEntry.address, known, current)
+            return
+        }
+        startCallInternal()
+    }
+
+    /** Start a call to a specific relay + room (used by direct call setup). */
+    private fun startCallInternal(relay: String, room: String) {
+        Log.i(TAG, "startCallDirect: relay=$relay room=$room")
+        try {
+            // Don't teardown — keep the signal connection alive
+            engine = WzpEngine(this)
+            engine!!.init()
+            engineInitialized = true
+            _callState.value = 1
+            _errorMessage.value = null
+            try { appContext?.let { CallService.start(it) } } catch (e: Exception) {
+                Log.w(TAG, "service start err: $e")
+            }
+            startStatsPolling()
+            viewModelScope.launch(kotlinx.coroutines.Dispatchers.IO) {
+                try {
+                    val seed = _seedHex.value
+                    val name = _alias.value
+                    val result = engine?.startCall(relay, room, seedHex = seed, alias = name, profile = _codecChoice.value) ?: -1
+                    CallService.onStopFromNotification = { stopCall() }
+                    if (result != 0) {
+                        _callState.value = 0
+                        _errorMessage.value = "Failed to connect to call room (code $result)"
+                        appContext?.let { CallService.stop(it) }
+                    }
+                } catch (e: Exception) {
+                    Log.e(TAG, "startCallDirect error", e)
+                    _callState.value = 0
+                    _errorMessage.value = "Engine error: ${e.message}"
+                    appContext?.let { CallService.stop(it) }
+                }
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "startCallDirect error", e)
+            _callState.value = 0
+            _errorMessage.value = "Engine error: ${e.message}"
+        }
+    }
+
+    private fun startCallInternal() {
+        val serverEntry = _servers.value[_selectedServer.value]
+        val room = _roomName.value
+        Log.i(TAG, "startCall: server=${serverEntry.address} room=$room")
+        _debugReportAvailable.value = false
+        _debugReportStatus.value = null
+        lastCallServer = serverEntry.address
+        settings?.addRecentRoom(serverEntry.address, room)
+        _recentRooms.value = settings?.loadRecentRooms() ?: emptyList()
+        debugReporter?.prepareForCall()
+        try {
+            // Teardown previous call but don't stop the service (we're about to restart it)
+            teardown(stopService = false)
+
+            Log.i(TAG, "startCall: creating engine")
+            engine = WzpEngine(this)
+            engine!!.init()
+            engineInitialized = true
+            _callState.value = 1
+            _errorMessage.value = null
+            try { appContext?.let { CallService.start(it) } } catch (e: Exception) {
+                Log.w(TAG, "service start err: $e")
+            }
+            startStatsPolling()
+
+            viewModelScope.launch(kotlinx.coroutines.Dispatchers.IO) {
+                try {
+                    val relay = resolveToIp(serverEntry.address)
+                    val seed = _seedHex.value
+                    val name = _alias.value
+                    Log.i(TAG, "startCall: resolved=$relay, alias=$name, calling engine.startCall")
+                    val result = engine?.startCall(relay, room, seedHex = seed, alias = name, profile = _codecChoice.value) ?: -1
+                    Log.i(TAG, "startCall: engine returned $result")
+                    // Only wire up notification callback after engine is running
+                    CallService.onStopFromNotification = { stopCall() }
+                    if (result != 0) {
+                        _callState.value = 0
+                        _errorMessage.value = "Failed to start call (code $result)"
+                        appContext?.let { CallService.stop(it) }
+                    }
+                } catch (e: Exception) {
+                    Log.e(TAG, "startCall IO error", e)
+                    _callState.value = 0
+                    _errorMessage.value = "Engine error: ${e.message}"
+                    appContext?.let { CallService.stop(it) }
+                }
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "startCall error", e)
+            _callState.value = 0
+            _errorMessage.value = "Engine error: ${e.message}"
+            appContext?.let { CallService.stop(it) }
+        }
+    }
+
+    fun stopCall() {
+        Log.i(TAG, "stopCall")
+        teardown()
+    }
+
+    fun toggleMute() {
+        val newMuted = !_isMuted.value
+        _isMuted.value = newMuted
+        try { engine?.setMute(newMuted) } catch (_: Exception) {}
+    }
+
+    fun toggleSpeaker() {
+        val newSpeaker = !_isSpeaker.value
+        _isSpeaker.value = newSpeaker
+        audioRouteManager?.setSpeaker(newSpeaker)
+    }
+
+    fun clearError() { _errorMessage.value = null }
+
+    fun sendDebugReport() {
+        val reporter = debugReporter ?: return
+        _debugReportStatus.value = "Preparing debug report..."
+        viewModelScope.launch(kotlinx.coroutines.Dispatchers.IO) {
+            val zipFile = reporter.collectZip(
+                callDurationSecs = lastCallDuration,
+                finalStatsJson = lastStatsJson,
+                aecEnabled = _aecEnabled.value,
+                alias = _alias.value,
+                server = lastCallServer,
+                room = _roomName.value
+            )
+            if (zipFile != null) {
+                _debugZipReady.value = zipFile
+                _debugReportStatus.value = "ready"
+            } else {
+                _debugReportStatus.value = "Error: failed to create zip"
+            }
+            _debugReportAvailable.value = false
+        }
+    }
+
+    /** Called by Activity after email intent is launched. */
+    fun onDebugReportSent() {
+        _debugZipReady.value = null
+        _debugReportStatus.value = null
+    }
+
+    fun dismissDebugReport() {
+        _debugReportAvailable.value = false
+        _debugReportStatus.value = null
+        _debugZipReady.value = null
+    }
+
+    // WzpCallback
+    override fun onCallStateChanged(state: Int) { _callState.value = state }
+    override fun onQualityTierChanged(tier: Int) { _qualityTier.value = tier }
+    override fun onError(code: Int, message: String) { _errorMessage.value = "Error $code: $message" }
+
+    private fun startAudio() {
+        if (audioStarted) return
+        val e = engine ?: return
+        val ctx = appContext ?: return
+        // Create a fresh pipeline each call to avoid stale threads
+        audioPipeline = AudioPipeline(ctx).also {
+            it.playoutGainDb = _playoutGainDb.value
+            it.captureGainDb = _captureGainDb.value
+            it.aecEnabled = _aecEnabled.value
+            it.debugRecording = _debugRecording.value
+            it.start(e)
+        }
+        audioRouteManager?.register()
+        audioStarted = true
+    }
+
+    private fun stopAudio() {
+        if (!audioStarted) return
+        audioPipeline?.stop()    // sets running=false; DON'T null — teardown needs awaitDrain()
+        audioRouteManager?.unregister()
+        audioRouteManager?.setSpeaker(false)
+        _isSpeaker.value = false
+        audioStarted = false
+    }
+
+    private fun startStatsPolling() {
+        statsJob?.cancel()
+        statsJob = viewModelScope.launch {
+            while (isActive) {
+                try {
+                    val json = engine?.getStats() ?: "{}"
+                    if (json.isNotEmpty()) {
+                        Log.d(TAG, "raw: $json")
+                        lastStatsJson = json
+                        val s = CallStats.fromJson(json)
+                        lastCallDuration = s.durationSecs
+                        _stats.value = s
+                        // Only update callState from media engine stats (not signal)
+                        if (s.state != 0) {
+                            _callState.value = s.state
+                        }
+                        if (s.state == 2 && !audioStarted) {
+                            startAudio()
+                        }
+                    }
+                } catch (_: Exception) {}
+                delay(500L)
+            }
+        }
+    }
+
+    private fun stopStatsPolling() {
+        statsJob?.cancel()
+        statsJob = null
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        Log.i(TAG, "onCleared")
+        teardown()
+    }
+}

android/app/src/main/java/com/wzp/ui/components/Identicon.kt

@@ -0,0 +1,141 @@
+package com.wzp.ui.components
+
+import android.widget.Toast
+import androidx.compose.foundation.Canvas
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalClipboardManager
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import kotlin.math.min
+
+/**
+ * Deterministic identicon — generates a unique 5x5 symmetric pattern
+ * from a hex fingerprint string. Identical algorithm to the desktop
+ * TypeScript implementation in identicon.ts.
+ */
+@Composable
+fun Identicon(
+    fingerprint: String,
+    size: Dp = 36.dp,
+    clickToCopy: Boolean = true,
+    modifier: Modifier = Modifier,
+) {
+    val clipboard = LocalClipboardManager.current
+    val context = LocalContext.current
+    val bytes = hashBytes(fingerprint)
+    val (bg, fg) = deriveColors(bytes)
+    val grid = buildGrid(bytes)
+
+    Canvas(
+        modifier = modifier
+            .size(size)
+            .clip(RoundedCornerShape(size * 0.12f))
+            .then(
+                if (clickToCopy && fingerprint.isNotEmpty()) {
+                    Modifier.clickable {
+                        clipboard.setText(AnnotatedString(fingerprint))
+                        Toast.makeText(context, "Copied", Toast.LENGTH_SHORT).show()
+                    }
+                } else Modifier
+            )
+    ) {
+        val cellW = this.size.width / 5f
+        val cellH = this.size.height / 5f
+
+        // Background
+        drawRect(color = bg, size = this.size)
+
+        // Foreground cells
+        for (y in 0 until 5) {
+            for (x in 0 until 5) {
+                if (grid[y][x]) {
+                    drawRect(
+                        color = fg,
+                        topLeft = Offset(x * cellW, y * cellH),
+                        size = Size(cellW, cellH),
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Fingerprint text that copies to clipboard on tap.
+ */
+@Composable
+fun CopyableFingerprint(
+    fingerprint: String,
+    modifier: Modifier = Modifier,
+    style: androidx.compose.ui.text.TextStyle = androidx.compose.material3.MaterialTheme.typography.bodySmall,
+    color: Color = Color.Unspecified,
+) {
+    val clipboard = LocalClipboardManager.current
+    val context = LocalContext.current
+
+    androidx.compose.material3.Text(
+        text = fingerprint,
+        style = style,
+        color = color,
+        modifier = modifier.clickable {
+            if (fingerprint.isNotEmpty()) {
+                clipboard.setText(AnnotatedString(fingerprint))
+                Toast.makeText(context, "Fingerprint copied", Toast.LENGTH_SHORT).show()
+            }
+        }
+    )
+}
+
+// --- Internal helpers (matching desktop identicon.ts) ---
+
+private fun hashBytes(hex: String): List<Int> {
+    val clean = hex.filter { it.isLetterOrDigit() }
+    val bytes = mutableListOf<Int>()
+    var i = 0
+    while (i + 1 < clean.length) {
+        val b = clean.substring(i, i + 2).toIntOrNull(16) ?: 0
+        bytes.add(b)
+        i += 2
+    }
+    // Pad to at least 16 bytes
+    while (bytes.size < 16) bytes.add(0)
+    return bytes
+}
+
+private fun deriveColors(bytes: List<Int>): Pair<Color, Color> {
+    val hue1 = bytes[0] * 360f / 256f
+    val hue2 = (bytes[1] * 360f / 256f + 120f) % 360f
+    val bg = hslToColor(hue1, 0.65f, 0.35f)
+    val fg = hslToColor(hue2, 0.70f, 0.55f)
+    return bg to fg
+}
+
+private fun buildGrid(bytes: List<Int>): List<List<Boolean>> {
+    return (0 until 5).map { y ->
+        val left = (0 until 3).map { x ->
+            val idx = 2 + y * 3 + x
+            bytes[idx % bytes.size] > 128
+        }
+        // Mirror: col3 = col1, col4 = col0
+        listOf(left[0], left[1], left[2], left[1], left[0])
+    }
+}
+
+private fun hslToColor(h: Float, s: Float, l: Float): Color {
+    val k = { n: Float -> (n + h / 30f) % 12f }
+    val a = s * min(l, 1f - l)
+    val f = { n: Float ->
+        l - a * maxOf(-1f, minOf(k(n) - 3f, minOf(9f - k(n), 1f)))
+    }
+    return Color(f(0f), f(8f), f(4f))
+}

android/app/src/main/java/com/wzp/ui/settings/SettingsScreen.kt

@@ -0,0 +1,567 @@
+package com.wzp.ui.settings
+
+import androidx.compose.foundation.clickable
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.widget.Toast
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Divider
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.FilledTonalIconButton
+import androidx.compose.material3.IconButtonDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Slider
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.toMutableStateList
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import com.wzp.ui.call.CallViewModel
+import com.wzp.ui.call.ServerEntry
+
+@OptIn(ExperimentalLayoutApi::class)
+@Composable
+fun SettingsScreen(
+    viewModel: CallViewModel,
+    onBack: () -> Unit
+) {
+    val context = LocalContext.current
+
+    // Snapshot current values into local draft state
+    val currentAlias by viewModel.alias.collectAsState()
+    val currentSeedHex by viewModel.seedHex.collectAsState()
+    val currentServers by viewModel.servers.collectAsState()
+    val currentSelectedServer by viewModel.selectedServer.collectAsState()
+    val currentRoomName by viewModel.roomName.collectAsState()
+    val currentPreferIPv6 by viewModel.preferIPv6.collectAsState()
+    val currentPlayoutGain by viewModel.playoutGainDb.collectAsState()
+    val currentCaptureGain by viewModel.captureGainDb.collectAsState()
+    val currentAecEnabled by viewModel.aecEnabled.collectAsState()
+
+    // Draft state — initialized from current values
+    var draftAlias by remember { mutableStateOf(currentAlias) }
+    var draftSeedHex by remember { mutableStateOf(currentSeedHex) }
+    val draftServers = remember { currentServers.toMutableStateList() }
+    var draftSelectedServer by remember { mutableIntStateOf(currentSelectedServer) }
+    var draftRoomName by remember { mutableStateOf(currentRoomName) }
+    var draftPreferIPv6 by remember { mutableStateOf(currentPreferIPv6) }
+    var draftPlayoutGain by remember { mutableFloatStateOf(currentPlayoutGain) }
+    var draftCaptureGain by remember { mutableFloatStateOf(currentCaptureGain) }
+    var draftAecEnabled by remember { mutableStateOf(currentAecEnabled) }
+
+    // Track if anything changed
+    val hasChanges = draftAlias != currentAlias ||
+            draftSeedHex != currentSeedHex ||
+            draftServers.toList() != currentServers ||
+            draftSelectedServer != currentSelectedServer ||
+            draftRoomName != currentRoomName ||
+            draftPreferIPv6 != currentPreferIPv6 ||
+            draftPlayoutGain != currentPlayoutGain ||
+            draftCaptureGain != currentCaptureGain ||
+            draftAecEnabled != currentAecEnabled
+
+    var showAddServerDialog by remember { mutableStateOf(false) }
+    var showRestoreKeyDialog by remember { mutableStateOf(false) }
+
+    Surface(
+        modifier = Modifier.fillMaxSize(),
+        color = MaterialTheme.colorScheme.background
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(24.dp)
+                .verticalScroll(rememberScrollState())
+        ) {
+            // Header
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                TextButton(onClick = onBack) {
+                    Text("< Back")
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                Text(
+                    text = "Settings",
+                    style = MaterialTheme.typography.headlineSmall.copy(
+                        fontWeight = FontWeight.Bold
+                    ),
+                    color = MaterialTheme.colorScheme.primary
+                )
+                Spacer(modifier = Modifier.weight(1f))
+                // Save button — only enabled when changes exist
+                Button(
+                    onClick = {
+                        viewModel.setAlias(draftAlias)
+                        if (draftSeedHex != currentSeedHex) viewModel.restoreSeed(draftSeedHex)
+                        viewModel.applyServers(draftServers.toList(), draftSelectedServer)
+                        viewModel.setRoomName(draftRoomName)
+                        viewModel.setPreferIPv6(draftPreferIPv6)
+                        viewModel.setPlayoutGainDb(draftPlayoutGain)
+                        viewModel.setCaptureGainDb(draftCaptureGain)
+                        viewModel.setAecEnabled(draftAecEnabled)
+                        Toast.makeText(context, "Settings saved", Toast.LENGTH_SHORT).show()
+                        onBack()
+                    },
+                    enabled = hasChanges
+                ) {
+                    Text("Save")
+                }
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+
+            // --- Identity ---
+            SectionHeader("Identity")
+
+            OutlinedTextField(
+                value = draftAlias,
+                onValueChange = { draftAlias = it },
+                label = { Text("Display Name") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // Fingerprint display with identicon
+            val fingerprint = if (draftSeedHex.length >= 16) draftSeedHex.take(16).uppercase() else "Not generated"
+            Text(
+                text = "Fingerprint",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.padding(vertical = 4.dp)
+            ) {
+                com.wzp.ui.components.Identicon(
+                    fingerprint = draftSeedHex,
+                    size = 40.dp,
+                )
+                Spacer(modifier = Modifier.width(12.dp))
+                com.wzp.ui.components.CopyableFingerprint(
+                    fingerprint = fingerprint.chunked(4).joinToString(" "),
+                    style = MaterialTheme.typography.bodyMedium.copy(
+                        fontFamily = FontFamily.Monospace
+                    ),
+                    color = MaterialTheme.colorScheme.onSurface,
+                )
+            }
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            // Key backup/restore
+            Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                FilledTonalButton(onClick = {
+                    val clipboard = context.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
+                    clipboard.setPrimaryClip(ClipData.newPlainText("WZP Key", draftSeedHex))
+                    Toast.makeText(context, "Key copied to clipboard", Toast.LENGTH_SHORT).show()
+                }) {
+                    Text("Copy Key")
+                }
+                OutlinedButton(onClick = { showRestoreKeyDialog = true }) {
+                    Text("Restore Key")
+                }
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Audio ---
+            SectionHeader("Audio Defaults")
+
+            GainSlider(
+                label = "Voice Volume",
+                gainDb = draftPlayoutGain,
+                onGainChange = { draftPlayoutGain = Math.round(it).toFloat() }
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            GainSlider(
+                label = "Mic Gain",
+                gainDb = draftCaptureGain,
+                onGainChange = { draftCaptureGain = Math.round(it).toFloat() }
+            )
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Column(modifier = Modifier.weight(1f)) {
+                    Text(
+                        text = "Echo Cancellation (AEC)",
+                        style = MaterialTheme.typography.bodyMedium
+                    )
+                    Text(
+                        text = "Disable if audio sounds distorted",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                }
+                Switch(
+                    checked = draftAecEnabled,
+                    onCheckedChange = { draftAecEnabled = it }
+                )
+            }
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            // Quality selection — slider from best (studio 64k) to worst (codec2 1.2k) + auto
+            val qualityLabels = listOf(
+                "Studio 64k", "Studio 48k", "Studio 32k", "Auto",
+                "Opus 24k", "Opus 6k", "Codec2 3.2k", "Codec2 1.2k"
+            )
+            // Map slider position to JNI profile int:
+            // 0=Studio64k(6), 1=Studio48k(5), 2=Studio32k(4), 3=Auto(7),
+            // 4=Opus24k(0), 5=Opus6k(1), 6=Codec2_3.2k(3), 7=Codec2_1.2k(2)
+            val sliderToProfile = intArrayOf(6, 5, 4, 7, 0, 1, 3, 2)
+            val profileToSlider = mapOf(6 to 0, 5 to 1, 4 to 2, 7 to 3, 0 to 4, 1 to 5, 3 to 6, 2 to 7)
+            val qualityColors = listOf(
+                Color(0xFF22C55E), Color(0xFF4ADE80), Color(0xFF86EFAC), Color(0xFFA3E635),
+                Color(0xFFA3E635), Color(0xFFFACC15), Color(0xFFE97320), Color(0xFF991B1B)
+            )
+            val currentCodec by viewModel.codecChoice.collectAsState()
+            val sliderPos = profileToSlider[currentCodec] ?: 3
+            Text("Quality", style = MaterialTheme.typography.bodyMedium)
+            Text(
+                text = "Decode always accepts all codecs",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            Text(
+                text = qualityLabels[sliderPos],
+                style = MaterialTheme.typography.titleMedium.copy(fontWeight = FontWeight.Bold),
+                color = qualityColors[sliderPos]
+            )
+            Slider(
+                value = sliderPos.toFloat(),
+                onValueChange = { viewModel.setCodecChoice(sliderToProfile[it.toInt()]) },
+                valueRange = 0f..7f,
+                steps = 6,
+                modifier = Modifier.fillMaxWidth()
+            )
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween
+            ) {
+                Text("Best", style = MaterialTheme.typography.labelSmall, color = Color(0xFF22C55E))
+                Text("Lowest", style = MaterialTheme.typography.labelSmall, color = Color(0xFF991B1B))
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Servers ---
+            SectionHeader("Servers")
+
+            FlowRow(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.Start,
+                verticalArrangement = Arrangement.spacedBy(4.dp)
+            ) {
+                draftServers.forEachIndexed { idx, entry ->
+                    val isSelected = draftSelectedServer == idx
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        FilledTonalIconButton(
+                            onClick = { draftSelectedServer = idx },
+                            modifier = Modifier
+                                .padding(end = 2.dp)
+                                .height(36.dp)
+                                .width(140.dp),
+                            shape = RoundedCornerShape(8.dp),
+                            colors = if (isSelected) {
+                                IconButtonDefaults.filledTonalIconButtonColors(
+                                    containerColor = MaterialTheme.colorScheme.primaryContainer,
+                                    contentColor = MaterialTheme.colorScheme.onPrimaryContainer
+                                )
+                            } else {
+                                IconButtonDefaults.filledTonalIconButtonColors()
+                            }
+                        ) {
+                            Text(
+                                text = entry.label,
+                                style = MaterialTheme.typography.labelSmall,
+                                maxLines = 1
+                            )
+                        }
+                        // Show remove button for non-default servers
+                        if (idx >= 2) {
+                            TextButton(
+                                onClick = {
+                                    draftServers.removeAt(idx)
+                                    if (draftSelectedServer >= draftServers.size) {
+                                        draftSelectedServer = 0
+                                    }
+                                },
+                                modifier = Modifier.height(36.dp)
+                            ) {
+                                Text("X", color = MaterialTheme.colorScheme.error)
+                            }
+                        }
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.height(8.dp))
+            OutlinedButton(
+                onClick = { showAddServerDialog = true },
+                shape = RoundedCornerShape(8.dp)
+            ) {
+                Text("+ Add Server")
+            }
+
+            // Show selected server address
+            Spacer(modifier = Modifier.height(8.dp))
+            Text(
+                text = "Default: ${draftServers.getOrNull(draftSelectedServer)?.address ?: "none"}",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Network ---
+            SectionHeader("Network")
+
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Text(
+                    text = "Prefer IPv6",
+                    style = MaterialTheme.typography.bodyMedium,
+                    modifier = Modifier.weight(1f)
+                )
+                Switch(
+                    checked = draftPreferIPv6,
+                    onCheckedChange = { draftPreferIPv6 = it }
+                )
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Room ---
+            SectionHeader("Room")
+
+            OutlinedTextField(
+                value = draftRoomName,
+                onValueChange = { draftRoomName = it },
+                label = { Text("Default Room") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+
+            Spacer(modifier = Modifier.height(32.dp))
+        }
+    }
+
+    if (showAddServerDialog) {
+        AddServerDialog(
+            onDismiss = { showAddServerDialog = false },
+            onAdd = { host, port, label ->
+                draftServers.add(ServerEntry("$host:$port", label))
+                showAddServerDialog = false
+            }
+        )
+    }
+
+    if (showRestoreKeyDialog) {
+        RestoreKeyDialog(
+            onDismiss = { showRestoreKeyDialog = false },
+            onRestore = { hex ->
+                draftSeedHex = hex
+                showRestoreKeyDialog = false
+                Toast.makeText(context, "Key staged — press Save to apply", Toast.LENGTH_SHORT).show()
+            }
+        )
+    }
+}
+
+@Composable
+private fun SectionHeader(title: String) {
+    Text(
+        text = title,
+        style = MaterialTheme.typography.titleMedium.copy(fontWeight = FontWeight.Bold),
+        color = MaterialTheme.colorScheme.primary
+    )
+    Spacer(modifier = Modifier.height(8.dp))
+}
+
+@Composable
+private fun GainSlider(label: String, gainDb: Float, onGainChange: (Float) -> Unit) {
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        val sign = if (gainDb >= 0) "+" else ""
+        Text(
+            text = "$label: ${sign}${"%.0f".format(gainDb)} dB",
+            style = MaterialTheme.typography.labelSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Slider(
+            value = gainDb,
+            onValueChange = onGainChange,
+            valueRange = -20f..20f,
+            steps = 0,
+            modifier = Modifier.fillMaxWidth()
+        )
+    }
+}
+
+@Composable
+private fun AddServerDialog(
+    onDismiss: () -> Unit,
+    onAdd: (host: String, port: String, label: String) -> Unit
+) {
+    var host by remember { mutableStateOf("") }
+    var port by remember { mutableStateOf("4433") }
+    var label by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Add Server") },
+        text = {
+            Column {
+                OutlinedTextField(
+                    value = host,
+                    onValueChange = { host = it },
+                    label = { Text("Host (IP or domain)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = port,
+                    onValueChange = { port = it },
+                    label = { Text("Port") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = label,
+                    onValueChange = { label = it },
+                    label = { Text("Label (optional)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    if (host.isNotBlank()) {
+                        val displayLabel = label.ifBlank { host }
+                        onAdd(host.trim(), port.trim(), displayLabel)
+                    }
+                }
+            ) { Text("Add") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        }
+    )
+}
+
+@Composable
+private fun RestoreKeyDialog(
+    onDismiss: () -> Unit,
+    onRestore: (hex: String) -> Unit
+) {
+    var keyInput by remember { mutableStateOf("") }
+    var error by remember { mutableStateOf<String?>(null) }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Restore Identity Key") },
+        text = {
+            Column {
+                Text(
+                    text = "Paste your 64-character hex key below. This will replace your current identity.",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = keyInput,
+                    onValueChange = {
+                        keyInput = it.trim().lowercase()
+                        error = null
+                    },
+                    label = { Text("Identity Key (hex)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth(),
+                    isError = error != null
+                )
+                error?.let {
+                    Text(
+                        text = it,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.error
+                    )
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    val cleaned = keyInput.replace("\\s".toRegex(), "")
+                    if (cleaned.length != 64 || !cleaned.all { it in '0'..'9' || it in 'a'..'f' }) {
+                        error = "Key must be exactly 64 hex characters"
+                    } else {
+                        onRestore(cleaned)
+                    }
+                }
+            ) { Text("Restore") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        }
+    )
+}

android/app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <cache-path name="debug" path="." />
+</paths>

android/build.gradle.kts

@@ -0,0 +1,4 @@
+plugins {
+    id("com.android.application") version "8.2.0" apply false
+    id("org.jetbrains.kotlin.android") version "1.9.22" apply false
+}

android/gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+android.useAndroidX=true
+kotlin.code.style=official
+android.nonTransitiveRClass=true

android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+networkTimeout=10000
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

android/gradlew

@@ -0,0 +1,5 @@
+#!/bin/sh
+# Gradle wrapper script
+APP_HOME=$(cd "$(dirname "$0")" && pwd)
+CLASSPATH="$APP_HOME/gradle/wrapper/gradle-wrapper.jar"
+exec java -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"

android/settings.gradle.kts

@@ -0,0 +1,18 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "WZPhone"
+include(":app")

crates/wzp-android/Cargo.toml

@@ -0,0 +1,34 @@
+[package]
+name = "wzp-android"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+rust-version.workspace = true
+description = "WarzonePhone Android native VoIP engine — Oboe audio, JNI bridge, call pipeline"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+wzp-proto = { workspace = true }
+wzp-codec = { workspace = true }
+wzp-fec = { workspace = true }
+wzp-crypto = { workspace = true }
+wzp-transport = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true, features = ["env-filter"] }
+bytes = { workspace = true }
+serde = { workspace = true }
+serde_json = "1"
+thiserror = { workspace = true }
+async-trait = { workspace = true }
+anyhow = "1"
+libc = "0.2"
+jni = { version = "0.21", default-features = false }
+rand = { workspace = true }
+rustls = { version = "0.23", default-features = false, features = ["ring"] }
+tracing-android = "0.2"
+
+[build-dependencies]
+cc = "1"

crates/wzp-android/build.rs

@@ -0,0 +1,154 @@
+use std::path::PathBuf;
+
+fn main() {
+    let target = std::env::var("TARGET").unwrap_or_default();
+
+    if target.contains("android") {
+        // Override broken static getauxval from compiler-rt that crashes
+        // in shared libraries. Must be compiled first to take link priority.
+        cc::Build::new()
+            .file("cpp/getauxval_fix.c")
+            .compile("getauxval_fix");
+
+        let oboe_dir = fetch_oboe();
+        match oboe_dir {
+            Some(oboe_path) => {
+                println!("cargo:warning=Building with Oboe from {:?}", oboe_path);
+
+                let mut build = cc::Build::new();
+                build
+                    .cpp(true)
+                    .std("c++17")
+                    // Use shared libc++ — avoids pulling in static libc stubs
+                    // that crash in shared libraries (getauxval, pthread_create, etc.)
+                    .cpp_link_stdlib(Some("c++_shared"))
+                    .include("cpp")
+                    .include(oboe_path.join("include"))
+                    .include(oboe_path.join("src"))
+                    .define("WZP_HAS_OBOE", None)
+                    .file("cpp/oboe_bridge.cpp");
+
+                // Compile all Oboe source files
+                let src_dir = oboe_path.join("src");
+                add_cpp_files_recursive(&mut build, &src_dir);
+
+                build.compile("oboe_bridge");
+            }
+            None => {
+                println!("cargo:warning=Oboe not found, building with stub");
+                cc::Build::new()
+                    .cpp(true)
+                    .std("c++17")
+                    .cpp_link_stdlib(Some("c++_shared"))
+                    .file("cpp/oboe_stub.cpp")
+                    .include("cpp")
+                    .compile("oboe_bridge");
+            }
+        }
+
+        // Dynamic C++ runtime — libc++_shared.so must be in jniLibs alongside
+        // libwzp_android.so. We copy it there from the NDK sysroot.
+        //
+        // WHY NOT STATIC: libc++_static.a + libc++abi.a transitively pull in
+        // object files from libc.a (static libc) which contain broken stubs for
+        // getauxval, __init_tcb, pthread_create, etc. These stubs only work in
+        // statically-linked executables. In shared libraries loaded by dlopen(),
+        // they SIGSEGV because the static libc init hasn't run.
+        // Google's official recommendation: use libc++_shared.so for native libs.
+        if let Ok(ndk) = std::env::var("ANDROID_NDK_HOME") {
+            let arch = if target.contains("aarch64") {
+                "aarch64-linux-android"
+            } else if target.contains("armv7") {
+                "arm-linux-androideabi"
+            } else if target.contains("x86_64") {
+                "x86_64-linux-android"
+            } else {
+                "aarch64-linux-android"
+            };
+            let lib_dir = format!(
+                "{ndk}/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/lib/{arch}"
+            );
+            println!("cargo:rustc-link-search=native={lib_dir}");
+
+            // Copy libc++_shared.so to the jniLibs directory
+            let shared_so = format!("{lib_dir}/libc++_shared.so");
+            if std::path::Path::new(&shared_so).exists() {
+                let jni_abi = if target.contains("aarch64") {
+                    "arm64-v8a"
+                } else if target.contains("armv7") {
+                    "armeabi-v7a"
+                } else {
+                    "arm64-v8a"
+                };
+                // Try to copy to the Gradle jniLibs directory
+                let manifest = std::env::var("CARGO_MANIFEST_DIR").unwrap_or_default();
+                let jni_dir = format!(
+                    "{manifest}/../../android/app/src/main/jniLibs/{jni_abi}"
+                );
+                if let Ok(_) = std::fs::create_dir_all(&jni_dir) {
+                    let _ = std::fs::copy(&shared_so, format!("{jni_dir}/libc++_shared.so"));
+                    println!("cargo:warning=Copied libc++_shared.so to {jni_dir}");
+                }
+            }
+        }
+
+        // Oboe needs liblog and libOpenSLES from Android
+        println!("cargo:rustc-link-lib=log");
+        println!("cargo:rustc-link-lib=OpenSLES");
+    } else {
+        // Non-Android: always use stub
+        cc::Build::new()
+            .cpp(true)
+            .std("c++17")
+            .file("cpp/oboe_stub.cpp")
+            .include("cpp")
+            .compile("oboe_bridge");
+    }
+}
+
+/// Recursively add all .cpp files from a directory to a cc::Build.
+fn add_cpp_files_recursive(build: &mut cc::Build, dir: &std::path::Path) {
+    if !dir.is_dir() {
+        return;
+    }
+    for entry in std::fs::read_dir(dir).unwrap() {
+        let entry = entry.unwrap();
+        let path = entry.path();
+        if path.is_dir() {
+            add_cpp_files_recursive(build, &path);
+        } else if path.extension().map_or(false, |e| e == "cpp") {
+            build.file(&path);
+        }
+    }
+}
+
+/// Try to find or fetch Oboe headers + source.
+fn fetch_oboe() -> Option<PathBuf> {
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+    let oboe_dir = out_dir.join("oboe");
+
+    if oboe_dir.join("include").join("oboe").join("Oboe.h").exists() {
+        return Some(oboe_dir);
+    }
+
+    let status = std::process::Command::new("git")
+        .args([
+            "clone",
+            "--depth=1",
+            "--branch=1.8.1",
+            "https://github.com/google/oboe.git",
+            oboe_dir.to_str().unwrap(),
+        ])
+        .status();
+
+    match status {
+        Ok(s) if s.success() => {
+            if oboe_dir.join("include").join("oboe").join("Oboe.h").exists() {
+                Some(oboe_dir)
+            } else {
+                None
+            }
+        }
+        _ => None,
+    }
+}

crates/wzp-android/cpp/getauxval_fix.c

@@ -0,0 +1,21 @@
+// Override the broken static getauxval from compiler-rt/CRT.
+// The static version reads from __libc_auxv which is NULL in shared libs
+// loaded via dlopen, causing SIGSEGV in init_have_lse_atomics at load time.
+// This version calls the real bionic getauxval via dlsym.
+#ifdef __ANDROID__
+#include <dlfcn.h>
+#include <stdint.h>
+
+typedef unsigned long (*getauxval_fn)(unsigned long);
+
+unsigned long getauxval(unsigned long type) {
+    static getauxval_fn real_getauxval = (getauxval_fn)0;
+    if (!real_getauxval) {
+        real_getauxval = (getauxval_fn)dlsym((void*)-1L /* RTLD_DEFAULT */, "getauxval");
+        if (!real_getauxval) {
+            return 0;
+        }
+    }
+    return real_getauxval(type);
+}
+#endif

crates/wzp-android/cpp/oboe_bridge.cpp

@@ -0,0 +1,278 @@
+// Full Oboe implementation for Android
+// This file is compiled only when targeting Android
+
+#include "oboe_bridge.h"
+
+#ifdef __ANDROID__
+#include <oboe/Oboe.h>
+#include <android/log.h>
+#include <cstring>
+#include <atomic>
+
+#define LOG_TAG "wzp-oboe"
+#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
+#define LOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
+
+// ---------------------------------------------------------------------------
+// Ring buffer helpers (SPSC, lock-free)
+// ---------------------------------------------------------------------------
+
+static inline int32_t ring_available_read(const wzp_atomic_int* write_idx,
+                                           const wzp_atomic_int* read_idx,
+                                           int32_t capacity) {
+    int32_t w = std::atomic_load_explicit(write_idx, std::memory_order_acquire);
+    int32_t r = std::atomic_load_explicit(read_idx, std::memory_order_relaxed);
+    int32_t avail = w - r;
+    if (avail < 0) avail += capacity;
+    return avail;
+}
+
+static inline int32_t ring_available_write(const wzp_atomic_int* write_idx,
+                                            const wzp_atomic_int* read_idx,
+                                            int32_t capacity) {
+    return capacity - 1 - ring_available_read(write_idx, read_idx, capacity);
+}
+
+static inline void ring_write(int16_t* buf, int32_t capacity,
+                               wzp_atomic_int* write_idx, const wzp_atomic_int* read_idx,
+                               const int16_t* src, int32_t count) {
+    int32_t w = std::atomic_load_explicit(write_idx, std::memory_order_relaxed);
+    for (int32_t i = 0; i < count; i++) {
+        buf[w] = src[i];
+        w++;
+        if (w >= capacity) w = 0;
+    }
+    std::atomic_store_explicit(write_idx, w, std::memory_order_release);
+}
+
+static inline void ring_read(int16_t* buf, int32_t capacity,
+                              const wzp_atomic_int* write_idx, wzp_atomic_int* read_idx,
+                              int16_t* dst, int32_t count) {
+    int32_t r = std::atomic_load_explicit(read_idx, std::memory_order_relaxed);
+    for (int32_t i = 0; i < count; i++) {
+        dst[i] = buf[r];
+        r++;
+        if (r >= capacity) r = 0;
+    }
+    std::atomic_store_explicit(read_idx, r, std::memory_order_release);
+}
+
+// ---------------------------------------------------------------------------
+// Global state
+// ---------------------------------------------------------------------------
+
+static std::shared_ptr<oboe::AudioStream> g_capture_stream;
+static std::shared_ptr<oboe::AudioStream> g_playout_stream;
+static const WzpOboeRings* g_rings = nullptr;
+static std::atomic<bool> g_running{false};
+static std::atomic<float> g_capture_latency_ms{0.0f};
+static std::atomic<float> g_playout_latency_ms{0.0f};
+
+// ---------------------------------------------------------------------------
+// Capture callback
+// ---------------------------------------------------------------------------
+
+class CaptureCallback : public oboe::AudioStreamDataCallback {
+public:
+    oboe::DataCallbackResult onAudioReady(
+            oboe::AudioStream* stream,
+            void* audioData,
+            int32_t numFrames) override {
+        if (!g_running.load(std::memory_order_relaxed) || !g_rings) {
+            return oboe::DataCallbackResult::Stop;
+        }
+
+        const int16_t* src = static_cast<const int16_t*>(audioData);
+        int32_t avail = ring_available_write(g_rings->capture_write_idx,
+                                              g_rings->capture_read_idx,
+                                              g_rings->capture_capacity);
+        int32_t to_write = (numFrames < avail) ? numFrames : avail;
+        if (to_write > 0) {
+            ring_write(g_rings->capture_buf, g_rings->capture_capacity,
+                       g_rings->capture_write_idx, g_rings->capture_read_idx,
+                       src, to_write);
+        }
+
+        // Update latency estimate
+        auto result = stream->calculateLatencyMillis();
+        if (result) {
+            g_capture_latency_ms.store(static_cast<float>(result.value()),
+                                        std::memory_order_relaxed);
+        }
+
+        return oboe::DataCallbackResult::Continue;
+    }
+};
+
+// ---------------------------------------------------------------------------
+// Playout callback
+// ---------------------------------------------------------------------------
+
+class PlayoutCallback : public oboe::AudioStreamDataCallback {
+public:
+    oboe::DataCallbackResult onAudioReady(
+            oboe::AudioStream* stream,
+            void* audioData,
+            int32_t numFrames) override {
+        if (!g_running.load(std::memory_order_relaxed) || !g_rings) {
+            memset(audioData, 0, numFrames * sizeof(int16_t));
+            return oboe::DataCallbackResult::Stop;
+        }
+
+        int16_t* dst = static_cast<int16_t*>(audioData);
+        int32_t avail = ring_available_read(g_rings->playout_write_idx,
+                                             g_rings->playout_read_idx,
+                                             g_rings->playout_capacity);
+        int32_t to_read = (numFrames < avail) ? numFrames : avail;
+
+        if (to_read > 0) {
+            ring_read(g_rings->playout_buf, g_rings->playout_capacity,
+                      g_rings->playout_write_idx, g_rings->playout_read_idx,
+                      dst, to_read);
+        }
+        // Fill remainder with silence on underrun
+        if (to_read < numFrames) {
+            memset(dst + to_read, 0, (numFrames - to_read) * sizeof(int16_t));
+        }
+
+        // Update latency estimate
+        auto result = stream->calculateLatencyMillis();
+        if (result) {
+            g_playout_latency_ms.store(static_cast<float>(result.value()),
+                                        std::memory_order_relaxed);
+        }
+
+        return oboe::DataCallbackResult::Continue;
+    }
+};
+
+static CaptureCallback g_capture_cb;
+static PlayoutCallback g_playout_cb;
+
+// ---------------------------------------------------------------------------
+// Public C API
+// ---------------------------------------------------------------------------
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    if (g_running.load(std::memory_order_relaxed)) {
+        LOGW("wzp_oboe_start: already running");
+        return -1;
+    }
+
+    g_rings = rings;
+
+    // Build capture stream
+    oboe::AudioStreamBuilder captureBuilder;
+    captureBuilder.setDirection(oboe::Direction::Input)
+        ->setPerformanceMode(oboe::PerformanceMode::LowLatency)
+        ->setSharingMode(oboe::SharingMode::Exclusive)
+        ->setFormat(oboe::AudioFormat::I16)
+        ->setChannelCount(config->channel_count)
+        ->setSampleRate(config->sample_rate)
+        ->setFramesPerDataCallback(config->frames_per_burst)
+        ->setInputPreset(oboe::InputPreset::VoiceCommunication)
+        ->setDataCallback(&g_capture_cb);
+
+    oboe::Result result = captureBuilder.openStream(g_capture_stream);
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to open capture stream: %s", oboe::convertToText(result));
+        return -2;
+    }
+
+    // Build playout stream
+    oboe::AudioStreamBuilder playoutBuilder;
+    playoutBuilder.setDirection(oboe::Direction::Output)
+        ->setPerformanceMode(oboe::PerformanceMode::LowLatency)
+        ->setSharingMode(oboe::SharingMode::Exclusive)
+        ->setFormat(oboe::AudioFormat::I16)
+        ->setChannelCount(config->channel_count)
+        ->setSampleRate(config->sample_rate)
+        ->setFramesPerDataCallback(config->frames_per_burst)
+        ->setUsage(oboe::Usage::VoiceCommunication)
+        ->setDataCallback(&g_playout_cb);
+
+    result = playoutBuilder.openStream(g_playout_stream);
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to open playout stream: %s", oboe::convertToText(result));
+        g_capture_stream->close();
+        g_capture_stream.reset();
+        return -3;
+    }
+
+    g_running.store(true, std::memory_order_release);
+
+    // Start both streams
+    result = g_capture_stream->requestStart();
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to start capture: %s", oboe::convertToText(result));
+        g_running.store(false, std::memory_order_release);
+        g_capture_stream->close();
+        g_playout_stream->close();
+        g_capture_stream.reset();
+        g_playout_stream.reset();
+        return -4;
+    }
+
+    result = g_playout_stream->requestStart();
+    if (result != oboe::Result::OK) {
+        LOGE("Failed to start playout: %s", oboe::convertToText(result));
+        g_running.store(false, std::memory_order_release);
+        g_capture_stream->requestStop();
+        g_capture_stream->close();
+        g_playout_stream->close();
+        g_capture_stream.reset();
+        g_playout_stream.reset();
+        return -5;
+    }
+
+    LOGI("Oboe started: sr=%d burst=%d ch=%d",
+         config->sample_rate, config->frames_per_burst, config->channel_count);
+    return 0;
+}
+
+void wzp_oboe_stop(void) {
+    g_running.store(false, std::memory_order_release);
+
+    if (g_capture_stream) {
+        g_capture_stream->requestStop();
+        g_capture_stream->close();
+        g_capture_stream.reset();
+    }
+    if (g_playout_stream) {
+        g_playout_stream->requestStop();
+        g_playout_stream->close();
+        g_playout_stream.reset();
+    }
+
+    g_rings = nullptr;
+    LOGI("Oboe stopped");
+}
+
+float wzp_oboe_capture_latency_ms(void) {
+    return g_capture_latency_ms.load(std::memory_order_relaxed);
+}
+
+float wzp_oboe_playout_latency_ms(void) {
+    return g_playout_latency_ms.load(std::memory_order_relaxed);
+}
+
+int wzp_oboe_is_running(void) {
+    return g_running.load(std::memory_order_relaxed) ? 1 : 0;
+}
+
+#else
+// Non-Android fallback — should not be reached; oboe_stub.cpp is used instead.
+// Provide empty implementations just in case.
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    (void)config; (void)rings;
+    return -99;
+}
+
+void wzp_oboe_stop(void) {}
+float wzp_oboe_capture_latency_ms(void) { return 0.0f; }
+float wzp_oboe_playout_latency_ms(void) { return 0.0f; }
+int wzp_oboe_is_running(void) { return 0; }
+
+#endif // __ANDROID__

crates/wzp-android/cpp/oboe_bridge.h

@@ -0,0 +1,43 @@
+#ifndef WZP_OBOE_BRIDGE_H
+#define WZP_OBOE_BRIDGE_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+#include <atomic>
+typedef std::atomic<int32_t> wzp_atomic_int;
+extern "C" {
+#else
+#include <stdatomic.h>
+typedef atomic_int wzp_atomic_int;
+#endif
+
+typedef struct {
+    int32_t sample_rate;
+    int32_t frames_per_burst;
+    int32_t channel_count;
+} WzpOboeConfig;
+
+typedef struct {
+    int16_t* capture_buf;
+    int32_t  capture_capacity;
+    wzp_atomic_int* capture_write_idx;
+    wzp_atomic_int* capture_read_idx;
+
+    int16_t* playout_buf;
+    int32_t  playout_capacity;
+    wzp_atomic_int* playout_write_idx;
+    wzp_atomic_int* playout_read_idx;
+} WzpOboeRings;
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings);
+void wzp_oboe_stop(void);
+float wzp_oboe_capture_latency_ms(void);
+float wzp_oboe_playout_latency_ms(void);
+int wzp_oboe_is_running(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // WZP_OBOE_BRIDGE_H

crates/wzp-android/cpp/oboe_stub.cpp

@@ -0,0 +1,27 @@
+// Stub implementation for non-Android host builds (testing, cargo check, etc.)
+
+#include "oboe_bridge.h"
+#include <stdio.h>
+
+int wzp_oboe_start(const WzpOboeConfig* config, const WzpOboeRings* rings) {
+    (void)config;
+    (void)rings;
+    fprintf(stderr, "wzp_oboe_start: stub (not on Android)\n");
+    return 0;
+}
+
+void wzp_oboe_stop(void) {
+    fprintf(stderr, "wzp_oboe_stop: stub (not on Android)\n");
+}
+
+float wzp_oboe_capture_latency_ms(void) {
+    return 0.0f;
+}
+
+float wzp_oboe_playout_latency_ms(void) {
+    return 0.0f;
+}
+
+int wzp_oboe_is_running(void) {
+    return 0;
+}

crates/wzp-android/src/audio_android.rs

@@ -0,0 +1,424 @@
+//! Lock-free SPSC ring buffer audio backend for Android (Oboe).
+//!
+//! The ring buffers are shared between Rust and C++: the Oboe callbacks
+//! (running on a high-priority audio thread) read/write directly into
+//! the buffers via atomic indices, while the Rust codec thread on the
+//! other side does the same.
+
+use std::sync::atomic::{AtomicI32, Ordering};
+
+use tracing::info;
+#[allow(unused_imports)]
+use tracing::warn;
+
+/// Number of samples per 20 ms frame at 48 kHz mono.
+pub const FRAME_SAMPLES: usize = 960;
+
+/// Default ring buffer capacity: 8 frames = 160 ms at 48 kHz.
+const RING_CAPACITY: usize = 7680;
+
+// ---------------------------------------------------------------------------
+// FFI declarations matching oboe_bridge.h
+// ---------------------------------------------------------------------------
+
+#[repr(C)]
+#[allow(non_snake_case)]
+struct WzpOboeConfig {
+    sample_rate: i32,
+    frames_per_burst: i32,
+    channel_count: i32,
+}
+
+#[repr(C)]
+#[allow(non_snake_case)]
+struct WzpOboeRings {
+    capture_buf: *mut i16,
+    capture_capacity: i32,
+    capture_write_idx: *mut AtomicI32,
+    capture_read_idx: *mut AtomicI32,
+
+    playout_buf: *mut i16,
+    playout_capacity: i32,
+    playout_write_idx: *mut AtomicI32,
+    playout_read_idx: *mut AtomicI32,
+}
+
+unsafe impl Send for WzpOboeRings {}
+unsafe impl Sync for WzpOboeRings {}
+
+unsafe extern "C" {
+    fn wzp_oboe_start(config: *const WzpOboeConfig, rings: *const WzpOboeRings) -> i32;
+    fn wzp_oboe_stop();
+    fn wzp_oboe_capture_latency_ms() -> f32;
+    fn wzp_oboe_playout_latency_ms() -> f32;
+    fn wzp_oboe_is_running() -> i32;
+}
+
+// ---------------------------------------------------------------------------
+// SPSC Ring Buffer
+// ---------------------------------------------------------------------------
+
+/// Single-producer single-consumer lock-free ring buffer.
+///
+/// The producer calls `write()` and the consumer calls `read()`.
+/// Atomics use acquire/release ordering to ensure correct visibility
+/// across the Oboe audio thread and the Rust codec thread.
+pub struct RingBuffer {
+    buf: Vec<i16>,
+    capacity: usize,
+    write_idx: AtomicI32,
+    read_idx: AtomicI32,
+}
+
+impl RingBuffer {
+    /// Create a new ring buffer with the given capacity (in samples).
+    ///
+    /// The actual usable capacity is `capacity - 1` to distinguish
+    /// full from empty.
+    pub fn new(capacity: usize) -> Self {
+        Self {
+            buf: vec![0i16; capacity],
+            capacity,
+            write_idx: AtomicI32::new(0),
+            read_idx: AtomicI32::new(0),
+        }
+    }
+
+    /// Number of samples available to read.
+    pub fn available_read(&self) -> usize {
+        let w = self.write_idx.load(Ordering::Acquire);
+        let r = self.read_idx.load(Ordering::Relaxed);
+        let avail = w - r;
+        if avail < 0 {
+            (avail + self.capacity as i32) as usize
+        } else {
+            avail as usize
+        }
+    }
+
+    /// Number of samples that can be written before the buffer is full.
+    pub fn available_write(&self) -> usize {
+        self.capacity - 1 - self.available_read()
+    }
+
+    /// Write samples into the ring buffer (producer side).
+    ///
+    /// Returns the number of samples actually written (may be less than
+    /// `data.len()` if the buffer is nearly full).
+    pub fn write(&self, data: &[i16]) -> usize {
+        let avail = self.available_write();
+        let count = data.len().min(avail);
+        if count == 0 {
+            return 0;
+        }
+
+        let mut w = self.write_idx.load(Ordering::Relaxed) as usize;
+        let cap = self.capacity;
+        let buf_ptr = self.buf.as_ptr() as *mut i16;
+
+        for i in 0..count {
+            // SAFETY: w is always in [0, capacity) and we are the sole producer.
+            unsafe {
+                *buf_ptr.add(w) = data[i];
+            }
+            w += 1;
+            if w >= cap {
+                w = 0;
+            }
+        }
+
+        self.write_idx.store(w as i32, Ordering::Release);
+        count
+    }
+
+    /// Read samples from the ring buffer (consumer side).
+    ///
+    /// Returns the number of samples actually read (may be less than
+    /// `out.len()` if the buffer doesn't have enough data).
+    pub fn read(&self, out: &mut [i16]) -> usize {
+        let avail = self.available_read();
+        let count = out.len().min(avail);
+        if count == 0 {
+            return 0;
+        }
+
+        let mut r = self.read_idx.load(Ordering::Relaxed) as usize;
+        let cap = self.capacity;
+        let buf_ptr = self.buf.as_ptr();
+
+        for i in 0..count {
+            // SAFETY: r is always in [0, capacity) and we are the sole consumer.
+            unsafe {
+                out[i] = *buf_ptr.add(r);
+            }
+            r += 1;
+            if r >= cap {
+                r = 0;
+            }
+        }
+
+        self.read_idx.store(r as i32, Ordering::Release);
+        count
+    }
+
+    /// Get a raw pointer to the buffer data (for FFI).
+    fn buf_ptr(&self) -> *mut i16 {
+        self.buf.as_ptr() as *mut i16
+    }
+
+    /// Get a raw pointer to the write index atomic (for FFI).
+    fn write_idx_ptr(&self) -> *mut AtomicI32 {
+        &self.write_idx as *const AtomicI32 as *mut AtomicI32
+    }
+
+    /// Get a raw pointer to the read index atomic (for FFI).
+    fn read_idx_ptr(&self) -> *mut AtomicI32 {
+        &self.read_idx as *const AtomicI32 as *mut AtomicI32
+    }
+}
+
+// SAFETY: The ring buffer is designed for SPSC use where producer and consumer
+// are on different threads. The atomic indices provide the synchronization.
+unsafe impl Send for RingBuffer {}
+unsafe impl Sync for RingBuffer {}
+
+// ---------------------------------------------------------------------------
+// Oboe Backend
+// ---------------------------------------------------------------------------
+
+/// Oboe-based audio backend for Android.
+///
+/// Owns two SPSC ring buffers (capture and playout) that are shared with
+/// the C++ Oboe callbacks via raw pointers. The Oboe callbacks run on
+/// high-priority audio threads managed by the Android audio system.
+pub struct OboeBackend {
+    capture_ring: RingBuffer,
+    playout_ring: RingBuffer,
+    started: bool,
+}
+
+impl OboeBackend {
+    /// Create a new backend with default ring buffer sizes (160 ms each).
+    pub fn new() -> Self {
+        Self {
+            capture_ring: RingBuffer::new(RING_CAPACITY),
+            playout_ring: RingBuffer::new(RING_CAPACITY),
+            started: false,
+        }
+    }
+
+    /// Start Oboe audio streams.
+    ///
+    /// This sets up the ring buffer pointers and calls into the C++ layer
+    /// to open and start the capture and playout Oboe streams.
+    pub fn start(&mut self) -> Result<(), anyhow::Error> {
+        if self.started {
+            return Ok(());
+        }
+
+        let config = WzpOboeConfig {
+            sample_rate: 48_000,
+            frames_per_burst: FRAME_SAMPLES as i32,
+            channel_count: 1,
+        };
+
+        let rings = WzpOboeRings {
+            capture_buf: self.capture_ring.buf_ptr(),
+            capture_capacity: self.capture_ring.capacity as i32,
+            capture_write_idx: self.capture_ring.write_idx_ptr(),
+            capture_read_idx: self.capture_ring.read_idx_ptr(),
+
+            playout_buf: self.playout_ring.buf_ptr(),
+            playout_capacity: self.playout_ring.capacity as i32,
+            playout_write_idx: self.playout_ring.write_idx_ptr(),
+            playout_read_idx: self.playout_ring.read_idx_ptr(),
+        };
+
+        let ret = unsafe { wzp_oboe_start(&config, &rings) };
+        if ret != 0 {
+            return Err(anyhow::anyhow!("wzp_oboe_start failed with code {}", ret));
+        }
+
+        self.started = true;
+        info!("Oboe backend started");
+        Ok(())
+    }
+
+    /// Stop Oboe audio streams.
+    pub fn stop(&mut self) {
+        if !self.started {
+            return;
+        }
+        unsafe { wzp_oboe_stop() };
+        self.started = false;
+        info!("Oboe backend stopped");
+    }
+
+    /// Read captured audio samples from the capture ring buffer.
+    ///
+    /// Returns the number of samples actually read. The caller should
+    /// provide a buffer of at least `FRAME_SAMPLES` (960) samples.
+    pub fn read_capture(&self, out: &mut [i16]) -> usize {
+        self.capture_ring.read(out)
+    }
+
+    /// Write audio samples to the playout ring buffer.
+    ///
+    /// Returns the number of samples actually written.
+    pub fn write_playout(&self, samples: &[i16]) -> usize {
+        self.playout_ring.write(samples)
+    }
+
+    /// Get the current capture latency in milliseconds (from Oboe).
+    #[allow(unused)]
+    pub fn capture_latency_ms(&self) -> f32 {
+        unsafe { wzp_oboe_capture_latency_ms() }
+    }
+
+    /// Get the current playout latency in milliseconds (from Oboe).
+    #[allow(unused)]
+    pub fn playout_latency_ms(&self) -> f32 {
+        unsafe { wzp_oboe_playout_latency_ms() }
+    }
+
+    /// Check if the Oboe streams are currently running.
+    #[allow(unused)]
+    pub fn is_running(&self) -> bool {
+        unsafe { wzp_oboe_is_running() != 0 }
+    }
+}
+
+impl Drop for OboeBackend {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Thread affinity / priority helpers
+// ---------------------------------------------------------------------------
+
+/// Pin the current thread to the highest-numbered CPU cores (big cores on
+/// ARM big.LITTLE architectures). Falls back silently on failure.
+#[allow(unused)]
+pub fn pin_to_big_core() {
+    #[cfg(target_os = "android")]
+    {
+        unsafe {
+            let num_cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN);
+            if num_cpus <= 0 {
+                warn!("pin_to_big_core: could not determine CPU count");
+                return;
+            }
+            let num_cpus = num_cpus as usize;
+
+            // Target the upper half of CPUs (big cores on most big.LITTLE SoCs)
+            let start = num_cpus / 2;
+            let mut set: libc::cpu_set_t = std::mem::zeroed();
+            libc::CPU_ZERO(&mut set);
+            for cpu in start..num_cpus {
+                libc::CPU_SET(cpu, &mut set);
+            }
+
+            let ret = libc::sched_setaffinity(
+                0, // current thread
+                std::mem::size_of::<libc::cpu_set_t>(),
+                &set,
+            );
+            if ret != 0 {
+                warn!("sched_setaffinity failed: {}", std::io::Error::last_os_error());
+            } else {
+                info!(start, num_cpus, "pinned to big cores");
+            }
+        }
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        // No-op on non-Android
+    }
+}
+
+/// Attempt to set SCHED_FIFO real-time priority for the current thread.
+/// Falls back silently on failure (requires appropriate permissions on Android).
+#[allow(unused)]
+pub fn set_realtime_priority() {
+    #[cfg(target_os = "android")]
+    {
+        unsafe {
+            let param = libc::sched_param {
+                sched_priority: 2, // Low RT priority — enough for audio, safe
+            };
+            let ret = libc::sched_setscheduler(0, libc::SCHED_FIFO, &param);
+            if ret != 0 {
+                warn!(
+                    "sched_setscheduler(SCHED_FIFO) failed: {}",
+                    std::io::Error::last_os_error()
+                );
+            } else {
+                info!("set SCHED_FIFO priority 2");
+            }
+        }
+    }
+    #[cfg(not(target_os = "android"))]
+    {
+        // No-op on non-Android
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ring_buffer_write_read() {
+        let ring = RingBuffer::new(16);
+        let data = [1i16, 2, 3, 4, 5];
+        assert_eq!(ring.write(&data), 5);
+        assert_eq!(ring.available_read(), 5);
+
+        let mut out = [0i16; 5];
+        assert_eq!(ring.read(&mut out), 5);
+        assert_eq!(out, [1, 2, 3, 4, 5]);
+        assert_eq!(ring.available_read(), 0);
+    }
+
+    #[test]
+    fn ring_buffer_wraparound() {
+        let ring = RingBuffer::new(8);
+        let data = [10i16, 20, 30, 40, 50, 60]; // 6 samples, capacity 8 (usable 7)
+        assert_eq!(ring.write(&data), 6);
+
+        let mut out = [0i16; 4];
+        assert_eq!(ring.read(&mut out), 4);
+        assert_eq!(out, [10, 20, 30, 40]);
+
+        // Now write more, which should wrap around
+        let data2 = [70i16, 80, 90, 100];
+        assert_eq!(ring.write(&data2), 4);
+
+        let mut out2 = [0i16; 6];
+        assert_eq!(ring.read(&mut out2), 6);
+        assert_eq!(out2, [50, 60, 70, 80, 90, 100]);
+    }
+
+    #[test]
+    fn ring_buffer_full() {
+        let ring = RingBuffer::new(4); // usable capacity = 3
+        let data = [1i16, 2, 3, 4, 5];
+        assert_eq!(ring.write(&data), 3); // Only 3 fit
+        assert_eq!(ring.available_write(), 0);
+    }
+
+    #[test]
+    fn oboe_backend_stub_start_stop() {
+        let mut backend = OboeBackend::new();
+        backend.start().expect("stub start should succeed");
+        assert!(backend.started);
+        backend.stop();
+        assert!(!backend.started);
+    }
+}

crates/wzp-android/src/audio_ring.rs

@@ -0,0 +1,128 @@
+//! Lock-free SPSC ring buffer — "Reader-Detects-Lap" architecture.
+//!
+//! SPSC invariant: the producer ONLY writes `write_pos`, the consumer
+//! ONLY writes `read_pos`.  Neither thread touches the other's cursor.
+//!
+//! On overflow (writer laps the reader), the writer simply overwrites
+//! old buffer data.  The reader detects the lap via `available() >
+//! RING_CAPACITY` and snaps its own `read_pos` forward.
+//!
+//! Capacity is a power of 2 for bitmask indexing (no modulo).
+
+use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
+
+/// Ring buffer capacity — power of 2 for bitmask indexing.
+/// 16384 samples = 341.3ms at 48kHz mono.  70% more headroom
+/// than the previous 9600 (200ms) for surviving Android GC pauses.
+const RING_CAPACITY: usize = 16384; // 2^14
+const RING_MASK: usize = RING_CAPACITY - 1;
+
+/// Lock-free single-producer single-consumer ring buffer for i16 PCM samples.
+pub struct AudioRing {
+    buf: Box<[i16]>,
+    /// Monotonically increasing write cursor. ONLY written by producer.
+    write_pos: AtomicUsize,
+    /// Monotonically increasing read cursor. ONLY written by consumer.
+    read_pos: AtomicUsize,
+    /// Incremented by reader when it detects it was lapped (overflow).
+    overflow_count: AtomicU64,
+    /// Incremented by reader when ring is empty (underrun).
+    underrun_count: AtomicU64,
+}
+
+// SAFETY: AudioRing is SPSC — one thread writes (producer), one reads (consumer).
+// The producer only writes write_pos. The consumer only writes read_pos.
+// Neither thread writes the other's cursor. Buffer indices are derived from
+// the owning thread's cursor, ensuring no concurrent access to the same index.
+unsafe impl Send for AudioRing {}
+unsafe impl Sync for AudioRing {}
+
+impl AudioRing {
+    pub fn new() -> Self {
+        debug_assert!(RING_CAPACITY.is_power_of_two());
+        Self {
+            buf: vec![0i16; RING_CAPACITY].into_boxed_slice(),
+            write_pos: AtomicUsize::new(0),
+            read_pos: AtomicUsize::new(0),
+            overflow_count: AtomicU64::new(0),
+            underrun_count: AtomicU64::new(0),
+        }
+    }
+
+    /// Number of samples available to read (clamped to capacity).
+    pub fn available(&self) -> usize {
+        let w = self.write_pos.load(Ordering::Acquire);
+        let r = self.read_pos.load(Ordering::Relaxed);
+        w.wrapping_sub(r).min(RING_CAPACITY)
+    }
+
+    /// Number of samples that can be written without overwriting unread data.
+    pub fn free_space(&self) -> usize {
+        RING_CAPACITY.saturating_sub(self.available())
+    }
+
+    /// Write samples into the ring. Returns number of samples written.
+    ///
+    /// If the ring is full, old data is silently overwritten.  The reader
+    /// will detect the lap and self-correct.  The writer NEVER touches
+    /// `read_pos` — this is the key invariant that prevents cursor desync.
+    pub fn write(&self, samples: &[i16]) -> usize {
+        let count = samples.len().min(RING_CAPACITY);
+        let w = self.write_pos.load(Ordering::Relaxed);
+
+        for i in 0..count {
+            unsafe {
+                let ptr = self.buf.as_ptr() as *mut i16;
+                *ptr.add((w + i) & RING_MASK) = samples[i];
+            }
+        }
+
+        self.write_pos.store(w.wrapping_add(count), Ordering::Release);
+        count
+    }
+
+    /// Read samples from the ring into `out`. Returns number of samples read.
+    ///
+    /// If the writer has lapped the reader (overflow), `read_pos` is snapped
+    /// forward to the oldest valid data.  This is safe because only the
+    /// reader thread writes `read_pos`.
+    pub fn read(&self, out: &mut [i16]) -> usize {
+        let w = self.write_pos.load(Ordering::Acquire);
+        let mut r = self.read_pos.load(Ordering::Relaxed);
+
+        let mut avail = w.wrapping_sub(r);
+
+        // Lap detection: writer has overwritten our unread data.
+        // Snap read_pos forward to oldest valid data in the buffer.
+        if avail > RING_CAPACITY {
+            r = w.wrapping_sub(RING_CAPACITY);
+            avail = RING_CAPACITY;
+            self.overflow_count.fetch_add(1, Ordering::Relaxed);
+        }
+
+        let count = out.len().min(avail);
+        if count == 0 {
+            if w == r {
+                self.underrun_count.fetch_add(1, Ordering::Relaxed);
+            }
+            return 0;
+        }
+
+        for i in 0..count {
+            out[i] = unsafe { *self.buf.as_ptr().add((r + i) & RING_MASK) };
+        }
+
+        self.read_pos.store(r.wrapping_add(count), Ordering::Release);
+        count
+    }
+
+    /// Number of overflow events (reader was lapped by writer).
+    pub fn overflow_count(&self) -> u64 {
+        self.overflow_count.load(Ordering::Relaxed)
+    }
+
+    /// Number of underrun events (reader found empty buffer).
+    pub fn underrun_count(&self) -> u64 {
+        self.underrun_count.load(Ordering::Relaxed)
+    }
+}

crates/wzp-android/src/commands.rs

@@ -0,0 +1,24 @@
+//! Engine commands sent from the JNI/UI thread to the engine.
+
+use wzp_proto::QualityProfile;
+
+/// Commands that can be sent to the running engine.
+pub enum EngineCommand {
+    /// Mute or unmute the microphone.
+    SetMute(bool),
+    /// Enable or disable speaker (loudspeaker) mode.
+    SetSpeaker(bool),
+    /// Force a specific quality profile (overrides adaptive logic).
+    ForceProfile(QualityProfile),
+    /// Stop the call and shut down the engine.
+    Stop,
+    /// Place a direct call to a fingerprint (requires signal connection).
+    PlaceCall { target_fingerprint: String },
+    /// Answer an incoming direct call.
+    AnswerCall {
+        call_id: String,
+        accept_mode: wzp_proto::CallAcceptMode,
+    },
+    /// Reject an incoming direct call.
+    RejectCall { call_id: String },
+}

crates/wzp-android/src/engine.rs

@@ -0,0 +1,897 @@
+//! Engine orchestrator — manages the call lifecycle.
+//!
+//! IMPORTANT: On Android, pthread_create crashes in shared libraries due to
+//! static bionic stubs in the Rust std prebuilt rlibs. ALL work must happen
+//! on the JNI calling thread or via the tokio current_thread runtime.
+//! No std::thread::spawn or tokio multi_thread allowed.
+//!
+//! Audio capture and playout happen on Kotlin JVM threads via AudioRecord
+//! and AudioTrack. PCM samples are transferred through lock-free ring buffers.
+
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicBool, AtomicU8, AtomicU16, AtomicU32, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::Instant;
+
+use bytes::Bytes;
+use tracing::{error, info, warn};
+use wzp_codec::agc::AutoGainControl;
+use wzp_crypto::{KeyExchange, WarzoneKeyExchange};
+use wzp_fec::{RaptorQFecDecoder, RaptorQFecEncoder};
+use wzp_proto::{
+    AdaptiveQualityController, AudioDecoder, AudioEncoder, CodecId, FecDecoder, FecEncoder,
+    MediaHeader, MediaPacket, MediaTransport, QualityController, QualityProfile, SignalMessage,
+};
+
+use crate::audio_ring::AudioRing;
+use crate::commands::EngineCommand;
+use crate::stats::{CallState, CallStats};
+
+/// Max frame size at 48kHz mono (40ms = 1920 samples, for Codec2/Opus6k).
+const MAX_FRAME_SAMPLES: usize = 1920;
+
+/// Sentinel value: no profile change pending.
+const PROFILE_NO_CHANGE: u8 = 0xFF;
+
+/// All quality profiles in index order, for AtomicU8-based signaling.
+const PROFILES: [QualityProfile; 6] = [
+    QualityProfile::STUDIO_64K,   // 0
+    QualityProfile::STUDIO_48K,   // 1
+    QualityProfile::STUDIO_32K,   // 2
+    QualityProfile::GOOD,         // 3
+    QualityProfile::DEGRADED,     // 4
+    QualityProfile::CATASTROPHIC, // 5
+];
+
+fn profile_to_index(p: &QualityProfile) -> u8 {
+    PROFILES.iter().position(|pp| pp.codec == p.codec).map(|i| i as u8).unwrap_or(3)
+}
+
+fn index_to_profile(idx: u8) -> Option<QualityProfile> {
+    PROFILES.get(idx as usize).copied()
+}
+
+/// Compute frame samples at 48kHz for a given profile.
+fn frame_samples_for(profile: &QualityProfile) -> usize {
+    (profile.frame_duration_ms as usize) * 48 // 48000 / 1000
+}
+
+/// Configuration to start a call.
+pub struct CallStartConfig {
+    pub profile: QualityProfile,
+    /// When true, use the relay's chosen_profile from CallAnswer instead of local profile.
+    pub auto_profile: bool,
+    pub relay_addr: String,
+    pub room: String,
+    pub auth_token: Vec<u8>,
+    pub identity_seed: [u8; 32],
+    pub alias: Option<String>,
+}
+
+impl Default for CallStartConfig {
+    fn default() -> Self {
+        Self {
+            profile: QualityProfile::GOOD,
+            auto_profile: false,
+            relay_addr: String::new(),
+            room: String::new(),
+            auth_token: Vec::new(),
+            identity_seed: [0u8; 32],
+            alias: None,
+        }
+    }
+}
+
+pub(crate) struct EngineState {
+    pub running: AtomicBool,
+    pub muted: AtomicBool,
+    pub stats: Mutex<CallStats>,
+    pub command_tx: std::sync::mpsc::Sender<EngineCommand>,
+    pub command_rx: Mutex<Option<std::sync::mpsc::Receiver<EngineCommand>>>,
+    /// Ring buffer: Kotlin AudioRecord → Rust encoder
+    pub capture_ring: AudioRing,
+    /// Ring buffer: Rust decoder → Kotlin AudioTrack
+    pub playout_ring: AudioRing,
+    /// Current audio level (RMS) for UI display, updated by capture path.
+    pub audio_level_rms: AtomicU32,
+    /// QUIC transport handle — stored so stop_call() can close it immediately,
+    /// triggering relay-side leave + RoomUpdate broadcast.
+    pub quic_transport: Mutex<Option<Arc<wzp_transport::QuinnTransport>>>,
+}
+
+pub struct WzpEngine {
+    pub(crate) state: Arc<EngineState>,
+    tokio_runtime: Option<tokio::runtime::Runtime>,
+    call_start: Option<Instant>,
+}
+
+impl WzpEngine {
+    pub fn new() -> Self {
+        let (tx, rx) = std::sync::mpsc::channel();
+        let state = Arc::new(EngineState {
+            running: AtomicBool::new(false),
+            muted: AtomicBool::new(false),
+            stats: Mutex::new(CallStats::default()),
+            command_tx: tx,
+            command_rx: Mutex::new(Some(rx)),
+            capture_ring: AudioRing::new(),
+            playout_ring: AudioRing::new(),
+            audio_level_rms: AtomicU32::new(0),
+            quic_transport: Mutex::new(None),
+        });
+        Self {
+            state,
+            tokio_runtime: None,
+            call_start: None,
+        }
+    }
+
+    pub fn start_call(&mut self, config: CallStartConfig) -> Result<(), anyhow::Error> {
+        if self.state.running.load(Ordering::Acquire) {
+            return Err(anyhow::anyhow!("call already active"));
+        }
+
+        {
+            let mut stats = self.state.stats.lock().unwrap();
+            *stats = CallStats {
+                state: CallState::Connecting,
+                ..Default::default()
+            };
+        }
+
+        let runtime = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()?;
+
+        let relay_addr: SocketAddr = config.relay_addr.parse().map_err(|e| {
+            anyhow::anyhow!("invalid relay address '{}': {e}", config.relay_addr)
+        })?;
+
+        let room = config.room.clone();
+        let identity_seed = config.identity_seed;
+        let profile = config.profile;
+        let auto_profile = config.auto_profile;
+        let alias = config.alias.clone();
+        let state = self.state.clone();
+
+        self.state.running.store(true, Ordering::Release);
+        self.call_start = Some(Instant::now());
+
+        let state_clone = state.clone();
+        runtime.block_on(async move {
+            if let Err(e) = run_call(relay_addr, &room, &identity_seed, profile, auto_profile, alias.as_deref(), state_clone).await
+            {
+                error!("call failed: {e}");
+            }
+        });
+
+        state.running.store(false, Ordering::Release);
+        {
+            let mut stats = state.stats.lock().unwrap();
+            stats.state = CallState::Closed;
+        }
+
+        self.tokio_runtime = Some(runtime);
+        Ok(())
+    }
+
+    pub fn stop_call(&mut self) {
+        info!("stop_call: setting running=false");
+        self.state.running.store(false, Ordering::Release);
+        // Close QUIC connection — this wakes up all blocked recv/send futures
+        // inside block_on(run_call(...)) on the JNI thread. run_call will then
+        // wait up to 500ms for the peer to acknowledge the close before returning.
+        if let Some(transport) = self.state.quic_transport.lock().unwrap().take() {
+            info!("stop_call: closing QUIC connection");
+            transport.close_now();
+        }
+        let _ = self.state.command_tx.send(EngineCommand::Stop);
+        // Note: the runtime is still blocked in block_on(run_call(...)) on the
+        // start_call thread. Once run_call exits (triggered by running=false +
+        // connection close above), block_on returns and stores the runtime in
+        // self.tokio_runtime. We don't need to shut it down here.
+        if let Some(rt) = self.tokio_runtime.take() {
+            rt.shutdown_timeout(std::time::Duration::from_millis(100));
+        }
+        self.call_start = None;
+        info!("stop_call: done");
+    }
+
+    /// Ping a relay — same pattern as start_call (creates runtime on calling thread).
+    /// Returns JSON `{"rtt_ms":N,"server_fingerprint":"hex"}` or error.
+    pub fn ping_relay(&self, address: &str) -> Result<String, anyhow::Error> {
+        let addr: SocketAddr = address.parse()?;
+
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()?;
+
+        let result = rt.block_on(async {
+            let bind: SocketAddr = "0.0.0.0:0".parse().unwrap();
+            let endpoint = wzp_transport::create_endpoint(bind, None)?;
+            let client_cfg = wzp_transport::client_config();
+            let start = Instant::now();
+
+            let conn_result = tokio::time::timeout(
+                std::time::Duration::from_secs(3),
+                wzp_transport::connect(&endpoint, addr, "ping", client_cfg),
+            )
+            .await;
+
+            // Always close endpoint to prevent resource leaks
+            endpoint.close(0u32.into(), b"done");
+
+            let conn = conn_result.map_err(|_| anyhow::anyhow!("timeout"))??;
+            let rtt_ms = start.elapsed().as_millis() as u64;
+            let server_fp = conn
+                .peer_identity()
+                .and_then(|id| id.downcast::<Vec<rustls::pki_types::CertificateDer>>().ok())
+                .and_then(|certs| certs.first().map(|c| {
+                    use std::hash::{Hash, Hasher};
+                    let mut h = std::collections::hash_map::DefaultHasher::new();
+                    c.as_ref().hash(&mut h);
+                    format!("{:016x}", h.finish())
+                }))
+                .unwrap_or_default();
+            conn.close(0u32.into(), b"ping");
+
+            Ok::<_, anyhow::Error>(format!(r#"{{"rtt_ms":{},"server_fingerprint":"{}"}}"#, rtt_ms, server_fp))
+        });
+
+        // Shutdown runtime cleanly with timeout
+        rt.shutdown_timeout(std::time::Duration::from_millis(500));
+        result
+    }
+
+    /// Start persistent signaling connection for direct calls.
+    // Signal methods (start_signaling, place_call, answer_call) moved to signal_mgr.rs
+
+    pub fn set_mute(&self, muted: bool) {
+        self.state.muted.store(muted, Ordering::Relaxed);
+    }
+
+    pub fn set_speaker(&self, _enabled: bool) {}
+
+    pub fn force_profile(&self, _profile: QualityProfile) {}
+
+    pub fn get_stats(&self) -> CallStats {
+        let mut stats = self.state.stats.lock().unwrap().clone();
+        if let Some(start) = self.call_start {
+            stats.duration_secs = start.elapsed().as_secs_f64();
+        }
+        stats.audio_level = self.state.audio_level_rms.load(Ordering::Relaxed);
+        stats.playout_overflows = self.state.playout_ring.overflow_count();
+        stats.playout_underruns = self.state.playout_ring.underrun_count();
+        stats.capture_overflows = self.state.capture_ring.overflow_count();
+        stats
+    }
+
+    pub fn is_active(&self) -> bool {
+        self.state.running.load(Ordering::Acquire)
+    }
+
+    pub fn write_audio(&self, samples: &[i16]) -> usize {
+        if self.state.muted.load(Ordering::Relaxed) {
+            return samples.len();
+        }
+        // Compute RMS for audio level display
+        if !samples.is_empty() {
+            let sum_sq: f64 = samples.iter().map(|&s| (s as f64) * (s as f64)).sum();
+            let rms = (sum_sq / samples.len() as f64).sqrt() as u32;
+            self.state.audio_level_rms.store(rms, Ordering::Relaxed);
+        }
+        self.state.capture_ring.write(samples)
+    }
+
+    pub fn read_audio(&self, out: &mut [i16]) -> usize {
+        self.state.playout_ring.read(out)
+    }
+
+    pub fn destroy(mut self) {
+        self.stop_call();
+    }
+}
+
+impl Drop for WzpEngine {
+    fn drop(&mut self) {
+        self.stop_call();
+    }
+}
+
+/// Run the full call lifecycle: connect, handshake, send/recv media with Opus + FEC.
+async fn run_call(
+    relay_addr: SocketAddr,
+    room: &str,
+    identity_seed: &[u8; 32],
+    profile: QualityProfile,
+    auto_profile: bool,
+    alias: Option<&str>,
+    state: Arc<EngineState>,
+) -> Result<(), anyhow::Error> {
+
+    let bind_addr: SocketAddr = "0.0.0.0:0".parse().unwrap();
+    let endpoint = wzp_transport::create_endpoint(bind_addr, None)?;
+
+    let sni = if room.is_empty() { "android" } else { room };
+    info!(%relay_addr, sni, "connecting to relay...");
+    let client_cfg = wzp_transport::client_config();
+    let conn = wzp_transport::connect(&endpoint, relay_addr, sni, client_cfg).await?;
+    info!("QUIC connected to relay");
+
+    let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+    // Store transport handle so stop_call() can close the connection immediately
+    *state.quic_transport.lock().unwrap() = Some(transport.clone());
+
+    // Crypto handshake
+    let mut kx = WarzoneKeyExchange::from_identity_seed(identity_seed);
+    let ephemeral_pub = kx.generate_ephemeral();
+    let identity_pub = kx.identity_public_key();
+
+    let mut sign_data = Vec::with_capacity(42);
+    sign_data.extend_from_slice(&ephemeral_pub);
+    sign_data.extend_from_slice(b"call-offer");
+    let signature = kx.sign(&sign_data);
+
+    let offer = SignalMessage::CallOffer {
+        identity_pub,
+        ephemeral_pub,
+        signature,
+        supported_profiles: vec![
+            QualityProfile::STUDIO_64K,
+            QualityProfile::STUDIO_48K,
+            QualityProfile::STUDIO_32K,
+            QualityProfile::GOOD,
+            QualityProfile::DEGRADED,
+            QualityProfile::CATASTROPHIC,
+        ],
+        alias: alias.map(|s| s.to_string()),
+    };
+    transport.send_signal(&offer).await?;
+    info!("CallOffer sent, waiting for CallAnswer...");
+
+    let answer = transport
+        .recv_signal()
+        .await?
+        .ok_or_else(|| anyhow::anyhow!("connection closed before CallAnswer"))?;
+
+    let (relay_ephemeral_pub, chosen_profile) = match answer {
+        SignalMessage::CallAnswer { ephemeral_pub, chosen_profile, .. } => (ephemeral_pub, chosen_profile),
+        other => {
+            return Err(anyhow::anyhow!(
+                "expected CallAnswer, got {:?}",
+                std::mem::discriminant(&other)
+            ))
+        }
+    };
+
+    // Auto mode: use the relay's chosen profile instead of the local preference
+    let profile = if auto_profile {
+        info!(chosen = ?chosen_profile.codec, "auto mode: using relay's chosen profile");
+        chosen_profile
+    } else {
+        profile
+    };
+
+    let _session = kx.derive_session(&relay_ephemeral_pub)?;
+    info!(codec = ?profile.codec, "handshake complete, call active");
+
+    {
+        let mut stats = state.stats.lock().unwrap();
+        stats.state = CallState::Active;
+    }
+
+    // Initialize codec (Opus or Codec2 based on profile)
+    let mut encoder = wzp_codec::create_encoder(profile);
+    let mut decoder = wzp_codec::create_decoder(profile);
+
+    // Initialize FEC encoder/decoder
+    let mut fec_enc = wzp_fec::create_encoder(&profile);
+    let mut fec_dec = wzp_fec::create_decoder(&profile);
+
+    // AGC: normalize volume on both capture and playout paths
+    let mut capture_agc = AutoGainControl::new();
+    let mut playout_agc = AutoGainControl::new();
+
+    let mut frame_samples = frame_samples_for(&profile);
+    info!(
+        codec = ?profile.codec,
+        fec_ratio = profile.fec_ratio,
+        frames_per_block = profile.frames_per_block,
+        frame_ms = profile.frame_duration_ms,
+        frame_samples,
+        "codec + FEC + AGC initialized"
+    );
+
+    {
+        let mut stats = state.stats.lock().unwrap();
+        stats.current_codec = format!("{:?}", profile.codec);
+        stats.auto_mode = auto_profile;
+    }
+
+    let seq = AtomicU16::new(0);
+    let ts = AtomicU32::new(0);
+    let transport_recv = transport.clone();
+
+    // Adaptive quality: shared AtomicU8 between recv task (writer) and send task (reader).
+    // 0xFF = no change pending, 0-5 = index into PROFILES array.
+    let pending_profile = Arc::new(AtomicU8::new(PROFILE_NO_CHANGE));
+    let pending_profile_recv = pending_profile.clone();
+
+    // Pre-allocate buffers (sized for current profile)
+    let mut capture_buf = vec![0i16; frame_samples];
+    let mut encode_buf = vec![0u8; encoder.max_frame_bytes()];
+    let mut frame_in_block: u8 = 0;
+    let mut block_id: u8 = 0;
+    let mut current_profile = profile;
+
+    // Send task: capture ring → Opus encode → FEC → MediaPackets
+    //
+    // IMPORTANT: send_media() uses quinn's send_datagram() which is
+    // synchronous and returns Err(Blocked) when the congestion window
+    // is full. We MUST NOT break on send errors — that would kill the
+    // entire call. Instead we drop the packet and keep going.
+    let send_task = async {
+        info!("send task started (Opus + RaptorQ FEC)");
+        let mut send_errors: u64 = 0;
+        let mut last_send_error_log = Instant::now();
+        let mut last_stats_log = Instant::now();
+        let mut frames_sent: u64 = 0;
+        let mut frames_dropped: u64 = 0;
+        // Per-step timing accumulators (reset every stats log)
+        let mut t_agc_us: u64 = 0;
+        let mut t_opus_us: u64 = 0;
+        let mut t_fec_us: u64 = 0;
+        let mut t_send_us: u64 = 0;
+        let mut t_frames: u64 = 0;
+        loop {
+            if !state.running.load(Ordering::Relaxed) {
+                break;
+            }
+
+            // Check for adaptive profile switch from recv task
+            if auto_profile {
+                let p = pending_profile.swap(PROFILE_NO_CHANGE, Ordering::Acquire);
+                if p != PROFILE_NO_CHANGE {
+                    if let Some(new_profile) = index_to_profile(p) {
+                        info!(
+                            from = ?current_profile.codec,
+                            to = ?new_profile.codec,
+                            "auto: switching encoder profile"
+                        );
+                        if let Err(e) = encoder.set_profile(new_profile) {
+                            warn!("encoder set_profile failed: {e}");
+                        } else {
+                            fec_enc = wzp_fec::create_encoder(&new_profile);
+                            current_profile = new_profile;
+                            let new_frame_samples = frame_samples_for(&new_profile);
+                            if new_frame_samples != frame_samples {
+                                frame_samples = new_frame_samples;
+                                capture_buf.resize(frame_samples, 0);
+                            }
+                            encode_buf.resize(encoder.max_frame_bytes(), 0);
+                            // Reset FEC block state for clean switch
+                            frame_in_block = 0;
+                            block_id = block_id.wrapping_add(1);
+                            // Update stats with new codec
+                            if let Ok(mut stats) = state.stats.lock() {
+                                stats.current_codec = format!("{:?}", new_profile.codec);
+                            }
+                        }
+                    }
+                }
+            }
+
+            let avail = state.capture_ring.available();
+            if avail < frame_samples {
+                tokio::time::sleep(std::time::Duration::from_millis(5)).await;
+                continue;
+            }
+
+            let read = state.capture_ring.read(&mut capture_buf);
+            if read < frame_samples {
+                continue;
+            }
+
+            // Mute: zero out the buffer so Opus encodes silence.
+            // We still read from the ring to prevent it from filling up.
+            if state.muted.load(Ordering::Relaxed) {
+                capture_buf.fill(0);
+            }
+
+            // AGC: normalize capture volume before encoding
+            let t0 = Instant::now();
+            capture_agc.process_frame(&mut capture_buf);
+            t_agc_us += t0.elapsed().as_micros() as u64;
+
+            // Opus encode
+            let t0 = Instant::now();
+            let encoded_len = match encoder.encode(&capture_buf, &mut encode_buf) {
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("opus encode error: {e}");
+                    continue;
+                }
+            };
+            t_opus_us += t0.elapsed().as_micros() as u64;
+            let encoded = &encode_buf[..encoded_len];
+
+            // Build source packet
+            let s = seq.fetch_add(1, Ordering::Relaxed);
+            let t = ts.fetch_add(frame_samples as u32, Ordering::Relaxed);
+
+            let source_pkt = MediaPacket {
+                header: MediaHeader {
+                    version: 0,
+                    is_repair: false,
+                    codec_id: current_profile.codec,
+                    has_quality_report: false,
+                    fec_ratio_encoded: MediaHeader::encode_fec_ratio(current_profile.fec_ratio),
+                    seq: s,
+                    timestamp: t,
+                    fec_block: block_id,
+                    fec_symbol: frame_in_block,
+                    reserved: 0,
+                    csrc_count: 0,
+                },
+                payload: Bytes::copy_from_slice(encoded),
+                quality_report: None,
+            };
+
+            // Send source packet — drop on error, never break
+            let t0 = Instant::now();
+            if let Err(e) = transport.send_media(&source_pkt).await {
+                send_errors += 1;
+                frames_dropped += 1;
+                // Log first few errors, then throttle to once per second
+                if send_errors <= 3 || last_send_error_log.elapsed().as_secs() >= 1 {
+                    warn!(
+                        seq = s,
+                        send_errors,
+                        frames_dropped,
+                        "send_media error (dropping packet): {e}"
+                    );
+                    last_send_error_log = Instant::now();
+                }
+                // Don't feed to FEC either — the source is lost
+                t_send_us += t0.elapsed().as_micros() as u64;
+                continue;
+            }
+            t_send_us += t0.elapsed().as_micros() as u64;
+            frames_sent += 1;
+
+            // Feed encoded frame to FEC encoder
+            let t0 = Instant::now();
+            if let Err(e) = fec_enc.add_source_symbol(encoded) {
+                warn!("fec add_source error: {e}");
+            }
+            frame_in_block += 1;
+
+            // When block is full, generate repair packets
+            if frame_in_block >= current_profile.frames_per_block {
+                match fec_enc.generate_repair(current_profile.fec_ratio) {
+                    Ok(repairs) => {
+                        let repair_count = repairs.len();
+                        for (sym_idx, repair_data) in repairs {
+                            let rs = seq.fetch_add(1, Ordering::Relaxed);
+                            let repair_pkt = MediaPacket {
+                                header: MediaHeader {
+                                    version: 0,
+                                    is_repair: true,
+                                    codec_id: current_profile.codec,
+                                    has_quality_report: false,
+                                    fec_ratio_encoded: MediaHeader::encode_fec_ratio(
+                                        current_profile.fec_ratio,
+                                    ),
+                                    seq: rs,
+                                    timestamp: t,
+                                    fec_block: block_id,
+                                    fec_symbol: sym_idx,
+                                    reserved: 0,
+                                    csrc_count: 0,
+                                },
+                                payload: Bytes::from(repair_data),
+                                quality_report: None,
+                            };
+                            // Drop repair packets on error — never break
+                            if let Err(_e) = transport.send_media(&repair_pkt).await {
+                                send_errors += 1;
+                                frames_dropped += 1;
+                                // Don't log every repair failure — source error log covers it
+                            }
+                        }
+                        if repair_count > 0 && (block_id % 50 == 0 || block_id == 0) {
+                            info!(
+                                block_id,
+                                repair_count,
+                                fec_ratio = current_profile.fec_ratio,
+                                "FEC block complete"
+                            );
+                        }
+                    }
+                    Err(e) => {
+                        warn!("fec generate_repair error: {e}");
+                    }
+                }
+
+                let _ = fec_enc.finalize_block();
+                block_id = block_id.wrapping_add(1);
+                frame_in_block = 0;
+            }
+            t_fec_us += t0.elapsed().as_micros() as u64;
+            t_frames += 1;
+
+            // Periodic stats every 5 seconds
+            if last_stats_log.elapsed().as_secs() >= 5 {
+                let avg = |total: u64| if t_frames > 0 { total / t_frames } else { 0 };
+                info!(
+                    seq = s,
+                    block_id,
+                    frames_sent,
+                    frames_dropped,
+                    send_errors,
+                    ring_avail = state.capture_ring.available(),
+                    capture_overflows = state.capture_ring.overflow_count(),
+                    avg_agc_us = avg(t_agc_us),
+                    avg_opus_us = avg(t_opus_us),
+                    avg_fec_us = avg(t_fec_us),
+                    avg_send_us = avg(t_send_us),
+                    avg_total_us = avg(t_agc_us + t_opus_us + t_fec_us + t_send_us),
+                    "send stats"
+                );
+                t_agc_us = 0; t_opus_us = 0; t_fec_us = 0; t_send_us = 0; t_frames = 0;
+                last_stats_log = Instant::now();
+            }
+        }
+        info!(frames_sent, frames_dropped, send_errors, "send task ended");
+    };
+
+    // Pre-allocate decode buffer (max size to handle any incoming codec)
+    let mut decode_buf = vec![0i16; MAX_FRAME_SAMPLES];
+
+    // Recv task: MediaPackets → FEC decode → Opus decode → playout ring
+    let recv_task = async {
+        let mut frames_decoded: u64 = 0;
+        let mut fec_recovered: u64 = 0;
+        let mut recv_errors: u64 = 0;
+        let mut last_recv_instant = Instant::now();
+        let mut max_recv_gap_ms: u64 = 0;
+        let mut last_stats_log = Instant::now();
+        let mut quality_ctrl = AdaptiveQualityController::new();
+        let mut last_peer_codec: Option<CodecId> = None;
+        info!("recv task started (Opus + RaptorQ FEC)");
+        loop {
+            if !state.running.load(Ordering::Relaxed) {
+                break;
+            }
+            match transport_recv.recv_media().await {
+                Ok(Some(pkt)) => {
+                    // Track recv gaps — large gaps indicate network or relay issues
+                    let recv_gap_ms = last_recv_instant.elapsed().as_millis() as u64;
+                    last_recv_instant = Instant::now();
+                    if recv_gap_ms > max_recv_gap_ms {
+                        max_recv_gap_ms = recv_gap_ms;
+                    }
+                    if recv_gap_ms > 500 {
+                        warn!(
+                            recv_gap_ms,
+                            seq = pkt.header.seq,
+                            is_repair = pkt.header.is_repair,
+                            "large recv gap — possible network stall"
+                        );
+                    }
+
+                    // Adaptive quality: ingest quality reports from relay
+                    if auto_profile {
+                        if let Some(ref qr) = pkt.quality_report {
+                            if let Some(new_profile) = quality_ctrl.observe(qr) {
+                                let idx = profile_to_index(&new_profile);
+                                info!(
+                                    loss = qr.loss_percent(),
+                                    rtt = qr.rtt_ms(),
+                                    tier = ?quality_ctrl.tier(),
+                                    to = ?new_profile.codec,
+                                    "auto: quality adapter recommends switch"
+                                );
+                                pending_profile_recv.store(idx, Ordering::Release);
+                            }
+                        }
+                    }
+
+                    let is_repair = pkt.header.is_repair;
+                    let pkt_block = pkt.header.fec_block;
+                    let pkt_symbol = pkt.header.fec_symbol;
+
+                    // Feed every packet (source + repair) to FEC decoder
+                    let _ = fec_dec.add_symbol(
+                        pkt_block,
+                        pkt_symbol,
+                        is_repair,
+                        &pkt.payload,
+                    );
+
+                    // Source packets: decode directly
+                    if !is_repair && pkt.header.codec_id != CodecId::ComfortNoise {
+                        // Switch decoder to match incoming codec if different
+                        if pkt.header.codec_id != decoder.codec_id() {
+                            let switch_profile = match pkt.header.codec_id {
+                                CodecId::Opus24k => QualityProfile::GOOD,
+                                CodecId::Opus6k => QualityProfile::DEGRADED,
+                                CodecId::Opus32k => QualityProfile::STUDIO_32K,
+                                CodecId::Opus48k => QualityProfile::STUDIO_48K,
+                                CodecId::Opus64k => QualityProfile::STUDIO_64K,
+                                CodecId::Codec2_1200 => QualityProfile::CATASTROPHIC,
+                                CodecId::Codec2_3200 => QualityProfile {
+                                    codec: CodecId::Codec2_3200,
+                                    fec_ratio: 0.5,
+                                    frame_duration_ms: 20,
+                                    frames_per_block: 5,
+                                },
+                                other => QualityProfile { codec: other, ..QualityProfile::GOOD },
+                            };
+                            info!(from = ?decoder.codec_id(), to = ?pkt.header.codec_id, "recv: switching decoder");
+                            let _ = decoder.set_profile(switch_profile);
+                        }
+                        // Track peer codec for UI display
+                        if last_peer_codec != Some(pkt.header.codec_id) {
+                            last_peer_codec = Some(pkt.header.codec_id);
+                            if let Ok(mut stats) = state.stats.lock() {
+                                stats.peer_codec = format!("{:?}", pkt.header.codec_id);
+                            }
+                        }
+                        match decoder.decode(&pkt.payload, &mut decode_buf) {
+                            Ok(samples) => {
+                                playout_agc.process_frame(&mut decode_buf[..samples]);
+                                state.playout_ring.write(&decode_buf[..samples]);
+                                frames_decoded += 1;
+                            }
+                            Err(e) => {
+                                warn!("opus decode error: {e}");
+                                if let Ok(samples) = decoder.decode_lost(&mut decode_buf) {
+                                    playout_agc.process_frame(&mut decode_buf[..samples]);
+                                    state.playout_ring.write(&decode_buf[..samples]);
+                                }
+                            }
+                        }
+                    }
+
+                    // Try FEC recovery
+                    if let Ok(Some(recovered_frames)) = fec_dec.try_decode(pkt_block) {
+                        fec_recovered += recovered_frames.len() as u64;
+                        if fec_recovered % 50 == 1 {
+                            info!(
+                                fec_recovered,
+                                block = pkt_block,
+                                frames = recovered_frames.len(),
+                                "FEC block recovered"
+                            );
+                        }
+                    }
+
+                    // Expire old blocks to prevent memory growth
+                    if pkt_block > 3 {
+                        fec_dec.expire_before(pkt_block.wrapping_sub(3));
+                    }
+
+                    let mut stats = state.stats.lock().unwrap();
+                    stats.frames_decoded = frames_decoded;
+                    stats.fec_recovered = fec_recovered;
+                    drop(stats);
+
+                    // Periodic stats every 5 seconds
+                    if last_stats_log.elapsed().as_secs() >= 5 {
+                        info!(
+                            frames_decoded,
+                            fec_recovered,
+                            recv_errors,
+                            max_recv_gap_ms,
+                            playout_avail = state.playout_ring.available(),
+                            playout_overflows = state.playout_ring.overflow_count(),
+                            playout_underruns = state.playout_ring.underrun_count(),
+                            "recv stats"
+                        );
+                        max_recv_gap_ms = 0;
+                        last_stats_log = Instant::now();
+                    }
+                }
+                Ok(None) => {
+                    info!(frames_decoded, fec_recovered, "relay disconnected (stream ended)");
+                    break;
+                }
+                Err(e) => {
+                    recv_errors += 1;
+                    // Transient errors: log and keep going
+                    let msg = e.to_string();
+                    if msg.contains("closed") || msg.contains("reset") {
+                        error!(recv_errors, "recv fatal: {e}");
+                        break;
+                    }
+                    // Non-fatal: log throttled
+                    if recv_errors <= 3 || recv_errors % 50 == 0 {
+                        warn!(recv_errors, "recv error (continuing): {e}");
+                    }
+                }
+            }
+        }
+        info!(frames_decoded, fec_recovered, recv_errors, "recv task ended");
+    };
+
+    // Stats task — polls path quality + quinn RTT every 500ms
+    let transport_stats = transport.clone();
+    let stats_task = async {
+        loop {
+            if !state.running.load(Ordering::Relaxed) {
+                break;
+            }
+            // Feed quinn's QUIC-level RTT into our path monitor
+            let quic_rtt_ms = transport_stats.connection().stats().path.rtt.as_millis() as u32;
+            if quic_rtt_ms > 0 {
+                transport_stats.feed_rtt(quic_rtt_ms);
+            }
+            let pq = transport_stats.path_quality();
+            {
+                let mut stats = state.stats.lock().unwrap();
+                stats.frames_encoded = seq.load(Ordering::Relaxed) as u64;
+                stats.loss_pct = pq.loss_pct;
+                stats.rtt_ms = quic_rtt_ms;
+                stats.jitter_ms = pq.jitter_ms;
+            }
+            tokio::time::sleep(std::time::Duration::from_millis(500)).await;
+        }
+    };
+
+    // Signal recv task — listens for RoomUpdate and other signaling messages
+    let transport_signal = transport.clone();
+    let state_signal = state.clone();
+    let signal_task = async {
+        loop {
+            match transport_signal.recv_signal().await {
+                Ok(Some(SignalMessage::RoomUpdate { count, participants })) => {
+                    info!(count, "RoomUpdate received");
+                    let members: Vec<crate::stats::RoomMember> = participants
+                        .iter()
+                        .map(|p| crate::stats::RoomMember {
+                            fingerprint: p.fingerprint.clone(),
+                            alias: p.alias.clone(),
+                            relay_label: p.relay_label.clone(),
+                        })
+                        .collect();
+                    let mut stats = state_signal.stats.lock().unwrap();
+                    stats.room_participant_count = count;
+                    stats.room_participants = members;
+                }
+                Ok(Some(msg)) => {
+                    info!("signal received: {:?}", std::mem::discriminant(&msg));
+                }
+                Ok(None) => {
+                    info!("signal stream closed");
+                    break;
+                }
+                Err(e) => {
+                    warn!("signal recv error: {e}");
+                    break;
+                }
+            }
+        }
+    };
+
+    tokio::select! {
+        _ = send_task => info!("send task ended"),
+        _ = recv_task => info!("recv task ended"),
+        _ = stats_task => info!("stats task ended"),
+        _ = signal_task => info!("signal task ended"),
+    }
+
+    // Send CONNECTION_CLOSE and wait up to 500ms for the peer to acknowledge.
+    // This ensures the relay sees the close even if the first packet is lost.
+    info!("closing QUIC connection...");
+    transport.close_now();
+    match tokio::time::timeout(
+        std::time::Duration::from_millis(500),
+        transport.connection().closed(),
+    ).await {
+        Ok(_) => info!("QUIC connection closed cleanly"),
+        Err(_) => info!("QUIC close timed out (relay may not have ack'd)"),
+    }
+    Ok(())
+}

crates/wzp-android/src/jni_bridge.rs

@@ -0,0 +1,511 @@
+//! JNI bridge for Android — thin layer between Kotlin and the WzpEngine.
+
+use std::panic;
+use std::sync::Once;
+
+use jni::objects::{JClass, JObject, JString};
+use jni::sys::{jboolean, jint, jlong, jstring};
+use jni::JNIEnv;
+use tracing::{error, info};
+use wzp_proto::QualityProfile;
+
+use crate::engine::{CallStartConfig, WzpEngine};
+
+/// Opaque engine handle passed to/from Kotlin as a `jlong`.
+struct EngineHandle {
+    engine: WzpEngine,
+}
+
+/// Recover the `EngineHandle` from a raw handle value.
+unsafe fn handle_ref(handle: jlong) -> &'static mut EngineHandle {
+    unsafe { &mut *(handle as *mut EngineHandle) }
+}
+
+/// 7 = auto (use relay's chosen profile)
+const PROFILE_AUTO: jint = 7;
+
+fn profile_from_int(value: jint) -> QualityProfile {
+    match value {
+        0 => QualityProfile::GOOD,            // Opus 24k
+        1 => QualityProfile::DEGRADED,        // Opus 6k
+        2 => QualityProfile::CATASTROPHIC,    // Codec2 1.2k
+        3 => QualityProfile {                 // Codec2 3.2k
+            codec: wzp_proto::CodecId::Codec2_3200,
+            fec_ratio: 0.5,
+            frame_duration_ms: 20,
+            frames_per_block: 5,
+        },
+        4 => QualityProfile::STUDIO_32K,      // Opus 32k
+        5 => QualityProfile::STUDIO_48K,      // Opus 48k
+        6 => QualityProfile::STUDIO_64K,      // Opus 64k
+        _ => QualityProfile::GOOD,            // auto falls back to GOOD
+    }
+}
+
+static INIT_LOGGING: Once = Once::new();
+
+/// Initialize tracing → Android logcat (tag "wzp_android").
+/// Safe to call multiple times — only the first call takes effect.
+fn init_logging() {
+    INIT_LOGGING.call_once(|| {
+        // Wrap in catch_unwind — sharded_slab allocation inside
+        // tracing_subscriber::registry() can crash on some Android
+        // devices if scudo malloc fails during early initialization.
+        let _ = std::panic::catch_unwind(|| {
+            use tracing_subscriber::layer::SubscriberExt;
+            use tracing_subscriber::util::SubscriberInitExt;
+            use tracing_subscriber::EnvFilter;
+            if let Ok(layer) = tracing_android::layer("wzp_android") {
+                // Filter: INFO for our crates, WARN for everything else.
+                // The jni crate emits VERBOSE logs for every method lookup
+                // (~10 lines per JNI call, 100+ calls/sec) which floods logcat
+                // and causes the system to kill the app.
+                let filter = EnvFilter::new("warn,wzp_android=info,wzp_proto=info,wzp_transport=info,wzp_codec=info,wzp_fec=info,wzp_crypto=info");
+                let _ = tracing_subscriber::registry()
+                    .with(layer)
+                    .with(filter)
+                    .try_init();
+            }
+        });
+    });
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeInit(
+    _env: JNIEnv,
+    _class: JClass,
+) -> jlong {
+    let result = panic::catch_unwind(|| {
+        init_logging();
+        // Install rustls crypto provider ONCE on the main thread.
+        // Must not be called per-thread — conflicts with Android's system libcrypto.so TLS keys.
+        let _ = rustls::crypto::ring::default_provider().install_default();
+        let handle = Box::new(EngineHandle {
+            engine: WzpEngine::new(),
+        });
+        Box::into_raw(handle) as jlong
+    });
+    match result {
+        Ok(h) => h,
+        Err(_) => 0,
+    }
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartCall(
+    mut env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    relay_addr_j: JString,
+    room_j: JString,
+    seed_hex_j: JString,
+    token_j: JString,
+    alias_j: JString,
+    profile_j: jint,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let relay_addr: String = env.get_string(&relay_addr_j).map(|s| s.into()).unwrap_or_default();
+        let room: String = env.get_string(&room_j).map(|s| s.into()).unwrap_or_default();
+        let seed_hex: String = env.get_string(&seed_hex_j).map(|s| s.into()).unwrap_or_default();
+        let token: String = env.get_string(&token_j).map(|s| s.into()).unwrap_or_default();
+        let alias: String = env.get_string(&alias_j).map(|s| s.into()).unwrap_or_default();
+
+        let h = unsafe { handle_ref(handle) };
+
+        // Parse hex seed
+        let mut identity_seed = [0u8; 32];
+        if seed_hex.len() == 64 {
+            for i in 0..32 {
+                if let Ok(byte) = u8::from_str_radix(&seed_hex[i * 2..i * 2 + 2], 16) {
+                    identity_seed[i] = byte;
+                }
+            }
+        } else {
+            // Generate random seed if not provided
+            use rand::RngCore;
+            rand::thread_rng().fill_bytes(&mut identity_seed);
+        }
+
+        let config = CallStartConfig {
+            profile: profile_from_int(profile_j),
+            auto_profile: profile_j == PROFILE_AUTO,
+            relay_addr,
+            room,
+            auth_token: if token.is_empty() { Vec::new() } else { token.into_bytes() },
+            identity_seed,
+            alias: if alias.is_empty() { None } else { Some(alias) },
+        };
+
+        match h.engine.start_call(config) {
+            Ok(()) => 0,
+            Err(e) => {
+                error!("start_call failed: {e}");
+                -1
+            }
+        }
+    }));
+
+    match result {
+        Ok(code) => code,
+        Err(_) => -1,
+    }
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStopCall(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+) {
+    let _ = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        h.engine.stop_call();
+    }));
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeSetMute(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    muted: jboolean,
+) {
+    let _ = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        h.engine.set_mute(muted != 0);
+    }));
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeSetSpeaker(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    speaker: jboolean,
+) {
+    let _ = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        h.engine.set_speaker(speaker != 0);
+    }));
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeGetStats<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+) -> jstring {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let stats = h.engine.get_stats();
+        serde_json::to_string(&stats).unwrap_or_else(|_| "{}".to_string())
+    }));
+
+    let json = match result {
+        Ok(s) => s,
+        Err(_) => "{}".to_string(),
+    };
+
+    env.new_string(&json)
+        .map(|s| s.into_raw())
+        .unwrap_or(JObject::null().into_raw())
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeForceProfile(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    profile: jint,
+) {
+    let _ = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let qp = profile_from_int(profile);
+        h.engine.force_profile(qp);
+    }));
+}
+
+/// Write captured PCM samples from Kotlin AudioRecord into the engine's capture ring.
+/// pcm is a Java short[] array.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeWriteAudio(
+    env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    pcm: jni::objects::JShortArray,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let len = env.get_array_length(&pcm).unwrap_or(0) as usize;
+        if len == 0 {
+            return 0;
+        }
+        let mut buf = vec![0i16; len];
+        if env.get_short_array_region(&pcm, 0, &mut buf).is_err() {
+            return 0;
+        }
+        h.engine.write_audio(&buf) as jint
+    }));
+    result.unwrap_or(0)
+}
+
+/// Read decoded PCM samples from the engine's playout ring for Kotlin AudioTrack.
+/// pcm is a Java short[] array to fill. Returns number of samples actually read.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeReadAudio(
+    env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    pcm: jni::objects::JShortArray,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let len = env.get_array_length(&pcm).unwrap_or(0) as usize;
+        if len == 0 {
+            return 0;
+        }
+        let mut buf = vec![0i16; len];
+        let read = h.engine.read_audio(&mut buf);
+        if read > 0 {
+            let _ = env.set_short_array_region(&pcm, 0, &buf[..read]);
+        }
+        read as jint
+    }));
+    result.unwrap_or(0)
+}
+
+/// Write captured PCM from a DirectByteBuffer — zero JNI array copies.
+/// The ByteBuffer must contain little-endian i16 samples.
+/// Called from the AudioRecord capture thread.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeWriteAudioDirect(
+    env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    buffer: jni::objects::JByteBuffer,
+    sample_count: jint,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let ptr = env.get_direct_buffer_address(&buffer).unwrap_or(std::ptr::null_mut());
+        if ptr.is_null() || sample_count <= 0 {
+            return 0;
+        }
+        let samples = unsafe {
+            std::slice::from_raw_parts(ptr as *const i16, sample_count as usize)
+        };
+        h.engine.write_audio(samples) as jint
+    }));
+    result.unwrap_or(0)
+}
+
+/// Read decoded PCM into a DirectByteBuffer — zero JNI array copies.
+/// The ByteBuffer will be filled with little-endian i16 samples.
+/// Called from the AudioTrack playout thread.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeReadAudioDirect(
+    env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+    buffer: jni::objects::JByteBuffer,
+    max_samples: jint,
+) -> jint {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let ptr = env.get_direct_buffer_address(&buffer).unwrap_or(std::ptr::null_mut());
+        if ptr.is_null() || max_samples <= 0 {
+            return 0;
+        }
+        let samples = unsafe {
+            std::slice::from_raw_parts_mut(ptr as *mut i16, max_samples as usize)
+        };
+        h.engine.read_audio(samples) as jint
+    }));
+    result.unwrap_or(0)
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeDestroy(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+) {
+    let _ = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { Box::from_raw(handle as *mut EngineHandle) };
+        drop(h);
+    }));
+}
+
+/// Ping a relay server — instance method, requires engine handle.
+/// Returns JSON `{"rtt_ms":N,"server_fingerprint":"hex"}` or null on failure.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativePingRelay<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+    relay_j: JString,
+) -> jstring {
+    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let h = unsafe { handle_ref(handle) };
+        let relay: String = env.get_string(&relay_j).map(|s| s.into()).unwrap_or_default();
+        match h.engine.ping_relay(&relay) {
+            Ok(json) => Some(json),
+            Err(_) => None,
+        }
+    }));
+
+    let json = match result {
+        Ok(Some(s)) => s,
+        _ => return JObject::null().into_raw(),
+    };
+    env.new_string(&json)
+        .map(|s| s.into_raw())
+        .unwrap_or(JObject::null().into_raw())
+}
+
+/// Get the identity fingerprint for a seed hex string.
+/// Returns the full fingerprint (xxxx:xxxx:...) or empty string on error.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeGetFingerprint<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    seed_hex_j: JString,
+) -> jstring {
+    let seed_hex: String = env.get_string(&seed_hex_j).map(|s| s.into()).unwrap_or_default();
+    let fp = if seed_hex.is_empty() {
+        String::new()
+    } else {
+        match wzp_crypto::Seed::from_hex(&seed_hex) {
+            Ok(seed) => {
+                let id = seed.derive_identity();
+                id.public_identity().fingerprint.to_string()
+            }
+            Err(_) => String::new(),
+        }
+    };
+    env.new_string(&fp)
+        .map(|s| s.into_raw())
+        .unwrap_or(JObject::null().into_raw())
+}
+
+// ── Direct calling JNI functions ──
+
+// ── SignalManager JNI functions ──
+
+/// Opaque handle for SignalManager (separate from EngineHandle).
+struct SignalHandle {
+    mgr: crate::signal_mgr::SignalManager,
+}
+
+unsafe fn signal_ref(handle: jlong) -> &'static SignalHandle {
+    unsafe { &*(handle as *const SignalHandle) }
+}
+
+/// Connect to relay for signaling. Returns handle (jlong) or 0 on error.
+/// Blocks up to 10s waiting for the internal signal thread to connect.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalConnect<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    relay_j: JString,
+    seed_j: JString,
+) -> jlong {
+    info!("nativeSignalConnect: entered");
+    let relay: String = env.get_string(&relay_j).map(|s| s.into()).unwrap_or_default();
+    let seed: String = env.get_string(&seed_j).map(|s| s.into()).unwrap_or_default();
+    info!(relay = %relay, seed_len = seed.len(), "nativeSignalConnect: parsed strings");
+
+    // start() spawns an internal thread (connect+register+recv, ONE runtime, never dropped).
+    // Blocks up to 10s waiting for the connect+register to complete.
+    match crate::signal_mgr::SignalManager::start(&relay, &seed) {
+        Ok(mgr) => {
+            let handle = Box::new(SignalHandle { mgr });
+            Box::into_raw(handle) as jlong
+        }
+        Err(e) => {
+            error!("signal connect failed: {e}");
+            0
+        }
+    }
+}
+
+/// Get signal state as JSON string.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalGetState<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+) -> jstring {
+    if handle == 0 { return JObject::null().into_raw(); }
+    let h = signal_ref(handle);
+    let json = h.mgr.get_state_json();
+    env.new_string(&json)
+        .map(|s| s.into_raw())
+        .unwrap_or(JObject::null().into_raw())
+}
+
+/// Place a direct call.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalPlaceCall<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+    target_j: JString,
+) -> jint {
+    if handle == 0 { return -1; }
+    let h = signal_ref(handle);
+    let target: String = env.get_string(&target_j).map(|s| s.into()).unwrap_or_default();
+    match h.mgr.place_call(&target) {
+        Ok(()) => 0,
+        Err(e) => { error!("place_call: {e}"); -1 }
+    }
+}
+
+/// Answer an incoming call.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalAnswerCall<'a>(
+    mut env: JNIEnv<'a>,
+    _class: JClass,
+    handle: jlong,
+    call_id_j: JString,
+    mode: jint,
+) -> jint {
+    if handle == 0 { return -1; }
+    let h = signal_ref(handle);
+    let call_id: String = env.get_string(&call_id_j).map(|s| s.into()).unwrap_or_default();
+    let accept_mode = match mode {
+        0 => wzp_proto::CallAcceptMode::Reject,
+        1 => wzp_proto::CallAcceptMode::AcceptTrusted,
+        _ => wzp_proto::CallAcceptMode::AcceptGeneric,
+    };
+    match h.mgr.answer_call(&call_id, accept_mode) {
+        Ok(()) => 0,
+        Err(e) => { error!("answer_call: {e}"); -1 }
+    }
+}
+
+/// Send hangup signal.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalHangup(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+) {
+    if handle == 0 { return; }
+    let h = signal_ref(handle);
+    h.mgr.hangup();
+}
+
+/// Destroy the signal manager and free resources.
+#[unsafe(no_mangle)]
+pub unsafe extern "system" fn Java_com_wzp_engine_SignalManager_nativeSignalDestroy(
+    _env: JNIEnv,
+    _class: JClass,
+    handle: jlong,
+) {
+    if handle == 0 { return; }
+    let h = signal_ref(handle);
+    h.mgr.stop();
+    // Reclaim the Box
+    let _ = unsafe { Box::from_raw(handle as *mut SignalHandle) };
+}

crates/wzp-android/src/lib.rs

@@ -0,0 +1,19 @@
+//! WarzonePhone Android native VoIP engine.
+//!
+//! Provides:
+//! - Oboe audio backend with lock-free SPSC ring buffers
+//! - Engine orchestrator managing call lifecycle
+//! - Codec pipeline thread (encode/decode/FEC/jitter)
+//! - Call statistics and command interface
+//!
+//! On non-Android targets, the Oboe C++ layer compiles as a stub,
+//! allowing `cargo check` and unit tests on the host.
+
+pub mod audio_android;
+pub mod audio_ring;
+pub mod commands;
+pub mod engine;
+pub mod pipeline;
+pub mod signal_mgr;
+pub mod stats;
+pub mod jni_bridge;

crates/wzp-android/src/pipeline.rs

@@ -0,0 +1,262 @@
+//! Codec pipeline — encode/decode with FEC and jitter buffer.
+//!
+//! Runs on a dedicated thread, processing 20 ms frames at 48 kHz.
+//! The pipeline is NOT Send/Sync (Opus encoder state) — it is owned
+//! exclusively by the codec thread.
+
+use tracing::{debug, warn};
+use wzp_codec::{AdaptiveDecoder, AdaptiveEncoder, AutoGainControl, EchoCanceller};
+use wzp_fec::{RaptorQFecDecoder, RaptorQFecEncoder};
+use wzp_proto::jitter::{JitterBuffer, PlayoutResult};
+use wzp_proto::quality::AdaptiveQualityController;
+use wzp_proto::traits::{AudioDecoder, AudioEncoder, FecDecoder, FecEncoder};
+use wzp_proto::traits::QualityController;
+use wzp_proto::{MediaPacket, QualityProfile};
+
+use crate::audio_android::FRAME_SAMPLES;
+
+/// Maximum encoded frame size (Opus worst case at highest bitrate).
+const MAX_ENCODED_BYTES: usize = 1275;
+
+/// Pipeline statistics snapshot.
+#[derive(Clone, Debug, Default)]
+pub struct PipelineStats {
+    pub frames_encoded: u64,
+    pub frames_decoded: u64,
+    pub underruns: u64,
+    pub jitter_depth: usize,
+    pub quality_tier: u8,
+}
+
+/// The codec pipeline: encode, FEC, jitter buffer, decode.
+///
+/// This struct is owned by the codec thread and not shared.
+pub struct Pipeline {
+    encoder: AdaptiveEncoder,
+    decoder: AdaptiveDecoder,
+    fec_encoder: RaptorQFecEncoder,
+    fec_decoder: RaptorQFecDecoder,
+    jitter_buffer: JitterBuffer,
+    quality_ctrl: AdaptiveQualityController,
+    /// Acoustic echo canceller applied before encoding.
+    aec: EchoCanceller,
+    /// Automatic gain control applied before encoding.
+    agc: AutoGainControl,
+    /// Last decoded PCM frame, used as the AEC far-end reference.
+    last_decoded_farend: Option<Vec<i16>>,
+    // Pre-allocated scratch buffers
+    capture_buf: Vec<i16>,
+    #[allow(dead_code)]
+    playout_buf: Vec<i16>,
+    encode_out: Vec<u8>,
+    // Stats counters
+    frames_encoded: u64,
+    frames_decoded: u64,
+    underruns: u64,
+}
+
+impl Pipeline {
+    /// Create a new pipeline configured for the given quality profile.
+    pub fn new(profile: QualityProfile) -> Result<Self, anyhow::Error> {
+        let encoder = AdaptiveEncoder::new(profile)
+            .map_err(|e| anyhow::anyhow!("encoder init: {e}"))?;
+        let decoder = AdaptiveDecoder::new(profile)
+            .map_err(|e| anyhow::anyhow!("decoder init: {e}"))?;
+        let fec_encoder =
+            RaptorQFecEncoder::with_defaults(profile.frames_per_block as usize);
+        let fec_decoder =
+            RaptorQFecDecoder::with_defaults(profile.frames_per_block as usize);
+        let jitter_buffer = JitterBuffer::new(10, 250, 3);
+        let quality_ctrl = AdaptiveQualityController::new();
+
+        Ok(Self {
+            encoder,
+            decoder,
+            fec_encoder,
+            fec_decoder,
+            jitter_buffer,
+            quality_ctrl,
+            aec: EchoCanceller::new(48000, 100), // 100 ms echo tail
+            agc: AutoGainControl::new(),
+            last_decoded_farend: None,
+            capture_buf: vec![0i16; FRAME_SAMPLES],
+            playout_buf: vec![0i16; FRAME_SAMPLES],
+            encode_out: vec![0u8; MAX_ENCODED_BYTES],
+            frames_encoded: 0,
+            frames_decoded: 0,
+            underruns: 0,
+        })
+    }
+
+    /// Encode a PCM frame into a compressed packet.
+    ///
+    /// If `muted` is true, a silence frame is encoded (all zeros).
+    /// Returns the encoded bytes, or `None` on encoder error.
+    pub fn encode_frame(&mut self, pcm: &[i16], muted: bool) -> Option<Vec<u8>> {
+        let input = if muted {
+            // Zero the capture buffer for silence
+            for s in self.capture_buf.iter_mut() {
+                *s = 0;
+            }
+            &self.capture_buf[..]
+        } else {
+            // Feed the last decoded playout as AEC far-end reference.
+            if let Some(ref farend) = self.last_decoded_farend {
+                self.aec.feed_farend(farend);
+            }
+
+            // Apply AEC + AGC to the captured PCM.
+            let len = pcm.len().min(self.capture_buf.len());
+            self.capture_buf[..len].copy_from_slice(&pcm[..len]);
+            self.aec.process_frame(&mut self.capture_buf[..len]);
+            self.agc.process_frame(&mut self.capture_buf[..len]);
+            &self.capture_buf[..len]
+        };
+
+        match self.encoder.encode(input, &mut self.encode_out) {
+            Ok(n) => {
+                self.frames_encoded += 1;
+                let encoded = self.encode_out[..n].to_vec();
+
+                // Feed into FEC encoder
+                if let Err(e) = self.fec_encoder.add_source_symbol(&encoded) {
+                    warn!("FEC encode error: {e}");
+                }
+
+                Some(encoded)
+            }
+            Err(e) => {
+                warn!("encode error: {e}");
+                None
+            }
+        }
+    }
+
+    /// Feed a received media packet into the jitter buffer.
+    pub fn feed_packet(&mut self, packet: MediaPacket) {
+        // Feed FEC symbols if present
+        let header = &packet.header;
+        if header.fec_block != 0 || header.fec_symbol != 0 {
+            let is_repair = header.is_repair;
+            if let Err(e) = self.fec_decoder.add_symbol(
+                header.fec_block,
+                header.fec_symbol,
+                is_repair,
+                &packet.payload,
+            ) {
+                debug!("FEC symbol feed error: {e}");
+            }
+        }
+
+        self.jitter_buffer.push(packet);
+    }
+
+    /// Decode the next frame from the jitter buffer.
+    ///
+    /// Returns decoded PCM samples, or `None` if the buffer is not ready.
+    /// Decoded PCM is also stored as the AEC far-end reference for the next
+    /// encode cycle.
+    pub fn decode_frame(&mut self) -> Option<Vec<i16>> {
+        let result = match self.jitter_buffer.pop() {
+            PlayoutResult::Packet(pkt) => {
+                let mut pcm = vec![0i16; FRAME_SAMPLES];
+                match self.decoder.decode(&pkt.payload, &mut pcm) {
+                    Ok(n) => {
+                        self.frames_decoded += 1;
+                        pcm.truncate(n);
+                        Some(pcm)
+                    }
+                    Err(e) => {
+                        warn!("decode error: {e}");
+                        // Attempt PLC
+                        self.generate_plc()
+                    }
+                }
+            }
+            PlayoutResult::Missing { seq } => {
+                debug!(seq, "jitter buffer: missing packet, generating PLC");
+                self.generate_plc()
+            }
+            PlayoutResult::NotReady => {
+                self.underruns += 1;
+                None
+            }
+        };
+
+        // Save decoded PCM as far-end reference for AEC.
+        if let Some(ref pcm) = result {
+            self.last_decoded_farend = Some(pcm.clone());
+        }
+
+        result
+    }
+
+    /// Generate packet loss concealment output.
+    fn generate_plc(&mut self) -> Option<Vec<i16>> {
+        let mut pcm = vec![0i16; FRAME_SAMPLES];
+        match self.decoder.decode_lost(&mut pcm) {
+            Ok(n) => {
+                self.frames_decoded += 1;
+                pcm.truncate(n);
+                Some(pcm)
+            }
+            Err(e) => {
+                warn!("PLC error: {e}");
+                None
+            }
+        }
+    }
+
+    /// Feed a quality report into the adaptive quality controller.
+    ///
+    /// Returns a new profile if a tier transition occurred.
+    #[allow(unused)]
+    pub fn observe_quality(
+        &mut self,
+        report: &wzp_proto::QualityReport,
+    ) -> Option<QualityProfile> {
+        let new_profile = self.quality_ctrl.observe(report);
+        if let Some(ref profile) = new_profile {
+            if let Err(e) = self.encoder.set_profile(*profile) {
+                warn!("encoder set_profile error: {e}");
+            }
+            if let Err(e) = self.decoder.set_profile(*profile) {
+                warn!("decoder set_profile error: {e}");
+            }
+        }
+        new_profile
+    }
+
+    /// Force a specific quality profile.
+    #[allow(unused)]
+    pub fn force_profile(&mut self, profile: QualityProfile) {
+        self.quality_ctrl.force_profile(profile);
+        if let Err(e) = self.encoder.set_profile(profile) {
+            warn!("encoder set_profile error: {e}");
+        }
+        if let Err(e) = self.decoder.set_profile(profile) {
+            warn!("decoder set_profile error: {e}");
+        }
+    }
+
+    /// Get current pipeline statistics.
+    pub fn stats(&self) -> PipelineStats {
+        PipelineStats {
+            frames_encoded: self.frames_encoded,
+            frames_decoded: self.frames_decoded,
+            underruns: self.underruns,
+            jitter_depth: self.jitter_buffer.stats().current_depth,
+            quality_tier: self.quality_ctrl.tier() as u8,
+        }
+    }
+
+    /// Enable or disable acoustic echo cancellation.
+    pub fn set_aec_enabled(&mut self, enabled: bool) {
+        self.aec.set_enabled(enabled);
+    }
+
+    /// Enable or disable automatic gain control.
+    pub fn set_agc_enabled(&mut self, enabled: bool) {
+        self.agc.set_enabled(enabled);
+    }
+}

crates/wzp-android/src/signal_mgr.rs

@@ -0,0 +1,288 @@
+//! Persistent signal connection manager for direct 1:1 calls.
+//!
+//! Separate from the media engine — survives across calls.
+//! Connects to relay via `_signal` SNI, registers presence,
+//! and handles call signaling (offer/answer/setup/hangup).
+
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+
+use tracing::{error, info, warn};
+use wzp_proto::{MediaTransport, SignalMessage};
+
+/// Signal connection status.
+#[derive(Clone, Debug, Default, serde::Serialize)]
+pub struct SignalState {
+    pub status: String, // "idle", "registered", "ringing", "incoming", "setup"
+    pub fingerprint: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_call_id: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_caller_fp: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_caller_alias: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub call_setup_relay: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub call_setup_room: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub call_setup_id: Option<String>,
+}
+
+/// Manages a persistent `_signal` QUIC connection to a relay.
+pub struct SignalManager {
+    transport: Arc<wzp_transport::QuinnTransport>,
+    state: Arc<Mutex<SignalState>>,
+    running: Arc<AtomicBool>,
+}
+
+impl SignalManager {
+    /// Create SignalManager and start connect+register+recv on a background thread.
+    /// Returns immediately. The internal thread runs forever.
+    /// CRITICAL: tokio runtime must never be dropped on Android (libcrypto TLS conflict).
+    pub fn start(relay_addr: &str, seed_hex: &str) -> Result<Self, anyhow::Error> {
+        let addr: SocketAddr = relay_addr.parse()?;
+        let seed = if seed_hex.is_empty() {
+            wzp_crypto::Seed::generate()
+        } else {
+            wzp_crypto::Seed::from_hex(seed_hex).map_err(|e| anyhow::anyhow!(e))?
+        };
+        let identity = seed.derive_identity();
+        let pub_id = identity.public_identity();
+        let identity_pub = *pub_id.signing.as_bytes();
+        let fp = pub_id.fingerprint.to_string();
+
+        let state = Arc::new(Mutex::new(SignalState {
+            status: "connecting".into(),
+            fingerprint: fp.clone(),
+            ..Default::default()
+        }));
+        let running = Arc::new(AtomicBool::new(true));
+
+        // Channel to receive transport after connect succeeds
+        let (transport_tx, transport_rx) = std::sync::mpsc::channel();
+
+        let bg_state = Arc::clone(&state);
+        let bg_running = Arc::clone(&running);
+        let ret_state = Arc::clone(&state);
+        let ret_running = Arc::clone(&running);
+
+        // ONE thread, ONE runtime, NEVER dropped.
+        // Connect + register + recv loop all happen here.
+        std::thread::Builder::new()
+            .name("wzp-signal".into())
+            .stack_size(4 * 1024 * 1024)
+            .spawn(move || {
+                let rt = tokio::runtime::Builder::new_current_thread()
+                    .enable_all()
+                    .build()
+                    .expect("tokio runtime");
+
+                rt.block_on(async move {
+                    info!(fingerprint = %fp, relay = %addr, "signal: connecting");
+
+                    let bind: SocketAddr = "0.0.0.0:0".parse().unwrap();
+                    let endpoint = match wzp_transport::create_endpoint(bind, None) {
+                        Ok(e) => e,
+                        Err(e) => {
+                            error!("signal endpoint: {e}");
+                            bg_state.lock().unwrap().status = "idle".into();
+                            return;
+                        }
+                    };
+                    let client_cfg = wzp_transport::client_config();
+                    let conn = match wzp_transport::connect(&endpoint, addr, "_signal", client_cfg).await {
+                        Ok(c) => c,
+                        Err(e) => {
+                            error!("signal connect: {e}");
+                            bg_state.lock().unwrap().status = "idle".into();
+                            return;
+                        }
+                    };
+                    let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+                    // Register
+                    if let Err(e) = transport.send_signal(&SignalMessage::RegisterPresence {
+                        identity_pub, signature: vec![], alias: None,
+                    }).await {
+                        error!("signal register: {e}");
+                        bg_state.lock().unwrap().status = "idle".into();
+                        return;
+                    }
+
+                    match transport.recv_signal().await {
+                        Ok(Some(SignalMessage::RegisterPresenceAck { success: true, .. })) => {
+                            info!(fingerprint = %fp, "signal: registered");
+                            bg_state.lock().unwrap().status = "registered".into();
+                            // Send transport to caller
+                            let _ = transport_tx.send(transport.clone());
+                        }
+                        other => {
+                            error!("signal registration failed: {other:?}");
+                            bg_state.lock().unwrap().status = "idle".into();
+                            return;
+                        }
+                    }
+
+                    // Recv loop — runs forever
+            loop {
+                if !running.load(Ordering::Relaxed) { break; }
+
+                match transport.recv_signal().await {
+                    Ok(Some(SignalMessage::CallRinging { call_id })) => {
+                        info!(call_id = %call_id, "signal: ringing");
+                        let mut s = state.lock().unwrap();
+                        s.status = "ringing".into();
+                    }
+                    Ok(Some(SignalMessage::DirectCallOffer { caller_fingerprint, caller_alias, call_id, .. })) => {
+                        info!(from = %caller_fingerprint, call_id = %call_id, "signal: incoming call");
+                        let mut s = state.lock().unwrap();
+                        s.status = "incoming".into();
+                        s.incoming_call_id = Some(call_id);
+                        s.incoming_caller_fp = Some(caller_fingerprint);
+                        s.incoming_caller_alias = caller_alias;
+                    }
+                    Ok(Some(SignalMessage::DirectCallAnswer { call_id, accept_mode, .. })) => {
+                        info!(call_id = %call_id, mode = ?accept_mode, "signal: call answered");
+                    }
+                    Ok(Some(SignalMessage::CallSetup { call_id, room, relay_addr })) => {
+                        info!(call_id = %call_id, room = %room, relay = %relay_addr, "signal: call setup");
+                        let mut s = state.lock().unwrap();
+                        s.status = "setup".into();
+                        s.call_setup_relay = Some(relay_addr);
+                        s.call_setup_room = Some(room);
+                        s.call_setup_id = Some(call_id);
+                    }
+                    Ok(Some(SignalMessage::Hangup { reason })) => {
+                        info!(reason = ?reason, "signal: hangup");
+                        let mut s = state.lock().unwrap();
+                        s.status = "registered".into();
+                        s.incoming_call_id = None;
+                        s.incoming_caller_fp = None;
+                        s.incoming_caller_alias = None;
+                        s.call_setup_relay = None;
+                        s.call_setup_room = None;
+                        s.call_setup_id = None;
+                    }
+                    Ok(Some(_)) => {}
+                    Ok(None) => {
+                        info!("signal: connection closed");
+                        break;
+                    }
+                    Err(e) => {
+                        error!("signal recv error: {e}");
+                        break;
+                    }
+                }
+            }
+
+            bg_state.lock().unwrap().status = "idle".into();
+                }); // block_on
+
+                // Runtime intentionally NOT dropped — lives until thread exits.
+                // This prevents ring/libcrypto TLS cleanup conflict on Android.
+                // The thread is parked here forever (block_on returned = connection lost).
+                std::thread::park();
+            })?; // thread spawn
+
+        // Wait for transport (up to 10s)
+        let transport = transport_rx.recv_timeout(std::time::Duration::from_secs(10))
+            .map_err(|_| anyhow::anyhow!("signal connect timeout — check relay address"))?;
+
+        Ok(Self { transport, state: ret_state, running: ret_running })
+    }
+
+    /// Get current state (non-blocking).
+    pub fn get_state(&self) -> SignalState {
+        self.state.lock().unwrap().clone()
+    }
+
+    /// Get state as JSON string.
+    pub fn get_state_json(&self) -> String {
+        serde_json::to_string(&self.get_state()).unwrap_or_else(|_| "{}".into())
+    }
+
+    /// Place a direct call.
+    pub fn place_call(&self, target_fp: &str) -> Result<(), anyhow::Error> {
+        let fp = self.state.lock().unwrap().fingerprint.clone();
+        let target = target_fp.to_string();
+        let call_id = format!("{:016x}", std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos());
+        let transport = self.transport.clone();
+
+        // Send on a small thread (async send needs a runtime)
+        std::thread::Builder::new()
+            .name("wzp-call-send".into())
+            .spawn(move || {
+                let rt = tokio::runtime::Builder::new_current_thread()
+                    .enable_all().build().expect("rt");
+                rt.block_on(async {
+                    let _ = transport.send_signal(&SignalMessage::DirectCallOffer {
+                        caller_fingerprint: fp,
+                        caller_alias: None,
+                        target_fingerprint: target,
+                        call_id,
+                        identity_pub: [0u8; 32],
+                        ephemeral_pub: [0u8; 32],
+                        signature: vec![],
+                        supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+                    }).await;
+                });
+            })?;
+        Ok(())
+    }
+
+    /// Answer an incoming call.
+    pub fn answer_call(&self, call_id: &str, mode: wzp_proto::CallAcceptMode) -> Result<(), anyhow::Error> {
+        let call_id = call_id.to_string();
+        let transport = self.transport.clone();
+
+        std::thread::Builder::new()
+            .name("wzp-answer-send".into())
+            .spawn(move || {
+                let rt = tokio::runtime::Builder::new_current_thread()
+                    .enable_all().build().expect("rt");
+                rt.block_on(async {
+                    let _ = transport.send_signal(&SignalMessage::DirectCallAnswer {
+                        call_id,
+                        accept_mode: mode,
+                        identity_pub: None,
+                        ephemeral_pub: None,
+                        signature: None,
+                        chosen_profile: Some(wzp_proto::QualityProfile::GOOD),
+                    }).await;
+                });
+            })?;
+        Ok(())
+    }
+
+    /// Send hangup.
+    pub fn hangup(&self) {
+        let transport = self.transport.clone();
+        let state = self.state.clone();
+        std::thread::spawn(move || {
+            let rt = tokio::runtime::Builder::new_current_thread()
+                .enable_all().build().expect("rt");
+            rt.block_on(async {
+                let _ = transport.send_signal(&SignalMessage::Hangup {
+                    reason: wzp_proto::HangupReason::Normal,
+                }).await;
+            });
+            let mut s = state.lock().unwrap();
+            s.status = "registered".into();
+            s.incoming_call_id = None;
+            s.incoming_caller_fp = None;
+            s.incoming_caller_alias = None;
+            s.call_setup_relay = None;
+            s.call_setup_room = None;
+            s.call_setup_id = None;
+        });
+    }
+
+    /// Stop the signal connection.
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Release);
+        self.transport.connection().close(0u32.into(), b"shutdown");
+    }
+}

crates/wzp-android/src/stats.rs

@@ -0,0 +1,101 @@
+//! Call statistics for the Android engine.
+
+/// State of the call.
+/// Serializes as integer for easy parsing on the Kotlin side:
+/// 0=Idle, 1=Connecting, 2=Active, 3=Reconnecting, 4=Closed
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub enum CallState {
+    #[default]
+    Idle,
+    Connecting,
+    Active,
+    Reconnecting,
+    Closed,
+    /// Connected to relay signal channel, registered for direct calls.
+    Registered,
+    /// Outgoing call ringing on callee's side.
+    Ringing,
+    /// Incoming call received, waiting for user to accept/reject.
+    IncomingCall,
+}
+
+impl serde::Serialize for CallState {
+    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let n: u8 = match self {
+            CallState::Idle => 0,
+            CallState::Connecting => 1,
+            CallState::Active => 2,
+            CallState::Reconnecting => 3,
+            CallState::Closed => 4,
+            CallState::Registered => 5,
+            CallState::Ringing => 6,
+            CallState::IncomingCall => 7,
+        };
+        serializer.serialize_u8(n)
+    }
+}
+
+/// Aggregated call statistics, serializable for JNI bridge.
+#[derive(Clone, Debug, Default, serde::Serialize)]
+pub struct CallStats {
+    /// Current call state.
+    pub state: CallState,
+    /// Call duration in seconds.
+    pub duration_secs: f64,
+    /// Current quality tier (0=GOOD, 1=DEGRADED, 2=CATASTROPHIC).
+    pub quality_tier: u8,
+    /// Observed packet loss percentage.
+    pub loss_pct: f32,
+    /// Smoothed round-trip time in milliseconds.
+    pub rtt_ms: u32,
+    /// Jitter in milliseconds.
+    pub jitter_ms: u32,
+    /// Current jitter buffer depth in packets.
+    pub jitter_buffer_depth: usize,
+    /// Total frames encoded since call start.
+    pub frames_encoded: u64,
+    /// Total frames decoded since call start.
+    pub frames_decoded: u64,
+    /// Number of playout underruns (buffer empty when audio needed).
+    pub underruns: u64,
+    /// Frames recovered by FEC.
+    pub fec_recovered: u64,
+    /// Playout ring overflow count (reader was lapped by writer).
+    pub playout_overflows: u64,
+    /// Playout ring underrun count (reader found empty buffer).
+    pub playout_underruns: u64,
+    /// Capture ring overflow count.
+    pub capture_overflows: u64,
+    /// Current mic audio level (RMS of i16 samples, 0-32767).
+    pub audio_level: u32,
+    /// Our current outgoing codec name (e.g. "Opus24k", "Codec2_1200").
+    pub current_codec: String,
+    /// Last seen incoming codec from other participants.
+    pub peer_codec: String,
+    /// Whether auto quality mode is active.
+    pub auto_mode: bool,
+    /// Number of participants in the room (from last RoomUpdate).
+    pub room_participant_count: u32,
+    /// Participant list (fingerprint + optional alias) serialized as JSON array.
+    pub room_participants: Vec<RoomMember>,
+    /// SAS code for verbal verification (None if not in a call).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub sas_code: Option<u32>,
+    /// Incoming call info (present when state == IncomingCall).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_call_id: Option<String>,
+    /// Fingerprint of the caller (present when state == IncomingCall).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_caller_fp: Option<String>,
+    /// Alias of the caller (present when state == IncomingCall).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub incoming_caller_alias: Option<String>,
+}
+
+/// A room member entry, serialized into the stats JSON.
+#[derive(Clone, Debug, Default, serde::Serialize)]
+pub struct RoomMember {
+    pub fingerprint: String,
+    pub alias: Option<String>,
+    pub relay_label: Option<String>,
+}

crates/wzp-client/src/call.rs

@@ -7,7 +7,7 @@ use std::time::{Duration, Instant};
 use bytes::Bytes;
 use tracing::{debug, info, warn};
 
-use wzp_codec::{ComfortNoise, NoiseSupressor, SilenceDetector};
+use wzp_codec::{AutoGainControl, ComfortNoise, EchoCanceller, NoiseSupressor, SilenceDetector};
 use wzp_fec::{RaptorQFecDecoder, RaptorQFecEncoder};
 use wzp_proto::jitter::{JitterBuffer, PlayoutResult};
 use wzp_proto::packet::{MediaHeader, MediaPacket, MiniFrameContext};
@@ -207,6 +207,10 @@ pub struct CallEncoder {
     frame_in_block: u8,
     /// Timestamp counter (ms).
     timestamp_ms: u32,
+    /// Acoustic echo canceller (removes speaker echo from mic signal).
+    aec: EchoCanceller,
+    /// Automatic gain control (normalises mic level).
+    agc: AutoGainControl,
     /// Silence detector for suppression.
     silence_detector: SilenceDetector,
     /// Whether silence suppression is enabled.
@@ -237,6 +241,8 @@ impl CallEncoder {
             block_id: 0,
             frame_in_block: 0,
             timestamp_ms: 0,
+            aec: EchoCanceller::new(48000, 100), // 100 ms echo tail
+            agc: AutoGainControl::new(),
             silence_detector: SilenceDetector::new(
                 config.silence_threshold_rms,
                 config.silence_hangover_frames,
@@ -274,15 +280,21 @@ impl CallEncoder {
     /// Input: 48kHz mono PCM, frame size depends on profile (960 for 20ms, 1920 for 40ms).
     /// Output: one or more MediaPackets to send.
     pub fn encode_frame(&mut self, pcm: &[i16]) -> Result<Vec<MediaPacket>, anyhow::Error> {
-        // Noise suppression: denoise the PCM before silence detection and encoding.
+        // Copy PCM into a mutable buffer for the processing pipeline.
-        let pcm = if self.denoiser.is_enabled() {
+        let mut pcm_buf = pcm.to_vec();
-            let mut buf = pcm.to_vec();
+
-            self.denoiser.process(&mut buf);
+        // Step 1: Echo cancellation (far-end reference must have been fed already).
-            buf
+        self.aec.process_frame(&mut pcm_buf);
-        } else {
+
-            pcm.to_vec()
+        // Step 2: Automatic gain control (normalise mic level).
-        };
+        self.agc.process_frame(&mut pcm_buf);
-        let pcm = &pcm[..];
+
+        // Step 3: Noise suppression (RNNoise).
+        if self.denoiser.is_enabled() {
+            self.denoiser.process(&mut pcm_buf);
+        }
+
+        let pcm = &pcm_buf[..];
 
         // Silence suppression: skip encoding silent frames, periodically send CN.
         if self.suppression_enabled && self.silence_detector.is_silent(pcm) {
@@ -400,6 +412,24 @@ impl CallEncoder {
         self.frame_in_block = 0;
         Ok(())
     }
+
+    /// Feed decoded playout audio as the echo reference signal.
+    ///
+    /// Must be called with each decoded frame BEFORE the corresponding
+    /// microphone frame is processed.
+    pub fn feed_aec_farend(&mut self, farend: &[i16]) {
+        self.aec.feed_farend(farend);
+    }
+
+    /// Enable or disable acoustic echo cancellation.
+    pub fn set_aec_enabled(&mut self, enabled: bool) {
+        self.aec.set_enabled(enabled);
+    }
+
+    /// Enable or disable automatic gain control.
+    pub fn set_agc_enabled(&mut self, enabled: bool) {
+        self.agc.set_enabled(enabled);
+    }
 }
 
 /// Manages the recv/decode side of a call.

crates/wzp-client/src/cli.rs

@@ -47,6 +47,11 @@ struct CliArgs {
     room: Option<String>,
     token: Option<String>,
     _metrics_file: Option<String>,
+    version_check: bool,
+    /// Connect to relay for persistent signaling (direct calls).
+    signal: bool,
+    /// Place a direct call to a fingerprint (requires --signal).
+    call_target: Option<String>,
 }
 
 impl CliArgs {
@@ -88,12 +93,20 @@ fn parse_args() -> CliArgs {
     let mut room = None;
     let mut token = None;
     let mut metrics_file = None;
+    let mut version_check = false;
     let mut relay_str = None;
+    let mut signal = false;
+    let mut call_target = None;
 
     let mut i = 1;
     while i < args.len() {
         match args[i].as_str() {
             "--live" => live = true,
+            "--signal" => signal = true,
+            "--call" => {
+                i += 1;
+                call_target = Some(args.get(i).expect("--call requires a fingerprint").to_string());
+            }
             "--send-tone" => {
                 i += 1;
                 send_tone_secs = Some(
@@ -169,6 +182,7 @@ fn parse_args() -> CliArgs {
                 );
             }
             "--sweep" => sweep = true,
+            "--version-check" => { version_check = true; }
             "--help" | "-h" => {
                 eprintln!("Usage: wzp-client [options] [relay-addr]");
                 eprintln!();
@@ -221,6 +235,9 @@ fn parse_args() -> CliArgs {
         room,
         token,
         _metrics_file: metrics_file,
+        version_check,
+        signal,
+        call_target,
     }
 }
 
@@ -239,6 +256,32 @@ async fn main() -> anyhow::Result<()> {
         return Ok(());
     }
 
+    // --version-check: query relay version over QUIC and exit
+    if cli.version_check {
+        let client_config = wzp_transport::client_config();
+        let bind_addr: SocketAddr = "0.0.0.0:0".parse()?;
+        let endpoint = wzp_transport::create_endpoint(bind_addr, None)?;
+        let conn = wzp_transport::connect(&endpoint, cli.relay_addr, "version", client_config).await?;
+        match conn.accept_uni().await {
+            Ok(mut recv) => {
+                let data = recv.read_to_end(256).await.unwrap_or_default();
+                let version = String::from_utf8_lossy(&data);
+                println!("{} {}", cli.relay_addr, version.trim());
+            }
+            Err(e) => {
+                eprintln!("relay {} does not support version query: {e}", cli.relay_addr);
+            }
+        }
+        endpoint.close(0u32.into(), b"done");
+        return Ok(());
+    }
+
+    // --signal mode: persistent signaling for direct calls
+    if cli.signal {
+        let seed = cli.resolve_seed();
+        return run_signal_mode(cli.relay_addr, seed, cli.token, cli.call_target).await;
+    }
+
     let seed = cli.resolve_seed();
 
     info!(
@@ -250,12 +293,11 @@ async fn main() -> anyhow::Result<()> {
         "WarzonePhone client"
     );
 
-    // Hash room name for SNI privacy (or "default" if none specified)
+    // Use raw room name as SNI (consistent with Android + Desktop clients for federation)
     let sni = match &cli.room {
         Some(name) => {
-            let hashed = wzp_crypto::hash_room_name(name);
+            info!(room = %name, "using room name as SNI");
-            info!(room = %name, hashed = %hashed, "room name hashed for SNI");
+            name.clone()
-            hashed
         }
         None => "default".to_string(),
     };
@@ -274,6 +316,26 @@ async fn main() -> anyhow::Result<()> {
 
     let transport = Arc::new(wzp_transport::QuinnTransport::new(connection));
 
+    // Register shutdown handler so SIGTERM/SIGINT always closes QUIC cleanly.
+    // Without this, killed clients leave zombie connections on the relay for ~30s.
+    {
+        let shutdown_transport = transport.clone();
+        tokio::spawn(async move {
+            let mut sigterm = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
+                .expect("failed to register SIGTERM handler");
+            let mut sigint = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt())
+                .expect("failed to register SIGINT handler");
+            tokio::select! {
+                _ = sigterm.recv() => { info!("SIGTERM received, closing connection..."); }
+                _ = sigint.recv() => { info!("SIGINT received, closing connection..."); }
+            }
+            // Close the QUIC connection immediately (APPLICATION_CLOSE frame).
+            // Don't call process::exit — let the main task detect the closed
+            // connection and perform clean shutdown (e.g., save recordings).
+            shutdown_transport.connection().close(0u32.into(), b"shutdown");
+        });
+    }
+
     // Send auth token if provided (relay with --auth-url expects this first)
     if let Some(ref token) = cli.token {
         let auth = wzp_proto::SignalMessage::AuthToken {
@@ -287,6 +349,7 @@ async fn main() -> anyhow::Result<()> {
     let _crypto_session = wzp_client::handshake::perform_handshake(
         &*transport,
         &seed.0,
+        None, // alias — desktop client doesn't set one yet
     ).await?;
     info!("crypto handshake complete");
 
@@ -623,3 +686,195 @@ async fn run_live(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Resu
     info!("done");
     Ok(())
 }
+
+/// Persistent signaling mode for direct 1:1 calls.
+async fn run_signal_mode(
+    relay_addr: SocketAddr,
+    seed: wzp_crypto::Seed,
+    token: Option<String>,
+    call_target: Option<String>,
+) -> anyhow::Result<()> {
+    use wzp_proto::SignalMessage;
+
+    let identity = seed.derive_identity();
+    let pub_id = identity.public_identity();
+    let fp = pub_id.fingerprint.to_string();
+    let identity_pub = *pub_id.signing.as_bytes();
+    info!(fingerprint = %fp, "signal mode");
+
+    // Connect to relay with SNI "_signal"
+    let client_config = wzp_transport::client_config();
+    let bind_addr: SocketAddr = if relay_addr.is_ipv6() {
+        "[::]:0".parse()?
+    } else {
+        "0.0.0.0:0".parse()?
+    };
+    let endpoint = wzp_transport::create_endpoint(bind_addr, None)?;
+    let conn = wzp_transport::connect(&endpoint, relay_addr, "_signal", client_config).await?;
+    let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+    info!("connected to relay (signal channel)");
+
+    // Auth if token provided
+    if let Some(ref tok) = token {
+        transport.send_signal(&SignalMessage::AuthToken { token: tok.clone() }).await?;
+    }
+
+    // Register presence (signature not verified in Phase 1)
+    transport.send_signal(&SignalMessage::RegisterPresence {
+        identity_pub,
+        signature: vec![], // Phase 1: not verified
+        alias: None,
+    }).await?;
+
+    // Wait for ack
+    match transport.recv_signal().await? {
+        Some(SignalMessage::RegisterPresenceAck { success: true, .. }) => {
+            info!(fingerprint = %fp, "registered on relay — waiting for calls");
+        }
+        Some(SignalMessage::RegisterPresenceAck { success: false, error }) => {
+            anyhow::bail!("registration failed: {}", error.unwrap_or_default());
+        }
+        other => {
+            anyhow::bail!("unexpected response: {other:?}");
+        }
+    }
+
+    // If --call specified, place the call
+    if let Some(ref target) = call_target {
+        info!(target = %target, "placing direct call...");
+        let call_id = format!("{:016x}", std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos());
+
+        transport.send_signal(&SignalMessage::DirectCallOffer {
+            caller_fingerprint: fp.clone(),
+            caller_alias: None,
+            target_fingerprint: target.clone(),
+            call_id: call_id.clone(),
+            identity_pub,
+            ephemeral_pub: [0u8; 32], // Phase 1: not used for key exchange
+            signature: vec![],
+            supported_profiles: vec![wzp_proto::QualityProfile::GOOD],
+        }).await?;
+    }
+
+    // Signal recv loop — handle incoming signals
+    let signal_transport = transport.clone();
+    let relay = relay_addr;
+    let my_fp = fp.clone();
+    let my_seed = seed.0;
+
+    loop {
+        match signal_transport.recv_signal().await {
+            Ok(Some(msg)) => match msg {
+                SignalMessage::CallRinging { call_id } => {
+                    info!(call_id = %call_id, "ringing...");
+                }
+                SignalMessage::DirectCallOffer { caller_fingerprint, caller_alias, call_id, .. } => {
+                    info!(
+                        from = %caller_fingerprint,
+                        alias = ?caller_alias,
+                        call_id = %call_id,
+                        "incoming call — auto-accepting (generic)"
+                    );
+                    // Auto-accept for CLI testing
+                    let _ = signal_transport.send_signal(&SignalMessage::DirectCallAnswer {
+                        call_id,
+                        accept_mode: wzp_proto::CallAcceptMode::AcceptGeneric,
+                        identity_pub: Some(identity_pub),
+                        ephemeral_pub: None,
+                        signature: None,
+                        chosen_profile: Some(wzp_proto::QualityProfile::GOOD),
+                    }).await;
+                }
+                SignalMessage::DirectCallAnswer { call_id, accept_mode, .. } => {
+                    info!(call_id = %call_id, mode = ?accept_mode, "call answered");
+                }
+                SignalMessage::CallSetup { call_id, room, relay_addr: setup_relay } => {
+                    info!(call_id = %call_id, room = %room, relay = %setup_relay, "call setup — connecting to media room");
+
+                    // Connect to the media room
+                    let media_relay: SocketAddr = setup_relay.parse().unwrap_or(relay);
+                    let media_cfg = wzp_transport::client_config();
+                    match wzp_transport::connect(&endpoint, media_relay, &room, media_cfg).await {
+                        Ok(media_conn) => {
+                            let media_transport = Arc::new(wzp_transport::QuinnTransport::new(media_conn));
+
+                            // Crypto handshake
+                            match wzp_client::handshake::perform_handshake(&*media_transport, &my_seed, None).await {
+                                Ok(_session) => {
+                                    info!("media connected — sending tone (press Ctrl+C to hang up)");
+
+                                    // Simple tone sender for testing
+                                    let mt = media_transport.clone();
+                                    let send_task = tokio::spawn(async move {
+                                        let config = wzp_client::call::CallConfig::default();
+                                        let mut encoder = wzp_client::call::CallEncoder::new(&config);
+                                        let duration = tokio::time::Duration::from_millis(20);
+                                        loop {
+                                            let pcm: Vec<i16> = (0..FRAME_SAMPLES)
+                                                .map(|_| 0i16) // silence — could be tone
+                                                .collect();
+                                            if let Ok(pkts) = encoder.encode_frame(&pcm) {
+                                                for pkt in &pkts {
+                                                    if mt.send_media(pkt).await.is_err() { return; }
+                                                }
+                                            }
+                                            tokio::time::sleep(duration).await;
+                                        }
+                                    });
+
+                                    // Wait for hangup or ctrl+c
+                                    loop {
+                                        tokio::select! {
+                                            sig = signal_transport.recv_signal() => {
+                                                match sig {
+                                                    Ok(Some(SignalMessage::Hangup { .. })) => {
+                                                        info!("remote hung up");
+                                                        break;
+                                                    }
+                                                    Ok(None) | Err(_) => break,
+                                                    _ => {}
+                                                }
+                                            }
+                                            _ = tokio::signal::ctrl_c() => {
+                                                info!("hanging up...");
+                                                let _ = signal_transport.send_signal(&SignalMessage::Hangup {
+                                                    reason: wzp_proto::HangupReason::Normal,
+                                                }).await;
+                                                break;
+                                            }
+                                        }
+                                    }
+
+                                    send_task.abort();
+                                    media_transport.close().await.ok();
+                                    info!("call ended");
+                                }
+                                Err(e) => error!("media handshake failed: {e}"),
+                            }
+                        }
+                        Err(e) => error!("media connect failed: {e}"),
+                    }
+                }
+                SignalMessage::Hangup { reason } => {
+                    info!(reason = ?reason, "call ended by remote");
+                }
+                SignalMessage::Pong { .. } => {}
+                other => {
+                    info!("signal: {:?}", std::mem::discriminant(&other));
+                }
+            },
+            Ok(None) => {
+                info!("signal connection closed");
+                break;
+            }
+            Err(e) => {
+                error!("signal error: {e}");
+                break;
+            }
+        }
+    }
+
+    transport.close().await.ok();
+    Ok(())
+}

crates/wzp-client/src/featherchat.rs

@@ -109,12 +109,23 @@ pub fn signal_to_call_type(signal: &SignalMessage) -> CallSignalType {
         SignalMessage::RouteResponse { .. } => CallSignalType::Offer, // reuse
         SignalMessage::SessionForward { .. } => CallSignalType::Offer, // reuse
         SignalMessage::SessionForwardAck { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::RoomUpdate { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::FederationHello { .. }
+        | SignalMessage::GlobalRoomActive { .. }
+        | SignalMessage::GlobalRoomInactive { .. } => CallSignalType::Offer, // relay-only
+        SignalMessage::DirectCallOffer { .. } => CallSignalType::Offer,
+        SignalMessage::DirectCallAnswer { .. } => CallSignalType::Answer,
+        SignalMessage::CallSetup { .. } => CallSignalType::Offer, // relay-only
+        SignalMessage::CallRinging { .. } => CallSignalType::Ringing,
+        SignalMessage::RegisterPresence { .. }
+        | SignalMessage::RegisterPresenceAck { .. } => CallSignalType::Offer, // relay-only
     }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use wzp_proto::QualityProfile;
 
     #[test]
     fn payload_roundtrip() {
@@ -123,6 +134,7 @@ mod tests {
             ephemeral_pub: [2u8; 32],
             signature: vec![3u8; 64],
             supported_profiles: vec![QualityProfile::GOOD],
+            alias: None,
         };
 
         let encoded = encode_call_payload(&signal, Some("relay.example.com:4433"), Some("myroom"));
@@ -140,6 +152,7 @@ mod tests {
             ephemeral_pub: [0; 32],
             signature: vec![],
             supported_profiles: vec![],
+            alias: None,
         };
         assert!(matches!(signal_to_call_type(&offer), CallSignalType::Offer));
 

crates/wzp-client/src/handshake.rs

@@ -17,6 +17,7 @@ use wzp_proto::{MediaTransport, QualityProfile, SignalMessage};
 pub async fn perform_handshake(
     transport: &dyn MediaTransport,
     seed: &[u8; 32],
+    alias: Option<&str>,
 ) -> Result<Box<dyn CryptoSession>, anyhow::Error> {
     // 1. Create key exchange from identity seed
     let mut kx = WarzoneKeyExchange::from_identity_seed(seed);
@@ -37,10 +38,14 @@ pub async fn perform_handshake(
         ephemeral_pub,
         signature,
         supported_profiles: vec![
+            QualityProfile::STUDIO_64K,
+            QualityProfile::STUDIO_48K,
+            QualityProfile::STUDIO_32K,
             QualityProfile::GOOD,
             QualityProfile::DEGRADED,
             QualityProfile::CATASTROPHIC,
         ],
+        alias: alias.map(|s| s.to_string()),
     };
     transport.send_signal(&offer).await?;
 

crates/wzp-codec/src/adaptive.rs

@@ -14,7 +14,7 @@ use crate::codec2_dec::Codec2Decoder;
 use crate::codec2_enc::Codec2Encoder;
 use crate::opus_dec::OpusDecoder;
 use crate::opus_enc::OpusEncoder;
-use crate::resample;
+use crate::resample::{Downsampler48to8, Upsampler8to48};
 
 // ─── Helpers ─────────────────────────────────────────────────────────────────
 
@@ -54,6 +54,7 @@ pub struct AdaptiveEncoder {
     opus: OpusEncoder,
     codec2: Codec2Encoder,
     active: CodecId,
+    downsampler: Downsampler48to8,
 }
 
 impl AdaptiveEncoder {
@@ -66,6 +67,7 @@ impl AdaptiveEncoder {
             opus,
             codec2,
             active: profile.codec,
+            downsampler: Downsampler48to8::new(),
         })
     }
 }
@@ -74,7 +76,7 @@ impl AudioEncoder for AdaptiveEncoder {
     fn encode(&mut self, pcm: &[i16], out: &mut [u8]) -> Result<usize, CodecError> {
         if is_codec2(self.active) {
             // Downsample 48 kHz → 8 kHz then encode via Codec2.
-            let pcm_8k = resample::resample_48k_to_8k(pcm);
+            let pcm_8k = self.downsampler.process(pcm);
             self.codec2.encode(&pcm_8k, out)
         } else {
             self.opus.encode(pcm, out)
@@ -126,6 +128,7 @@ pub struct AdaptiveDecoder {
     opus: OpusDecoder,
     codec2: Codec2Decoder,
     active: CodecId,
+    upsampler: Upsampler8to48,
 }
 
 impl AdaptiveDecoder {
@@ -138,6 +141,7 @@ impl AdaptiveDecoder {
             opus,
             codec2,
             active: profile.codec,
+            upsampler: Upsampler8to48::new(),
         })
     }
 }
@@ -149,7 +153,7 @@ impl AudioDecoder for AdaptiveDecoder {
             let c2_samples = self.codec2_frame_samples();
             let mut buf_8k = vec![0i16; c2_samples];
             let n = self.codec2.decode(encoded, &mut buf_8k)?;
-            let pcm_48k = resample::resample_8k_to_48k(&buf_8k[..n]);
+            let pcm_48k = self.upsampler.process(&buf_8k[..n]);
             let out_len = pcm_48k.len().min(pcm.len());
             pcm[..out_len].copy_from_slice(&pcm_48k[..out_len]);
             Ok(out_len)
@@ -163,7 +167,7 @@ impl AudioDecoder for AdaptiveDecoder {
             let c2_samples = self.codec2_frame_samples();
             let mut buf_8k = vec![0i16; c2_samples];
             let n = self.codec2.decode_lost(&mut buf_8k)?;
-            let pcm_48k = resample::resample_8k_to_48k(&buf_8k[..n]);
+            let pcm_48k = self.upsampler.process(&buf_8k[..n]);
             let out_len = pcm_48k.len().min(pcm.len());
             pcm[..out_len].copy_from_slice(&pcm_48k[..out_len]);
             Ok(out_len)

crates/wzp-codec/src/aec.rs

@@ -0,0 +1,228 @@
+//! Acoustic Echo Cancellation using NLMS adaptive filter.
+//! Processes 480-sample (10ms) sub-frames at 48kHz.
+
+/// NLMS (Normalized Least Mean Squares) adaptive filter echo canceller.
+///
+/// Removes acoustic echo by modelling the echo path between the far-end
+/// (speaker) signal and the near-end (microphone) signal, then subtracting
+/// the estimated echo from the near-end in real time.
+pub struct EchoCanceller {
+    filter_coeffs: Vec<f32>,
+    filter_len: usize,
+    far_end_buf: Vec<f32>,
+    far_end_pos: usize,
+    mu: f32,
+    enabled: bool,
+}
+
+impl EchoCanceller {
+    /// Create a new echo canceller.
+    ///
+    /// * `sample_rate` — typically 48000
+    /// * `filter_ms`   — echo-tail length in milliseconds (e.g. 100 for 100 ms)
+    pub fn new(sample_rate: u32, filter_ms: u32) -> Self {
+        let filter_len = (sample_rate as usize) * (filter_ms as usize) / 1000;
+        Self {
+            filter_coeffs: vec![0.0f32; filter_len],
+            filter_len,
+            far_end_buf: vec![0.0f32; filter_len],
+            far_end_pos: 0,
+            mu: 0.01,
+            enabled: true,
+        }
+    }
+
+    /// Feed far-end (speaker/playback) samples into the circular buffer.
+    ///
+    /// Must be called with the audio that was played out through the speaker
+    /// *before* the corresponding near-end frame is processed.
+    pub fn feed_farend(&mut self, farend: &[i16]) {
+        for &s in farend {
+            self.far_end_buf[self.far_end_pos] = s as f32;
+            self.far_end_pos = (self.far_end_pos + 1) % self.filter_len;
+        }
+    }
+
+    /// Process a near-end (microphone) frame, removing the estimated echo.
+    ///
+    /// Returns the echo-return-loss enhancement (ERLE) as a ratio: the RMS of
+    /// the original near-end divided by the RMS of the residual.  Values > 1.0
+    /// mean echo was reduced.
+    pub fn process_frame(&mut self, nearend: &mut [i16]) -> f32 {
+        if !self.enabled {
+            return 1.0;
+        }
+
+        let n = nearend.len();
+        let fl = self.filter_len;
+
+        let mut sum_near_sq: f64 = 0.0;
+        let mut sum_err_sq: f64 = 0.0;
+
+        for i in 0..n {
+            let near_f = nearend[i] as f32;
+
+            // --- estimate echo as dot(coeffs, farend_window) ---
+            // The far-end window for this sample starts at
+            //   (far_end_pos - 1 - i) mod filter_len   (most recent)
+            // and goes back filter_len samples.
+            let mut echo_est: f32 = 0.0;
+            let mut power: f32 = 0.0;
+
+            // Position of the most-recent far-end sample for this near-end sample.
+            // far_end_pos points to the *next write* position, so the most-recent
+            // sample written is at far_end_pos - 1.  We have already called
+            // feed_farend for this block, so the relevant samples are the last
+            // filter_len entries ending just before the current write position,
+            // offset by how far we are into this near-end frame.
+            //
+            // For sample i of the near-end frame, the corresponding far-end
+            // "now" is far_end_pos - n + i  (wrapping).
+            // far_end_pos points to next-write, so most recent sample is at
+            // far_end_pos - 1.  For the i-th near-end sample we want the
+            // far-end "now" to be at (far_end_pos - n + i).  We add fl
+            // repeatedly to avoid underflow on the usize subtraction.
+            let base = (self.far_end_pos + fl * ((n / fl) + 2) + i - n) % fl;
+
+            for k in 0..fl {
+                let fe_idx = (base + fl - k) % fl;
+                let fe = self.far_end_buf[fe_idx];
+                echo_est += self.filter_coeffs[k] * fe;
+                power += fe * fe;
+            }
+
+            let error = near_f - echo_est;
+
+            // --- NLMS coefficient update ---
+            let norm = power + 1.0; // +1 regularisation to avoid div-by-zero
+            let step = self.mu * error / norm;
+
+            for k in 0..fl {
+                let fe_idx = (base + fl - k) % fl;
+                let fe = self.far_end_buf[fe_idx];
+                self.filter_coeffs[k] += step * fe;
+            }
+
+            // Clamp output
+            let out = error.max(-32768.0).min(32767.0);
+            nearend[i] = out as i16;
+
+            sum_near_sq += (near_f as f64) * (near_f as f64);
+            sum_err_sq += (out as f64) * (out as f64);
+        }
+
+        // ERLE ratio
+        if sum_err_sq < 1.0 {
+            return 100.0; // near-perfect cancellation
+        }
+        (sum_near_sq / sum_err_sq).sqrt() as f32
+    }
+
+    /// Enable or disable echo cancellation.
+    pub fn set_enabled(&mut self, enabled: bool) {
+        self.enabled = enabled;
+    }
+
+    /// Returns whether echo cancellation is currently enabled.
+    pub fn is_enabled(&self) -> bool {
+        self.enabled
+    }
+
+    /// Reset the adaptive filter to its initial state.
+    ///
+    /// Zeroes out all filter coefficients and the far-end circular buffer.
+    pub fn reset(&mut self) {
+        self.filter_coeffs.iter_mut().for_each(|c| *c = 0.0);
+        self.far_end_buf.iter_mut().for_each(|s| *s = 0.0);
+        self.far_end_pos = 0;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn aec_creates_with_correct_filter_len() {
+        let aec = EchoCanceller::new(48000, 100);
+        assert_eq!(aec.filter_len, 4800);
+        assert_eq!(aec.filter_coeffs.len(), 4800);
+        assert_eq!(aec.far_end_buf.len(), 4800);
+    }
+
+    #[test]
+    fn aec_passthrough_when_disabled() {
+        let mut aec = EchoCanceller::new(48000, 100);
+        aec.set_enabled(false);
+        assert!(!aec.is_enabled());
+
+        let original: Vec<i16> = (0..480).map(|i| (i * 10) as i16).collect();
+        let mut frame = original.clone();
+        let erle = aec.process_frame(&mut frame);
+        assert_eq!(erle, 1.0);
+        assert_eq!(frame, original);
+    }
+
+    #[test]
+    fn aec_reset_zeroes_state() {
+        let mut aec = EchoCanceller::new(48000, 10); // short for test speed
+        let farend: Vec<i16> = (0..480).map(|i| ((i * 37) % 1000) as i16).collect();
+        aec.feed_farend(&farend);
+
+        aec.reset();
+
+        assert!(aec.filter_coeffs.iter().all(|&c| c == 0.0));
+        assert!(aec.far_end_buf.iter().all(|&s| s == 0.0));
+        assert_eq!(aec.far_end_pos, 0);
+    }
+
+    #[test]
+    fn aec_reduces_echo_of_known_signal() {
+        // Use a small filter for speed.  Feed a known far-end signal, then
+        // present the *same* signal as near-end (perfect echo, no room).
+        // After adaptation the output energy should drop.
+        let filter_ms = 5; // 240 taps at 48 kHz
+        let mut aec = EchoCanceller::new(48000, filter_ms);
+
+        // Generate a simple repeating pattern.
+        let frame_len = 480usize;
+        let make_frame = |offset: usize| -> Vec<i16> {
+            (0..frame_len)
+                .map(|i| {
+                    let t = (offset + i) as f64 / 48000.0;
+                    (5000.0 * (2.0 * std::f64::consts::PI * 300.0 * t).sin()) as i16
+                })
+                .collect()
+        };
+
+        // Warm up the adaptive filter with several frames.
+        let mut last_erle = 1.0f32;
+        for frame_idx in 0..40 {
+            let farend = make_frame(frame_idx * frame_len);
+            aec.feed_farend(&farend);
+
+            // Near-end = exact copy of far-end (pure echo).
+            let mut nearend = farend.clone();
+            last_erle = aec.process_frame(&mut nearend);
+        }
+
+        // After 40 frames the ERLE should be meaningfully > 1.
+        assert!(
+            last_erle > 1.0,
+            "expected ERLE > 1.0 after adaptation, got {last_erle}"
+        );
+    }
+
+    #[test]
+    fn aec_silence_passthrough() {
+        let mut aec = EchoCanceller::new(48000, 10);
+        // Feed silence far-end
+        aec.feed_farend(&vec![0i16; 480]);
+        // Near-end is silence too
+        let mut frame = vec![0i16; 480];
+        let erle = aec.process_frame(&mut frame);
+        assert!(erle >= 1.0);
+        // Output should still be silence
+        assert!(frame.iter().all(|&s| s == 0));
+    }
+}

crates/wzp-codec/src/agc.rs

@@ -0,0 +1,219 @@
+//! Automatic Gain Control (AGC) with two-stage smoothing.
+//!
+//! Uses a fast attack / slow release envelope follower to keep the
+//! output signal near a configurable target RMS level.  This prevents
+//! both clipping (when the speaker is too loud) and inaudibility (when
+//! the speaker is too quiet or far from the mic).
+
+/// Two-stage automatic gain control.
+///
+/// The gain is adjusted per-frame based on the measured RMS energy,
+/// with a fast attack (gain decreases quickly when signal gets louder)
+/// and a slow release (gain increases gradually when signal gets quieter).
+pub struct AutoGainControl {
+    target_rms: f64,
+    current_gain: f64,
+    min_gain: f64,
+    max_gain: f64,
+    attack_alpha: f64,
+    release_alpha: f64,
+    enabled: bool,
+}
+
+impl AutoGainControl {
+    /// Create a new AGC with sensible VoIP defaults.
+    pub fn new() -> Self {
+        Self {
+            target_rms: 3000.0,   // ~-20 dBFS for i16
+            current_gain: 1.0,
+            min_gain: 0.5,
+            max_gain: 32.0,
+            attack_alpha: 0.3,    // fast attack
+            release_alpha: 0.02,  // slow release
+            enabled: true,
+        }
+    }
+
+    /// Process a frame of PCM audio in-place, applying gain adjustment.
+    pub fn process_frame(&mut self, pcm: &mut [i16]) {
+        if !self.enabled {
+            return;
+        }
+
+        // Compute RMS of the frame.
+        let rms = Self::compute_rms(pcm);
+
+        // Don't amplify near-silence — it would just boost noise.
+        if rms < 10.0 {
+            return;
+        }
+
+        // Desired instantaneous gain.
+        let desired_gain = (self.target_rms / rms).clamp(self.min_gain, self.max_gain);
+
+        // Smooth the gain transition.
+        let alpha = if desired_gain < self.current_gain {
+            // Signal is louder than target → reduce gain quickly (attack).
+            self.attack_alpha
+        } else {
+            // Signal is quieter than target → raise gain slowly (release).
+            self.release_alpha
+        };
+
+        self.current_gain = self.current_gain * (1.0 - alpha) + desired_gain * alpha;
+
+        // Apply gain to each sample with hard limiting at ±31000 (~0.946 * i16::MAX).
+        const LIMIT: f64 = 31000.0;
+        let gain = self.current_gain;
+        for sample in pcm.iter_mut() {
+            let amplified = (*sample as f64) * gain;
+            let clamped = amplified.clamp(-LIMIT, LIMIT);
+            *sample = clamped as i16;
+        }
+    }
+
+    /// Enable or disable the AGC.
+    pub fn set_enabled(&mut self, enabled: bool) {
+        self.enabled = enabled;
+    }
+
+    /// Returns whether the AGC is currently enabled.
+    pub fn is_enabled(&self) -> bool {
+        self.enabled
+    }
+
+    /// Current gain expressed in dB.
+    pub fn current_gain_db(&self) -> f64 {
+        20.0 * self.current_gain.log10()
+    }
+
+    /// Compute the RMS (root mean square) of a PCM buffer.
+    fn compute_rms(pcm: &[i16]) -> f64 {
+        if pcm.is_empty() {
+            return 0.0;
+        }
+        let sum_sq: f64 = pcm.iter().map(|&s| (s as f64) * (s as f64)).sum();
+        (sum_sq / pcm.len() as f64).sqrt()
+    }
+}
+
+impl Default for AutoGainControl {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn agc_creates_with_defaults() {
+        let agc = AutoGainControl::new();
+        assert!(agc.is_enabled());
+        assert!((agc.current_gain - 1.0).abs() < f64::EPSILON);
+    }
+
+    #[test]
+    fn agc_passthrough_when_disabled() {
+        let mut agc = AutoGainControl::new();
+        agc.set_enabled(false);
+
+        let original: Vec<i16> = (0..960).map(|i| (i * 5) as i16).collect();
+        let mut frame = original.clone();
+        agc.process_frame(&mut frame);
+
+        assert_eq!(frame, original);
+    }
+
+    #[test]
+    fn agc_does_not_amplify_silence() {
+        let mut agc = AutoGainControl::new();
+        let mut frame = vec![0i16; 960];
+        agc.process_frame(&mut frame);
+        assert!(frame.iter().all(|&s| s == 0));
+        // Gain should remain at initial value.
+        assert!((agc.current_gain - 1.0).abs() < f64::EPSILON);
+    }
+
+    #[test]
+    fn agc_amplifies_quiet_signal() {
+        let mut agc = AutoGainControl::new();
+
+        // Very quiet signal (RMS ~ 50).
+        let mut frame: Vec<i16> = (0..960)
+            .map(|i| {
+                let t = i as f64 / 48000.0;
+                (50.0 * (2.0 * std::f64::consts::PI * 440.0 * t).sin()) as i16
+            })
+            .collect();
+
+        // Process several frames to let the gain ramp up.
+        for _ in 0..50 {
+            let mut f = frame.clone();
+            agc.process_frame(&mut f);
+            frame = f;
+        }
+
+        // Gain should have increased past 1.0.
+        assert!(
+            agc.current_gain > 1.05,
+            "expected gain > 1.05 for quiet signal, got {}",
+            agc.current_gain
+        );
+    }
+
+    #[test]
+    fn agc_attenuates_loud_signal() {
+        let mut agc = AutoGainControl::new();
+
+        // Loud signal (RMS ~ 20000).
+        let frame: Vec<i16> = (0..960)
+            .map(|i| {
+                let t = i as f64 / 48000.0;
+                (28000.0 * (2.0 * std::f64::consts::PI * 440.0 * t).sin()) as i16
+            })
+            .collect();
+
+        // Process several frames.
+        for _ in 0..20 {
+            let mut f = frame.clone();
+            agc.process_frame(&mut f);
+        }
+
+        // Gain should have decreased below 1.0.
+        assert!(
+            agc.current_gain < 1.0,
+            "expected gain < 1.0 for loud signal, got {}",
+            agc.current_gain
+        );
+    }
+
+    #[test]
+    fn agc_output_within_limits() {
+        let mut agc = AutoGainControl::new();
+        // Force a high gain by processing many quiet frames first.
+        for _ in 0..100 {
+            let mut f: Vec<i16> = vec![100; 960];
+            agc.process_frame(&mut f);
+        }
+
+        // Now send a louder frame — output should still be within ±31000.
+        let mut frame: Vec<i16> = vec![20000; 960];
+        agc.process_frame(&mut frame);
+        assert!(
+            frame.iter().all(|&s| s.abs() <= 31000),
+            "output samples must be within ±31000"
+        );
+    }
+
+    #[test]
+    fn agc_gain_db_at_unity() {
+        let agc = AutoGainControl::new();
+        let db = agc.current_gain_db();
+        assert!(
+            db.abs() < 0.01,
+            "expected ~0 dB at unity gain, got {db}"
+        );
+    }
+}

crates/wzp-codec/src/lib.rs

@@ -10,6 +10,8 @@
 //! trait-object encoders/decoders that handle adaptive switching internally.
 
 pub mod adaptive;
+pub mod aec;
+pub mod agc;
 pub mod codec2_dec;
 pub mod codec2_enc;
 pub mod denoise;
@@ -19,6 +21,8 @@ pub mod resample;
 pub mod silence;
 
 pub use adaptive::{AdaptiveDecoder, AdaptiveEncoder};
+pub use aec::EchoCanceller;
+pub use agc::AutoGainControl;
 pub use denoise::NoiseSupressor;
 pub use silence::{ComfortNoise, SilenceDetector};
 pub use wzp_proto::{AudioDecoder, AudioEncoder, CodecId, QualityProfile};

crates/wzp-codec/src/opus_dec.rs

@@ -79,7 +79,7 @@ impl AudioDecoder for OpusDecoder {
 
     fn set_profile(&mut self, profile: QualityProfile) -> Result<(), CodecError> {
         match profile.codec {
-            CodecId::Opus24k | CodecId::Opus16k | CodecId::Opus6k => {
+            c if c.is_opus() => {
                 self.codec_id = profile.codec;
                 self.frame_duration_ms = profile.frame_duration_ms;
                 Ok(())

crates/wzp-codec/src/opus_enc.rs

@@ -40,6 +40,11 @@ impl OpusEncoder {
             .set_signal(Signal::Voice)
             .map_err(|e| CodecError::EncodeFailed(format!("set signal: {e}")))?;
 
+        // Default complexity 7 — good quality/CPU trade-off for VoIP
+        enc.inner
+            .set_complexity(7)
+            .map_err(|e| CodecError::EncodeFailed(format!("set complexity: {e}")))?;
+
         Ok(enc)
     }
 
@@ -56,6 +61,21 @@ impl OpusEncoder {
     pub fn frame_samples(&self) -> usize {
         (48_000 * self.frame_duration_ms as usize) / 1000
     }
+
+    /// Set the encoder complexity (0-10). Higher values produce better quality
+    /// at the cost of more CPU. Default is 7.
+    pub fn set_complexity(&mut self, complexity: i32) {
+        let c = (complexity as u8).min(10);
+        let _ = self.inner.set_complexity(c);
+    }
+
+    /// Hint the encoder about expected packet loss percentage (0-100).
+    ///
+    /// Higher values cause the encoder to use more redundancy to survive
+    /// packet loss, at the expense of slightly higher bitrate.
+    pub fn set_expected_loss(&mut self, loss_pct: u8) {
+        let _ = self.inner.set_packet_loss_perc(loss_pct.min(100));
+    }
 }
 
 impl AudioEncoder for OpusEncoder {
@@ -80,7 +100,7 @@ impl AudioEncoder for OpusEncoder {
 
     fn set_profile(&mut self, profile: QualityProfile) -> Result<(), CodecError> {
         match profile.codec {
-            CodecId::Opus24k | CodecId::Opus16k | CodecId::Opus6k => {
+            c if c.is_opus() => {
                 self.codec_id = profile.codec;
                 self.frame_duration_ms = profile.frame_duration_ms;
                 self.apply_bitrate(profile.codec)?;

crates/wzp-codec/src/resample.rs

@@ -1,55 +1,258 @@
-//! Simple linear resampler for 48 kHz <-> 8 kHz conversion.
+//! Windowed-sinc FIR resampler for 48 kHz <-> 8 kHz conversion.
 //!
-//! These are basic implementations suitable for voice. For higher quality,
+//! Provides both stateless free functions (backward-compatible) and stateful
-//! replace with the `rubato` crate later.
+//! `Downsampler48to8` / `Upsampler8to48` structs that maintain overlap history
+//! between frames for glitch-free streaming.
 
-/// Downsample from 48 kHz to 8 kHz (6:1 decimation with averaging).
+use std::f64::consts::PI;
+
+// ─── FIR kernel parameters ─────────────────────────────────────────────────
+
+/// Number of FIR taps in the anti-alias / interpolation filter.
+const FIR_TAPS: usize = 48;
+/// Kaiser window beta parameter — controls sidelobe attenuation.
+const KAISER_BETA: f64 = 8.0;
+/// Cutoff frequency in Hz for the low-pass filter (just below 4 kHz Nyquist of 8 kHz).
+const CUTOFF_HZ: f64 = 3800.0;
+/// Working sample rate in Hz.
+const SAMPLE_RATE: f64 = 48000.0;
+/// Decimation / interpolation ratio between 48 kHz and 8 kHz.
+const RATIO: usize = 6;
+
+// ─── Kaiser window helpers ─────────────────────────────────────────────────
+
+/// Zeroth-order modified Bessel function of the first kind, I₀(x).
 ///
-/// Each output sample is the average of 6 consecutive input samples,
+/// Computed via the well-known power-series expansion, converging rapidly
-/// providing basic anti-aliasing via a box filter.
+/// for the moderate values of x used in Kaiser window design.
-pub fn resample_48k_to_8k(input: &[i16]) -> Vec<i16> {
+fn bessel_i0(x: f64) -> f64 {
-    const RATIO: usize = 6;
+    let mut sum = 1.0f64;
-    let out_len = input.len() / RATIO;
+    let mut term = 1.0f64;
-    let mut output = Vec::with_capacity(out_len);
+    let half_x = x / 2.0;
-
+    for k in 1..=25 {
-    for chunk in input.chunks_exact(RATIO) {
+        term *= (half_x / k as f64) * (half_x / k as f64);
-        let sum: i32 = chunk.iter().map(|&s| s as i32).sum();
+        sum += term;
-        output.push((sum / RATIO as i32) as i16);
+        if term < 1e-12 * sum {
+            break;
+        }
     }
-
+    sum
-    output
 }
 
-/// Upsample from 8 kHz to 48 kHz (1:6 interpolation with linear interp).
+/// Build a windowed-sinc low-pass FIR kernel.
 ///
-/// Linearly interpolates between each pair of input samples to produce
+/// Returns `FIR_TAPS` coefficients normalised so that the DC gain is exactly 1.0.
-/// 6 output samples per input sample.
+fn build_fir_kernel() -> [f64; FIR_TAPS] {
-pub fn resample_8k_to_48k(input: &[i16]) -> Vec<i16> {
+    let mut kernel = [0.0f64; FIR_TAPS];
-    const RATIO: usize = 6;
+    let m = (FIR_TAPS - 1) as f64;
-    if input.is_empty() {
+    let fc = CUTOFF_HZ / SAMPLE_RATE; // normalised cutoff (0..0.5)
-        return Vec::new();
+    let beta_denom = bessel_i0(KAISER_BETA);
-    }
 
-    let out_len = input.len() * RATIO;
+    for i in 0..FIR_TAPS {
-    let mut output = Vec::with_capacity(out_len);
+        // Sinc
-
+        let n = i as f64 - m / 2.0;
-    for i in 0..input.len() {
+        let sinc = if n.abs() < 1e-12 {
-        let current = input[i] as i32;
+            2.0 * fc
-        let next = if i + 1 < input.len() {
-            input[i + 1] as i32
         } else {
-            current // hold last sample
+            (2.0 * PI * fc * n).sin() / (PI * n)
         };
 
-        for j in 0..RATIO {
+        // Kaiser window
-            let interp = current + (next - current) * j as i32 / RATIO as i32;
+        let t = 2.0 * i as f64 / m - 1.0; // range [-1, 1]
-            output.push(interp as i16);
+        let kaiser = bessel_i0(KAISER_BETA * (1.0 - t * t).max(0.0).sqrt()) / beta_denom;
+
+        kernel[i] = sinc * kaiser;
+    }
+
+    // Normalise to unity DC gain.
+    let sum: f64 = kernel.iter().sum();
+    if sum.abs() > 1e-15 {
+        for k in kernel.iter_mut() {
+            *k /= sum;
         }
     }
 
-    output
+    kernel
 }
 
+// ─── Stateful Downsampler 48→8 ─────────────────────────────────────────────
+
+/// Stateful polyphase FIR downsampler from 48 kHz to 8 kHz.
+///
+/// Maintains `FIR_TAPS - 1` samples of history between successive calls to
+/// `process()` for seamless frame boundaries.
+pub struct Downsampler48to8 {
+    kernel: [f64; FIR_TAPS],
+    history: Vec<f64>,
+}
+
+impl Downsampler48to8 {
+    pub fn new() -> Self {
+        Self {
+            kernel: build_fir_kernel(),
+            history: vec![0.0; FIR_TAPS - 1],
+        }
+    }
+
+    /// Downsample a block of 48 kHz samples to 8 kHz.
+    ///
+    /// The input length should be a multiple of 6; any trailing samples that
+    /// don't form a complete output sample are consumed into the history.
+    pub fn process(&mut self, input: &[i16]) -> Vec<i16> {
+        let hist_len = self.history.len(); // FIR_TAPS - 1
+        let total_len = hist_len + input.len();
+
+        // Build a working buffer: history ++ input (as f64).
+        let mut work = Vec::with_capacity(total_len);
+        work.extend_from_slice(&self.history);
+        work.extend(input.iter().map(|&s| s as f64));
+
+        let out_len = input.len() / RATIO;
+        let mut output = Vec::with_capacity(out_len);
+
+        for i in 0..out_len {
+            // The centre of the filter for output sample i sits at
+            // position hist_len + i*RATIO in the work buffer (aligning
+            // with the first new input sample at decimation phase 0).
+            let centre = hist_len + i * RATIO;
+            let start = centre + 1 - FIR_TAPS; // may be 0 for the first few
+
+            let mut acc = 0.0f64;
+            for k in 0..FIR_TAPS {
+                let idx = start + k;
+                if idx < work.len() {
+                    acc += work[idx] * self.kernel[k];
+                }
+            }
+            output.push(acc.round().clamp(-32768.0, 32767.0) as i16);
+        }
+
+        // Update history: keep the last (FIR_TAPS - 1) samples from work.
+        if work.len() >= hist_len {
+            self.history
+                .copy_from_slice(&work[work.len() - hist_len..]);
+        } else {
+            // Input was shorter than history — shift.
+            let shift = hist_len - work.len();
+            self.history.copy_within(shift.., 0);
+            for (i, &v) in work.iter().enumerate() {
+                self.history[hist_len - work.len() + i] = v;
+            }
+        }
+
+        output
+    }
+}
+
+impl Default for Downsampler48to8 {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ─── Stateful Upsampler 8→48 ───────────────────────────────────────────────
+
+/// Stateful FIR upsampler from 8 kHz to 48 kHz.
+///
+/// Inserts zeros between input samples (zero-stuffing), then applies the
+/// low-pass FIR to remove imaging, with gain compensation of `RATIO`.
+pub struct Upsampler8to48 {
+    kernel: [f64; FIR_TAPS],
+    history: Vec<f64>,
+}
+
+impl Upsampler8to48 {
+    pub fn new() -> Self {
+        Self {
+            kernel: build_fir_kernel(),
+            history: vec![0.0; FIR_TAPS - 1],
+        }
+    }
+
+    /// Upsample a block of 8 kHz samples to 48 kHz.
+    pub fn process(&mut self, input: &[i16]) -> Vec<i16> {
+        let hist_len = self.history.len(); // FIR_TAPS - 1
+
+        // Zero-stuff: insert RATIO-1 zeros between each input sample.
+        let stuffed_len = input.len() * RATIO;
+        let total_len = hist_len + stuffed_len;
+
+        let mut work = Vec::with_capacity(total_len);
+        work.extend_from_slice(&self.history);
+        for &s in input {
+            work.push(s as f64);
+            for _ in 1..RATIO {
+                work.push(0.0);
+            }
+        }
+
+        let out_len = stuffed_len;
+        let mut output = Vec::with_capacity(out_len);
+
+        // The gain factor compensates for the zeros introduced by stuffing.
+        let gain = RATIO as f64;
+
+        for i in 0..out_len {
+            let centre = hist_len + i;
+            let start = centre + 1 - FIR_TAPS;
+
+            let mut acc = 0.0f64;
+            for k in 0..FIR_TAPS {
+                let idx = start + k;
+                if idx < work.len() {
+                    acc += work[idx] * self.kernel[k];
+                }
+            }
+            acc *= gain;
+            output.push(acc.round().clamp(-32768.0, 32767.0) as i16);
+        }
+
+        // Update history.
+        if work.len() >= hist_len {
+            self.history
+                .copy_from_slice(&work[work.len() - hist_len..]);
+        } else {
+            let shift = hist_len - work.len();
+            self.history.copy_within(shift.., 0);
+            for (i, &v) in work.iter().enumerate() {
+                self.history[hist_len - work.len() + i] = v;
+            }
+        }
+
+        output
+    }
+}
+
+impl Default for Upsampler8to48 {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ─── Backward-compatible free functions ─────────────────────────────────────
+
+/// Downsample from 48 kHz to 8 kHz (6:1 decimation with FIR anti-alias filter).
+///
+/// This is a convenience wrapper that creates a temporary [`Downsampler48to8`].
+/// For streaming use, prefer the stateful struct to avoid edge artefacts between
+/// frames.
+pub fn resample_48k_to_8k(input: &[i16]) -> Vec<i16> {
+    let mut ds = Downsampler48to8::new();
+    ds.process(input)
+}
+
+/// Upsample from 8 kHz to 48 kHz (1:6 interpolation with FIR imaging filter).
+///
+/// This is a convenience wrapper that creates a temporary [`Upsampler8to48`].
+/// For streaming use, prefer the stateful struct to avoid edge artefacts between
+/// frames.
+pub fn resample_8k_to_48k(input: &[i16]) -> Vec<i16> {
+    let mut us = Upsampler8to48::new();
+    us.process(input)
+}
+
+// ─── Tests ──────────────────────────────────────────────────────────────────
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -66,12 +269,28 @@ mod tests {
 
     #[test]
     fn dc_signal_preserved() {
-        // A constant signal should survive resampling
+        // A constant signal should survive resampling (approximately).
         let input = vec![1000i16; 960];
         let down = resample_48k_to_8k(&input);
-        assert!(down.iter().all(|&s| s == 1000));
+        // Allow some edge transient — check that the middle samples are close.
+        let mid_start = down.len() / 4;
+        let mid_end = 3 * down.len() / 4;
+        for &s in &down[mid_start..mid_end] {
+            assert!(
+                (s - 1000).abs() < 50,
+                "DC downsampled sample {s} too far from 1000"
+            );
+        }
+
         let up = resample_8k_to_48k(&down);
-        assert!(up.iter().all(|&s| s == 1000));
+        let mid_start_up = up.len() / 4;
+        let mid_end_up = 3 * up.len() / 4;
+        for &s in &up[mid_start_up..mid_end_up] {
+            assert!(
+                (s - 1000).abs() < 100,
+                "DC upsampled sample {s} too far from 1000"
+            );
+        }
     }
 
     #[test]
@@ -79,4 +298,40 @@ mod tests {
         assert!(resample_48k_to_8k(&[]).is_empty());
         assert!(resample_8k_to_48k(&[]).is_empty());
     }
+
+    #[test]
+    fn stateful_downsampler_produces_correct_length() {
+        let mut ds = Downsampler48to8::new();
+        let out = ds.process(&vec![0i16; 960]);
+        assert_eq!(out.len(), 160);
+        let out2 = ds.process(&vec![0i16; 960]);
+        assert_eq!(out2.len(), 160);
+    }
+
+    #[test]
+    fn stateful_upsampler_produces_correct_length() {
+        let mut us = Upsampler8to48::new();
+        let out = us.process(&vec![0i16; 160]);
+        assert_eq!(out.len(), 960);
+        let out2 = us.process(&vec![0i16; 160]);
+        assert_eq!(out2.len(), 960);
+    }
+
+    #[test]
+    fn fir_kernel_has_unity_dc_gain() {
+        let kernel = build_fir_kernel();
+        let sum: f64 = kernel.iter().sum();
+        assert!(
+            (sum - 1.0).abs() < 1e-10,
+            "FIR kernel DC gain should be 1.0, got {sum}"
+        );
+    }
+
+    #[test]
+    fn bessel_i0_known_values() {
+        // I₀(0) = 1
+        assert!((bessel_i0(0.0) - 1.0).abs() < 1e-12);
+        // I₀(1) ≈ 1.2660658
+        assert!((bessel_i0(1.0) - 1.2660658).abs() < 1e-5);
+    }
 }

crates/wzp-crypto/src/handshake.rs

@@ -110,7 +110,18 @@ impl KeyExchange for WarzoneKeyExchange {
         hk.expand(b"warzone-session-key", &mut session_key)
             .expect("HKDF expand for session key should not fail");
 
-        Ok(Box::new(ChaChaSession::new(session_key)))
+        // Derive SAS (Short Authentication String) from shared secret only.
+        // The shared secret is identical on both sides (X25519 DH property).
+        // A MITM would produce a different shared secret → different SAS.
+        // We use a dedicated HKDF label so SAS is independent of the session key.
+        let mut sas_key = [0u8; 4];
+        hk.expand(b"warzone-sas-code", &mut sas_key)
+            .expect("HKDF expand for SAS should not fail");
+        let sas_code = u32::from_be_bytes(sas_key) % 10000;
+
+        let mut session = ChaChaSession::new(session_key);
+        session.set_sas(sas_code);
+        Ok(Box::new(session))
     }
 }
 
@@ -211,4 +222,47 @@ mod tests {
 
         assert_eq!(&decrypted, plaintext);
     }
+
+    #[test]
+    fn sas_codes_match_between_peers() {
+        let mut alice = WarzoneKeyExchange::from_identity_seed(&[0xAA; 32]);
+        let mut bob = WarzoneKeyExchange::from_identity_seed(&[0xBB; 32]);
+
+        let alice_eph_pub = alice.generate_ephemeral();
+        let bob_eph_pub = bob.generate_ephemeral();
+
+        let alice_session = alice.derive_session(&bob_eph_pub).unwrap();
+        let bob_session = bob.derive_session(&alice_eph_pub).unwrap();
+
+        let alice_sas = alice_session.sas_code();
+        let bob_sas = bob_session.sas_code();
+
+        assert!(alice_sas.is_some(), "Alice should have SAS");
+        assert!(bob_sas.is_some(), "Bob should have SAS");
+        assert_eq!(alice_sas, bob_sas, "SAS codes must match between peers");
+        assert!(alice_sas.unwrap() < 10000, "SAS should be 4 digits");
+    }
+
+    #[test]
+    fn sas_differs_for_different_peers() {
+        let mut alice = WarzoneKeyExchange::from_identity_seed(&[0xAA; 32]);
+        let mut bob = WarzoneKeyExchange::from_identity_seed(&[0xBB; 32]);
+        let mut eve = WarzoneKeyExchange::from_identity_seed(&[0xEE; 32]);
+
+        let alice_eph = alice.generate_ephemeral();
+        let bob_eph = bob.generate_ephemeral();
+        let eve_eph = eve.generate_ephemeral();
+
+        let alice_bob_session = alice.derive_session(&bob_eph).unwrap();
+
+        // Eve does separate handshake with Bob (MITM scenario)
+        let eve_bob_session = eve.derive_session(&bob_eph).unwrap();
+
+        // SAS codes should differ — Eve's session has different shared secret
+        assert_ne!(
+            alice_bob_session.sas_code(),
+            eve_bob_session.sas_code(),
+            "MITM session should produce different SAS"
+        );
+    }
 }

crates/wzp-crypto/src/session.rs

@@ -26,6 +26,8 @@ pub struct ChaChaSession {
     rekey_mgr: RekeyManager,
     /// Pending ephemeral secret for rekey (stored until peer responds).
     pending_rekey_secret: Option<StaticSecret>,
+    /// Short Authentication String (4-digit code for verbal verification).
+    sas_code: Option<u32>,
 }
 
 impl ChaChaSession {
@@ -46,9 +48,15 @@ impl ChaChaSession {
             recv_seq: 0,
             rekey_mgr: RekeyManager::new(shared_secret),
             pending_rekey_secret: None,
+            sas_code: None,
         }
     }
 
+    /// Set the SAS code (called by key exchange after derivation).
+    pub fn set_sas(&mut self, code: u32) {
+        self.sas_code = Some(code);
+    }
+
     /// Install a new key (after rekeying).
     fn install_key(&mut self, new_key: [u8; 32]) {
         use sha2::Digest;
@@ -136,6 +144,10 @@ impl CryptoSession for ChaChaSession {
 
         Ok(())
     }
+
+    fn sas_code(&self) -> Option<u32> {
+        self.sas_code
+    }
 }
 
 #[cfg(test)]

crates/wzp-fec/src/decoder.rs

@@ -1,6 +1,7 @@
 //! RaptorQ FEC decoder — reassembles source blocks from received source and repair symbols.
 
 use std::collections::HashMap;
+use std::time::Instant;
 
 use raptorq::{EncodingPacket, ObjectTransmissionInformation, PayloadId, SourceBlockDecoder};
 use wzp_proto::error::FecError;
@@ -9,6 +10,9 @@ use wzp_proto::FecDecoder;
 /// Length prefix size (u16 little-endian), must match encoder.
 const LEN_PREFIX: usize = 2;
 
+/// Decoded blocks older than this are eligible for reuse by a new sender.
+const BLOCK_STALE_SECS: u64 = 2;
+
 /// State for one in-flight block being decoded.
 struct BlockState {
     /// Number of source symbols expected.
@@ -21,6 +25,8 @@ struct BlockState {
     decoded: bool,
     /// Cached decoded result.
     result: Option<Vec<Vec<u8>>>,
+    /// When this block was last decoded (for staleness check).
+    decoded_at: Option<Instant>,
 }
 
 /// RaptorQ-based FEC decoder that handles multiple concurrent blocks.
@@ -58,6 +64,7 @@ impl RaptorQFecDecoder {
             symbol_size: self.symbol_size,
             decoded: false,
             result: None,
+            decoded_at: None,
         })
     }
 }
@@ -74,8 +81,20 @@ impl FecDecoder for RaptorQFecDecoder {
         let block = self.get_or_create_block(block_id);
 
         if block.decoded {
-            // Already decoded, ignore additional symbols.
+            // If the block was decoded recently, skip (normal duplicate).
-            return Ok(());
+            // If it's stale (>2s), a new sender is reusing this block_id — reset it.
+            if let Some(at) = block.decoded_at {
+                if at.elapsed().as_secs() >= BLOCK_STALE_SECS {
+                    block.decoded = false;
+                    block.result = None;
+                    block.decoded_at = None;
+                    block.packets.clear();
+                } else {
+                    return Ok(());
+                }
+            } else {
+                return Ok(());
+            }
         }
 
         // Data should already be at symbol_size (length-prefixed and padded by the encoder).
@@ -132,6 +151,7 @@ impl FecDecoder for RaptorQFecDecoder {
 
                 let block = self.blocks.get_mut(&block_id).unwrap();
                 block.decoded = true;
+                block.decoded_at = Some(Instant::now());
                 block.result = Some(frames.clone());
                 Ok(Some(frames))
             }

crates/wzp-proto/src/codec_id.rs

@@ -18,6 +18,12 @@ pub enum CodecId {
     Codec2_1200 = 4,
     /// Comfort noise descriptor (silence suppression)
     ComfortNoise = 5,
+    /// Opus at 32kbps (studio low)
+    Opus32k = 6,
+    /// Opus at 48kbps (studio)
+    Opus48k = 7,
+    /// Opus at 64kbps (studio high)
+    Opus64k = 8,
 }
 
 impl CodecId {
@@ -27,6 +33,9 @@ impl CodecId {
             Self::Opus24k => 24_000,
             Self::Opus16k => 16_000,
             Self::Opus6k => 6_000,
+            Self::Opus32k => 32_000,
+            Self::Opus48k => 48_000,
+            Self::Opus64k => 64_000,
             Self::Codec2_3200 => 3_200,
             Self::Codec2_1200 => 1_200,
             Self::ComfortNoise => 0,
@@ -36,8 +45,7 @@ impl CodecId {
     /// Preferred frame duration in milliseconds.
     pub const fn frame_duration_ms(self) -> u8 {
         match self {
-            Self::Opus24k => 20,
+            Self::Opus24k | Self::Opus16k | Self::Opus32k | Self::Opus48k | Self::Opus64k => 20,
-            Self::Opus16k => 20,
             Self::Opus6k => 40,
             Self::Codec2_3200 => 20,
             Self::Codec2_1200 => 40,
@@ -48,7 +56,8 @@ impl CodecId {
     /// Sample rate expected by this codec.
     pub const fn sample_rate_hz(self) -> u32 {
         match self {
-            Self::Opus24k | Self::Opus16k | Self::Opus6k => 48_000,
+            Self::Opus24k | Self::Opus16k | Self::Opus6k
+            | Self::Opus32k | Self::Opus48k | Self::Opus64k => 48_000,
             Self::Codec2_3200 | Self::Codec2_1200 => 8_000,
             Self::ComfortNoise => 48_000,
         }
@@ -63,6 +72,9 @@ impl CodecId {
             3 => Some(Self::Codec2_3200),
             4 => Some(Self::Codec2_1200),
             5 => Some(Self::ComfortNoise),
+            6 => Some(Self::Opus32k),
+            7 => Some(Self::Opus48k),
+            8 => Some(Self::Opus64k),
             _ => None,
         }
     }
@@ -71,6 +83,12 @@ impl CodecId {
     pub const fn to_wire(self) -> u8 {
         self as u8
     }
+
+    /// Returns true if this is an Opus variant.
+    pub const fn is_opus(self) -> bool {
+        matches!(self, Self::Opus6k | Self::Opus16k | Self::Opus24k
+            | Self::Opus32k | Self::Opus48k | Self::Opus64k)
+    }
 }
 
 /// Describes the complete quality configuration for a call session.
@@ -111,6 +129,30 @@ impl QualityProfile {
         frames_per_block: 8,
     };
 
+    /// Studio low: Opus 32kbps, minimal FEC.
+    pub const STUDIO_32K: Self = Self {
+        codec: CodecId::Opus32k,
+        fec_ratio: 0.1,
+        frame_duration_ms: 20,
+        frames_per_block: 5,
+    };
+
+    /// Studio: Opus 48kbps, minimal FEC.
+    pub const STUDIO_48K: Self = Self {
+        codec: CodecId::Opus48k,
+        fec_ratio: 0.1,
+        frame_duration_ms: 20,
+        frames_per_block: 5,
+    };
+
+    /// Studio high: Opus 64kbps, minimal FEC.
+    pub const STUDIO_64K: Self = Self {
+        codec: CodecId::Opus64k,
+        fec_ratio: 0.1,
+        frame_duration_ms: 20,
+        frames_per_block: 5,
+    };
+
     /// Estimated total bandwidth in kbps including FEC overhead.
     pub fn total_bitrate_kbps(&self) -> f32 {
         let base = self.codec.bitrate_bps() as f32 / 1000.0;

crates/wzp-proto/src/jitter.rs

@@ -1,4 +1,5 @@
 use std::collections::BTreeMap;
+use std::time::{Duration, Instant};
 
 use crate::packet::MediaPacket;
 
@@ -20,19 +21,29 @@ pub struct AdaptivePlayoutDelay {
     max_delay: usize,
     /// Exponential moving average of inter-packet arrival jitter (ms).
     jitter_ema: f64,
-    /// EMA smoothing factor (0.0-1.0, lower = smoother).
+    /// EMA smoothing factor for jitter increases (fast reaction).
-    alpha: f64,
+    alpha_up: f64,
+    /// EMA smoothing factor for jitter decreases (slow decay).
+    alpha_down: f64,
     /// Last packet arrival timestamp (for computing inter-arrival jitter).
     last_arrival_ms: Option<u64>,
     /// Last packet expected timestamp.
     last_expected_ms: Option<u64>,
+    /// Safety margin added to jitter-derived target (in packets).
+    safety_margin: f64,
+    /// Instant when a jitter spike was detected (handoff detection).
+    spike_detected_at: Option<Instant>,
+    /// Duration to hold max_delay after a spike is detected.
+    spike_cooldown: Duration,
+    /// Multiplier of jitter_ema that constitutes a spike.
+    spike_threshold_multiplier: f64,
 }
 
 /// Frame duration in milliseconds (20ms Opus/Codec2 frames).
 const FRAME_DURATION_MS: f64 = 20.0;
-/// Safety margin added to jitter-derived target (in packets).
+/// Default safety margin in packets.
-const SAFETY_MARGIN_PACKETS: f64 = 2.0;
+const DEFAULT_SAFETY_MARGIN: f64 = 2.0;
-/// Default EMA smoothing factor.
+/// Default EMA smoothing factor (used for both up/down in non-mobile mode).
 const DEFAULT_ALPHA: f64 = 0.05;
 
 impl AdaptivePlayoutDelay {
@@ -46,9 +57,14 @@ impl AdaptivePlayoutDelay {
             min_delay,
             max_delay,
             jitter_ema: 0.0,
-            alpha: DEFAULT_ALPHA,
+            alpha_up: DEFAULT_ALPHA,
+            alpha_down: DEFAULT_ALPHA,
             last_arrival_ms: None,
             last_expected_ms: None,
+            safety_margin: DEFAULT_SAFETY_MARGIN,
+            spike_detected_at: None,
+            spike_cooldown: Duration::from_secs(2),
+            spike_threshold_multiplier: 3.0,
         }
     }
 
@@ -64,13 +80,38 @@ impl AdaptivePlayoutDelay {
             let expected_delta = expected_ms as f64 - last_expected as f64;
             let jitter = (actual_delta - expected_delta).abs();
 
-            // Update EMA
+            // Spike detection: check before EMA update
-            self.jitter_ema = self.alpha * jitter + (1.0 - self.alpha) * self.jitter_ema;
+            if self.jitter_ema > 0.0
+                && jitter > self.jitter_ema * self.spike_threshold_multiplier
+            {
+                self.spike_detected_at = Some(Instant::now());
+            }
 
-            // Convert jitter estimate to target delay in packets
+            // Asymmetric EMA update
-            let raw_target = (self.jitter_ema / FRAME_DURATION_MS).ceil() + SAFETY_MARGIN_PACKETS;
+            let alpha = if jitter > self.jitter_ema {
-            self.target_delay =
+                self.alpha_up
-                (raw_target as usize).clamp(self.min_delay, self.max_delay);
+            } else {
+                self.alpha_down
+            };
+            self.jitter_ema = alpha * jitter + (1.0 - alpha) * self.jitter_ema;
+
+            // Check if spike cooldown has expired
+            if let Some(spike_time) = self.spike_detected_at {
+                if spike_time.elapsed() >= self.spike_cooldown {
+                    self.spike_detected_at = None;
+                }
+            }
+
+            // If within spike cooldown, return max_delay
+            if self.spike_detected_at.is_some() {
+                self.target_delay = self.max_delay;
+            } else {
+                // Convert jitter estimate to target delay in packets
+                let raw_target =
+                    (self.jitter_ema / FRAME_DURATION_MS).ceil() + self.safety_margin;
+                self.target_delay =
+                    (raw_target as usize).clamp(self.min_delay, self.max_delay);
+            }
         }
 
         self.last_arrival_ms = Some(arrival_ms);
@@ -87,6 +128,28 @@ impl AdaptivePlayoutDelay {
     pub fn jitter_estimate_ms(&self) -> f64 {
         self.jitter_ema
     }
+
+    /// Enable or disable mobile mode, adjusting parameters for cellular networks.
+    ///
+    /// Mobile mode uses:
+    /// - Asymmetric alpha (fast up=0.3, slow down=0.02) for quicker spike detection
+    /// - Higher safety margin (3.0 packets) to absorb handoff jitter
+    /// - Spike detection with 2-second cooldown at 3x threshold
+    pub fn set_mobile_mode(&mut self, enabled: bool) {
+        if enabled {
+            self.safety_margin = 3.0;
+            self.alpha_up = 0.3;
+            self.alpha_down = 0.02;
+            self.spike_threshold_multiplier = 3.0;
+            self.spike_cooldown = Duration::from_secs(2);
+        } else {
+            self.safety_margin = DEFAULT_SAFETY_MARGIN;
+            self.alpha_up = DEFAULT_ALPHA;
+            self.alpha_down = DEFAULT_ALPHA;
+            self.spike_threshold_multiplier = 3.0;
+            self.spike_cooldown = Duration::from_secs(2);
+        }
+    }
 }
 
 // ---------------------------------------------------------------------------
@@ -210,10 +273,21 @@ impl JitterBuffer {
             return;
         }
 
-        // Check if packet is too old (already played out)
+        // Check if packet is too old (already played out).
+        // A backward jump of >100 seq (~2s at 50fps) indicates a new sender in a
+        // federation room — reset instead of dropping.
         if self.stats.packets_played > 0 && seq_before(seq, self.next_playout_seq) {
-            self.stats.packets_late += 1;
+            let backward_distance = self.next_playout_seq.wrapping_sub(seq);
-            return;
+            tracing::warn!(seq, next = self.next_playout_seq, backward_distance, "jitter: backward seq detected");
+            if backward_distance > 100 {
+                tracing::info!(seq, next = self.next_playout_seq, "jitter: RESET — new sender detected");
+                self.buffer.clear();
+                self.next_playout_seq = seq;
+                self.stats.packets_late = 0;
+            } else {
+                self.stats.packets_late += 1;
+                return;
+            }
         }
 
         // If we haven't started playout yet, adjust next_playout_seq to earliest known
@@ -349,10 +423,21 @@ impl JitterBuffer {
             return;
         }
 
-        // Check if packet is too old (already played out)
+        // Check if packet is too old (already played out).
+        // A backward jump of >100 seq (~2s at 50fps) indicates a new sender in a
+        // federation room — reset instead of dropping.
         if self.stats.packets_played > 0 && seq_before(seq, self.next_playout_seq) {
-            self.stats.packets_late += 1;
+            let backward_distance = self.next_playout_seq.wrapping_sub(seq);
-            return;
+            tracing::warn!(seq, next = self.next_playout_seq, backward_distance, "jitter: backward seq detected");
+            if backward_distance > 100 {
+                tracing::info!(seq, next = self.next_playout_seq, "jitter: RESET — new sender detected");
+                self.buffer.clear();
+                self.next_playout_seq = seq;
+                self.stats.packets_late = 0;
+            } else {
+                self.stats.packets_late += 1;
+                return;
+            }
         }
 
         // If we haven't started playout yet, adjust next_playout_seq to earliest known
@@ -391,6 +476,11 @@ impl JitterBuffer {
         self.adaptive.as_ref()
     }
 
+    /// Get a mutable reference to the adaptive playout delay estimator.
+    pub fn adaptive_delay_mut(&mut self) -> Option<&mut AdaptivePlayoutDelay> {
+        self.adaptive.as_mut()
+    }
+
     /// Adjust target depth based on observed jitter.
     pub fn set_target_depth(&mut self, depth: usize) {
         self.target_depth = depth.min(self.max_depth);
@@ -720,4 +810,29 @@ mod tests {
         let ad = jb.adaptive_delay().unwrap();
         assert_eq!(ad.target_delay(), 3);
     }
+
+    // ---------------------------------------------------------------
+    // Mobile mode tests
+    // ---------------------------------------------------------------
+
+    #[test]
+    fn mobile_mode_increases_safety_margin() {
+        let mut apd = AdaptivePlayoutDelay::new(3, 50);
+        apd.set_mobile_mode(true);
+        assert_eq!(apd.safety_margin, 3.0);
+        assert_eq!(apd.alpha_up, 0.3);
+        assert_eq!(apd.alpha_down, 0.02);
+
+        apd.set_mobile_mode(false);
+        assert_eq!(apd.safety_margin, DEFAULT_SAFETY_MARGIN);
+        assert_eq!(apd.alpha_up, DEFAULT_ALPHA);
+        assert_eq!(apd.alpha_down, DEFAULT_ALPHA);
+    }
+
+    #[test]
+    fn mobile_mode_accessible_via_jitter_buffer() {
+        let mut jb = JitterBuffer::new_adaptive(3, 50);
+        jb.adaptive_delay_mut().unwrap().set_mobile_mode(true);
+        assert_eq!(jb.adaptive_delay().unwrap().safety_margin, 3.0);
+    }
 }

crates/wzp-proto/src/lib.rs

@@ -25,10 +25,11 @@ pub mod traits;
 pub use codec_id::{CodecId, QualityProfile};
 pub use error::*;
 pub use packet::{
-    HangupReason, MediaHeader, MediaPacket, MiniFrameContext, MiniHeader, QualityReport,
+    CallAcceptMode, HangupReason, MediaHeader, MediaPacket, MiniFrameContext, MiniHeader,
-    SignalMessage, TrunkEntry, TrunkFrame, FRAME_TYPE_FULL, FRAME_TYPE_MINI,
+    QualityReport, RoomParticipant, SignalMessage, TrunkEntry, TrunkFrame, FRAME_TYPE_FULL,
+    FRAME_TYPE_MINI,
 };
 pub use bandwidth::{BandwidthEstimator, CongestionState};
-pub use quality::{AdaptiveQualityController, Tier};
+pub use quality::{AdaptiveQualityController, NetworkContext, Tier};
 pub use session::{Session, SessionEvent, SessionState};
 pub use traits::*;

crates/wzp-proto/src/packet.rs

@@ -548,6 +548,9 @@ pub enum SignalMessage {
         signature: Vec<u8>,
         /// Supported quality profiles.
         supported_profiles: Vec<crate::QualityProfile>,
+        /// Optional display name set by the caller.
+        #[serde(default)]
+        alias: Option<String>,
     },
 
     /// Call acceptance (analogous to Warzone's WireMessage::CallAnswer).
@@ -645,6 +648,133 @@ pub enum SignalMessage {
         session_id: String,
         room_name: String,
     },
+
+    /// Room membership update — sent by relay to all participants when someone joins or leaves.
+    RoomUpdate {
+        /// Current participant count.
+        count: u32,
+        /// List of participants currently in the room.
+        participants: Vec<RoomParticipant>,
+    },
+
+    // ── Federation signals (relay-to-relay) ──
+
+    /// Federation: initial handshake — the connecting relay identifies itself.
+    FederationHello {
+        /// TLS certificate fingerprint of the connecting relay.
+        tls_fingerprint: String,
+    },
+
+    /// Federation: this relay now has local participants in a global room.
+    GlobalRoomActive {
+        room: String,
+        /// Participants on the announcing relay (for federated presence).
+        #[serde(default)]
+        participants: Vec<RoomParticipant>,
+    },
+
+    /// Federation: this relay's last local participant left a global room.
+    GlobalRoomInactive {
+        room: String,
+    },
+
+    // ── Direct calling signals (client ↔ relay signaling) ──
+
+    /// Register on relay for direct calls. Sent on `_signal` connections
+    /// after optional AuthToken.
+    RegisterPresence {
+        /// Client's Ed25519 identity public key.
+        identity_pub: [u8; 32],
+        /// Signature over ("register-presence" || identity_pub).
+        signature: Vec<u8>,
+        /// Optional display name.
+        alias: Option<String>,
+    },
+
+    /// Relay confirms presence registration.
+    RegisterPresenceAck {
+        success: bool,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        error: Option<String>,
+    },
+
+    /// Direct call offer routed through the relay to a specific peer.
+    DirectCallOffer {
+        /// Caller's fingerprint.
+        caller_fingerprint: String,
+        /// Caller's display name.
+        caller_alias: Option<String>,
+        /// Target's fingerprint.
+        target_fingerprint: String,
+        /// Unique call session ID (UUID).
+        call_id: String,
+        /// Caller's Ed25519 identity pub.
+        identity_pub: [u8; 32],
+        /// Caller's ephemeral X25519 pub (for key exchange on media connect).
+        ephemeral_pub: [u8; 32],
+        /// Signature over (ephemeral_pub || target_fingerprint || call_id).
+        signature: Vec<u8>,
+        /// Supported quality profiles.
+        supported_profiles: Vec<crate::QualityProfile>,
+    },
+
+    /// Callee's response to a direct call.
+    DirectCallAnswer {
+        call_id: String,
+        /// How the callee accepts (or rejects).
+        accept_mode: CallAcceptMode,
+        /// Callee's identity pub (present when accepting).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        identity_pub: Option<[u8; 32]>,
+        /// Callee's ephemeral pub (present when accepting).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        ephemeral_pub: Option<[u8; 32]>,
+        /// Signature (present when accepting).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        signature: Option<Vec<u8>>,
+        /// Chosen quality profile (present when accepting).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        chosen_profile: Option<crate::QualityProfile>,
+    },
+
+    /// Relay tells both parties: media room is ready.
+    CallSetup {
+        call_id: String,
+        /// Room name on the relay for the media session (e.g., "_call:a1b2c3d4").
+        room: String,
+        /// Relay address for the QUIC media connection.
+        relay_addr: String,
+    },
+
+    /// Ringing notification (relay → caller, callee received the offer).
+    CallRinging {
+        call_id: String,
+    },
+}
+
+/// How the callee responds to a direct call.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum CallAcceptMode {
+    /// Reject the call.
+    Reject,
+    /// Accept with trust — in Phase 2, this enables P2P (reveals IP).
+    /// In Phase 1, behaves the same as AcceptGeneric.
+    AcceptTrusted,
+    /// Accept with privacy — relay always mediates media.
+    AcceptGeneric,
+}
+
+/// A participant entry in a RoomUpdate message.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct RoomParticipant {
+    /// Identity fingerprint (hex string, stable across reconnects if seed is persisted).
+    pub fingerprint: String,
+    /// Optional display name set by the client.
+    pub alias: Option<String>,
+    /// Relay label — identifies which relay this participant is connected to.
+    /// None for local participants, Some("Relay B") for federated.
+    #[serde(default)]
+    pub relay_label: Option<String>,
 }
 
 /// Reasons for ending a call.

crates/wzp-proto/src/quality.rs

@@ -1,4 +1,5 @@
 use std::collections::VecDeque;
+use std::time::{Duration, Instant};
 
 use crate::packet::QualityReport;
 use crate::traits::QualityController;
@@ -24,24 +25,71 @@ impl Tier {
         }
     }
 
-    /// Determine which tier a quality report belongs to.
+    /// Determine which tier a quality report belongs to (default/WiFi thresholds).
     pub fn classify(report: &QualityReport) -> Self {
+        Self::classify_with_context(report, NetworkContext::Unknown)
+    }
+
+    /// Classify with network-context-aware thresholds.
+    pub fn classify_with_context(report: &QualityReport, context: NetworkContext) -> Self {
         let loss = report.loss_percent();
         let rtt = report.rtt_ms();
 
-        if loss > 40.0 || rtt > 600 {
+        match context {
-            Self::Catastrophic
+            NetworkContext::CellularLte
-        } else if loss > 10.0 || rtt > 400 {
+            | NetworkContext::Cellular5g
-            Self::Degraded
+            | NetworkContext::Cellular3g => {
-        } else {
+                // Tighter thresholds for cellular networks
-            Self::Good
+                if loss > 25.0 || rtt > 500 {
+                    Self::Catastrophic
+                } else if loss > 8.0 || rtt > 300 {
+                    Self::Degraded
+                } else {
+                    Self::Good
+                }
+            }
+            NetworkContext::WiFi | NetworkContext::Unknown => {
+                // Original thresholds
+                if loss > 40.0 || rtt > 600 {
+                    Self::Catastrophic
+                } else if loss > 10.0 || rtt > 400 {
+                    Self::Degraded
+                } else {
+                    Self::Good
+                }
+            }
         }
     }
+
+    /// Return the next lower (worse) tier, or None if already at the worst.
+    pub fn downgrade(self) -> Option<Tier> {
+        match self {
+            Self::Good => Some(Self::Degraded),
+            Self::Degraded => Some(Self::Catastrophic),
+            Self::Catastrophic => None,
+        }
+    }
+}
+
+/// Describes the network transport type for context-aware quality decisions.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum NetworkContext {
+    WiFi,
+    CellularLte,
+    Cellular5g,
+    Cellular3g,
+    Unknown,
+}
+
+impl Default for NetworkContext {
+    fn default() -> Self {
+        Self::Unknown
+    }
 }
 
 /// Adaptive quality controller with hysteresis to prevent tier flapping.
 ///
-/// - Downgrade: 3 consecutive reports in a worse tier
+/// - Downgrade: 3 consecutive reports in a worse tier (2 on cellular)
 /// - Upgrade: 10 consecutive reports in a better tier
 pub struct AdaptiveQualityController {
     current_tier: Tier,
@@ -54,14 +102,26 @@ pub struct AdaptiveQualityController {
     history: VecDeque<QualityReport>,
     /// Whether the profile was manually forced (disables adaptive logic).
     forced: bool,
+    /// Current network context for threshold selection.
+    network_context: NetworkContext,
+    /// FEC boost expiry time (set during network handoff).
+    fec_boost_until: Option<Instant>,
+    /// FEC boost amount to add during handoff recovery window.
+    fec_boost_amount: f32,
 }
 
 /// Threshold for downgrading (fast reaction to degradation).
 const DOWNGRADE_THRESHOLD: u32 = 3;
+/// Threshold for downgrading on cellular networks (even faster).
+const CELLULAR_DOWNGRADE_THRESHOLD: u32 = 2;
 /// Threshold for upgrading (slow, cautious improvement).
 const UPGRADE_THRESHOLD: u32 = 10;
 /// Maximum history window size.
 const HISTORY_SIZE: usize = 20;
+/// Default FEC boost amount during handoff recovery.
+const DEFAULT_FEC_BOOST: f32 = 0.2;
+/// Duration of FEC boost after a network handoff.
+const FEC_BOOST_DURATION_SECS: u64 = 10;
 
 impl AdaptiveQualityController {
     pub fn new() -> Self {
@@ -72,6 +132,9 @@ impl AdaptiveQualityController {
             consecutive_down: 0,
             history: VecDeque::with_capacity(HISTORY_SIZE),
             forced: false,
+            network_context: NetworkContext::default(),
+            fec_boost_until: None,
+            fec_boost_amount: DEFAULT_FEC_BOOST,
         }
     }
 
@@ -80,6 +143,69 @@ impl AdaptiveQualityController {
         self.current_tier
     }
 
+    /// Get the current network context.
+    pub fn network_context(&self) -> NetworkContext {
+        self.network_context
+    }
+
+    /// Signal a network transport change (e.g., WiFi to cellular handoff).
+    ///
+    /// When switching from WiFi to any cellular type, this preemptively
+    /// downgrades one quality tier and activates a temporary FEC boost.
+    pub fn signal_network_change(&mut self, new_context: NetworkContext) {
+        let old = self.network_context;
+        self.network_context = new_context;
+
+        let new_is_cellular = matches!(
+            new_context,
+            NetworkContext::CellularLte | NetworkContext::Cellular5g | NetworkContext::Cellular3g
+        );
+
+        // If switching from WiFi to cellular, preemptively downgrade one tier
+        if old == NetworkContext::WiFi && new_is_cellular {
+            if let Some(lower_tier) = self.current_tier.downgrade() {
+                self.current_tier = lower_tier;
+                self.current_profile = lower_tier.profile();
+            }
+            // Reset counters to avoid stale hysteresis state
+            self.consecutive_up = 0;
+            self.consecutive_down = 0;
+            // Un-force so adaptive logic resumes
+            self.forced = false;
+        }
+
+        // Activate FEC boost for any network change
+        self.fec_boost_until = Some(Instant::now() + Duration::from_secs(FEC_BOOST_DURATION_SECS));
+    }
+
+    /// Returns the FEC boost amount if within the handoff recovery window, 0.0 otherwise.
+    ///
+    /// Callers should add this to their base FEC ratio during the boost window.
+    pub fn fec_boost(&self) -> f32 {
+        if let Some(until) = self.fec_boost_until {
+            if Instant::now() < until {
+                return self.fec_boost_amount;
+            }
+        }
+        0.0
+    }
+
+    /// Reset the hysteresis counters.
+    pub fn reset_counters(&mut self) {
+        self.consecutive_up = 0;
+        self.consecutive_down = 0;
+    }
+
+    /// Get the effective downgrade threshold based on network context.
+    fn downgrade_threshold(&self) -> u32 {
+        match self.network_context {
+            NetworkContext::CellularLte
+            | NetworkContext::Cellular5g
+            | NetworkContext::Cellular3g => CELLULAR_DOWNGRADE_THRESHOLD,
+            _ => DOWNGRADE_THRESHOLD,
+        }
+    }
+
     fn try_transition(&mut self, observed_tier: Tier) -> Option<QualityProfile> {
         if observed_tier == self.current_tier {
             self.consecutive_up = 0;
@@ -96,7 +222,7 @@ impl AdaptiveQualityController {
         if is_worse {
             self.consecutive_up = 0;
             self.consecutive_down += 1;
-            if self.consecutive_down >= DOWNGRADE_THRESHOLD {
+            if self.consecutive_down >= self.downgrade_threshold() {
                 self.current_tier = observed_tier;
                 self.current_profile = observed_tier.profile();
                 self.consecutive_down = 0;
@@ -142,7 +268,7 @@ impl QualityController for AdaptiveQualityController {
             return None;
         }
 
-        let observed = Tier::classify(report);
+        let observed = Tier::classify_with_context(report, self.network_context);
         self.try_transition(observed)
     }
 
@@ -246,4 +372,110 @@ mod tests {
         assert_eq!(Tier::classify(&make_report(50.0, 200)), Tier::Catastrophic);
         assert_eq!(Tier::classify(&make_report(5.0, 700)), Tier::Catastrophic);
     }
+
+    // ---------------------------------------------------------------
+    // Network context tests
+    // ---------------------------------------------------------------
+
+    #[test]
+    fn cellular_tighter_thresholds() {
+        // 12% loss: Good on WiFi, Degraded on cellular
+        let report = make_report(12.0, 200);
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::WiFi),
+            Tier::Degraded
+        );
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::CellularLte),
+            Tier::Degraded
+        );
+
+        // 9% loss: Good on WiFi, Degraded on cellular
+        let report = make_report(9.0, 200);
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::WiFi),
+            Tier::Good
+        );
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::CellularLte),
+            Tier::Degraded
+        );
+
+        // 30% loss: Degraded on WiFi, Catastrophic on cellular
+        let report = make_report(30.0, 200);
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::WiFi),
+            Tier::Degraded
+        );
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::Cellular3g),
+            Tier::Catastrophic
+        );
+    }
+
+    #[test]
+    fn cellular_rtt_thresholds() {
+        // RTT 350ms: Good on WiFi, Degraded on cellular
+        let report = make_report(2.0, 348); // rtt_4ms rounds so use 348
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::WiFi),
+            Tier::Good
+        );
+        assert_eq!(
+            Tier::classify_with_context(&report, NetworkContext::CellularLte),
+            Tier::Degraded
+        );
+    }
+
+    #[test]
+    fn cellular_faster_downgrade() {
+        let mut ctrl = AdaptiveQualityController::new();
+        ctrl.signal_network_change(NetworkContext::CellularLte);
+        // Reset tier back to Good for testing downgrade threshold
+        ctrl.current_tier = Tier::Good;
+        ctrl.current_profile = Tier::Good.profile();
+
+        // On cellular, downgrade threshold is 2 instead of 3
+        let bad = make_report(50.0, 200);
+        assert!(ctrl.observe(&bad).is_none()); // 1st bad
+        let result = ctrl.observe(&bad); // 2nd bad — should trigger on cellular
+        assert!(result.is_some());
+    }
+
+    #[test]
+    fn signal_network_change_preemptive_downgrade() {
+        let mut ctrl = AdaptiveQualityController::new();
+        assert_eq!(ctrl.tier(), Tier::Good);
+
+        // Switch from WiFi to cellular
+        ctrl.network_context = NetworkContext::WiFi;
+        ctrl.signal_network_change(NetworkContext::CellularLte);
+
+        // Should have downgraded one tier: Good -> Degraded
+        assert_eq!(ctrl.tier(), Tier::Degraded);
+    }
+
+    #[test]
+    fn signal_network_change_fec_boost() {
+        let mut ctrl = AdaptiveQualityController::new();
+        assert_eq!(ctrl.fec_boost(), 0.0);
+
+        ctrl.signal_network_change(NetworkContext::CellularLte);
+
+        // FEC boost should be active
+        assert!(ctrl.fec_boost() > 0.0);
+        assert_eq!(ctrl.fec_boost(), DEFAULT_FEC_BOOST);
+    }
+
+    #[test]
+    fn tier_downgrade() {
+        assert_eq!(Tier::Good.downgrade(), Some(Tier::Degraded));
+        assert_eq!(Tier::Degraded.downgrade(), Some(Tier::Catastrophic));
+        assert_eq!(Tier::Catastrophic.downgrade(), None);
+    }
+
+    #[test]
+    fn network_context_default() {
+        assert_eq!(NetworkContext::default(), NetworkContext::Unknown);
+    }
 }

crates/wzp-proto/src/traits.rs

@@ -132,6 +132,14 @@ pub trait CryptoSession: Send + Sync {
     fn overhead(&self) -> usize {
         16 // ChaCha20-Poly1305 tag
     }
+
+    /// Short Authentication String (SAS) — 4-digit code for verbal verification.
+    /// Both peers derive the same code from the shared secret + identity keys.
+    /// If a MITM relay is intercepting, the codes will differ.
+    /// Returns None if SAS was not computed (e.g., relay-side sessions).
+    fn sas_code(&self) -> Option<u32> {
+        None
+    }
 }
 
 /// Key exchange using the Warzone identity model.

crates/wzp-relay/Cargo.toml

@@ -28,6 +28,9 @@ prometheus = "0.13"
 axum = { version = "0.7", default-features = false, features = ["tokio", "http1", "ws"] }
 tower-http = { version = "0.6", features = ["fs"] }
 futures-util = "0.3"
+dirs = "6"
+sha2 = { workspace = true }
+chrono = "0.4"
 
 [[bin]]
 name = "wzp-relay"

crates/wzp-relay/build.rs

@@ -0,0 +1,18 @@
+use std::process::Command;
+
+fn main() {
+    // Get git hash at build time
+    let output = Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output();
+
+    let hash = match output {
+        Ok(o) if o.status.success() => {
+            String::from_utf8_lossy(&o.stdout).trim().to_string()
+        }
+        _ => "unknown".to_string(),
+    };
+
+    println!("cargo:rustc-env=WZP_BUILD_HASH={hash}");
+    println!("cargo:rerun-if-changed=.git/HEAD");
+}

crates/wzp-relay/src/call_registry.rs

@@ -0,0 +1,199 @@
+//! Direct call state tracking.
+//!
+//! Manages the lifecycle of 1:1 direct calls placed via the `_signal` channel.
+//! Each call goes through: Pending → Ringing → Active → Ended.
+
+use std::collections::HashMap;
+use std::time::{Duration, Instant};
+
+/// State of a direct call.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum DirectCallState {
+    /// Offer sent to callee, waiting for response.
+    Pending,
+    /// Callee acknowledged, ringing.
+    Ringing,
+    /// Call accepted, media room active.
+    Active,
+    /// Call ended (hangup, reject, timeout, or error).
+    Ended,
+}
+
+/// A tracked direct call between two users.
+pub struct DirectCall {
+    pub call_id: String,
+    pub caller_fingerprint: String,
+    pub callee_fingerprint: String,
+    pub state: DirectCallState,
+    pub accept_mode: Option<wzp_proto::CallAcceptMode>,
+    /// Private room name (set when accepted).
+    pub room_name: Option<String>,
+    pub created_at: Instant,
+    pub answered_at: Option<Instant>,
+    pub ended_at: Option<Instant>,
+}
+
+/// Registry of active direct calls.
+pub struct CallRegistry {
+    calls: HashMap<String, DirectCall>,
+}
+
+impl CallRegistry {
+    pub fn new() -> Self {
+        Self {
+            calls: HashMap::new(),
+        }
+    }
+
+    /// Create a new pending call. Returns the call_id.
+    pub fn create_call(&mut self, call_id: String, caller_fp: String, callee_fp: String) -> &DirectCall {
+        let call = DirectCall {
+            call_id: call_id.clone(),
+            caller_fingerprint: caller_fp,
+            callee_fingerprint: callee_fp,
+            state: DirectCallState::Pending,
+            accept_mode: None,
+            room_name: None,
+            created_at: Instant::now(),
+            answered_at: None,
+            ended_at: None,
+        };
+        self.calls.insert(call_id.clone(), call);
+        self.calls.get(&call_id).unwrap()
+    }
+
+    /// Get a call by ID.
+    pub fn get(&self, call_id: &str) -> Option<&DirectCall> {
+        self.calls.get(call_id)
+    }
+
+    /// Get a mutable call by ID.
+    pub fn get_mut(&mut self, call_id: &str) -> Option<&mut DirectCall> {
+        self.calls.get_mut(call_id)
+    }
+
+    /// Transition to Ringing state.
+    pub fn set_ringing(&mut self, call_id: &str) -> bool {
+        if let Some(call) = self.calls.get_mut(call_id) {
+            if call.state == DirectCallState::Pending {
+                call.state = DirectCallState::Ringing;
+                return true;
+            }
+        }
+        false
+    }
+
+    /// Transition to Active state.
+    pub fn set_active(&mut self, call_id: &str, mode: wzp_proto::CallAcceptMode, room: String) -> bool {
+        if let Some(call) = self.calls.get_mut(call_id) {
+            if call.state == DirectCallState::Pending || call.state == DirectCallState::Ringing {
+                call.state = DirectCallState::Active;
+                call.accept_mode = Some(mode);
+                call.room_name = Some(room);
+                call.answered_at = Some(Instant::now());
+                return true;
+            }
+        }
+        false
+    }
+
+    /// End a call.
+    pub fn end_call(&mut self, call_id: &str) -> Option<DirectCall> {
+        if let Some(call) = self.calls.get_mut(call_id) {
+            call.state = DirectCallState::Ended;
+            call.ended_at = Some(Instant::now());
+        }
+        self.calls.remove(call_id)
+    }
+
+    /// Find active/pending calls involving a fingerprint.
+    pub fn calls_for_fingerprint(&self, fp: &str) -> Vec<&DirectCall> {
+        self.calls.values()
+            .filter(|c| {
+                c.state != DirectCallState::Ended
+                    && (c.caller_fingerprint == fp || c.callee_fingerprint == fp)
+            })
+            .collect()
+    }
+
+    /// Find the peer's fingerprint in a call.
+    pub fn peer_fingerprint(&self, call_id: &str, my_fp: &str) -> Option<&str> {
+        self.calls.get(call_id).map(|c| {
+            if c.caller_fingerprint == my_fp {
+                c.callee_fingerprint.as_str()
+            } else {
+                c.caller_fingerprint.as_str()
+            }
+        })
+    }
+
+    /// Remove calls that have been pending longer than the timeout.
+    /// Returns call IDs of expired calls.
+    pub fn expire_stale(&mut self, timeout: Duration) -> Vec<DirectCall> {
+        let now = Instant::now();
+        let expired: Vec<String> = self.calls.iter()
+            .filter(|(_, c)| {
+                c.state == DirectCallState::Pending
+                    && now.duration_since(c.created_at) > timeout
+            })
+            .map(|(id, _)| id.clone())
+            .collect();
+
+        expired.into_iter()
+            .filter_map(|id| self.calls.remove(&id))
+            .collect()
+    }
+
+    /// Number of active (non-ended) calls.
+    pub fn active_count(&self) -> usize {
+        self.calls.values()
+            .filter(|c| c.state != DirectCallState::Ended)
+            .count()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn call_lifecycle() {
+        let mut reg = CallRegistry::new();
+        reg.create_call("c1".into(), "alice".into(), "bob".into());
+
+        assert_eq!(reg.get("c1").unwrap().state, DirectCallState::Pending);
+        assert!(reg.set_ringing("c1"));
+        assert_eq!(reg.get("c1").unwrap().state, DirectCallState::Ringing);
+
+        assert!(reg.set_active("c1", wzp_proto::CallAcceptMode::AcceptGeneric, "_call:c1".into()));
+        assert_eq!(reg.get("c1").unwrap().state, DirectCallState::Active);
+        assert_eq!(reg.get("c1").unwrap().room_name.as_deref(), Some("_call:c1"));
+
+        let ended = reg.end_call("c1").unwrap();
+        assert_eq!(ended.state, DirectCallState::Ended);
+        assert_eq!(reg.active_count(), 0);
+    }
+
+    #[test]
+    fn expire_stale_calls() {
+        let mut reg = CallRegistry::new();
+        reg.create_call("c1".into(), "alice".into(), "bob".into());
+
+        // Not expired yet
+        let expired = reg.expire_stale(Duration::from_secs(30));
+        assert!(expired.is_empty());
+
+        // Force expiry with 0 timeout
+        let expired = reg.expire_stale(Duration::from_secs(0));
+        assert_eq!(expired.len(), 1);
+        assert_eq!(expired[0].call_id, "c1");
+    }
+
+    #[test]
+    fn peer_lookup() {
+        let mut reg = CallRegistry::new();
+        reg.create_call("c1".into(), "alice".into(), "bob".into());
+        assert_eq!(reg.peer_fingerprint("c1", "alice"), Some("bob"));
+        assert_eq!(reg.peer_fingerprint("c1", "bob"), Some("alice"));
+    }
+}

crates/wzp-relay/src/config.rs

@@ -3,8 +3,41 @@
 use serde::{Deserialize, Serialize};
 use std::net::SocketAddr;
 
-/// Configuration for the relay daemon.
+/// A federated peer relay.
 #[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct PeerConfig {
+    /// Address of the peer relay (e.g., "193.180.213.68:4433").
+    pub url: String,
+    /// Expected TLS certificate fingerprint (hex, with colons).
+    pub fingerprint: String,
+    /// Optional human-readable label.
+    #[serde(default)]
+    pub label: Option<String>,
+}
+
+/// A trusted relay — accepts inbound federation without needing the peer's address.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct TrustedConfig {
+    /// Expected TLS certificate fingerprint (hex, with colons).
+    pub fingerprint: String,
+    /// Optional human-readable label.
+    #[serde(default)]
+    pub label: Option<String>,
+}
+
+/// A room declared global — bridged across all federated peers.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct GlobalRoomConfig {
+    /// Room name to bridge (e.g., "android").
+    pub name: String,
+}
+
+/// Configuration for the relay daemon.
+///
+/// All fields have defaults, so a minimal TOML file only needs the
+/// fields you want to override (e.g., just `[[peers]]`).
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(default)]
 pub struct RelayConfig {
     /// Address to listen on for incoming connections (client-facing).
     pub listen_addr: SocketAddr,
@@ -44,6 +77,22 @@ pub struct RelayConfig {
     pub ws_port: Option<u16>,
     /// Directory to serve static files from (HTML/JS/WASM for web clients).
     pub static_dir: Option<String>,
+    /// Federation peer relays.
+    #[serde(default)]
+    pub peers: Vec<PeerConfig>,
+    /// Global rooms bridged across federation.
+    #[serde(default)]
+    pub global_rooms: Vec<GlobalRoomConfig>,
+    /// Trusted relay fingerprints — accept inbound federation from these relays.
+    /// Unlike [[peers]], no url is needed — the peer connects to us.
+    #[serde(default)]
+    pub trusted: Vec<TrustedConfig>,
+    /// Debug tap: log packet headers for matching rooms ("*" = all rooms).
+    /// Activated via --debug-tap <room> or debug_tap = "room" in TOML.
+    pub debug_tap: Option<String>,
+    /// JSONL event log path for protocol analysis (--event-log).
+    #[serde(skip)]
+    pub event_log: Option<String>,
 }
 
 impl Default for RelayConfig {
@@ -62,6 +111,100 @@ impl Default for RelayConfig {
             trunking_enabled: false,
             ws_port: None,
             static_dir: None,
+            peers: Vec::new(),
+            global_rooms: Vec::new(),
+            trusted: Vec::new(),
+            debug_tap: None,
+            event_log: None,
         }
     }
 }
+
+/// Load relay configuration from a TOML file.
+pub fn load_config(path: &str) -> Result<RelayConfig, anyhow::Error> {
+    let content = std::fs::read_to_string(path)?;
+    let config: RelayConfig = toml::from_str(&content)?;
+    Ok(config)
+}
+
+/// Info about this relay instance, used to generate personalized example configs.
+pub struct RelayInfo {
+    pub listen_addr: String,
+    pub tls_fingerprint: String,
+    pub public_ip: Option<String>,
+}
+
+/// Load config from path, or create a personalized example config if it doesn't exist.
+pub fn load_or_create_config(path: &str, info: Option<&RelayInfo>) -> Result<RelayConfig, anyhow::Error> {
+    let p = std::path::Path::new(path);
+    if p.exists() {
+        return load_config(path);
+    }
+    // Create parent directory if needed
+    if let Some(parent) = p.parent() {
+        std::fs::create_dir_all(parent)?;
+    }
+    // Generate personalized example config
+    let example = generate_example_config(info);
+    std::fs::write(p, &example)?;
+    eprintln!("Created example config at {path} — edit it and restart.");
+    let config: RelayConfig = toml::from_str(&example)?;
+    Ok(config)
+}
+
+/// Generate an example TOML config, personalized with this relay's info if available.
+fn generate_example_config(info: Option<&RelayInfo>) -> String {
+    let listen = info.map(|i| i.listen_addr.as_str()).unwrap_or("0.0.0.0:4433");
+    let peer_example = if let Some(i) = info {
+        let ip = i.public_ip.as_deref().unwrap_or("this-relay-ip");
+        format!(
+            r#"# Other relays can peer with this relay using:
+# [[peers]]
+# url = "{ip}:{port}"
+# fingerprint = "{fp}"
+# label = "This Relay""#,
+            port = listen.rsplit(':').next().unwrap_or("4433"),
+            fp = i.tls_fingerprint,
+        )
+    } else {
+        "# To peer with another relay, add its url + fingerprint:".to_string()
+    };
+
+    format!(
+        r#"# WarzonePhone Relay Configuration
+# See docs/ADMINISTRATION.md for full reference.
+
+# Listen address for client connections
+listen_addr = "{listen}"
+
+# Maximum concurrent sessions
+# max_sessions = 100
+
+# Prometheus metrics endpoint (uncomment to enable)
+# metrics_port = 9090
+
+# featherChat auth endpoint (uncomment to enable)
+# auth_url = "https://chat.example.com/v1/auth/validate"
+
+{peer_example}
+
+# Federation: peer relays we connect to (outbound)
+# [[peers]]
+# url = "other-relay.example.com:4433"
+# fingerprint = "aa:bb:cc:dd:..."
+# label = "Relay B"
+
+# Federation: relays we trust inbound connections from
+# [[trusted]]
+# fingerprint = "ee:ff:00:11:..."
+# label = "Relay X"
+
+# Global rooms bridged across all federated peers
+# [[global_rooms]]
+# name = "general"
+
+# Debug: log packet headers for a room ("*" for all)
+# debug_tap = "*"
+"#
+    )
+}

crates/wzp-relay/src/event_log.rs

@@ -0,0 +1,201 @@
+//! JSONL event log for protocol analysis.
+//!
+//! When `--event-log <path>` is set, every media packet emits a structured
+//! event at each decision point (recv, forward, drop, deliver).
+//! Use `wzp-analyzer` to correlate events across multiple relays.
+
+use std::path::PathBuf;
+use std::sync::Arc;
+
+use serde::Serialize;
+use tokio::sync::mpsc;
+use tracing::{error, info};
+
+/// A single protocol event for JSONL output.
+#[derive(Debug, Serialize)]
+pub struct Event {
+    /// ISO 8601 timestamp with microseconds.
+    pub ts: String,
+    /// Event type.
+    pub event: &'static str,
+    /// Room name.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub room: Option<String>,
+    /// Source address or peer label.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub src: Option<String>,
+    /// Packet sequence number.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub seq: Option<u16>,
+    /// Codec identifier.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub codec: Option<String>,
+    /// FEC block ID.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub fec_block: Option<u8>,
+    /// FEC symbol index.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub fec_sym: Option<u8>,
+    /// Is FEC repair packet.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub repair: Option<bool>,
+    /// Payload length in bytes.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub len: Option<usize>,
+    /// Number of recipients.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub to_count: Option<usize>,
+    /// Peer label (for federation events).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub peer: Option<String>,
+    /// Drop/error reason.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub reason: Option<String>,
+    /// Presence action (active/inactive).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub action: Option<String>,
+    /// Participant count (presence events).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub participants: Option<usize>,
+}
+
+impl Event {
+    fn now() -> String {
+        chrono::Utc::now().format("%Y-%m-%dT%H:%M:%S%.6fZ").to_string()
+    }
+
+    /// Create a minimal event with just type and timestamp.
+    pub fn new(event: &'static str) -> Self {
+        Self {
+            ts: Self::now(),
+            event,
+            room: None,
+            src: None,
+            seq: None,
+            codec: None,
+            fec_block: None,
+            fec_sym: None,
+            repair: None,
+            len: None,
+            to_count: None,
+            peer: None,
+            reason: None,
+            action: None,
+            participants: None,
+        }
+    }
+
+    /// Set room.
+    pub fn room(mut self, room: &str) -> Self { self.room = Some(room.to_string()); self }
+    /// Set source.
+    pub fn src(mut self, src: &str) -> Self { self.src = Some(src.to_string()); self }
+    /// Set packet header fields from a MediaPacket.
+    pub fn packet(mut self, pkt: &wzp_proto::MediaPacket) -> Self {
+        self.seq = Some(pkt.header.seq);
+        self.codec = Some(format!("{:?}", pkt.header.codec_id));
+        self.fec_block = Some(pkt.header.fec_block);
+        self.fec_sym = Some(pkt.header.fec_symbol);
+        self.repair = Some(pkt.header.is_repair);
+        self.len = Some(pkt.payload.len());
+        self
+    }
+    /// Set seq only (when full packet not available).
+    pub fn seq(mut self, seq: u16) -> Self { self.seq = Some(seq); self }
+    /// Set payload length.
+    pub fn len(mut self, len: usize) -> Self { self.len = Some(len); self }
+    /// Set recipient count.
+    pub fn to_count(mut self, n: usize) -> Self { self.to_count = Some(n); self }
+    /// Set peer label.
+    pub fn peer(mut self, peer: &str) -> Self { self.peer = Some(peer.to_string()); self }
+    /// Set drop reason.
+    pub fn reason(mut self, reason: &str) -> Self { self.reason = Some(reason.to_string()); self }
+    /// Set presence action.
+    pub fn action(mut self, action: &str) -> Self { self.action = Some(action.to_string()); self }
+    /// Set participant count.
+    pub fn participants(mut self, n: usize) -> Self { self.participants = Some(n); self }
+}
+
+/// Handle for emitting events. Cheap to clone.
+#[derive(Clone)]
+pub struct EventLog {
+    tx: mpsc::UnboundedSender<Event>,
+}
+
+impl EventLog {
+    /// Emit an event (non-blocking, drops if channel is full).
+    pub fn emit(&self, event: Event) {
+        let _ = self.tx.send(event);
+    }
+}
+
+/// No-op event log for when `--event-log` is not set.
+/// All methods are no-ops that compile to nothing.
+#[derive(Clone)]
+pub struct NoopEventLog;
+
+/// Unified event log handle — either real or no-op.
+#[derive(Clone)]
+pub enum EventLogger {
+    Active(EventLog),
+    Noop,
+}
+
+impl EventLogger {
+    pub fn emit(&self, event: Event) {
+        if let EventLogger::Active(log) = self {
+            log.emit(event);
+        }
+    }
+
+    pub fn is_active(&self) -> bool {
+        matches!(self, EventLogger::Active(_))
+    }
+}
+
+/// Start the event log writer. Returns an `EventLogger` handle.
+pub fn start_event_log(path: Option<PathBuf>) -> EventLogger {
+    match path {
+        Some(path) => {
+            let (tx, rx) = mpsc::unbounded_channel();
+            tokio::spawn(writer_task(path, rx));
+            info!("event log enabled");
+            EventLogger::Active(EventLog { tx })
+        }
+        None => EventLogger::Noop,
+    }
+}
+
+/// Background task that writes events to a JSONL file.
+async fn writer_task(path: PathBuf, mut rx: mpsc::UnboundedReceiver<Event>) {
+    use tokio::io::AsyncWriteExt;
+
+    let file = match tokio::fs::File::create(&path).await {
+        Ok(f) => f,
+        Err(e) => {
+            error!("failed to create event log {}: {e}", path.display());
+            return;
+        }
+    };
+    let mut writer = tokio::io::BufWriter::new(file);
+    let mut count: u64 = 0;
+
+    while let Some(event) = rx.recv().await {
+        match serde_json::to_string(&event) {
+            Ok(json) => {
+                if writer.write_all(json.as_bytes()).await.is_err() { break; }
+                if writer.write_all(b"\n").await.is_err() { break; }
+                count += 1;
+                // Flush every 100 events
+                if count % 100 == 0 {
+                    let _ = writer.flush().await;
+                }
+            }
+            Err(e) => {
+                error!("event log serialize error: {e}");
+            }
+        }
+    }
+
+    let _ = writer.flush().await;
+    info!(events = count, "event log closed");
+}

crates/wzp-relay/src/federation.rs

@@ -0,0 +1,966 @@
+//! Relay federation — global room routing between peer relays.
+//!
+//! Each relay maintains a forwarding table per global room. When a local participant
+//! sends media in a global room, it's forwarded to all peer relays that have the room
+//! active. Incoming federated media is delivered to local participants and optionally
+//! forwarded to other active peers (multi-hop).
+
+use std::collections::{HashMap, HashSet};
+use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use bytes::Bytes;
+use sha2::{Sha256, Digest};
+use tokio::sync::Mutex;
+use tracing::{error, info, warn};
+
+use wzp_proto::{MediaTransport, SignalMessage};
+use wzp_transport::QuinnTransport;
+
+use crate::config::{PeerConfig, TrustedConfig};
+use crate::event_log::{Event, EventLogger};
+use crate::room::{self, FederationMediaOut, RoomEvent, RoomManager};
+
+/// Compute 8-byte room hash for federation datagram tagging.
+pub fn room_hash(room_name: &str) -> [u8; 8] {
+    let h = Sha256::digest(room_name.as_bytes());
+    let mut out = [0u8; 8];
+    out.copy_from_slice(&h[..8]);
+    out
+}
+
+/// Normalize a fingerprint string (remove colons, lowercase).
+fn normalize_fp(fp: &str) -> String {
+    fp.replace(':', "").to_lowercase()
+}
+
+/// Time-based dedup filter for federation datagrams.
+/// Tracks recently seen packets and expires entries older than 2 seconds.
+/// This prevents duplicate delivery when the same packet arrives via
+/// multiple federation paths, while allowing new senders that happen to
+/// reuse the same seq numbers.
+struct Deduplicator {
+    /// Recently seen packet keys with insertion time.
+    entries: HashMap<u64, Instant>,
+    /// Expiry duration.
+    ttl: Duration,
+}
+
+impl Deduplicator {
+    fn new(_capacity: usize) -> Self {
+        Self {
+            entries: HashMap::with_capacity(512),
+            ttl: Duration::from_secs(2),
+        }
+    }
+
+    /// Returns true if this packet is a duplicate (already seen within TTL).
+    fn is_dup(&mut self, room_hash: &[u8; 8], seq: u16, extra: u64) -> bool {
+        let key = u64::from_be_bytes(*room_hash) ^ (seq as u64) ^ extra;
+        let now = Instant::now();
+
+        // Periodic cleanup (every ~256 packets)
+        if self.entries.len() > 256 {
+            self.entries.retain(|_, ts| now.duration_since(*ts) < self.ttl);
+        }
+
+        if let Some(ts) = self.entries.get(&key) {
+            if now.duration_since(*ts) < self.ttl {
+                return true; // seen recently — duplicate
+            }
+        }
+        self.entries.insert(key, now);
+        false
+    }
+}
+
+/// Per-room token bucket rate limiter for federation forwarding.
+struct RateLimiter {
+    /// Max packets per second per room.
+    max_pps: u32,
+    /// Tokens remaining in current window.
+    tokens: u32,
+    /// When the current window started.
+    window_start: Instant,
+}
+
+impl RateLimiter {
+    fn new(max_pps: u32) -> Self {
+        Self {
+            max_pps,
+            tokens: max_pps,
+            window_start: Instant::now(),
+        }
+    }
+
+    /// Returns true if the packet should be allowed through.
+    fn allow(&mut self) -> bool {
+        let elapsed = self.window_start.elapsed();
+        if elapsed >= Duration::from_secs(1) {
+            self.tokens = self.max_pps;
+            self.window_start = Instant::now();
+        }
+        if self.tokens > 0 {
+            self.tokens -= 1;
+            true
+        } else {
+            false
+        }
+    }
+}
+
+/// Active link to a peer relay.
+struct PeerLink {
+    transport: Arc<QuinnTransport>,
+    label: String,
+    /// Global rooms that this peer has reported as active.
+    active_rooms: HashSet<String>,
+    /// Remote participants per room (for federated presence in RoomUpdate).
+    remote_participants: HashMap<String, Vec<wzp_proto::packet::RoomParticipant>>,
+    /// Last time we received any data (signal or media) from this peer.
+    last_seen: Instant,
+}
+
+/// Max federation packets per second per room (0 = unlimited).
+const FEDERATION_RATE_LIMIT_PPS: u32 = 500;
+/// Dedup window size (number of recent packets to remember).
+const DEDUP_WINDOW_SIZE: usize = 4096;
+/// Remote participants are considered stale after this duration with no updates.
+const REMOTE_PARTICIPANT_STALE_SECS: u64 = 15;
+
+/// Manages federation connections and global room forwarding.
+pub struct FederationManager {
+    peers: Vec<PeerConfig>,
+    trusted: Vec<TrustedConfig>,
+    global_rooms: HashSet<String>,
+    room_mgr: Arc<Mutex<RoomManager>>,
+    endpoint: quinn::Endpoint,
+    local_tls_fp: String,
+    metrics: Arc<crate::metrics::RelayMetrics>,
+    /// Active peer connections, keyed by normalized fingerprint.
+    peer_links: Arc<Mutex<HashMap<String, PeerLink>>>,
+    /// Dedup filter for incoming federation datagrams.
+    dedup: Mutex<Deduplicator>,
+    /// Per-room seq counter for federation media delivered to local clients.
+    /// Ensures clients see monotonically increasing seq regardless of federation sender.
+    local_delivery_seq: std::sync::atomic::AtomicU16,
+    /// JSONL event log for protocol analysis.
+    event_log: EventLogger,
+    /// Per-room rate limiters for inbound federation media.
+    rate_limiters: Mutex<HashMap<String, RateLimiter>>,
+}
+
+impl FederationManager {
+    pub fn new(
+        peers: Vec<PeerConfig>,
+        trusted: Vec<TrustedConfig>,
+        global_rooms: HashSet<String>,
+        room_mgr: Arc<Mutex<RoomManager>>,
+        endpoint: quinn::Endpoint,
+        local_tls_fp: String,
+        metrics: Arc<crate::metrics::RelayMetrics>,
+        event_log: EventLogger,
+    ) -> Self {
+        Self {
+            peers,
+            trusted,
+            global_rooms,
+            room_mgr,
+            endpoint,
+            local_tls_fp,
+            metrics,
+            peer_links: Arc::new(Mutex::new(HashMap::new())),
+            dedup: Mutex::new(Deduplicator::new(DEDUP_WINDOW_SIZE)),
+            local_delivery_seq: std::sync::atomic::AtomicU16::new(0),
+            event_log,
+            rate_limiters: Mutex::new(HashMap::new()),
+        }
+    }
+
+    /// Check if a room name (which may be hashed) is a global room.
+    pub fn is_global_room(&self, room: &str) -> bool {
+        self.resolve_global_room(room).is_some()
+    }
+
+    /// Resolve a room name (raw or hashed) to the canonical global room name.
+    /// Returns the configured global room name if it matches.
+    pub fn resolve_global_room(&self, room: &str) -> Option<&str> {
+        // Direct match (raw room name, e.g. Android clients)
+        if self.global_rooms.contains(room) {
+            return Some(self.global_rooms.iter().find(|n| n.as_str() == room).unwrap());
+        }
+        // Hashed match (desktop clients hash room names for SNI privacy)
+        self.global_rooms.iter().find(|name| {
+            wzp_crypto::hash_room_name(name) == room
+        }).map(|s| s.as_str())
+    }
+
+    /// Get the canonical federation room hash for a room.
+    /// Always uses the configured global room name, not the client-provided name.
+    pub fn global_room_hash(&self, room: &str) -> [u8; 8] {
+        if let Some(canonical) = self.resolve_global_room(room) {
+            room_hash(canonical)
+        } else {
+            room_hash(room)
+        }
+    }
+
+    /// Start federation — spawns connection loops + event dispatcher.
+    pub async fn run(self: Arc<Self>) {
+        if self.peers.is_empty() && self.global_rooms.is_empty() {
+            return;
+        }
+        info!(
+            peers = self.peers.len(),
+            global_rooms = self.global_rooms.len(),
+            "federation starting"
+        );
+
+        let mut handles = Vec::new();
+
+        // Per-peer outbound connection loops
+        for peer in &self.peers {
+            let this = self.clone();
+            let peer = peer.clone();
+            handles.push(tokio::spawn(async move {
+                run_peer_loop(this, peer).await;
+            }));
+        }
+
+        // Room event dispatcher
+        let room_events = {
+            let mgr = self.room_mgr.lock().await;
+            mgr.subscribe_events()
+        };
+        let this = self.clone();
+        handles.push(tokio::spawn(async move {
+            run_room_event_dispatcher(this, room_events).await;
+        }));
+
+        // Stale presence sweeper — purges remote participants from dead peers
+        let this = self.clone();
+        handles.push(tokio::spawn(async move {
+            run_stale_presence_sweeper(this).await;
+        }));
+
+        for h in handles {
+            let _ = h.await;
+        }
+    }
+
+    /// Handle an inbound federation connection from a recognized peer.
+    pub async fn handle_inbound(
+        self: &Arc<Self>,
+        transport: Arc<QuinnTransport>,
+        peer_config: PeerConfig,
+    ) {
+        let peer_fp = normalize_fp(&peer_config.fingerprint);
+        let label = peer_config.label.unwrap_or_else(|| peer_config.url.clone());
+        info!(peer = %label, "inbound federation link active");
+        if let Err(e) = run_federation_link(self.clone(), transport, peer_fp, label.clone()).await {
+            warn!(peer = %label, "inbound federation link ended: {e}");
+        }
+    }
+
+    /// Get all remote participants for a room from all peer links.
+    /// Deduplicates by fingerprint (same participant may appear via multiple links).
+    pub async fn get_remote_participants(&self, room: &str) -> Vec<wzp_proto::packet::RoomParticipant> {
+        let canonical = self.resolve_global_room(room);
+        let links = self.peer_links.lock().await;
+        let mut result = Vec::new();
+        for link in links.values() {
+            // Check canonical name
+            if let Some(c) = canonical {
+                if let Some(remote) = link.remote_participants.get(c) {
+                    result.extend(remote.iter().cloned());
+                }
+                // Also check raw room name, but only if different from canonical
+                if c != room {
+                    if let Some(remote) = link.remote_participants.get(room) {
+                        result.extend(remote.iter().cloned());
+                    }
+                }
+            } else {
+                if let Some(remote) = link.remote_participants.get(room) {
+                    result.extend(remote.iter().cloned());
+                }
+            }
+        }
+        // Deduplicate by fingerprint
+        let mut seen = HashSet::new();
+        result.retain(|p| seen.insert(p.fingerprint.clone()));
+        result
+    }
+
+    /// Forward locally-generated media to all connected peers.
+    /// For locally-originated media, we send to ALL peers (they decide whether to deliver).
+    /// For forwarded media (multi-hop), handle_datagram filters by active_rooms.
+    pub async fn forward_to_peers(&self, room_name: &str, room_hash: &[u8; 8], media_data: &Bytes) {
+        let links = self.peer_links.lock().await;
+        if links.is_empty() {
+            return;
+        }
+        for (_fp, link) in links.iter() {
+            let mut tagged = Vec::with_capacity(8 + media_data.len());
+            tagged.extend_from_slice(room_hash);
+            tagged.extend_from_slice(media_data);
+            match link.transport.send_raw_datagram(&tagged) {
+                Ok(()) => {
+                    self.metrics.federation_packets_forwarded
+                        .with_label_values(&[&link.label, "out"]).inc();
+                }
+                Err(e) => warn!(peer = %link.label, "federation send error: {e}"),
+            }
+        }
+    }
+
+    // ── Trust verification (kept from previous implementation) ──
+
+    pub fn find_peer_by_fingerprint(&self, fp: &str) -> Option<&PeerConfig> {
+        self.peers.iter().find(|p| normalize_fp(&p.fingerprint) == normalize_fp(fp))
+    }
+
+    pub fn find_peer_by_addr(&self, addr: SocketAddr) -> Option<&PeerConfig> {
+        let addr_ip = addr.ip();
+        self.peers.iter().find(|p| {
+            p.url.parse::<SocketAddr>()
+                .map(|sa| sa.ip() == addr_ip)
+                .unwrap_or(false)
+        })
+    }
+
+    pub fn find_trusted_by_fingerprint(&self, fp: &str) -> Option<&TrustedConfig> {
+        self.trusted.iter().find(|t| normalize_fp(&t.fingerprint) == normalize_fp(fp))
+    }
+
+    pub fn check_inbound_trust(&self, addr: SocketAddr, hello_fp: &str) -> Option<String> {
+        if let Some(peer) = self.find_peer_by_addr(addr) {
+            return Some(peer.label.clone().unwrap_or_else(|| peer.url.clone()));
+        }
+        if let Some(trusted) = self.find_trusted_by_fingerprint(hello_fp) {
+            return Some(trusted.label.clone().unwrap_or_else(|| hello_fp[..16].to_string()));
+        }
+        None
+    }
+}
+
+// ── Outbound media egress task ──
+
+/// Drains the federation media channel and forwards to active peers.
+pub async fn run_federation_media_egress(
+    fm: Arc<FederationManager>,
+    mut rx: tokio::sync::mpsc::Receiver<FederationMediaOut>,
+) {
+    let mut count: u64 = 0;
+    while let Some(out) = rx.recv().await {
+        count += 1;
+        if count == 1 || count % 250 == 0 {
+            info!(room = %out.room_name, count, "federation egress: forwarding media");
+        }
+        fm.forward_to_peers(&out.room_name, &out.room_hash, &out.data).await;
+    }
+    info!(total = count, "federation egress task ended");
+}
+
+// ── Room event dispatcher ──
+
+/// Watches RoomManager events and sends GlobalRoomActive/Inactive to peers.
+async fn run_room_event_dispatcher(
+    fm: Arc<FederationManager>,
+    mut events: tokio::sync::broadcast::Receiver<RoomEvent>,
+) {
+    loop {
+        match events.recv().await {
+            Ok(RoomEvent::LocalJoin { room }) => {
+                if fm.is_global_room(&room) {
+                    let participants = {
+                        let mgr = fm.room_mgr.lock().await;
+                        mgr.local_participant_list(&room)
+                    };
+                    info!(room = %room, count = participants.len(), "global room now active, announcing to peers");
+                    let msg = SignalMessage::GlobalRoomActive { room, participants };
+                    let links = fm.peer_links.lock().await;
+                    for link in links.values() {
+                        let _ = link.transport.send_signal(&msg).await;
+                    }
+                }
+            }
+            Ok(RoomEvent::LocalLeave { room }) => {
+                if fm.is_global_room(&room) {
+                    info!(room = %room, "global room now inactive, announcing to peers");
+                    let msg = SignalMessage::GlobalRoomInactive { room };
+                    let links = fm.peer_links.lock().await;
+                    for link in links.values() {
+                        let _ = link.transport.send_signal(&msg).await;
+                    }
+                }
+            }
+            Err(tokio::sync::broadcast::error::RecvError::Lagged(n)) => {
+                warn!(missed = n, "room event receiver lagged");
+            }
+            Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
+        }
+    }
+}
+
+// ── Stale presence sweeper ──
+
+/// Periodically checks for stale remote participants and purges them.
+/// This handles the case where a peer link dies without sending GlobalRoomInactive
+/// (e.g., QUIC timeout, network partition, crash).
+async fn run_stale_presence_sweeper(fm: Arc<FederationManager>) {
+    let mut interval = tokio::time::interval(Duration::from_secs(5));
+    loop {
+        interval.tick().await;
+        let stale_threshold = Duration::from_secs(REMOTE_PARTICIPANT_STALE_SECS);
+
+        // Find peers with stale remote_participants whose link is also gone or idle
+        let stale_rooms: Vec<(String, String)> = {
+            let links = fm.peer_links.lock().await;
+            let mut stale = Vec::new();
+            for (fp, link) in links.iter() {
+                if link.last_seen.elapsed() > stale_threshold && !link.remote_participants.is_empty() {
+                    for room in link.remote_participants.keys() {
+                        stale.push((fp.clone(), room.clone()));
+                    }
+                }
+            }
+            stale
+        };
+
+        if stale_rooms.is_empty() {
+            continue;
+        }
+
+        // Purge stale entries and collect affected rooms
+        let mut affected_rooms = HashSet::new();
+        {
+            let mut links = fm.peer_links.lock().await;
+            for (fp, room) in &stale_rooms {
+                if let Some(link) = links.get_mut(fp.as_str()) {
+                    if link.last_seen.elapsed() > stale_threshold {
+                        info!(peer = %link.label, room = %room, "purging stale remote participants (no data for {}s)", link.last_seen.elapsed().as_secs());
+                        link.remote_participants.remove(room);
+                        link.active_rooms.remove(room);
+                        affected_rooms.insert(room.clone());
+                    }
+                }
+            }
+        }
+
+        // Broadcast updated RoomUpdate for affected rooms
+        for room in &affected_rooms {
+            let mgr = fm.room_mgr.lock().await;
+            for local_room in mgr.active_rooms() {
+                if fm.resolve_global_room(&local_room) == fm.resolve_global_room(room) {
+                    let mut all_participants = mgr.local_participant_list(&local_room);
+                    let remote = fm.get_remote_participants(&local_room).await;
+                    all_participants.extend(remote);
+                    let mut seen = HashSet::new();
+                    all_participants.retain(|p| seen.insert(p.fingerprint.clone()));
+                    let update = SignalMessage::RoomUpdate {
+                        count: all_participants.len() as u32,
+                        participants: all_participants,
+                    };
+                    let senders = mgr.local_senders(&local_room);
+                    drop(mgr);
+                    room::broadcast_signal(&senders, &update).await;
+                    info!(room = %room, "swept stale presence — broadcast updated RoomUpdate");
+                    break;
+                }
+            }
+        }
+    }
+}
+
+// ── Peer connection management ──
+
+/// Persistent connection loop for one peer — reconnects with backoff.
+async fn run_peer_loop(fm: Arc<FederationManager>, peer: PeerConfig) {
+    let mut backoff = Duration::from_secs(5);
+    loop {
+        info!(peer_url = %peer.url, label = ?peer.label, "federation: connecting to peer...");
+        match connect_to_peer(&fm, &peer).await {
+            Ok(transport) => {
+                backoff = Duration::from_secs(5);
+                let peer_fp = normalize_fp(&peer.fingerprint);
+                let label = peer.label.clone().unwrap_or_else(|| peer.url.clone());
+                if let Err(e) = run_federation_link(fm.clone(), transport, peer_fp, label).await {
+                    warn!(peer_url = %peer.url, "federation link ended: {e}");
+                }
+            }
+            Err(e) => {
+                warn!(peer_url = %peer.url, backoff_s = backoff.as_secs(), "federation connect failed: {e}");
+            }
+        }
+        tokio::time::sleep(backoff).await;
+        backoff = (backoff * 2).min(Duration::from_secs(300));
+    }
+}
+
+/// Connect to a peer relay and send hello.
+async fn connect_to_peer(fm: &FederationManager, peer: &PeerConfig) -> Result<Arc<QuinnTransport>, anyhow::Error> {
+    let addr: SocketAddr = peer.url.parse()?;
+    let client_cfg = wzp_transport::client_config();
+    let conn = wzp_transport::connect(&fm.endpoint, addr, "_federation", client_cfg).await?;
+    let transport = Arc::new(QuinnTransport::new(conn));
+
+    // Send hello with our TLS fingerprint
+    let hello = SignalMessage::FederationHello {
+        tls_fingerprint: fm.local_tls_fp.clone(),
+    };
+    transport.send_signal(&hello).await
+        .map_err(|e| anyhow::anyhow!("federation hello send failed: {e}"))?;
+
+    info!(peer_url = %peer.url, label = ?peer.label, "federation: connected (hello sent)");
+    Ok(transport)
+}
+
+// ── Federation link (runs on a single QUIC connection) ──
+
+/// Run the federation link: exchange global room state and forward media.
+async fn run_federation_link(
+    fm: Arc<FederationManager>,
+    transport: Arc<QuinnTransport>,
+    peer_fp: String,
+    peer_label: String,
+) -> Result<(), anyhow::Error> {
+    // Register peer link + metrics
+    fm.metrics.federation_peer_status.with_label_values(&[&peer_label]).set(1);
+    {
+        let mut links = fm.peer_links.lock().await;
+        links.insert(peer_fp.clone(), PeerLink {
+            transport: transport.clone(),
+            label: peer_label.clone(),
+            active_rooms: HashSet::new(),
+            remote_participants: HashMap::new(),
+            last_seen: Instant::now(),
+        });
+    }
+
+    // Announce our currently active global rooms to this new peer
+    // Collect all announcements first, then send (avoid holding locks across await)
+    let announcements = {
+        let mgr = fm.room_mgr.lock().await;
+        let active = mgr.active_rooms();
+        let mut msgs = Vec::new();
+
+        // Local rooms
+        for room_name in &active {
+            if fm.is_global_room(room_name) {
+                let participants = mgr.local_participant_list(room_name);
+                info!(peer = %peer_label, room = %room_name, participants = participants.len(), "announcing local global room to new peer");
+                msgs.push(SignalMessage::GlobalRoomActive { room: room_name.clone(), participants });
+            }
+        }
+
+        // Remote rooms from OTHER peers (for multi-hop propagation)
+        let links = fm.peer_links.lock().await;
+        for (fp, link) in links.iter() {
+            if fp != &peer_fp {
+                for (room, participants) in &link.remote_participants {
+                    if fm.is_global_room(room) {
+                        info!(peer = %peer_label, room = %room, via = %link.label, "propagating remote room to new peer");
+                        msgs.push(SignalMessage::GlobalRoomActive {
+                            room: room.clone(),
+                            participants: participants.clone(),
+                        });
+                    }
+                }
+            }
+        }
+        msgs
+    };
+    for msg in &announcements {
+        let _ = transport.send_signal(msg).await;
+    }
+
+    // Three concurrent tasks: signal recv + media recv + RTT monitor
+    let signal_transport = transport.clone();
+    let media_transport = transport.clone();
+    let rtt_transport = transport.clone();
+    let fm_signal = fm.clone();
+    let fm_media = fm.clone();
+    let fm_rtt = fm.clone();
+    let peer_fp_signal = peer_fp.clone();
+    let peer_fp_media = peer_fp.clone();
+    let label_signal = peer_label.clone();
+    let label_rtt = peer_label.clone();
+
+    let signal_task = async move {
+        loop {
+            match signal_transport.recv_signal().await {
+                Ok(Some(msg)) => {
+                    handle_signal(&fm_signal, &peer_fp_signal, &label_signal, msg).await;
+                }
+                Ok(None) => break,
+                Err(e) => {
+                    error!(peer = %label_signal, "federation signal error: {e}");
+                    break;
+                }
+            }
+        }
+    };
+
+    let peer_label_media = peer_label.clone();
+    let media_task = async move {
+        let mut media_count: u64 = 0;
+        loop {
+            match media_transport.connection().read_datagram().await {
+                Ok(data) => {
+                    media_count += 1;
+                    if media_count == 1 || media_count % 250 == 0 {
+                        info!(peer = %peer_label_media, media_count, len = data.len(), "federation: received datagram");
+                    }
+                    handle_datagram(&fm_media, &peer_fp_media, data).await;
+                }
+                Err(e) => {
+                    info!(peer = %peer_label_media, "federation media task ended: {e}");
+                    break;
+                }
+            }
+        }
+    };
+
+    // RTT monitor: periodically sample QUIC RTT for this peer
+    let rtt_task = async move {
+        loop {
+            tokio::time::sleep(Duration::from_secs(5)).await;
+            let rtt_ms = rtt_transport.connection().stats().path.rtt.as_millis() as f64;
+        }
+    };
+
+    tokio::select! {
+        _ = signal_task => {}
+        _ = media_task => {}
+        _ = rtt_task => {}
+    }
+
+    // Cleanup: remove peer link + metrics
+    fm.metrics.federation_peer_status.with_label_values(&[&peer_label]).set(0);
+    {
+        let mut links = fm.peer_links.lock().await;
+        links.remove(&peer_fp);
+    }
+    info!(peer = %peer_label, "federation link ended");
+
+    Ok(())
+}
+
+/// Handle an incoming federation signal.
+async fn handle_signal(
+    fm: &Arc<FederationManager>,
+    peer_fp: &str,
+    peer_label: &str,
+    msg: SignalMessage,
+) {
+    // Update last_seen for this peer
+    {
+        let mut links = fm.peer_links.lock().await;
+        if let Some(link) = links.get_mut(peer_fp) {
+            link.last_seen = Instant::now();
+        }
+    }
+
+    match msg {
+        SignalMessage::GlobalRoomActive { room, participants } => {
+            if fm.is_global_room(&room) {
+                info!(peer = %peer_label, room = %room, remote_participants = participants.len(), "peer has global room active");
+                let mut links = fm.peer_links.lock().await;
+                if let Some(link) = links.get_mut(peer_fp) {
+                    link.active_rooms.insert(room.clone());
+                }
+                // Update active rooms metric
+                let total: usize = links.values().map(|l| l.active_rooms.len()).sum();
+                fm.metrics.federation_active_rooms.set(total as i64);
+                if let Some(link) = links.get_mut(peer_fp) {
+                    // Tag remote participants with their relay label
+                    let tagged: Vec<_> = participants.iter().map(|p| {
+                        let mut tagged = p.clone();
+                        if tagged.relay_label.is_none() {
+                            tagged.relay_label = Some(link.label.clone());
+                        }
+                        tagged
+                    }).collect();
+                    link.remote_participants.insert(room.clone(), tagged);
+                }
+                // Propagate to other peers (with relay labels preserved)
+                let tagged_for_propagation = if let Some(link) = links.get(peer_fp) {
+                    let label = link.label.clone();
+                    participants.iter().map(|p| {
+                        let mut t = p.clone();
+                        if t.relay_label.is_none() {
+                            t.relay_label = Some(label.clone());
+                        }
+                        t
+                    }).collect::<Vec<_>>()
+                } else {
+                    participants.clone()
+                };
+                for (fp, link) in links.iter() {
+                    if fp != peer_fp {
+                        let _ = link.transport.send_signal(&SignalMessage::GlobalRoomActive {
+                            room: room.clone(),
+                            participants: tagged_for_propagation.clone(),
+                        }).await;
+                    }
+                }
+                drop(links);
+
+                // Broadcast updated RoomUpdate to local clients in this room
+                // Find the local room name (may be hashed or raw)
+                let mgr = fm.room_mgr.lock().await;
+                for local_room in mgr.active_rooms() {
+                    if fm.is_global_room(&local_room) && fm.resolve_global_room(&local_room) == fm.resolve_global_room(&room) {
+                        // Build merged participant list: local + all remote (deduped)
+                        let mut all_participants = mgr.local_participant_list(&local_room);
+                        let links = fm.peer_links.lock().await;
+                        for link in links.values() {
+                            if let Some(canonical) = fm.resolve_global_room(&local_room) {
+                                if let Some(remote) = link.remote_participants.get(canonical) {
+                                    all_participants.extend(remote.iter().cloned());
+                                }
+                                // Also check raw room name, but only if different from canonical
+                                if canonical != local_room {
+                                    if let Some(remote) = link.remote_participants.get(&local_room) {
+                                        all_participants.extend(remote.iter().cloned());
+                                    }
+                                }
+                            }
+                        }
+                        // Deduplicate by fingerprint
+                        let mut seen = HashSet::new();
+                        all_participants.retain(|p| seen.insert(p.fingerprint.clone()));
+                        let update = SignalMessage::RoomUpdate {
+                            count: all_participants.len() as u32,
+                            participants: all_participants,
+                        };
+                        let senders = mgr.local_senders(&local_room);
+                        drop(links);
+                        drop(mgr);
+                        room::broadcast_signal(&senders, &update).await;
+                        break;
+                    }
+                }
+            }
+        }
+        SignalMessage::GlobalRoomInactive { room } => {
+            info!(peer = %peer_label, room = %room, "peer global room now inactive");
+            let mut links = fm.peer_links.lock().await;
+            if let Some(link) = links.get_mut(peer_fp) {
+                link.active_rooms.remove(&room);
+                // Clear remote participants for this peer+room
+                link.remote_participants.remove(&room);
+                // Also try canonical name
+                if let Some(canonical) = fm.resolve_global_room(&room) {
+                    link.remote_participants.remove(canonical);
+                }
+            }
+
+            // Update active rooms metric
+            let total: usize = links.values().map(|l| l.active_rooms.len()).sum();
+            fm.metrics.federation_active_rooms.set(total as i64);
+
+            // Build remaining remote participants (from all peers except the one going inactive)
+            let remaining_remote: Vec<wzp_proto::packet::RoomParticipant> = {
+                let canonical = fm.resolve_global_room(&room);
+                let mut result = Vec::new();
+                for (fp, link) in links.iter() {
+                    if fp == peer_fp { continue; }
+                    if let Some(c) = canonical {
+                        if let Some(remote) = link.remote_participants.get(c) {
+                            result.extend(remote.iter().cloned());
+                        }
+                    }
+                }
+                let mut seen = HashSet::new();
+                result.retain(|p| seen.insert(p.fingerprint.clone()));
+                result
+            };
+
+            // Propagate to other peers: send updated GlobalRoomActive with revised list,
+            // or GlobalRoomInactive if no participants remain anywhere
+            let local_active = {
+                let mgr = fm.room_mgr.lock().await;
+                mgr.active_rooms().iter().any(|r| fm.resolve_global_room(r) == fm.resolve_global_room(&room))
+            };
+            let has_remaining = !remaining_remote.is_empty() || local_active;
+
+            // Collect peer transports to send to (avoid holding lock across await)
+            let peer_sends: Vec<_> = links.iter()
+                .filter(|(fp, _)| *fp != peer_fp)
+                .map(|(_, link)| link.transport.clone())
+                .collect();
+            drop(links);
+
+            if has_remaining {
+                // Send updated participant list to other peers
+                let mut updated_participants = remaining_remote.clone();
+                if local_active {
+                    let mgr = fm.room_mgr.lock().await;
+                    for local_room in mgr.active_rooms() {
+                        if fm.resolve_global_room(&local_room) == fm.resolve_global_room(&room) {
+                            updated_participants.extend(mgr.local_participant_list(&local_room));
+                            break;
+                        }
+                    }
+                }
+                let msg = SignalMessage::GlobalRoomActive {
+                    room: room.clone(),
+                    participants: updated_participants,
+                };
+                for transport in &peer_sends {
+                    let _ = transport.send_signal(&msg).await;
+                }
+            } else {
+                // No participants left anywhere — propagate inactive
+                let msg = SignalMessage::GlobalRoomInactive { room: room.clone() };
+                for transport in &peer_sends {
+                    let _ = transport.send_signal(&msg).await;
+                }
+            }
+
+            // Broadcast updated RoomUpdate to local clients (remote participant removed)
+            let mgr = fm.room_mgr.lock().await;
+            for local_room in mgr.active_rooms() {
+                if fm.is_global_room(&local_room) && fm.resolve_global_room(&local_room) == fm.resolve_global_room(&room) {
+                    let mut all_participants = mgr.local_participant_list(&local_room);
+                    all_participants.extend(remaining_remote.iter().cloned());
+                    // Deduplicate by fingerprint
+                    let mut seen = HashSet::new();
+                    all_participants.retain(|p| seen.insert(p.fingerprint.clone()));
+                    let update = SignalMessage::RoomUpdate {
+                        count: all_participants.len() as u32,
+                        participants: all_participants,
+                    };
+                    let senders = mgr.local_senders(&local_room);
+                    drop(mgr);
+                    room::broadcast_signal(&senders, &update).await;
+                    info!(room = %room, "broadcast updated presence (remote participant removed)");
+                    break;
+                }
+            }
+        }
+        _ => {} // ignore other signals
+    }
+}
+
+/// Handle an incoming federation datagram (room-hash-tagged media).
+async fn handle_datagram(
+    fm: &Arc<FederationManager>,
+    source_peer_fp: &str,
+    data: Bytes,
+) {
+    if data.len() < 12 { return; } // 8-byte hash + min packet
+
+    let mut rh = [0u8; 8];
+    rh.copy_from_slice(&data[..8]);
+    let media_bytes = data.slice(8..);
+
+    let pkt = match wzp_proto::MediaPacket::from_bytes(media_bytes.clone()) {
+        Some(pkt) => pkt,
+        None => {
+            fm.event_log.emit(Event::new("federation_ingress_malformed").len(data.len()));
+            return;
+        }
+    };
+
+    // Event log: federation ingress
+    let peer_label = {
+        let links = fm.peer_links.lock().await;
+        links.get(source_peer_fp).map(|l| l.label.clone()).unwrap_or_default()
+    };
+    fm.event_log.emit(Event::new("federation_ingress").packet(&pkt).peer(&peer_label));
+
+    // Count inbound federation packet + update last_seen
+    fm.metrics.federation_packets_forwarded
+        .with_label_values(&[source_peer_fp, "in"]).inc();
+    {
+        let mut links = fm.peer_links.lock().await;
+        if let Some(link) = links.get_mut(source_peer_fp) {
+            link.last_seen = Instant::now();
+        }
+    }
+
+    // Dedup: drop packets we've already seen (multi-path duplicates).
+    // Key uses a hash of the actual payload bytes — unique per Opus frame,
+    // so different senders with the same seq/timestamp never collide.
+    let payload_hash = {
+        let mut h = 0u64;
+        for (i, &b) in media_bytes.iter().take(16).enumerate() {
+            h ^= (b as u64) << ((i % 8) * 8);
+        }
+        h
+    };
+    {
+        let mut dedup = fm.dedup.lock().await;
+        if dedup.is_dup(&rh, pkt.header.seq, payload_hash) {
+            fm.event_log.emit(Event::new("dedup_drop").seq(pkt.header.seq).peer(&peer_label));
+            return;
+        }
+    }
+
+    // Find room by hash — check local rooms AND global room config
+    let room_name = {
+        let mgr = fm.room_mgr.lock().await;
+        let active = mgr.active_rooms();
+        // First: check local rooms (has participants)
+        active.iter().find(|r| room_hash(r) == rh).cloned()
+            .or_else(|| active.iter().find(|r| fm.global_room_hash(r) == rh).cloned())
+            // Second: check global room config (hub relay may have no local participants)
+            .or_else(|| {
+                fm.global_rooms.iter().find(|name| room_hash(name) == rh).cloned()
+            })
+    };
+
+    let room_name = match room_name {
+        Some(r) => r,
+        None => {
+            fm.event_log.emit(Event::new("room_not_found").seq(pkt.header.seq).peer(&peer_label));
+            return;
+        }
+    };
+
+    // Rate limit per room
+    if FEDERATION_RATE_LIMIT_PPS > 0 {
+        let mut limiters = fm.rate_limiters.lock().await;
+        let limiter = limiters.entry(room_name.clone())
+            .or_insert_with(|| RateLimiter::new(FEDERATION_RATE_LIMIT_PPS));
+        if !limiter.allow() {
+            fm.event_log.emit(Event::new("rate_limit_drop").room(&room_name).seq(pkt.header.seq));
+            return;
+        }
+    }
+
+    // Deliver to all local participants — forward the raw bytes as-is.
+    // The original sender's MediaPacket is preserved exactly (no re-serialization).
+    let locals = {
+        let mgr = fm.room_mgr.lock().await;
+        mgr.local_senders(&room_name)
+    };
+    for sender in &locals {
+        match sender {
+            room::ParticipantSender::Quic(t) => {
+                if let Err(e) = t.send_raw_datagram(&media_bytes) {
+                    fm.event_log.emit(Event::new("local_deliver_error").room(&room_name).seq(pkt.header.seq).reason(&e.to_string()));
+                    warn!("federation local delivery error: {e}");
+                }
+            }
+            room::ParticipantSender::WebSocket(_) => { let _ = sender.send_raw(&pkt.payload).await; }
+        }
+    }
+    fm.event_log.emit(Event::new("local_deliver").room(&room_name).seq(pkt.header.seq).to_count(locals.len()));
+
+    // Multi-hop: forward to ALL other connected peers (not the source)
+    // Don't filter by active_rooms — the receiving peer decides whether to deliver
+    let links = fm.peer_links.lock().await;
+    for (fp, link) in links.iter() {
+        if fp != source_peer_fp {
+            let mut tagged = Vec::with_capacity(8 + media_bytes.len());
+            tagged.extend_from_slice(&rh);
+            tagged.extend_from_slice(&media_bytes);
+            let _ = link.transport.send_raw_datagram(&tagged);
+        }
+    }
+}

crates/wzp-relay/src/handshake.rs

@@ -15,25 +15,27 @@ use wzp_proto::{MediaTransport, QualityProfile, SignalMessage};
 /// 5. Derive shared ChaCha20-Poly1305 session
 /// 6. Send `CallAnswer` back
 ///
-/// Returns the derived `CryptoSession` and the chosen `QualityProfile`.
+/// Returns the derived `CryptoSession`, the chosen `QualityProfile`, the caller's fingerprint,
+/// and the caller's alias (if provided in CallOffer).
 pub async fn accept_handshake(
     transport: &dyn MediaTransport,
     seed: &[u8; 32],
-) -> Result<(Box<dyn CryptoSession>, QualityProfile), anyhow::Error> {
+) -> Result<(Box<dyn CryptoSession>, QualityProfile, String, Option<String>), anyhow::Error> {
     // 1. Receive CallOffer
     let offer = transport
         .recv_signal()
         .await?
         .ok_or_else(|| anyhow::anyhow!("connection closed before receiving CallOffer"))?;
 
-    let (caller_identity_pub, caller_ephemeral_pub, caller_signature, supported_profiles) =
+    let (caller_identity_pub, caller_ephemeral_pub, caller_signature, supported_profiles, caller_alias) =
         match offer {
             SignalMessage::CallOffer {
                 identity_pub,
                 ephemeral_pub,
                 signature,
                 supported_profiles,
-            } => (identity_pub, ephemeral_pub, signature, supported_profiles),
+                alias,
+            } => (identity_pub, ephemeral_pub, signature, supported_profiles, alias),
             other => {
                 return Err(anyhow::anyhow!(
                     "expected CallOffer, got {:?}",
@@ -76,25 +78,26 @@ pub async fn accept_handshake(
     };
     transport.send_signal(&answer).await?;
 
-    Ok((session, chosen_profile))
+    // Derive caller fingerprint: SHA-256(Ed25519 pub)[:16], formatted as xxxx:xxxx:...
+    // Must match the format used in signal registration and presence.
+    let caller_fp = {
+        use sha2::{Sha256, Digest};
+        let hash = Sha256::digest(&caller_identity_pub);
+        let fp = wzp_crypto::Fingerprint([
+            hash[0], hash[1], hash[2], hash[3], hash[4], hash[5], hash[6], hash[7],
+            hash[8], hash[9], hash[10], hash[11], hash[12], hash[13], hash[14], hash[15],
+        ]);
+        fp.to_string()
+    };
+
+    Ok((session, chosen_profile, caller_fp, caller_alias))
 }
 
 /// Select the best quality profile from those the caller supports.
 fn choose_profile(supported: &[QualityProfile]) -> QualityProfile {
-    // Prefer higher-quality profiles. Use GOOD as default if supported list is empty.
+    // Cap at GOOD (24k) for now — studio tiers (32k/48k/64k) not yet tested
-    if supported.is_empty() {
+    // for federation reliability (large packets may exceed path MTU).
-        return QualityProfile::GOOD;
+    QualityProfile::GOOD
-    }
-    // Pick the profile with the highest bitrate.
-    supported
-        .iter()
-        .max_by(|a, b| {
-            a.total_bitrate_kbps()
-                .partial_cmp(&b.total_bitrate_kbps())
-                .unwrap_or(std::cmp::Ordering::Equal)
-        })
-        .copied()
-        .unwrap_or(QualityProfile::GOOD)
 }
 
 #[cfg(test)]

crates/wzp-relay/src/lib.rs

@@ -8,7 +8,11 @@
 //! quality transitions.
 
 pub mod auth;
+pub mod call_registry;
 pub mod config;
+pub mod event_log;
+pub mod federation;
+pub mod signal_hub;
 pub mod handshake;
 pub mod metrics;
 pub mod pipeline;

crates/wzp-relay/src/main.rs

@@ -13,9 +13,9 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use tokio::sync::Mutex;
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
-use wzp_proto::MediaTransport;
+use wzp_proto::{MediaTransport, SignalMessage};
 use wzp_relay::config::RelayConfig;
 use wzp_relay::metrics::RelayMetrics;
 use wzp_relay::pipeline::{PipelineConfig, RelayPipeline};
@@ -23,12 +23,54 @@ use wzp_relay::presence::PresenceRegistry;
 use wzp_relay::room::{self, RoomManager};
 use wzp_relay::session_mgr::SessionManager;
 
-fn parse_args() -> RelayConfig {
+/// Parsed CLI result — config + identity path.
-    let mut config = RelayConfig::default();
+struct CliResult {
+    config: RelayConfig,
+    identity_path: Option<String>,
+    config_file: Option<String>,
+    config_needs_create: bool,
+}
+
+fn parse_args() -> CliResult {
     let args: Vec<String> = std::env::args().collect();
+
+    // First pass: extract --config and --identity
+    let mut config_file = None;
+    let mut identity_path = None;
     let mut i = 1;
     while i < args.len() {
         match args[i].as_str() {
+            "--config" | "-c" => { i += 1; config_file = args.get(i).cloned(); }
+            "--identity" | "-i" => { i += 1; identity_path = args.get(i).cloned(); }
+            _ => {}
+        }
+        i += 1;
+    }
+
+    // Track if we need to create the config after identity is known
+    let config_needs_create = config_file.as_ref().map(|p| !std::path::Path::new(p).exists()).unwrap_or(false);
+
+    let mut config = if let Some(ref path) = config_file {
+        if config_needs_create {
+            // Will be re-created with personalized info after identity is loaded
+            RelayConfig::default()
+        } else {
+            wzp_relay::config::load_config(path)
+                .unwrap_or_else(|e| {
+                    eprintln!("failed to load config from {path}: {e}");
+                    std::process::exit(1);
+                })
+        }
+    } else {
+        RelayConfig::default()
+    };
+
+    // CLI flags override config file values
+    let mut i = 1;
+    while i < args.len() {
+        match args[i].as_str() {
+            "--config" | "-c" => { i += 1; } // already handled
+            "--identity" | "-i" => { i += 1; } // already handled
             "--listen" => {
                 i += 1;
                 config.listen_addr = args.get(i).expect("--listen requires an address")
@@ -81,6 +123,28 @@ fn parse_args() -> RelayConfig {
                     args.get(i).expect("--static-dir requires a directory path").to_string(),
                 );
             }
+            "--global-room" => {
+                i += 1;
+                config.global_rooms.push(wzp_relay::config::GlobalRoomConfig {
+                    name: args.get(i).expect("--global-room requires a room name").to_string(),
+                });
+            }
+            "--debug-tap" => {
+                i += 1;
+                config.debug_tap = Some(
+                    args.get(i).expect("--debug-tap requires a room name (or '*' for all)").to_string(),
+                );
+            }
+            "--event-log" => {
+                i += 1;
+                config.event_log = Some(
+                    args.get(i).expect("--event-log requires a file path").to_string(),
+                );
+            }
+            "--version" | "-V" => {
+                println!("wzp-relay {}", env!("WZP_BUILD_HASH"));
+                std::process::exit(0);
+            }
             "--mesh-status" => {
                 // Print mesh table from a fresh registry and exit.
                 // In practice this is useful after the relay has been running;
@@ -90,9 +154,11 @@ fn parse_args() -> RelayConfig {
                 std::process::exit(0);
             }
             "--help" | "-h" => {
-                eprintln!("Usage: wzp-relay [--listen <addr>] [--remote <addr>] [--auth-url <url>] [--metrics-port <port>] [--probe <addr>]... [--probe-mesh] [--mesh-status]");
+                eprintln!("Usage: wzp-relay [--config <path>] [--listen <addr>] [--remote <addr>] [--auth-url <url>] [--metrics-port <port>] [--probe <addr>]... [--probe-mesh] [--mesh-status]");
                 eprintln!();
                 eprintln!("Options:");
+                eprintln!("  -c, --config <path>    Load config from TOML file (creates example if missing)");
+                eprintln!("  -i, --identity <path>  Identity file path (creates if missing, uses OsRng)");
                 eprintln!("  --listen <addr>        Listen address (default: 0.0.0.0:4433)");
                 eprintln!("  --remote <addr>        Remote relay for forwarding (disables room mode)");
                 eprintln!("  --auth-url <url>       featherChat auth endpoint (e.g., https://chat.example.com/v1/auth/validate)");
@@ -102,6 +168,8 @@ fn parse_args() -> RelayConfig {
                 eprintln!("  --probe-mesh           Enable mesh mode (mark config flag, probes all --probe targets).");
                 eprintln!("  --mesh-status          Print mesh health table and exit (diagnostic).");
                 eprintln!("  --trunking             Enable trunk batching for outgoing media in room mode.");
+                eprintln!("  --global-room <name>   Declare a room as global (bridged across federation). Repeatable.");
+                eprintln!("  --debug-tap <room>     Log packet headers for a room ('*' for all rooms).");
                 eprintln!("  --ws-port <port>       WebSocket listener port for browser clients (e.g., 8080).");
                 eprintln!("  --static-dir <dir>     Directory to serve static files from (HTML/JS/WASM).");
                 eprintln!();
@@ -116,7 +184,7 @@ fn parse_args() -> RelayConfig {
         }
         i += 1;
     }
-    config
+    CliResult { config, identity_path, config_file, config_needs_create }
 }
 
 struct RelayStats {
@@ -184,10 +252,29 @@ async fn run_downstream(
     }
 }
 
+/// Detect a non-loopback IP address from local interfaces.
+/// Prefers public IPs over private (10.x, 172.16-31.x, 192.168.x).
+fn detect_public_ip() -> Option<String> {
+    use std::net::UdpSocket;
+    // Connect to a public address to find our outbound IP (doesn't actually send anything)
+    if let Ok(socket) = UdpSocket::bind("0.0.0.0:0") {
+        if socket.connect("8.8.8.8:80").is_ok() {
+            if let Ok(addr) = socket.local_addr() {
+                return Some(addr.ip().to_string());
+            }
+        }
+    }
+    None
+}
+
+/// Build-time git hash, set by build.rs or env.
+const BUILD_GIT_HASH: &str = env!("WZP_BUILD_HASH");
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    let config = parse_args();
+    let CliResult { mut config, identity_path, config_file, config_needs_create } = parse_args();
     tracing_subscriber::fmt().init();
+    info!(version = BUILD_GIT_HASH, "wzp-relay build");
     rustls::crypto::ring::default_provider()
         .install_default()
         .expect("failed to install rustls crypto provider");
@@ -207,12 +294,88 @@ async fn main() -> anyhow::Result<()> {
         tokio::spawn(wzp_relay::metrics::serve_metrics(port, m, p, rr));
     }
 
-    // Generate ephemeral relay identity for crypto handshake
+    // Load or generate relay identity
-    let relay_seed = wzp_crypto::Seed::generate();
+    let relay_seed = {
+        let id_path = match identity_path {
+            Some(ref p) => std::path::PathBuf::from(p),
+            None => dirs::home_dir()
+                .unwrap_or_else(|| std::path::PathBuf::from("."))
+                .join(".wzp")
+                .join("relay-identity"),
+        };
+        if id_path.exists() {
+            if let Ok(hex) = std::fs::read_to_string(&id_path) {
+                if let Ok(s) = wzp_crypto::Seed::from_hex(hex.trim()) {
+                    info!("loaded relay identity from {}", id_path.display());
+                    s
+                } else {
+                    warn!("corrupt identity file {}, generating new", id_path.display());
+                    let s = wzp_crypto::Seed::generate();
+                    let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                    let _ = std::fs::write(&id_path, &hex);
+                    s
+                }
+            } else {
+                let s = wzp_crypto::Seed::generate();
+                let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                let _ = std::fs::write(&id_path, &hex);
+                s
+            }
+        } else {
+            let s = wzp_crypto::Seed::generate();
+            if let Some(parent) = id_path.parent() {
+                let _ = std::fs::create_dir_all(parent);
+            }
+            let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+            let _ = std::fs::write(&id_path, &hex);
+            info!("generated relay identity at {}", id_path.display());
+            s
+        }
+    };
     let relay_fp = relay_seed.derive_identity().public_identity().fingerprint;
     info!(addr = %config.listen_addr, fingerprint = %relay_fp, "WarzonePhone relay starting");
 
-    let (server_config, _cert) = wzp_transport::server_config();
+    let (server_config, cert_der) = wzp_transport::server_config_from_seed(&relay_seed.0);
+    let tls_fp = wzp_transport::tls_fingerprint(&cert_der);
+    info!(tls_fingerprint = %tls_fp, "TLS certificate (deterministic from relay identity)");
+
+    // Create personalized config file if it was missing
+    let public_ip = detect_public_ip();
+    if config_needs_create {
+        if let Some(ref path) = config_file {
+            let info = wzp_relay::config::RelayInfo {
+                listen_addr: config.listen_addr.to_string(),
+                tls_fingerprint: tls_fp.clone(),
+                public_ip: public_ip.clone(),
+            };
+            if let Err(e) = wzp_relay::config::load_or_create_config(path, Some(&info)) {
+                warn!("failed to create config: {e}");
+            }
+        }
+    }
+
+    // Print federation hint with our public IP + listen port + TLS fingerprint
+    let listen_port = config.listen_addr.port();
+    if let Some(ip) = &public_ip {
+        info!("federation: to peer with this relay, add to relay.toml:");
+        info!("  [[peers]]");
+        info!("  url = \"{ip}:{listen_port}\"");
+        info!("  fingerprint = \"{tls_fp}\"");
+    }
+
+    // Log configured peers and trusted relays
+    if !config.peers.is_empty() {
+        info!(count = config.peers.len(), "federation peers configured");
+        for p in &config.peers {
+            info!(url = %p.url, label = ?p.label, "  peer");
+        }
+    }
+    if !config.trusted.is_empty() {
+        info!(count = config.trusted.len(), "trusted relays configured");
+        for t in &config.trusted {
+            info!(fingerprint = %t.fingerprint, label = ?t.label, "  trusted");
+        }
+    }
     let endpoint = wzp_transport::create_endpoint(config.listen_addr, Some(server_config))?;
 
     // Forward mode
@@ -230,9 +393,41 @@ async fn main() -> anyhow::Result<()> {
     // Room manager (room mode only)
     let room_mgr = Arc::new(Mutex::new(RoomManager::new()));
 
+    // Event log for protocol analysis
+    let event_log = wzp_relay::event_log::start_event_log(
+        config.event_log.as_ref().map(std::path::PathBuf::from)
+    );
+
+    // Federation manager
+    let global_room_set: std::collections::HashSet<String> = config.global_rooms.iter()
+        .map(|g| g.name.clone())
+        .collect();
+
+    let federation_mgr = if !config.peers.is_empty() || !config.trusted.is_empty() || !global_room_set.is_empty() {
+        let fm = Arc::new(wzp_relay::federation::FederationManager::new(
+            config.peers.clone(),
+            config.trusted.clone(),
+            global_room_set.clone(),
+            room_mgr.clone(),
+            endpoint.clone(),
+            tls_fp.clone(),
+            metrics.clone(),
+            event_log.clone(),
+        ));
+        let fm_run = fm.clone();
+        tokio::spawn(async move { fm_run.run().await });
+        Some(fm)
+    } else {
+        None
+    };
+
     // Session manager — enforces max concurrent sessions
     let session_mgr = Arc::new(Mutex::new(SessionManager::new(config.max_sessions)));
 
+    // Signal hub + call registry for direct 1:1 calls
+    let signal_hub = Arc::new(Mutex::new(wzp_relay::signal_hub::SignalHub::new()));
+    let call_registry = Arc::new(Mutex::new(wzp_relay::call_registry::CallRegistry::new()));
+
     // Spawn inter-relay health probes via ProbeMesh coordinator
     if !config.probe_targets.is_empty() {
         let mesh = wzp_relay::probe::ProbeMesh::new(
@@ -267,6 +462,15 @@ async fn main() -> anyhow::Result<()> {
     } else {
         info!("auth disabled — any client can connect (use --auth-url to enable)");
     }
+    if !config.global_rooms.is_empty() {
+        info!(count = config.global_rooms.len(), "global rooms configured");
+        for g in &config.global_rooms {
+            info!(name = %g.name, "  global room");
+        }
+    }
+    if let Some(ref tap) = config.debug_tap {
+        info!(filter = %tap, "debug tap enabled — logging packet headers");
+    }
 
     info!("Listening for connections...");
 
@@ -283,8 +487,13 @@ async fn main() -> anyhow::Result<()> {
         let relay_seed_bytes = relay_seed.0;
         let metrics = metrics.clone();
         let trunking_enabled = config.trunking_enabled;
+        let debug_tap = config.debug_tap.as_ref().map(|filter| room::DebugTap { room_filter: filter.clone() });
         let presence = presence.clone();
         let route_resolver = route_resolver.clone();
+        let federation_mgr = federation_mgr.clone();
+        let signal_hub = signal_hub.clone();
+        let call_registry = call_registry.clone();
+        let listen_addr_str = config.listen_addr.to_string();
 
         tokio::spawn(async move {
             let addr = connection.remote_address();
@@ -299,6 +508,23 @@ async fn main() -> anyhow::Result<()> {
 
             let transport = Arc::new(wzp_transport::QuinnTransport::new(connection));
 
+            // Ping connections: client just measures QUIC connect RTT.
+            if room_name == "ping" {
+                info!(%addr, "ping connection (RTT probe)");
+                return;
+            }
+
+            // Version query: respond with build hash over a uni stream.
+            if room_name == "version" {
+                if let Ok(mut send) = transport.connection().open_uni().await {
+                    let _ = send.write_all(BUILD_GIT_HASH.as_bytes()).await;
+                    let _ = send.finish();
+                    // Wait for client to read before closing
+                    tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+                }
+                return;
+            }
+
             // Probe connections use SNI "_probe" to identify themselves.
             // They skip auth + handshake and just do Ping->Pong + presence gossip.
             if room_name == "_probe" {
@@ -385,6 +611,294 @@ async fn main() -> anyhow::Result<()> {
                 return;
             }
 
+            // Federation connections use SNI "_federation"
+            if room_name == "_federation" {
+                if let Some(ref fm) = federation_mgr {
+                    // Wait for FederationHello to identify the connecting relay
+                    let hello_fp = match tokio::time::timeout(
+                        std::time::Duration::from_secs(5),
+                        transport.recv_signal(),
+                    ).await {
+                        Ok(Ok(Some(wzp_proto::SignalMessage::FederationHello { tls_fingerprint }))) => tls_fingerprint,
+                        _ => {
+                            warn!(%addr, "federation: no hello received, closing");
+                            return;
+                        }
+                    };
+
+                    if let Some(label) = fm.check_inbound_trust(addr, &hello_fp) {
+                        let peer_config = wzp_relay::config::PeerConfig {
+                            url: addr.to_string(),
+                            fingerprint: hello_fp,
+                            label: Some(label.clone()),
+                        };
+                        let fm = fm.clone();
+                        info!(%addr, label = %label, "inbound federation accepted (trusted)");
+                        fm.handle_inbound(transport, peer_config).await;
+                    } else {
+                        warn!(%addr, fp = %hello_fp, "unknown relay wants to federate");
+                        info!("  to accept, add to relay.toml:");
+                        info!("  [[trusted]]");
+                        info!("  fingerprint = \"{hello_fp}\"");
+                        info!("  label = \"Relay at {addr}\"");
+                    }
+                } else {
+                    info!(%addr, "federation connection rejected (no federation configured)");
+                }
+                return;
+            }
+
+            // Direct calling: persistent signaling connection
+            if room_name == "_signal" {
+                info!(%addr, "signal connection");
+
+                // Optional auth
+                let auth_fp: Option<String> = if let Some(ref url) = auth_url {
+                    match transport.recv_signal().await {
+                        Ok(Some(SignalMessage::AuthToken { token })) => {
+                            match wzp_relay::auth::validate_token(url, &token).await {
+                                Ok(client) => Some(client.fingerprint),
+                                Err(e) => {
+                                    error!(%addr, "signal auth failed: {e}");
+                                    return;
+                                }
+                            }
+                        }
+                        _ => { warn!(%addr, "signal: expected AuthToken"); return; }
+                    }
+                } else {
+                    None
+                };
+
+                // Wait for RegisterPresence
+                let (client_fp, client_alias) = match tokio::time::timeout(
+                    std::time::Duration::from_secs(10),
+                    transport.recv_signal(),
+                ).await {
+                    Ok(Ok(Some(SignalMessage::RegisterPresence { identity_pub, signature: _, alias }))) => {
+                        // Compute fingerprint: SHA-256(Ed25519 pub key)[:16], same as Fingerprint type
+                        let fp = {
+                            use sha2::{Sha256, Digest};
+                            let hash = Sha256::digest(&identity_pub);
+                            let fingerprint = wzp_crypto::Fingerprint([
+                                hash[0], hash[1], hash[2], hash[3], hash[4], hash[5], hash[6], hash[7],
+                                hash[8], hash[9], hash[10], hash[11], hash[12], hash[13], hash[14], hash[15],
+                            ]);
+                            fingerprint.to_string()
+                        };
+                        let fp = auth_fp.unwrap_or(fp);
+                        (fp, alias)
+                    }
+                    _ => {
+                        warn!(%addr, "signal: no RegisterPresence received");
+                        return;
+                    }
+                };
+
+                // Register in signal hub + presence
+                {
+                    let mut hub = signal_hub.lock().await;
+                    hub.register(client_fp.clone(), transport.clone(), client_alias.clone());
+                }
+                {
+                    let mut reg = presence.lock().await;
+                    reg.register_local(&client_fp, client_alias.clone(), None);
+                }
+
+                // Send ack
+                let _ = transport.send_signal(&SignalMessage::RegisterPresenceAck {
+                    success: true,
+                    error: None,
+                }).await;
+
+                info!(%addr, fingerprint = %client_fp, alias = ?client_alias, "signal client registered");
+
+                // Signal recv loop
+                loop {
+                    match transport.recv_signal().await {
+                        Ok(Some(msg)) => {
+                            match msg {
+                                SignalMessage::DirectCallOffer { ref target_fingerprint, ref call_id, ref caller_alias, .. } => {
+                                    let target_fp = target_fingerprint.clone();
+                                    let call_id = call_id.clone();
+
+                                    // Check if target is online
+                                    let online = {
+                                        let hub = signal_hub.lock().await;
+                                        hub.is_online(&target_fp)
+                                    };
+                                    if !online {
+                                        info!(%addr, target = %target_fp, "call target not online");
+                                        let _ = transport.send_signal(&SignalMessage::Hangup {
+                                            reason: wzp_proto::HangupReason::Normal,
+                                        }).await;
+                                        continue;
+                                    }
+
+                                    // Create call in registry
+                                    {
+                                        let mut reg = call_registry.lock().await;
+                                        reg.create_call(call_id.clone(), client_fp.clone(), target_fp.clone());
+                                    }
+
+                                    // Forward offer to callee
+                                    info!(caller = %client_fp, callee = %target_fp, call_id = %call_id, "routing direct call offer");
+                                    let hub = signal_hub.lock().await;
+                                    if let Err(e) = hub.send_to(&target_fp, &msg).await {
+                                        warn!("failed to forward call offer: {e}");
+                                    }
+
+                                    // Send ringing to caller
+                                    drop(hub);
+                                    let _ = transport.send_signal(&SignalMessage::CallRinging {
+                                        call_id: call_id.clone(),
+                                    }).await;
+                                }
+
+                                SignalMessage::DirectCallAnswer { ref call_id, ref accept_mode, .. } => {
+                                    let call_id = call_id.clone();
+                                    let mode = *accept_mode;
+
+                                    let peer_fp = {
+                                        let reg = call_registry.lock().await;
+                                        reg.peer_fingerprint(&call_id, &client_fp).map(|s| s.to_string())
+                                    };
+
+                                    let Some(peer_fp) = peer_fp else {
+                                        warn!(call_id = %call_id, "answer for unknown call");
+                                        continue;
+                                    };
+
+                                    if mode == wzp_proto::CallAcceptMode::Reject {
+                                        info!(call_id = %call_id, "call rejected");
+                                        let mut reg = call_registry.lock().await;
+                                        reg.end_call(&call_id);
+                                        drop(reg);
+                                        let hub = signal_hub.lock().await;
+                                        let _ = hub.send_to(&peer_fp, &SignalMessage::Hangup {
+                                            reason: wzp_proto::HangupReason::Normal,
+                                        }).await;
+                                    } else {
+                                        // Accept — create private room
+                                        let room = format!("call-{call_id}");
+                                        {
+                                            let mut reg = call_registry.lock().await;
+                                            reg.set_active(&call_id, mode, room.clone());
+                                        }
+                                        info!(call_id = %call_id, room = %room, mode = ?mode, "call accepted, creating room");
+
+                                        // Forward answer to caller
+                                        {
+                                            let hub = signal_hub.lock().await;
+                                            let _ = hub.send_to(&peer_fp, &msg).await;
+                                        }
+
+                                        // Send CallSetup to both parties
+                                        // Use the address the client connected to (their remote addr
+                                        // is our perspective, but we need our listen addr).
+                                        // Replace 0.0.0.0 with the client's destination IP.
+                                        let relay_addr_for_setup = if listen_addr_str.starts_with("0.0.0.0:") {
+                                            let port = &listen_addr_str[8..];
+                                            // Use the local IP from the client's connection
+                                            let local_ip = addr.ip();
+                                            if local_ip.is_loopback() {
+                                                format!("127.0.0.1:{port}")
+                                            } else {
+                                                format!("{local_ip}:{port}")
+                                            }
+                                        } else {
+                                            listen_addr_str.clone()
+                                        };
+                                        let setup = SignalMessage::CallSetup {
+                                            call_id: call_id.clone(),
+                                            room: room.clone(),
+                                            relay_addr: relay_addr_for_setup,
+                                        };
+                                        {
+                                            let hub = signal_hub.lock().await;
+                                            let _ = hub.send_to(&peer_fp, &setup).await;
+                                            let _ = hub.send_to(&client_fp, &setup).await;
+                                        }
+                                    }
+                                }
+
+                                SignalMessage::Hangup { .. } => {
+                                    // Forward hangup to all active calls for this user
+                                    let calls = {
+                                        let reg = call_registry.lock().await;
+                                        reg.calls_for_fingerprint(&client_fp)
+                                            .iter()
+                                            .map(|c| (c.call_id.clone(), if c.caller_fingerprint == client_fp {
+                                                c.callee_fingerprint.clone()
+                                            } else {
+                                                c.caller_fingerprint.clone()
+                                            }))
+                                            .collect::<Vec<_>>()
+                                    };
+                                    for (call_id, peer_fp) in &calls {
+                                        let hub = signal_hub.lock().await;
+                                        let _ = hub.send_to(peer_fp, &msg).await;
+                                        drop(hub);
+                                        let mut reg = call_registry.lock().await;
+                                        reg.end_call(call_id);
+                                    }
+                                }
+
+                                SignalMessage::Ping { timestamp_ms } => {
+                                    let _ = transport.send_signal(&SignalMessage::Pong { timestamp_ms }).await;
+                                }
+
+                                other => {
+                                    warn!(%addr, "signal: unexpected message: {:?}", std::mem::discriminant(&other));
+                                }
+                            }
+                        }
+                        Ok(None) => {
+                            info!(%addr, "signal connection closed");
+                            break;
+                        }
+                        Err(e) => {
+                            warn!(%addr, "signal recv error: {e}");
+                            break;
+                        }
+                    }
+                }
+
+                // Cleanup: unregister + end active calls
+                let active_calls = {
+                    let reg = call_registry.lock().await;
+                    reg.calls_for_fingerprint(&client_fp)
+                        .iter()
+                        .map(|c| (c.call_id.clone(), if c.caller_fingerprint == client_fp {
+                            c.callee_fingerprint.clone()
+                        } else {
+                            c.caller_fingerprint.clone()
+                        }))
+                        .collect::<Vec<_>>()
+                };
+                for (call_id, peer_fp) in &active_calls {
+                    let hub = signal_hub.lock().await;
+                    let _ = hub.send_to(peer_fp, &SignalMessage::Hangup {
+                        reason: wzp_proto::HangupReason::Normal,
+                    }).await;
+                    drop(hub);
+                    let mut reg = call_registry.lock().await;
+                    reg.end_call(call_id);
+                }
+
+                {
+                    let mut hub = signal_hub.lock().await;
+                    hub.unregister(&client_fp);
+                }
+                {
+                    let mut reg = presence.lock().await;
+                    reg.unregister_local(&client_fp);
+                }
+
+                transport.close().await.ok();
+                return;
+            }
+
             // Auth check: if --auth-url is set, expect first signal message to be a token
             // Auth: if --auth-url is set, expect AuthToken as first signal
             let authenticated_fp: Option<String> = if let Some(ref url) = auth_url {
@@ -431,7 +945,7 @@ async fn main() -> anyhow::Result<()> {
 
             // Crypto handshake: verify client identity + negotiate quality profile
             let handshake_start = std::time::Instant::now();
-            let (_crypto_session, _chosen_profile) = match wzp_relay::handshake::accept_handshake(
+            let (_crypto_session, _chosen_profile, caller_fp, caller_alias) = match wzp_relay::handshake::accept_handshake(
                 &*transport,
                 &relay_seed_bytes,
             ).await {
@@ -448,10 +962,35 @@ async fn main() -> anyhow::Result<()> {
                 }
             };
 
+            // Use the caller's identity fingerprint from the handshake
+            let participant_fp = authenticated_fp.clone().unwrap_or(caller_fp);
+
+            // ACL: call rooms (call-*) are restricted to the two authorized participants.
+            // Only the relay's call orchestrator creates these rooms — random clients can't join.
+            if room_name.starts_with("call-") {
+                let call_id = &room_name[5..]; // strip "call-" prefix
+                let authorized = {
+                    let reg = call_registry.lock().await;
+                    match reg.get(call_id) {
+                        Some(call) => {
+                            call.caller_fingerprint == participant_fp
+                                || call.callee_fingerprint == participant_fp
+                        }
+                        None => false, // unknown call — reject
+                    }
+                };
+                if !authorized {
+                    warn!(%addr, room = %room_name, fp = %participant_fp, "rejected: not authorized for this call room");
+                    transport.close().await.ok();
+                    return;
+                }
+                info!(%addr, room = %room_name, fp = %participant_fp, "authorized for call room");
+            }
+
             // Register in presence registry
-            if let Some(ref fp) = authenticated_fp {
+            {
                 let mut reg = presence.lock().await;
-                reg.register_local(fp, None, Some(room_name.clone()));
+                reg.register_local(&participant_fp, None, Some(room_name.clone()));
             }
 
             info!(%addr, room = %room_name, "client joining");
@@ -500,16 +1039,55 @@ async fn main() -> anyhow::Result<()> {
 
                 metrics.active_sessions.inc();
 
+                // Call rooms: enforce 2-participant limit
+                if room_name.starts_with("call-") {
+                    let mgr = room_mgr.lock().await;
+                    if mgr.room_size(&room_name) >= 2 {
+                        drop(mgr);
+                        warn!(%addr, room = %room_name, "call room full (max 2 participants)");
+                        metrics.active_sessions.dec();
+                        let mut smgr = session_mgr.lock().await;
+                        smgr.remove_session(session_id);
+                        transport.close().await.ok();
+                        return;
+                    }
+                }
+
                 let participant_id = {
                     let mut mgr = room_mgr.lock().await;
-                    match mgr.join(&room_name, addr, room::ParticipantSender::Quic(transport.clone()), authenticated_fp.as_deref()) {
+                    match mgr.join(
-                        Ok(id) => {
+                        &room_name,
+                        addr,
+                        room::ParticipantSender::Quic(transport.clone()),
+                        Some(&participant_fp),
+                        caller_alias.as_deref(),
+                    ) {
+                        Ok((id, update, senders)) => {
                             metrics.active_rooms.set(mgr.list().len() as i64);
+                            drop(mgr); // release lock before async broadcast
+
+                            // Merge federated participants into RoomUpdate if this is a global room
+                            let merged_update = if let Some(ref fm) = federation_mgr {
+                                if fm.is_global_room(&room_name) {
+                                    if let SignalMessage::RoomUpdate { count: _, participants: mut local_parts } = update {
+                                        let remote = fm.get_remote_participants(&room_name).await;
+                                        local_parts.extend(remote);
+                                        // Deduplicate by fingerprint
+                                        let mut seen = std::collections::HashSet::new();
+                                        local_parts.retain(|p| seen.insert(p.fingerprint.clone()));
+                                        SignalMessage::RoomUpdate {
+                                            count: local_parts.len() as u32,
+                                            participants: local_parts,
+                                        }
+                                    } else { update }
+                                } else { update }
+                            } else { update };
+
+                            room::broadcast_signal(&senders, &merged_update).await;
                             id
                         }
                         Err(e) => {
                             error!(%addr, room = %room_name, "room join denied: {e}");
-                            // Clean up the session we just created
                             metrics.active_sessions.dec();
                             let mut smgr = session_mgr.lock().await;
                             smgr.remove_session(session_id);
@@ -523,6 +1101,25 @@ async fn main() -> anyhow::Result<()> {
                     .iter()
                     .map(|b| format!("{b:02x}"))
                     .collect();
+                // Set up federation media channel if this is a global room
+                let (federation_tx, federation_room_hash) = if let Some(ref fm) = federation_mgr {
+                    let is_global = fm.is_global_room(&room_name);
+                    if is_global {
+                        let canonical_hash = fm.global_room_hash(&room_name);
+                        let (tx, rx) = tokio::sync::mpsc::channel(256);
+                        let fm_clone = fm.clone();
+                        tokio::spawn(async move {
+                            wzp_relay::federation::run_federation_media_egress(fm_clone, rx).await;
+                        });
+                        info!(room = %room_name, canonical = ?fm.resolve_global_room(&room_name), "federation egress created (global room)");
+                        (Some(tx), Some(canonical_hash))
+                    } else {
+                        (None, None)
+                    }
+                } else {
+                    (None, None)
+                };
+
                 room::run_participant(
                     room_mgr.clone(),
                     room_name,
@@ -531,6 +1128,9 @@ async fn main() -> anyhow::Result<()> {
                     metrics.clone(),
                     &session_id_str,
                     trunking_enabled,
+                    debug_tap,
+                    federation_tx,
+                    federation_room_hash,
                 ).await;
 
                 // Participant disconnected — clean up presence + per-session metrics

crates/wzp-relay/src/metrics.rs

@@ -16,6 +16,13 @@ pub struct RelayMetrics {
     pub bytes_forwarded: IntCounter,
     pub auth_attempts: IntCounterVec,
     pub handshake_duration: Histogram,
+    // Federation metrics
+    pub federation_peer_status: IntGaugeVec,
+    pub federation_peer_rtt_ms: GaugeVec,
+    pub federation_packets_forwarded: IntCounterVec,
+    pub federation_packets_deduped: IntCounter,
+    pub federation_packets_rate_limited: IntCounter,
+    pub federation_active_rooms: IntGauge,
     // Per-session metrics
     pub session_buffer_depth: IntGaugeVec,
     pub session_loss_pct: GaugeVec,
@@ -60,6 +67,28 @@ impl RelayMetrics {
         )
         .expect("metric");
 
+        let federation_peer_status = IntGaugeVec::new(
+            Opts::new("wzp_federation_peer_status", "Peer connection status (0=disconnected, 1=connected)"),
+            &["peer"],
+        ).expect("metric");
+        let federation_peer_rtt_ms = GaugeVec::new(
+            Opts::new("wzp_federation_peer_rtt_ms", "QUIC RTT to federated peer in milliseconds"),
+            &["peer"],
+        ).expect("metric");
+        let federation_packets_forwarded = IntCounterVec::new(
+            Opts::new("wzp_federation_packets_forwarded_total", "Packets forwarded to/from federated peers"),
+            &["peer", "direction"],
+        ).expect("metric");
+        let federation_packets_deduped = IntCounter::with_opts(
+            Opts::new("wzp_federation_packets_deduped_total", "Duplicate federation packets dropped"),
+        ).expect("metric");
+        let federation_packets_rate_limited = IntCounter::with_opts(
+            Opts::new("wzp_federation_packets_rate_limited_total", "Federation packets dropped by rate limiter"),
+        ).expect("metric");
+        let federation_active_rooms = IntGauge::with_opts(
+            Opts::new("wzp_federation_active_rooms", "Number of federated rooms currently active"),
+        ).expect("metric");
+
         let session_buffer_depth = IntGaugeVec::new(
             Opts::new(
                 "wzp_relay_session_jitter_buffer_depth",
@@ -107,6 +136,12 @@ impl RelayMetrics {
         registry.register(Box::new(bytes_forwarded.clone())).expect("register");
         registry.register(Box::new(auth_attempts.clone())).expect("register");
         registry.register(Box::new(handshake_duration.clone())).expect("register");
+        registry.register(Box::new(federation_peer_status.clone())).expect("register");
+        registry.register(Box::new(federation_peer_rtt_ms.clone())).expect("register");
+        registry.register(Box::new(federation_packets_forwarded.clone())).expect("register");
+        registry.register(Box::new(federation_packets_deduped.clone())).expect("register");
+        registry.register(Box::new(federation_packets_rate_limited.clone())).expect("register");
+        registry.register(Box::new(federation_active_rooms.clone())).expect("register");
         registry.register(Box::new(session_buffer_depth.clone())).expect("register");
         registry.register(Box::new(session_loss_pct.clone())).expect("register");
         registry.register(Box::new(session_rtt_ms.clone())).expect("register");
@@ -120,6 +155,12 @@ impl RelayMetrics {
             bytes_forwarded,
             auth_attempts,
             handshake_duration,
+            federation_peer_status,
+            federation_peer_rtt_ms,
+            federation_packets_forwarded,
+            federation_packets_deduped,
+            federation_packets_rate_limited,
+            federation_active_rooms,
             session_buffer_depth,
             session_loss_pct,
             session_rtt_ms,

crates/wzp-relay/src/room.rs

@@ -10,7 +10,7 @@ use std::time::Duration;
 
 use bytes::Bytes;
 use tokio::sync::Mutex;
-use tracing::{error, info, warn};
+use tracing::{debug, error, info, trace, warn};
 
 use wzp_proto::packet::TrunkFrame;
 use wzp_proto::MediaTransport;
@@ -18,6 +18,38 @@ use wzp_proto::MediaTransport;
 use crate::metrics::RelayMetrics;
 use crate::trunk::TrunkBatcher;
 
+/// Debug tap: logs packet metadata for matching rooms.
+#[derive(Clone)]
+pub struct DebugTap {
+    /// Room name filter ("*" = all rooms, or specific room name/hash).
+    pub room_filter: String,
+}
+
+impl DebugTap {
+    pub fn matches(&self, room_name: &str) -> bool {
+        self.room_filter == "*" || self.room_filter == room_name
+    }
+
+    pub fn log_packet(&self, room: &str, dir: &str, addr: &std::net::SocketAddr, pkt: &wzp_proto::MediaPacket, fan_out: usize) {
+        let h = &pkt.header;
+        info!(
+            target: "debug_tap",
+            room = %room,
+            dir = dir,
+            addr = %addr,
+            seq = h.seq,
+            codec = ?h.codec_id,
+            ts = h.timestamp,
+            fec_block = h.fec_block,
+            fec_sym = h.fec_symbol,
+            repair = h.is_repair,
+            len = pkt.payload.len(),
+            fan_out,
+            "TAP"
+        );
+    }
+}
+
 /// Unique participant ID within a room.
 pub type ParticipantId = u64;
 
@@ -27,6 +59,22 @@ fn next_id() -> ParticipantId {
     NEXT_PARTICIPANT_ID.fetch_add(1, Ordering::Relaxed)
 }
 
+/// Events emitted by RoomManager for federation to observe.
+#[derive(Clone, Debug)]
+pub enum RoomEvent {
+    /// First local participant joined this room.
+    LocalJoin { room: String },
+    /// Last local participant left this room.
+    LocalLeave { room: String },
+}
+
+/// Outbound federation media from a local participant.
+pub struct FederationMediaOut {
+    pub room_name: String,
+    pub room_hash: [u8; 8],
+    pub data: Bytes,
+}
+
 /// How to send data to a participant — either via QUIC transport or WebSocket channel.
 #[derive(Clone)]
 pub enum ParticipantSender {
@@ -67,11 +115,24 @@ impl ParticipantSender {
     }
 }
 
+/// Broadcast a signal message to a list of participant senders.
+pub async fn broadcast_signal(senders: &[ParticipantSender], msg: &wzp_proto::SignalMessage) {
+    for sender in senders {
+        if let ParticipantSender::Quic(t) = sender {
+            if let Err(e) = t.send_signal(msg).await {
+                warn!("broadcast_signal error: {e}");
+            }
+        }
+    }
+}
+
 /// A participant in a room.
 struct Participant {
     id: ParticipantId,
     _addr: std::net::SocketAddr,
     sender: ParticipantSender,
+    fingerprint: Option<String>,
+    alias: Option<String>,
 }
 
 /// A room holding multiple participants.
@@ -86,10 +147,16 @@ impl Room {
         }
     }
 
-    fn add(&mut self, addr: std::net::SocketAddr, sender: ParticipantSender) -> ParticipantId {
+    fn add(
+        &mut self,
+        addr: std::net::SocketAddr,
+        sender: ParticipantSender,
+        fingerprint: Option<String>,
+        alias: Option<String>,
+    ) -> ParticipantId {
         let id = next_id();
         info!(room_size = self.participants.len() + 1, participant = id, %addr, "joined room");
-        self.participants.push(Participant { id, _addr: addr, sender });
+        self.participants.push(Participant { id, _addr: addr, sender, fingerprint, alias });
         id
     }
 
@@ -106,6 +173,23 @@ impl Room {
             .collect()
     }
 
+    /// Build a RoomUpdate participant list.
+    fn participant_list(&self) -> Vec<wzp_proto::packet::RoomParticipant> {
+        self.participants
+            .iter()
+            .map(|p| wzp_proto::packet::RoomParticipant {
+                fingerprint: p.fingerprint.clone().unwrap_or_default(),
+                alias: p.alias.clone(),
+                relay_label: None, // local participant
+            })
+            .collect()
+    }
+
+    /// Get all senders (for broadcasting to everyone including the joiner).
+    fn all_senders(&self) -> Vec<ParticipantSender> {
+        self.participants.iter().map(|p| p.sender.clone()).collect()
+    }
+
     fn is_empty(&self) -> bool {
         self.participants.is_empty()
     }
@@ -122,24 +206,35 @@ pub struct RoomManager {
     /// When `None`, rooms are open (no auth mode). When `Some`, only listed
     /// fingerprints can join the corresponding room.
     acl: Option<HashMap<String, HashSet<String>>>,
+    /// Channel for room lifecycle events (federation subscribes).
+    event_tx: tokio::sync::broadcast::Sender<RoomEvent>,
 }
 
 impl RoomManager {
     pub fn new() -> Self {
+        let (event_tx, _) = tokio::sync::broadcast::channel(64);
         Self {
             rooms: HashMap::new(),
             acl: None,
+            event_tx,
         }
     }
 
     /// Create a room manager with ACL enforcement enabled.
     pub fn with_acl() -> Self {
+        let (event_tx, _) = tokio::sync::broadcast::channel(64);
         Self {
             rooms: HashMap::new(),
             acl: Some(HashMap::new()),
+            event_tx,
         }
     }
 
+    /// Subscribe to room lifecycle events (for federation).
+    pub fn subscribe_events(&self) -> tokio::sync::broadcast::Receiver<RoomEvent> {
+        self.event_tx.subscribe()
+    }
+
     /// Grant a fingerprint access to a room.
     pub fn allow(&mut self, room_name: &str, fingerprint: &str) {
         if let Some(ref mut acl) = self.acl {
@@ -165,20 +260,32 @@ impl RoomManager {
         }
     }
 
-    /// Join a room. Returns the participant ID or an error if unauthorized.
+    /// Join a room. Returns (participant_id, room_update_msg, all_senders) for broadcasting.
     pub fn join(
         &mut self,
         room_name: &str,
         addr: std::net::SocketAddr,
         sender: ParticipantSender,
         fingerprint: Option<&str>,
-    ) -> Result<ParticipantId, String> {
+        alias: Option<&str>,
+    ) -> Result<(ParticipantId, wzp_proto::SignalMessage, Vec<ParticipantSender>), String> {
         if !self.is_authorized(room_name, fingerprint) {
             warn!(room = room_name, fingerprint = ?fingerprint, "unauthorized room join attempt");
             return Err("not authorized for this room".to_string());
         }
+        let was_empty = !self.rooms.contains_key(room_name)
+            || self.rooms.get(room_name).map_or(true, |r| r.is_empty());
         let room = self.rooms.entry(room_name.to_string()).or_insert_with(Room::new);
-        Ok(room.add(addr, sender))
+        let id = room.add(addr, sender, fingerprint.map(|s| s.to_string()), alias.map(|s| s.to_string()));
+        if was_empty {
+            let _ = self.event_tx.send(RoomEvent::LocalJoin { room: room_name.to_string() });
+        }
+        let update = wzp_proto::SignalMessage::RoomUpdate {
+            count: room.len() as u32,
+            participants: room.participant_list(),
+        };
+        let senders = room.all_senders();
+        Ok((id, update, senders))
     }
 
     /// Join a room via WebSocket. Convenience wrapper around `join()`.
@@ -189,17 +296,49 @@ impl RoomManager {
         sender: tokio::sync::mpsc::Sender<Bytes>,
         fingerprint: Option<&str>,
     ) -> Result<ParticipantId, String> {
-        self.join(room_name, addr, ParticipantSender::WebSocket(sender), fingerprint)
+        let (id, _update, _senders) = self.join(room_name, addr, ParticipantSender::WebSocket(sender), fingerprint, None)?;
+        Ok(id)
     }
 
-    /// Leave a room. Removes the room if empty.
+    /// Get list of active room names.
-    pub fn leave(&mut self, room_name: &str, participant_id: ParticipantId) {
+    pub fn active_rooms(&self) -> Vec<String> {
+        self.rooms.keys().cloned().collect()
+    }
+
+    /// Get participant list for a room (fingerprint + alias).
+    pub fn local_participant_list(&self, room_name: &str) -> Vec<wzp_proto::packet::RoomParticipant> {
+        self.rooms.get(room_name)
+            .map(|room| room.participant_list())
+            .unwrap_or_default()
+    }
+
+    /// Get all senders for participants in a room (for federation inbound media delivery).
+    pub fn local_senders(&self, room_name: &str) -> Vec<ParticipantSender> {
+        self.rooms.get(room_name)
+            .map(|room| room.participants.iter()
+                .map(|p| p.sender.clone())
+                .collect())
+            .unwrap_or_default()
+    }
+
+    /// Leave a room. Returns (room_update_msg, remaining_senders) for broadcasting, or None if room is now empty.
+    pub fn leave(&mut self, room_name: &str, participant_id: ParticipantId) -> Option<(wzp_proto::SignalMessage, Vec<ParticipantSender>)> {
         if let Some(room) = self.rooms.get_mut(room_name) {
             room.remove(participant_id);
             if room.is_empty() {
                 self.rooms.remove(room_name);
+                let _ = self.event_tx.send(RoomEvent::LocalLeave { room: room_name.to_string() });
                 info!(room = room_name, "room closed (empty)");
+                return None;
             }
+            let update = wzp_proto::SignalMessage::RoomUpdate {
+                count: room.len() as u32,
+                participants: room.participant_list(),
+            };
+            let senders = room.all_senders();
+            Some((update, senders))
+        } else {
+            None
         }
     }
 
@@ -298,6 +437,9 @@ pub async fn run_participant(
     metrics: Arc<RelayMetrics>,
     session_id: &str,
     trunking_enabled: bool,
+    debug_tap: Option<DebugTap>,
+    federation_tx: Option<tokio::sync::mpsc::Sender<FederationMediaOut>>,
+    federation_room_hash: Option<[u8; 8]>,
 ) {
     if trunking_enabled {
         run_participant_trunked(
@@ -306,7 +448,7 @@ pub async fn run_participant(
         .await;
     } else {
         run_participant_plain(
-            room_mgr, room_name, participant_id, transport, metrics, session_id,
+            room_mgr, room_name, participant_id, transport, metrics, session_id, debug_tap, federation_tx, federation_room_hash,
         )
         .await;
     }
@@ -320,58 +462,145 @@ async fn run_participant_plain(
     transport: Arc<wzp_transport::QuinnTransport>,
     metrics: Arc<RelayMetrics>,
     session_id: &str,
+    debug_tap: Option<DebugTap>,
+    federation_tx: Option<tokio::sync::mpsc::Sender<FederationMediaOut>>,
+    federation_room_hash: Option<[u8; 8]>,
 ) {
     let addr = transport.connection().remote_address();
     let mut packets_forwarded = 0u64;
+    let mut last_recv_instant = std::time::Instant::now();
+    let mut max_recv_gap_ms = 0u64;
+    let mut max_forward_ms = 0u64;
+    let mut send_errors = 0u64;
+    let mut last_log_instant = std::time::Instant::now();
+
+    info!(
+        room = %room_name,
+        participant = participant_id,
+        %addr,
+        session = session_id,
+        "forwarding loop started (plain)"
+    );
 
     loop {
+        let recv_start = std::time::Instant::now();
         let pkt = match transport.recv_media().await {
             Ok(Some(pkt)) => pkt,
             Ok(None) => {
-                info!(%addr, participant = participant_id, "disconnected");
+                info!(%addr, participant = participant_id, forwarded = packets_forwarded, "disconnected (stream ended)");
                 break;
             }
             Err(e) => {
                 let msg = e.to_string();
                 if msg.contains("timed out") || msg.contains("reset") || msg.contains("closed") {
-                    info!(%addr, participant = participant_id, "connection closed: {e}");
+                    info!(%addr, participant = participant_id, forwarded = packets_forwarded, "connection closed: {e}");
                 } else {
-                    error!(%addr, participant = participant_id, "recv error: {e}");
+                    error!(%addr, participant = participant_id, forwarded = packets_forwarded, "recv error: {e}");
                 }
                 break;
             }
         };
 
+        let recv_gap_ms = last_recv_instant.elapsed().as_millis() as u64;
+        last_recv_instant = std::time::Instant::now();
+        if recv_gap_ms > max_recv_gap_ms {
+            max_recv_gap_ms = recv_gap_ms;
+        }
+        // Log if recv gap is suspiciously large (>200ms = missed ~10 packets)
+        if recv_gap_ms > 200 {
+            warn!(
+                room = %room_name,
+                participant = participant_id,
+                recv_gap_ms,
+                seq = pkt.header.seq,
+                "large recv gap"
+            );
+        }
+
         // Update per-session quality metrics if a quality report is present
         if let Some(ref report) = pkt.quality_report {
             metrics.update_session_quality(session_id, report);
         }
 
         // Get current list of other participants
+        let lock_start = std::time::Instant::now();
         let others = {
             let mgr = room_mgr.lock().await;
             mgr.others(&room_name, participant_id)
         };
+        let lock_ms = lock_start.elapsed().as_millis() as u64;
+        if lock_ms > 10 {
+            warn!(
+                room = %room_name,
+                participant = participant_id,
+                lock_ms,
+                "slow room_mgr lock"
+            );
+        }
+
+        // Debug tap: log packet metadata
+        if let Some(ref tap) = debug_tap {
+            if tap.matches(&room_name) {
+                tap.log_packet(&room_name, "in", &addr, &pkt, others.len());
+            }
+        }
 
         // Forward to all others
+        let fwd_start = std::time::Instant::now();
         let pkt_bytes = pkt.payload.len() as u64;
         for other in &others {
             match other {
                 ParticipantSender::Quic(t) => {
-                    let _ = t.send_media(&pkt).await;
+                    if let Err(e) = t.send_media(&pkt).await {
+                        send_errors += 1;
+                        if send_errors <= 5 || send_errors % 100 == 0 {
+                            warn!(
+                                room = %room_name,
+                                participant = participant_id,
+                                peer = %t.connection().remote_address(),
+                                total_send_errors = send_errors,
+                                "send_media error: {e}"
+                            );
+                        }
+                    }
                 }
                 ParticipantSender::WebSocket(_) => {
-                    // WS clients receive raw payload bytes
                     let _ = other.send_raw(&pkt.payload).await;
                 }
             }
         }
 
+        // Federation: forward to active peer relays via channel
+        if let Some(ref fed_tx) = federation_tx {
+            let data = pkt.to_bytes();
+            let _ = fed_tx.try_send(FederationMediaOut {
+                room_name: room_name.clone(),
+                room_hash: federation_room_hash.unwrap_or_else(|| crate::federation::room_hash(&room_name)),
+                data,
+            });
+        }
+
+        let fwd_ms = fwd_start.elapsed().as_millis() as u64;
+        if fwd_ms > max_forward_ms {
+            max_forward_ms = fwd_ms;
+        }
+        if fwd_ms > 50 {
+            warn!(
+                room = %room_name,
+                participant = participant_id,
+                fwd_ms,
+                fan_out = others.len(),
+                "slow forward"
+            );
+        }
+
         let fan_out = others.len() as u64;
         metrics.packets_forwarded.inc_by(fan_out);
         metrics.bytes_forwarded.inc_by(pkt_bytes * fan_out);
         packets_forwarded += 1;
-        if packets_forwarded % 500 == 0 {
+
+        // Periodic stats log every 5 seconds
+        if last_log_instant.elapsed() >= Duration::from_secs(5) {
             let room_size = {
                 let mgr = room_mgr.lock().await;
                 mgr.room_size(&room_name)
@@ -381,14 +610,24 @@ async fn run_participant_plain(
                 participant = participant_id,
                 forwarded = packets_forwarded,
                 room_size,
+                fan_out,
+                max_recv_gap_ms,
+                max_forward_ms,
+                send_errors,
                 "participant stats"
             );
+            max_recv_gap_ms = 0;
+            max_forward_ms = 0;
+            last_log_instant = std::time::Instant::now();
         }
     }
 
-    // Clean up
+    // Clean up — leave room and broadcast update to remaining participants
     let mut mgr = room_mgr.lock().await;
-    mgr.leave(&room_name, participant_id);
+    if let Some((update, senders)) = mgr.leave(&room_name, participant_id) {
+        drop(mgr); // release lock before async broadcast
+        broadcast_signal(&senders, &update).await;
+    }
 }
 
 /// Trunked forwarding loop — batches outgoing packets per peer.
@@ -404,6 +643,19 @@ async fn run_participant_trunked(
 
     let addr = transport.connection().remote_address();
     let mut packets_forwarded = 0u64;
+    let mut last_recv_instant = std::time::Instant::now();
+    let mut max_recv_gap_ms = 0u64;
+    let mut max_forward_ms = 0u64;
+    let mut send_errors = 0u64;
+    let mut last_log_instant = std::time::Instant::now();
+
+    info!(
+        room = %room_name,
+        participant = participant_id,
+        %addr,
+        session = session_id,
+        "forwarding loop started (trunked)"
+    );
 
     // Per-peer TrunkedForwarders, keyed by the raw pointer of the peer
     // transport (stable for the Arc's lifetime).  We use the remote address
@@ -425,24 +677,50 @@ async fn run_participant_trunked(
                 let pkt = match result {
                     Ok(Some(pkt)) => pkt,
                     Ok(None) => {
-                        info!(%addr, participant = participant_id, "disconnected");
+                        info!(%addr, participant = participant_id, forwarded = packets_forwarded, "disconnected (stream ended)");
                         break;
                     }
                     Err(e) => {
-                        error!(%addr, participant = participant_id, "recv error: {e}");
+                        error!(%addr, participant = participant_id, forwarded = packets_forwarded, "recv error: {e}");
                         break;
                     }
                 };
 
+                let recv_gap_ms = last_recv_instant.elapsed().as_millis() as u64;
+                last_recv_instant = std::time::Instant::now();
+                if recv_gap_ms > max_recv_gap_ms {
+                    max_recv_gap_ms = recv_gap_ms;
+                }
+                if recv_gap_ms > 200 {
+                    warn!(
+                        room = %room_name,
+                        participant = participant_id,
+                        recv_gap_ms,
+                        seq = pkt.header.seq,
+                        "large recv gap (trunked)"
+                    );
+                }
+
                 if let Some(ref report) = pkt.quality_report {
                     metrics.update_session_quality(session_id, report);
                 }
 
+                let lock_start = std::time::Instant::now();
                 let others = {
                     let mgr = room_mgr.lock().await;
                     mgr.others(&room_name, participant_id)
                 };
+                let lock_ms = lock_start.elapsed().as_millis() as u64;
+                if lock_ms > 10 {
+                    warn!(
+                        room = %room_name,
+                        participant = participant_id,
+                        lock_ms,
+                        "slow room_mgr lock (trunked)"
+                    );
+                }
 
+                let fwd_start = std::time::Instant::now();
                 let pkt_bytes = pkt.payload.len() as u64;
                 for other in &others {
                     match other {
@@ -452,21 +730,44 @@ async fn run_participant_trunked(
                                 .entry(peer_addr)
                                 .or_insert_with(|| TrunkedForwarder::new(t.clone(), sid_bytes));
                             if let Err(e) = fwd.send(&pkt).await {
-                                let _ = e;
+                                send_errors += 1;
+                                if send_errors <= 5 || send_errors % 100 == 0 {
+                                    warn!(
+                                        room = %room_name,
+                                        participant = participant_id,
+                                        peer = %peer_addr,
+                                        total_send_errors = send_errors,
+                                        "trunked send error: {e}"
+                                    );
+                                }
                             }
                         }
                         ParticipantSender::WebSocket(_) => {
-                            // WS clients bypass trunking — send raw payload directly
                             let _ = other.send_raw(&pkt.payload).await;
                         }
                     }
                 }
+                let fwd_ms = fwd_start.elapsed().as_millis() as u64;
+                if fwd_ms > max_forward_ms {
+                    max_forward_ms = fwd_ms;
+                }
+                if fwd_ms > 50 {
+                    warn!(
+                        room = %room_name,
+                        participant = participant_id,
+                        fwd_ms,
+                        fan_out = others.len(),
+                        "slow forward (trunked)"
+                    );
+                }
 
                 let fan_out = others.len() as u64;
                 metrics.packets_forwarded.inc_by(fan_out);
                 metrics.bytes_forwarded.inc_by(pkt_bytes * fan_out);
                 packets_forwarded += 1;
-                if packets_forwarded % 500 == 0 {
+
+                // Periodic stats every 5 seconds
+                if last_log_instant.elapsed() >= Duration::from_secs(5) {
                     let room_size = {
                         let mgr = room_mgr.lock().await;
                         mgr.room_size(&room_name)
@@ -476,15 +777,30 @@ async fn run_participant_trunked(
                         participant = participant_id,
                         forwarded = packets_forwarded,
                         room_size,
+                        fan_out,
+                        max_recv_gap_ms,
+                        max_forward_ms,
+                        send_errors,
                         "participant stats (trunked)"
                     );
+                    max_recv_gap_ms = 0;
+                    max_forward_ms = 0;
+                    last_log_instant = std::time::Instant::now();
                 }
             }
 
             _ = flush_interval.tick() => {
                 for fwd in forwarders.values_mut() {
                     if let Err(e) = fwd.flush().await {
-                        let _ = e;
+                        send_errors += 1;
+                        if send_errors <= 5 || send_errors % 100 == 0 {
+                            warn!(
+                                room = %room_name,
+                                participant = participant_id,
+                                total_send_errors = send_errors,
+                                "trunk flush error: {e}"
+                            );
+                        }
                     }
                 }
             }
@@ -497,7 +813,10 @@ async fn run_participant_trunked(
     }
 
     let mut mgr = room_mgr.lock().await;
-    mgr.leave(&room_name, participant_id);
+    if let Some((update, senders)) = mgr.leave(&room_name, participant_id) {
+        drop(mgr);
+        broadcast_signal(&senders, &update).await;
+    }
 }
 
 /// Parse up to the first 2 bytes of a hex session-id string into `[u8; 2]`.

crates/wzp-relay/src/signal_hub.rs

@@ -0,0 +1,105 @@
+//! Persistent signaling connection manager.
+//!
+//! Tracks clients connected via `_signal` SNI. Routes call signals
+//! (DirectCallOffer, DirectCallAnswer, Hangup) between registered users.
+
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::time::Instant;
+
+use tracing::{info, warn};
+use wzp_proto::{MediaTransport, SignalMessage};
+use wzp_transport::QuinnTransport;
+
+/// A client connected via `_signal` for direct calling.
+pub struct SignalClient {
+    pub fingerprint: String,
+    pub alias: Option<String>,
+    pub transport: Arc<QuinnTransport>,
+    pub connected_at: Instant,
+}
+
+/// Manages persistent signaling connections.
+pub struct SignalHub {
+    clients: HashMap<String, SignalClient>,
+}
+
+impl SignalHub {
+    pub fn new() -> Self {
+        Self {
+            clients: HashMap::new(),
+        }
+    }
+
+    /// Register a new signaling client.
+    pub fn register(&mut self, fp: String, transport: Arc<QuinnTransport>, alias: Option<String>) {
+        info!(fingerprint = %fp, alias = ?alias, "signal client registered");
+        self.clients.insert(fp.clone(), SignalClient {
+            fingerprint: fp,
+            alias,
+            transport,
+            connected_at: Instant::now(),
+        });
+    }
+
+    /// Unregister a signaling client. Returns the client if found.
+    pub fn unregister(&mut self, fp: &str) -> Option<SignalClient> {
+        let client = self.clients.remove(fp);
+        if client.is_some() {
+            info!(fingerprint = %fp, "signal client unregistered");
+        }
+        client
+    }
+
+    /// Look up a client by fingerprint.
+    pub fn get(&self, fp: &str) -> Option<&SignalClient> {
+        self.clients.get(fp)
+    }
+
+    /// Check if a fingerprint is online.
+    pub fn is_online(&self, fp: &str) -> bool {
+        self.clients.contains_key(fp)
+    }
+
+    /// Send a signal message to a client by fingerprint.
+    pub async fn send_to(&self, fp: &str, msg: &SignalMessage) -> Result<(), String> {
+        match self.clients.get(fp) {
+            Some(client) => {
+                client.transport.send_signal(msg).await
+                    .map_err(|e| format!("send to {fp}: {e}"))
+            }
+            None => Err(format!("{fp} not online")),
+        }
+    }
+
+    /// Number of connected signaling clients.
+    pub fn online_count(&self) -> usize {
+        self.clients.len()
+    }
+
+    /// List all online fingerprints.
+    pub fn online_fingerprints(&self) -> Vec<&str> {
+        self.clients.keys().map(|s| s.as_str()).collect()
+    }
+
+    /// Get alias for a fingerprint.
+    pub fn alias(&self, fp: &str) -> Option<&str> {
+        self.clients.get(fp).and_then(|c| c.alias.as_deref())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn register_unregister() {
+        let mut hub = SignalHub::new();
+        assert_eq!(hub.online_count(), 0);
+        assert!(!hub.is_online("alice"));
+
+        // Can't easily construct QuinnTransport in a unit test,
+        // so we just test the HashMap logic conceptually.
+        // Integration tests cover the full flow.
+    }
+}

crates/wzp-transport/Cargo.toml

@@ -16,6 +16,9 @@ async-trait = { workspace = true }
 serde_json = "1"
 rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
 rcgen = "0.13"
+ed25519-dalek = { workspace = true }
+hkdf = { workspace = true }
+sha2 = { workspace = true }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }

crates/wzp-transport/src/config.rs

@@ -6,20 +6,74 @@ use std::time::Duration;
 use quinn::crypto::rustls::QuicClientConfig;
 use quinn::crypto::rustls::QuicServerConfig;
 
-/// Create a server configuration with a self-signed certificate (for testing).
+/// Create a server configuration with a self-signed certificate (random keypair).
 ///
-/// Tunes QUIC transport parameters for lossy VoIP:
+/// The certificate changes on every call. Use `server_config_from_seed` for
-/// - 30s idle timeout
+/// a deterministic certificate that survives relay restarts.
-/// - 5s keep-alive interval
-/// - DATAGRAM extension enabled
-/// - Conservative flow control for bandwidth-constrained links
 pub fn server_config() -> (quinn::ServerConfig, Vec<u8>) {
     let cert_key = rcgen::generate_simple_self_signed(vec!["localhost".to_string()])
         .expect("failed to generate self-signed cert");
     let cert_der = rustls::pki_types::CertificateDer::from(cert_key.cert);
     let key_der =
         rustls::pki_types::PrivateKeyDer::try_from(cert_key.key_pair.serialize_der()).unwrap();
+    build_server_config(cert_der, key_der)
+}
 
+/// Create a server configuration with a deterministic self-signed certificate
+/// derived from a 32-byte seed. Same seed = same cert = same TLS fingerprint.
+pub fn server_config_from_seed(seed: &[u8; 32]) -> (quinn::ServerConfig, Vec<u8>) {
+    use ed25519_dalek::pkcs8::EncodePrivateKey;
+    use ed25519_dalek::SigningKey;
+    use hkdf::Hkdf;
+    use sha2::Sha256;
+
+    // Derive Ed25519 key bytes from seed via HKDF
+    let hk = Hkdf::<Sha256>::new(None, seed);
+    let mut ed_bytes = [0u8; 32];
+    hk.expand(b"wzp-tls-ed25519", &mut ed_bytes)
+        .expect("HKDF expand failed");
+
+    // Create Ed25519 signing key and export as PKCS8 DER
+    let signing_key = SigningKey::from_bytes(&ed_bytes);
+    let pkcs8_doc = signing_key.to_pkcs8_der()
+        .expect("failed to encode Ed25519 key as PKCS8");
+    let key_der_for_rcgen = rustls::pki_types::PrivateKeyDer::try_from(pkcs8_doc.as_bytes().to_vec())
+        .expect("failed to wrap PKCS8 DER");
+
+    // Create rcgen KeyPair from DER
+    let key_pair = rcgen::KeyPair::from_der_and_sign_algo(
+        &key_der_for_rcgen,
+        &rcgen::PKCS_ED25519,
+    )
+    .expect("failed to create KeyPair from seed-derived Ed25519 key");
+
+    // Build self-signed cert with this deterministic keypair
+    let params = rcgen::CertificateParams::new(vec!["localhost".to_string()])
+        .expect("failed to create CertificateParams");
+    let cert = params.self_signed(&key_pair).expect("failed to self-sign cert");
+    let cert_der = rustls::pki_types::CertificateDer::from(cert.der().to_vec());
+    let key_der = rustls::pki_types::PrivateKeyDer::try_from(key_pair.serialize_der())
+        .expect("failed to serialize key DER");
+
+    build_server_config(cert_der, key_der)
+}
+
+/// Compute a hex-formatted SHA-256 fingerprint of a DER-encoded certificate.
+///
+/// Format: `xx:xx:xx:xx:...` (32 bytes = 64 hex chars with colons).
+pub fn tls_fingerprint(cert_der: &[u8]) -> String {
+    use sha2::{Sha256, Digest};
+    let hash = Sha256::digest(cert_der);
+    hash.iter()
+        .map(|b| format!("{b:02x}"))
+        .collect::<Vec<_>>()
+        .join(":")
+}
+
+fn build_server_config(
+    cert_der: rustls::pki_types::CertificateDer<'static>,
+    key_der: rustls::pki_types::PrivateKeyDer<'static>,
+) -> (quinn::ServerConfig, Vec<u8>) {
     let mut server_crypto = rustls::ServerConfig::builder()
         .with_no_client_auth()
         .with_single_cert(vec![cert_der.clone()], key_der)

crates/wzp-transport/src/lib.rs

@@ -22,7 +22,7 @@ pub mod path_monitor;
 pub mod quic;
 pub mod reliable;
 
-pub use config::{client_config, server_config};
+pub use config::{client_config, server_config, server_config_from_seed, tls_fingerprint};
 pub use connection::{accept, connect, create_endpoint};
 pub use path_monitor::PathMonitor;
 pub use quic::QuinnTransport;

crates/wzp-transport/src/path_monitor.rs

@@ -136,6 +136,11 @@ impl PathMonitor {
         }
     }
 
+    /// Get raw packet counts for debugging.
+    pub fn counts(&self) -> (u64, u64) {
+        (self.total_sent, self.total_received)
+    }
+
     /// Estimate bandwidth in kbps from bytes received over time.
     fn estimate_bandwidth_kbps(&self) -> u32 {
         if let (Some(first), Some(last)) = (self.first_recv_time_ms, self.last_recv_time_ms) {
@@ -149,6 +154,27 @@ impl PathMonitor {
         }
         0
     }
+
+    /// Detect whether a network handoff likely occurred.
+    ///
+    /// Returns `true` if the most recent RTT jitter measurement exceeds 3x
+    /// the EWMA-smoothed jitter average, which is characteristic of a cellular
+    /// network handoff (tower switch, WiFi-to-cellular transition, etc.).
+    pub fn detect_handoff(&self) -> bool {
+        // We need at least two RTT observations to have a meaningful jitter value,
+        // and the EWMA must be non-zero to avoid division/multiplication by zero.
+        if self.jitter_ewma <= 0.0 {
+            return false;
+        }
+
+        if let (Some(last_rtt), Some(_)) = (self.last_rtt_ms, Some(self.rtt_ewma)) {
+            // Compute the most recent instantaneous jitter (RTT deviation from EWMA)
+            let instant_jitter = (last_rtt - self.rtt_ewma).abs();
+            instant_jitter > self.jitter_ewma * 3.0
+        } else {
+            false
+        }
+    }
 }
 
 impl Default for PathMonitor {

crates/wzp-transport/src/quic.rs

@@ -33,6 +33,29 @@ impl QuinnTransport {
         &self.connection
     }
 
+    /// Send raw bytes as a QUIC datagram (no MediaPacket framing).
+    pub fn send_raw_datagram(&self, data: &[u8]) -> Result<(), TransportError> {
+        self.connection
+            .send_datagram(bytes::Bytes::copy_from_slice(data))
+            .map_err(|e| TransportError::Internal(format!("datagram: {e}")))
+    }
+
+    /// Close the QUIC connection immediately (synchronous, no async needed).
+    /// The relay will detect the close and remove this participant from the room.
+    pub fn close_now(&self) {
+        self.connection.close(quinn::VarInt::from_u32(0), b"hangup");
+    }
+
+    /// Feed an external RTT observation (e.g. from QUIC path stats) into the path monitor.
+    pub fn feed_rtt(&self, rtt_ms: u32) {
+        self.path_monitor.lock().unwrap().observe_rtt(rtt_ms);
+    }
+
+    /// Get raw packet counts from path monitor (sent, received).
+    pub fn monitor_counts(&self) -> (u64, u64) {
+        self.path_monitor.lock().unwrap().counts()
+    }
+
     /// Get the maximum datagram payload size, if datagrams are supported.
     pub fn max_datagram_size(&self) -> Option<usize> {
         datagram::max_datagram_payload(&self.connection)
@@ -120,7 +143,7 @@ impl MediaTransport for QuinnTransport {
             }
         };
 
-        match datagram::deserialize_media(data) {
+        match datagram::deserialize_media(data.clone()) {
             Some(packet) => {
                 // Record receive observation
                 {
@@ -133,8 +156,10 @@ impl MediaTransport for QuinnTransport {
                 Ok(Some(packet))
             }
             None => {
-                tracing::warn!("received malformed media datagram");
+                tracing::warn!(len = data.len(), "skipping malformed media datagram, continuing");
-                Ok(None)
+                // Don't return Ok(None) — that signals connection closed.
+                // Recurse to read the next datagram instead.
+                Box::pin(self.recv_media()).await
             }
         }
     }

crates/wzp-wasm/Cargo.toml

@@ -1,25 +0,0 @@
-[package]
-name = "wzp-wasm"
-version = "0.1.0"
-edition = "2021"
-description = "WarzonePhone WASM bindings — FEC (RaptorQ) + crypto (ChaCha20-Poly1305, X25519)"
-
-[lib]
-crate-type = ["cdylib", "rlib"]
-
-[dependencies]
-wasm-bindgen = "0.2"
-raptorq = "2"
-js-sys = "0.3"
-
-# Crypto (ChaCha20-Poly1305 + X25519 key exchange)
-chacha20poly1305 = "0.10"
-hkdf = "0.12"
-sha2 = "0.10"
-x25519-dalek = { version = "2", features = ["static_secrets"] }
-rand = "0.8"
-getrandom = { version = "0.2", features = ["js"] }  # CRITICAL for WASM randomness
-
-[profile.release]
-opt-level = "s"
-lto = true

crates/wzp-wasm/src/lib.rs

@@ -1,692 +0,0 @@
-//! WarzonePhone WASM bindings.
-//!
-//! Exports two subsystems for browser-side usage:
-//!
-//! **FEC** — RaptorQ forward error correction (encode/decode).
-//! Audio frames are padded to a fixed symbol size (default 256 bytes) with a
-//! 2-byte little-endian length prefix, matching the native wzp-fec wire format.
-//!
-//! Wire format per symbol:
-//!   [block_id:1][symbol_idx:1][is_repair:1][symbol_data:symbol_size]
-//!
-//! Encoder output: concatenated symbols in the above format when a block completes.
-//! Decoder input: individual symbols in the above format.
-//! Decoder output: concatenated original source data (length-prefix stripped).
-//!
-//! **Crypto** — X25519 key exchange + ChaCha20-Poly1305 AEAD encryption.
-//! Mirrors `wzp-crypto` nonce/session/handshake logic so WASM and native
-//! peers produce interoperable ciphertext.
-
-use wasm_bindgen::prelude::*;
-use raptorq::{
-    EncodingPacket, ObjectTransmissionInformation, PayloadId, SourceBlockDecoder,
-    SourceBlockEncoder,
-};
-
-/// Header size prepended to each symbol on the wire: block_id + symbol_idx + is_repair.
-const HEADER_SIZE: usize = 3;
-
-/// Length prefix size inside each padded symbol (u16 LE), matching wzp-fec.
-const LEN_PREFIX: usize = 2;
-
-// ---------------------------------------------------------------------------
-// Encoder
-// ---------------------------------------------------------------------------
-
-#[wasm_bindgen]
-pub struct WzpFecEncoder {
-    block_id: u8,
-    frames_per_block: usize,
-    symbol_size: usize,
-    source_symbols: Vec<Vec<u8>>,
-}
-
-#[wasm_bindgen]
-impl WzpFecEncoder {
-    /// Create a new FEC encoder.
-    ///
-    /// * `block_size` — number of source symbols (audio frames) per FEC block.
-    /// * `symbol_size` — padded byte size of each symbol (default 256).
-    #[wasm_bindgen(constructor)]
-    pub fn new(block_size: usize, symbol_size: usize) -> Self {
-        Self {
-            block_id: 0,
-            frames_per_block: block_size,
-            symbol_size,
-            source_symbols: Vec::with_capacity(block_size),
-        }
-    }
-
-    /// Add a source symbol (audio frame).
-    ///
-    /// Returns encoded packets (all source + repair) when the block is complete,
-    /// or `undefined` if the block is still accumulating.
-    ///
-    /// Each returned packet carries the 3-byte header:
-    ///   `[block_id][symbol_idx][is_repair]` followed by `symbol_size` bytes.
-    pub fn add_symbol(&mut self, data: &[u8]) -> Option<Vec<u8>> {
-        self.source_symbols.push(data.to_vec());
-
-        if self.source_symbols.len() >= self.frames_per_block {
-            Some(self.encode_block())
-        } else {
-            None
-        }
-    }
-
-    /// Force-flush the current (possibly partial) block.
-    ///
-    /// Returns all source + repair symbols with headers, or empty vec if no
-    /// symbols have been accumulated.
-    pub fn flush(&mut self) -> Vec<u8> {
-        if self.source_symbols.is_empty() {
-            return Vec::new();
-        }
-        self.encode_block()
-    }
-
-    /// Internal: encode accumulated source symbols into a block, generate repair,
-    /// and return the concatenated wire-format output.
-    fn encode_block(&mut self) -> Vec<u8> {
-        let ss = self.symbol_size;
-        let num_source = self.source_symbols.len();
-        let block_id = self.block_id;
-
-        // Build length-prefixed, padded block data (matches wzp-fec format).
-        let block_data = self.build_block_data();
-
-        let config =
-            ObjectTransmissionInformation::with_defaults(block_data.len() as u64, ss as u16);
-        let encoder = SourceBlockEncoder::new(block_id, &config, &block_data);
-
-        // Generate source packets.
-        let source_packets = encoder.source_packets();
-
-        // Generate repair packets — 50% overhead by default.
-        let num_repair = ((num_source as f32) * 0.5).ceil() as u32;
-        let repair_packets = encoder.repair_packets(0, num_repair);
-
-        // Allocate output buffer.
-        let total_packets = source_packets.len() + repair_packets.len();
-        let packet_wire_size = HEADER_SIZE + ss;
-        let mut output = Vec::with_capacity(total_packets * packet_wire_size);
-
-        // Write source symbols.
-        for (i, pkt) in source_packets.iter().enumerate() {
-            output.push(block_id);
-            output.push(i as u8);
-            output.push(0); // is_repair = false
-            let pkt_data = pkt.data();
-            let copy_len = pkt_data.len().min(ss);
-            output.extend_from_slice(&pkt_data[..copy_len]);
-            // Pad if shorter.
-            if copy_len < ss {
-                output.resize(output.len() + (ss - copy_len), 0);
-            }
-        }
-
-        // Write repair symbols.
-        for (i, pkt) in repair_packets.iter().enumerate() {
-            output.push(block_id);
-            output.push((num_source + i) as u8);
-            output.push(1); // is_repair = true
-            let pkt_data = pkt.data();
-            let copy_len = pkt_data.len().min(ss);
-            output.extend_from_slice(&pkt_data[..copy_len]);
-            if copy_len < ss {
-                output.resize(output.len() + (ss - copy_len), 0);
-            }
-        }
-
-        // Advance block.
-        self.block_id = self.block_id.wrapping_add(1);
-        self.source_symbols.clear();
-
-        output
-    }
-
-    /// Build the contiguous, length-prefixed block data buffer.
-    fn build_block_data(&self) -> Vec<u8> {
-        let ss = self.symbol_size;
-        let mut data = vec![0u8; self.source_symbols.len() * ss];
-        for (i, sym) in self.source_symbols.iter().enumerate() {
-            let max_payload = ss - LEN_PREFIX;
-            let payload_len = sym.len().min(max_payload);
-            let offset = i * ss;
-            data[offset..offset + LEN_PREFIX]
-                .copy_from_slice(&(payload_len as u16).to_le_bytes());
-            data[offset + LEN_PREFIX..offset + LEN_PREFIX + payload_len]
-                .copy_from_slice(&sym[..payload_len]);
-        }
-        data
-    }
-}
-
-// ---------------------------------------------------------------------------
-// Decoder
-// ---------------------------------------------------------------------------
-
-/// Per-block decoder state.
-struct BlockState {
-    packets: Vec<EncodingPacket>,
-    decoded: bool,
-    result: Option<Vec<u8>>,
-}
-
-#[wasm_bindgen]
-pub struct WzpFecDecoder {
-    frames_per_block: usize,
-    symbol_size: usize,
-    blocks: Vec<(u8, BlockState)>, // poor man's map (no std HashMap in tiny WASM)
-}
-
-#[wasm_bindgen]
-impl WzpFecDecoder {
-    /// Create a new FEC decoder.
-    ///
-    /// * `block_size` — expected number of source symbols per block.
-    /// * `symbol_size` — padded byte size of each symbol (must match encoder).
-    #[wasm_bindgen(constructor)]
-    pub fn new(block_size: usize, symbol_size: usize) -> Self {
-        Self {
-            frames_per_block: block_size,
-            symbol_size,
-            blocks: Vec::new(),
-        }
-    }
-
-    /// Feed a received symbol.
-    ///
-    /// Returns the decoded block (concatenated original frames, unpadded) if
-    /// enough symbols have been received to recover the block, or `undefined`.
-    pub fn add_symbol(
-        &mut self,
-        block_id: u8,
-        symbol_idx: u8,
-        _is_repair: bool,
-        data: &[u8],
-    ) -> Option<Vec<u8>> {
-        let ss = self.symbol_size;
-
-        // Pad incoming data to symbol_size.
-        let mut padded = vec![0u8; ss];
-        let len = data.len().min(ss);
-        padded[..len].copy_from_slice(&data[..len]);
-
-        let esi = symbol_idx as u32;
-        let packet = EncodingPacket::new(PayloadId::new(block_id, esi), padded);
-
-        // Find or create block state.
-        let block = self.get_or_create_block(block_id);
-
-        if block.decoded {
-            return block.result.clone();
-        }
-
-        block.packets.push(packet);
-
-        // Attempt decode.
-        self.try_decode(block_id)
-    }
-
-    /// Try to decode a block; returns the original frames if successful.
-    fn try_decode(&mut self, block_id: u8) -> Option<Vec<u8>> {
-        let ss = self.symbol_size;
-        let num_source = self.frames_per_block;
-        let block_length = (num_source as u64) * (ss as u64);
-
-        let block = self.get_block_mut(block_id)?;
-        if block.decoded {
-            return block.result.clone();
-        }
-
-        let config =
-            ObjectTransmissionInformation::with_defaults(block_length, ss as u16);
-        let mut decoder = SourceBlockDecoder::new(block_id, &config, block_length);
-
-        let decoded = decoder.decode(block.packets.clone());
-
-        match decoded {
-            Some(data) => {
-                // Extract original frames by stripping length prefixes.
-                let mut output = Vec::new();
-                for i in 0..num_source {
-                    let offset = i * ss;
-                    if offset + LEN_PREFIX > data.len() {
-                        break;
-                    }
-                    let payload_len = u16::from_le_bytes([
-                        data[offset],
-                        data[offset + 1],
-                    ]) as usize;
-                    let payload_start = offset + LEN_PREFIX;
-                    let payload_end = (payload_start + payload_len).min(data.len());
-                    output.extend_from_slice(&data[payload_start..payload_end]);
-                }
-
-                let block = self.get_block_mut(block_id).unwrap();
-                block.decoded = true;
-                block.result = Some(output.clone());
-                Some(output)
-            }
-            None => None,
-        }
-    }
-
-    fn get_or_create_block(&mut self, block_id: u8) -> &mut BlockState {
-        if let Some(pos) = self.blocks.iter().position(|(id, _)| *id == block_id) {
-            return &mut self.blocks[pos].1;
-        }
-        self.blocks.push((
-            block_id,
-            BlockState {
-                packets: Vec::new(),
-                decoded: false,
-                result: None,
-            },
-        ));
-        let last = self.blocks.len() - 1;
-        &mut self.blocks[last].1
-    }
-
-    fn get_block_mut(&mut self, block_id: u8) -> Option<&mut BlockState> {
-        self.blocks
-            .iter_mut()
-            .find(|(id, _)| *id == block_id)
-            .map(|(_, state)| state)
-    }
-}
-
-// =========================================================================
-// Crypto — X25519 key exchange
-// =========================================================================
-
-/// X25519 key exchange: generate ephemeral keypair and derive shared secret.
-///
-/// Usage from JS:
-/// ```js
-/// const kx = new WzpKeyExchange();
-/// const ourPub = kx.public_key();         // Uint8Array(32)
-/// // ... send ourPub to peer, receive peerPub ...
-/// const secret = kx.derive_shared_secret(peerPub); // Uint8Array(32)
-/// const session = new WzpCryptoSession(secret);
-/// ```
-#[wasm_bindgen]
-pub struct WzpKeyExchange {
-    secret: x25519_dalek::StaticSecret,
-    public: x25519_dalek::PublicKey,
-}
-
-#[wasm_bindgen]
-impl WzpKeyExchange {
-    /// Generate a new random X25519 keypair.
-    #[wasm_bindgen(constructor)]
-    pub fn new() -> Self {
-        let secret = x25519_dalek::StaticSecret::random_from_rng(rand::rngs::OsRng);
-        let public = x25519_dalek::PublicKey::from(&secret);
-        Self { secret, public }
-    }
-
-    /// Our public key (32 bytes).
-    pub fn public_key(&self) -> Vec<u8> {
-        self.public.as_bytes().to_vec()
-    }
-
-    /// Derive a 32-byte session key from the peer's public key.
-    ///
-    /// Raw DH output is expanded via HKDF-SHA256 with info="warzone-session-key",
-    /// matching `wzp-crypto::handshake::WarzoneKeyExchange::derive_session`.
-    pub fn derive_shared_secret(&self, peer_public: &[u8]) -> Result<Vec<u8>, JsValue> {
-        if peer_public.len() != 32 {
-            return Err(JsValue::from_str("peer public key must be 32 bytes"));
-        }
-        let mut peer_bytes = [0u8; 32];
-        peer_bytes.copy_from_slice(peer_public);
-        let peer_pk = x25519_dalek::PublicKey::from(peer_bytes);
-
-        // Rebuild secret from bytes (StaticSecret doesn't impl Clone).
-        let secret_bytes = self.secret.to_bytes();
-        let secret_clone = x25519_dalek::StaticSecret::from(secret_bytes);
-        let shared = secret_clone.diffie_hellman(&peer_pk);
-
-        // HKDF expand — same derivation as wzp-crypto handshake.rs
-        use hkdf::Hkdf;
-        use sha2::Sha256;
-        let hk = Hkdf::<Sha256>::new(None, shared.as_bytes());
-        let mut session_key = [0u8; 32];
-        hk.expand(b"warzone-session-key", &mut session_key)
-            .expect("HKDF expand should not fail for 32-byte output");
-
-        Ok(session_key.to_vec())
-    }
-}
-
-// =========================================================================
-// Crypto — ChaCha20-Poly1305 AEAD session
-// =========================================================================
-
-/// Build a 12-byte nonce (mirrors `wzp-crypto::nonce::build_nonce`).
-///
-/// Layout: `session_id[4] || seq(u32 BE) || direction(1) || pad(3 zero)`.
-fn build_nonce(session_id: &[u8; 4], seq: u32, direction: u8) -> [u8; 12] {
-    let mut nonce = [0u8; 12];
-    nonce[0..4].copy_from_slice(session_id);
-    nonce[4..8].copy_from_slice(&seq.to_be_bytes());
-    nonce[8] = direction;
-    nonce
-}
-
-/// Symmetric encryption session using ChaCha20-Poly1305.
-///
-/// Mirrors `wzp-crypto::session::ChaChaSession` for WASM.  Nonce derivation
-/// and key setup are identical so WASM and native peers interoperate.
-#[wasm_bindgen]
-pub struct WzpCryptoSession {
-    cipher: chacha20poly1305::ChaCha20Poly1305,
-    session_id: [u8; 4],
-    send_seq: u32,
-    recv_seq: u32,
-}
-
-#[wasm_bindgen]
-impl WzpCryptoSession {
-    /// Create from a 32-byte shared secret (output of `WzpKeyExchange.derive_shared_secret`).
-    #[wasm_bindgen(constructor)]
-    pub fn new(shared_secret: &[u8]) -> Result<WzpCryptoSession, JsValue> {
-        if shared_secret.len() != 32 {
-            return Err(JsValue::from_str("shared secret must be 32 bytes"));
-        }
-
-        use chacha20poly1305::KeyInit;
-        use sha2::Digest;
-
-        let session_id_hash = sha2::Sha256::digest(shared_secret);
-        let mut session_id = [0u8; 4];
-        session_id.copy_from_slice(&session_id_hash[..4]);
-
-        let cipher = chacha20poly1305::ChaCha20Poly1305::new_from_slice(shared_secret)
-            .map_err(|e| JsValue::from_str(&format!("invalid key: {}", e)))?;
-
-        Ok(Self {
-            cipher,
-            session_id,
-            send_seq: 0,
-            recv_seq: 0,
-        })
-    }
-
-    /// Encrypt a media payload with AAD (typically the 12-byte MediaHeader).
-    ///
-    /// Returns `ciphertext || poly1305_tag` (plaintext.len() + 16 bytes).
-    pub fn encrypt(&mut self, header_aad: &[u8], plaintext: &[u8]) -> Result<Vec<u8>, JsValue> {
-        use chacha20poly1305::aead::{Aead, Payload};
-        use chacha20poly1305::Nonce;
-
-        let nonce_bytes = build_nonce(&self.session_id, self.send_seq, 0); // 0 = Send
-        let nonce = Nonce::from_slice(&nonce_bytes);
-
-        let payload = Payload {
-            msg: plaintext,
-            aad: header_aad,
-        };
-
-        let ciphertext = self
-            .cipher
-            .encrypt(nonce, payload)
-            .map_err(|_| JsValue::from_str("encryption failed"))?;
-
-        self.send_seq = self.send_seq.wrapping_add(1);
-        Ok(ciphertext)
-    }
-
-    /// Decrypt a media payload with AAD.
-    ///
-    /// Returns plaintext on success, or throws on auth failure.
-    pub fn decrypt(&mut self, header_aad: &[u8], ciphertext: &[u8]) -> Result<Vec<u8>, JsValue> {
-        use chacha20poly1305::aead::{Aead, Payload};
-        use chacha20poly1305::Nonce;
-
-        // direction=0 (Send) matches the sender's nonce — same as native code.
-        let nonce_bytes = build_nonce(&self.session_id, self.recv_seq, 0);
-        let nonce = Nonce::from_slice(&nonce_bytes);
-
-        let payload = Payload {
-            msg: ciphertext,
-            aad: header_aad,
-        };
-
-        let plaintext = self
-            .cipher
-            .decrypt(nonce, payload)
-            .map_err(|_| JsValue::from_str("decryption failed — bad key or corrupted data"))?;
-
-        self.recv_seq = self.recv_seq.wrapping_add(1);
-        Ok(plaintext)
-    }
-
-    /// Current send sequence number (for diagnostics / UI stats).
-    pub fn send_seq(&self) -> u32 {
-        self.send_seq
-    }
-
-    /// Current receive sequence number (for diagnostics / UI stats).
-    pub fn recv_seq(&self) -> u32 {
-        self.recv_seq
-    }
-}
-
-// ---------------------------------------------------------------------------
-// Tests (native only — not compiled to WASM)
-// ---------------------------------------------------------------------------
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn encode_decode_roundtrip() {
-        let block_size = 5;
-        let symbol_size = 256;
-
-        let mut encoder = WzpFecEncoder::new(block_size, symbol_size);
-        let mut decoder = WzpFecDecoder::new(block_size, symbol_size);
-
-        // Create test frames of varying sizes.
-        let frames: Vec<Vec<u8>> = (0..block_size)
-            .map(|i| vec![(i as u8).wrapping_mul(37).wrapping_add(7); 80 + i * 10])
-            .collect();
-
-        // Feed frames to encoder; last one triggers block encoding.
-        let mut wire_data = None;
-        for frame in &frames {
-            wire_data = encoder.add_symbol(frame);
-        }
-        let wire_data = wire_data.expect("block should be complete");
-
-        // Parse wire packets and feed to decoder.
-        let packet_size = HEADER_SIZE + symbol_size;
-        assert_eq!(wire_data.len() % packet_size, 0);
-
-        let mut result = None;
-        for chunk in wire_data.chunks(packet_size) {
-            let blk_id = chunk[0];
-            let sym_idx = chunk[1];
-            let is_repair = chunk[2] != 0;
-            let sym_data = &chunk[HEADER_SIZE..];
-            if let Some(decoded) = decoder.add_symbol(blk_id, sym_idx, is_repair, sym_data) {
-                result = Some(decoded);
-                break;
-            }
-        }
-
-        let decoded_data = result.expect("should decode with all symbols");
-
-        // Verify: decoded data should be all original frames concatenated.
-        let mut expected = Vec::new();
-        for frame in &frames {
-            expected.extend_from_slice(frame);
-        }
-        assert_eq!(decoded_data, expected);
-    }
-
-    #[test]
-    fn decode_with_packet_loss() {
-        let block_size = 5;
-        let symbol_size = 256;
-
-        let mut encoder = WzpFecEncoder::new(block_size, symbol_size);
-        let mut decoder = WzpFecDecoder::new(block_size, symbol_size);
-
-        let frames: Vec<Vec<u8>> = (0..block_size)
-            .map(|i| vec![(i as u8).wrapping_mul(37).wrapping_add(7); 100])
-            .collect();
-
-        let mut wire_data = None;
-        for frame in &frames {
-            wire_data = encoder.add_symbol(frame);
-        }
-        let wire_data = wire_data.unwrap();
-
-        let packet_size = HEADER_SIZE + symbol_size;
-        let packets: Vec<&[u8]> = wire_data.chunks(packet_size).collect();
-
-        // Drop 2 source packets (simulate 40% source loss).
-        // We have 5 source + 3 repair = 8 packets. Drop packets at index 1 and 3.
-        let mut result = None;
-        for (i, chunk) in packets.iter().enumerate() {
-            if i == 1 || i == 3 {
-                continue; // simulate loss
-            }
-            let blk_id = chunk[0];
-            let sym_idx = chunk[1];
-            let is_repair = chunk[2] != 0;
-            let sym_data = &chunk[HEADER_SIZE..];
-            if let Some(decoded) = decoder.add_symbol(blk_id, sym_idx, is_repair, sym_data) {
-                result = Some(decoded);
-                break;
-            }
-        }
-
-        let decoded_data = result.expect("should recover with FEC despite 2 lost packets");
-
-        let mut expected = Vec::new();
-        for frame in &frames {
-            expected.extend_from_slice(frame);
-        }
-        assert_eq!(decoded_data, expected);
-    }
-
-    #[test]
-    fn flush_partial_block() {
-        let mut encoder = WzpFecEncoder::new(5, 256);
-
-        // Add only 3 of 5 expected symbols, then flush.
-        encoder.add_symbol(&[1; 50]);
-        encoder.add_symbol(&[2; 60]);
-        encoder.add_symbol(&[3; 70]);
-
-        let wire_data = encoder.flush();
-        assert!(!wire_data.is_empty());
-
-        // Verify block_id advanced.
-        assert_eq!(encoder.block_id, 1);
-    }
-
-    // -- Crypto tests -------------------------------------------------------
-
-    #[test]
-    fn crypto_encrypt_decrypt_roundtrip() {
-        let key = [0x42u8; 32];
-        let mut alice = WzpCryptoSession::new(&key).unwrap();
-        let mut bob = WzpCryptoSession::new(&key).unwrap();
-
-        let header = b"test-header";
-        let plaintext = b"hello warzone from wasm";
-
-        let ciphertext = alice.encrypt(header, plaintext).unwrap();
-        let decrypted = bob.decrypt(header, &ciphertext).unwrap();
-
-        assert_eq!(&decrypted, plaintext);
-    }
-
-    // NOTE: crypto_wrong_aad_fails and crypto_wrong_key_fails return
-    // Err(JsValue) which aborts on non-wasm32 (JsValue::from_str uses an
-    // extern "C" shim that panics with "cannot unwind").  These tests are
-    // gated to wasm32-only; on native the encrypt/decrypt roundtrip and
-    // nonce-layout tests provide sufficient coverage.
-
-    #[cfg(target_arch = "wasm32")]
-    #[test]
-    fn crypto_wrong_aad_fails() {
-        let key = [0x42u8; 32];
-        let mut alice = WzpCryptoSession::new(&key).unwrap();
-        let mut bob = WzpCryptoSession::new(&key).unwrap();
-
-        let ciphertext = alice.encrypt(b"correct", b"secret").unwrap();
-        let result = bob.decrypt(b"wrong", &ciphertext);
-        assert!(result.is_err());
-    }
-
-    #[cfg(target_arch = "wasm32")]
-    #[test]
-    fn crypto_wrong_key_fails() {
-        let mut alice = WzpCryptoSession::new(&[0xAA; 32]).unwrap();
-        let mut eve = WzpCryptoSession::new(&[0xBB; 32]).unwrap();
-
-        let ciphertext = alice.encrypt(b"hdr", b"secret").unwrap();
-        let result = eve.decrypt(b"hdr", &ciphertext);
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn crypto_multiple_packets() {
-        let key = [0x42u8; 32];
-        let mut alice = WzpCryptoSession::new(&key).unwrap();
-        let mut bob = WzpCryptoSession::new(&key).unwrap();
-
-        for i in 0..100u32 {
-            let msg = format!("message {}", i);
-            let ct = alice.encrypt(b"hdr", msg.as_bytes()).unwrap();
-            let pt = bob.decrypt(b"hdr", &ct).unwrap();
-            assert_eq!(pt, msg.as_bytes());
-        }
-        assert_eq!(alice.send_seq(), 100);
-        assert_eq!(bob.recv_seq(), 100);
-    }
-
-    #[test]
-    fn key_exchange_roundtrip() {
-        let alice_kx = WzpKeyExchange::new();
-        let bob_kx = WzpKeyExchange::new();
-
-        let alice_secret = alice_kx
-            .derive_shared_secret(&bob_kx.public_key())
-            .unwrap();
-        let bob_secret = bob_kx
-            .derive_shared_secret(&alice_kx.public_key())
-            .unwrap();
-
-        assert_eq!(alice_secret, bob_secret);
-        assert_eq!(alice_secret.len(), 32);
-
-        // Verify the derived secret actually works for encrypt/decrypt.
-        let mut alice_session = WzpCryptoSession::new(&alice_secret).unwrap();
-        let mut bob_session = WzpCryptoSession::new(&bob_secret).unwrap();
-
-        let ct = alice_session.encrypt(b"hdr", b"hello").unwrap();
-        let pt = bob_session.decrypt(b"hdr", &ct).unwrap();
-        assert_eq!(&pt, b"hello");
-    }
-
-    #[test]
-    fn nonce_layout_matches_native() {
-        // Verify our build_nonce matches wzp-crypto::nonce::build_nonce layout.
-        let sid = [0xAA, 0xBB, 0xCC, 0xDD];
-        let seq: u32 = 0x00000100;
-        let nonce = build_nonce(&sid, seq, 1); // 1 = Recv direction
-        assert_eq!(&nonce[0..4], &[0xAA, 0xBB, 0xCC, 0xDD]);
-        assert_eq!(&nonce[4..8], &[0x00, 0x00, 0x01, 0x00]);
-        assert_eq!(nonce[8], 1);
-        assert_eq!(&nonce[9..12], &[0, 0, 0]);
-    }
-}

crates/wzp-web/src/main.rs

@@ -272,7 +272,7 @@ async fn handle_ws(socket: WebSocket, room: String, state: AppState) {
     // Crypto handshake with relay
     let handshake_start = std::time::Instant::now();
     let bridge_seed = wzp_crypto::Seed::generate();
-    match wzp_client::handshake::perform_handshake(&*transport, &bridge_seed.0).await {
+    match wzp_client::handshake::perform_handshake(&*transport, &bridge_seed.0, None).await {
         Ok(_session) => {
             let elapsed = handshake_start.elapsed().as_secs_f64();
             state.metrics.handshake_latency.observe(elapsed);

crates/wzp-web/static/index.html

@@ -10,10 +10,6 @@
   .container { text-align: center; max-width: 420px; padding: 2rem; }
   h1 { font-size: 1.5rem; margin-bottom: 0.5rem; color: #00d4ff; }
   .subtitle { color: #888; font-size: 0.85rem; margin-bottom: 1.5rem; }
-  .variant-badge { display: inline-block; background: #2a2a4a; border: 1px solid #444; color: #00d4ff; font-size: 0.65rem; padding: 0.15rem 0.5rem; border-radius: 4px; margin-left: 0.4rem; vertical-align: middle; font-family: monospace; letter-spacing: 0.05em; }
-  .variant-selector { margin-bottom: 1.2rem; display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; }
-  .variant-selector label { font-size: 0.75rem; color: #888; cursor: pointer; display: flex; align-items: center; gap: 0.25rem; }
-  .variant-selector input[type="radio"] { accent-color: #00d4ff; }
   .room-input { margin-bottom: 1.5rem; }
   .room-input input { background: #2a2a4a; border: 1px solid #444; color: #e0e0e0; padding: 0.6rem 1rem; font-size: 1rem; border-radius: 8px; width: 200px; text-align: center; }
   .room-input input:focus { outline: none; border-color: #00d4ff; }
@@ -35,22 +31,15 @@
 </head>
 <body>
 <div class="container">
-  <h1>WarzonePhone <span class="variant-badge" id="variantBadge">PURE</span></h1>
+  <h1>WarzonePhone</h1>
   <p class="subtitle">Lossy VoIP Protocol</p>
-
-  <div class="variant-selector">
-    <label><input type="radio" name="variant" value="pure"> Pure JS</label>
-    <label><input type="radio" name="variant" value="hybrid"> Hybrid</label>
-    <label><input type="radio" name="variant" value="full"> Full WASM</label>
-  </div>
-
   <div class="room-input">
     <label for="room">Room</label>
     <input type="text" id="room" placeholder="enter room name" value="">
   </div>
-  <button id="callBtn">Connect</button>
+  <button id="callBtn" onclick="toggleCall()">Connect</button>
   <div class="controls" id="controls" style="display:none;">
-    <label><input type="checkbox" id="pttMode"> Radio mode (push-to-talk)</label>
+    <label><input type="checkbox" id="pttMode" onchange="togglePTT()"> Radio mode (push-to-talk)</label>
   </div>
   <button id="pttBtn">Hold to Talk</button>
   <div class="level"><div class="level-bar" id="levelBar"></div></div>
@@ -58,158 +47,302 @@
   <div class="stats" id="stats"></div>
 </div>
 
-<script src="js/wzp-core.js"></script>
 <script>
-// ---------------------------------------------------------------------------
+const SAMPLE_RATE = 48000;
-// Load the selected variant script dynamically
+const FRAME_SIZE = 960;
-// ---------------------------------------------------------------------------
+
+let ws = null;
+let audioCtx = null;
+let mediaStream = null;
+let captureNode = null;
+let playbackNode = null;
+let active = false;
+let transmitting = true; // in open-mic mode, always transmitting
+let pttMode = false;
+let framesSent = 0;
+let framesRecv = 0;
+let startTime = 0;
+let statsInterval = null;
+
+// Use room from URL path or input field
+function getRoom() {
+  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
+  if (path && path !== 'index.html') return path;
+  const hash = location.hash.replace('#', '');
+  if (hash) return hash;
+  return document.getElementById('room').value.trim() || 'default';
+}
+
+// Pre-fill room input from URL on page load
 (function() {
-  var variant = WZPCore.detectVariant();
+  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
-  var scriptMap = {
+  if (path && path !== 'index.html') {
-    pure:      'js/wzp-pure.js',
+    document.getElementById('room').value = path;
-    hybrid:    'js/wzp-hybrid.js',
+  }
-    full:      'js/wzp-full.js',
-    'ws':      'js/wzp-ws.js',
-    'ws-fec':  'js/wzp-ws-fec.js',
-    'ws-full': 'js/wzp-ws-full.js',
-  };
-  var src = scriptMap[variant] || scriptMap.pure;
-  var s = document.createElement('script');
-  s.src = src;
-  s.onload = function() { wzpBoot(); };
-  s.onerror = function() {
-    WZPCore.updateStatus('Failed to load variant: ' + variant);
-  };
-  document.body.appendChild(s);
 })();
 
-// ---------------------------------------------------------------------------
+function setStatus(msg) { document.getElementById('status').textContent = msg; }
-// Boot: wire UI to the loaded client variant
+function setStats(msg) { document.getElementById('stats').textContent = msg; }
-// ---------------------------------------------------------------------------
-function wzpBoot() {
-  var client = null;
-  var capture = null;
-  var playback = null;
-  var transmitting = true;
 
-  var ui = WZPCore.initUI({
+function toggleCall() {
-    onConnect: function(room) {
+  if (active) stopCall();
-      doConnect(room);
+  else startCall();
-    },
+}
-    onDisconnect: function() {
-      doDisconnect();
-    },
-    onTransmit: function(tx) {
-      transmitting = tx;
-    },
-  });
 
-  async function doConnect(room) {
+async function startCall() {
-    WZPCore.updateStatus('Requesting microphone...');
+  const btn = document.getElementById('callBtn');
+  const room = getRoom();
+  if (!room) { setStatus('Enter a room name'); return; }
 
-    var audioCtx;
+  btn.disabled = true;
-    try {
+  setStatus('Requesting microphone...');
-      audioCtx = await WZPCore.startAudioContext();
-    } catch (e) {
-      WZPCore.updateStatus('Audio init failed: ' + e.message);
-      ui.setConnected(false);
-      return;
-    }
 
-    // Build WebSocket URL
+  try {
-    var proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
+    mediaStream = await navigator.mediaDevices.getUserMedia({
-    var wsUrl = proto + '//' + location.host + '/ws/' + encodeURIComponent(room);
+      audio: { sampleRate: SAMPLE_RATE, channelCount: 1, echoCancellation: true, noiseSuppression: true }
-
+    });
-    // Create client based on detected variant
+  } catch(e) {
-    var variant = WZPCore.detectVariant();
+    setStatus('Mic access denied: ' + e.message);
-    var ClientClass = {
+    btn.disabled = false;
-      pure:      window.WZPPureClient,
+    return;
-      hybrid:    window.WZPHybridClient,
-      full:      window.WZPFullClient,
-      'ws':      window.WZPWsClient,
-      'ws-fec':  window.WZPWsFecClient,
-      'ws-full': window.WZPWsFullClient,
-    }[variant] || window.WZPPureClient;
-
-    var clientOpts = {
-      wsUrl: wsUrl,
-      room: room,
-      onAudio: function(pcm) {
-        if (playback) playback.play(pcm);
-      },
-      onStatus: function(msg) {
-        WZPCore.updateStatus(msg);
-      },
-      onStats: function(stats) {
-        WZPCore.updateStats(stats);
-      },
-    };
-
-    // Full variant: add WebTransport URL for direct relay connection
-    if (variant === 'full') {
-      clientOpts.url = location.origin.replace('http', 'https');
-    }
-
-    client = new ClientClass(clientOpts);
-
-    // Load WASM for variants that need it
-    if (client.loadWasm) {
-      try {
-        WZPCore.updateStatus('Loading WASM module...');
-        await client.loadWasm();
-      } catch (e) {
-        WZPCore.updateStatus('WASM load failed: ' + e.message);
-        ui.setConnected(false);
-        return;
-      }
-    }
-
-    try {
-      await client.connect();
-    } catch (e) {
-      WZPCore.updateStatus('Connection failed: ' + e.message);
-      ui.setConnected(false);
-      return;
-    }
-
-    // Start audio capture and playback
-    try {
-      capture = await WZPCore.connectCapture(audioCtx, function(pcmBuffer) {
-        if (!transmitting) return;
-        var pcm = new Int16Array(pcmBuffer);
-        WZPCore.updateLevel(pcm);
-        if (client) client.sendAudio(pcmBuffer);
-      });
-
-      playback = await WZPCore.connectPlayback(audioCtx);
-    } catch (e) {
-      WZPCore.updateStatus('Audio error: ' + e.message);
-      if (client) client.disconnect();
-      client = null;
-      ui.setConnected(false);
-      return;
-    }
-
-    ui.setConnected(true);
   }
 
-  function doDisconnect() {
+  audioCtx = new AudioContext({ sampleRate: SAMPLE_RATE });
-    if (capture) { capture.stop(); capture = null; }
-    if (playback) { playback.stop(); playback = null; }
-    if (client) { client.disconnect(); client = null; }
 
-    var audioCtx = WZPCore.getAudioContext();
+  // Connect WebSocket with room name
-    if (audioCtx && audioCtx.state !== 'closed') {
+  const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
-      audioCtx.close();
+  const wsUrl = proto + '//' + location.host + '/ws/' + encodeURIComponent(room);
+  setStatus('Connecting to room: ' + room + '...');
+
+  ws = new WebSocket(wsUrl);
+  ws.binaryType = 'arraybuffer';
+
+  ws.onopen = async () => {
+    setStatus('Connected to room: ' + room);
+    btn.textContent = 'Disconnect';
+    btn.classList.add('active');
+    btn.disabled = false;
+    active = true;
+    framesSent = 0;
+    framesRecv = 0;
+    startTime = Date.now();
+    showControls(true);
+    await startAudioCapture();
+    await startAudioPlayback();
+    startStatsUpdate();
+  };
+
+  ws.onmessage = (event) => {
+    const pcmData = new Int16Array(event.data);
+    framesRecv++;
+    playAudio(pcmData);
+  };
+
+  ws.onclose = () => {
+    if (active) {
+      setStatus('Disconnected — reconnecting to ' + room + '...');
+      setTimeout(() => { if (active) { cleanupAudio(); startCall(); } }, 1000);
+    } else {
+      setStatus('Disconnected');
     }
+  };
 
-    WZPCore.updateStatus('');
+  ws.onerror = () => {
-    WZPCore.updateStats('');
+    if (active) {
-    document.getElementById('levelBar').style.width = '0%';
+      setStatus('Error — reconnecting...');
+      setTimeout(() => { if (active) { cleanupAudio(); startCall(); } }, 1000);
+    }
+  };
+}
 
-    ui.setConnected(false);
+function stopCall() {
+  active = false;
+  const btn = document.getElementById('callBtn');
+  btn.textContent = 'Connect';
+  btn.classList.remove('active');
+  btn.disabled = false;
+  showControls(false);
+  cleanupAudio();
+  if (ws) { ws.close(); ws = null; }
+  if (statsInterval) { clearInterval(statsInterval); statsInterval = null; }
+  setStatus('');
+  setStats('');
+}
+
+function cleanupAudio() {
+  if (captureNode) { captureNode.disconnect(); captureNode = null; }
+  if (playbackNode) { playbackNode.disconnect(); playbackNode = null; }
+  if (audioCtx) { audioCtx.close(); audioCtx = null; workletLoaded = false; }
+  if (mediaStream) { mediaStream.getTracks().forEach(t => t.stop()); mediaStream = null; }
+}
+
+let workletLoaded = false;
+
+async function loadWorkletModule() {
+  if (workletLoaded) return true;
+  if (typeof AudioWorkletNode === 'undefined' || !audioCtx.audioWorklet) {
+    console.warn('AudioWorklet API not supported in this browser — using ScriptProcessorNode fallback');
+    return false;
+  }
+  try {
+    await audioCtx.audioWorklet.addModule('audio-processor.js');
+    workletLoaded = true;
+    return true;
+  } catch(e) {
+    console.warn('AudioWorklet module failed to load — using ScriptProcessorNode fallback:', e);
+    return false;
   }
 }
+
+async function startAudioCapture() {
+  const source = audioCtx.createMediaStreamSource(mediaStream);
+  const hasWorklet = await loadWorkletModule();
+
+  if (hasWorklet) {
+    captureNode = new AudioWorkletNode(audioCtx, 'wzp-capture-processor');
+    captureNode.port.onmessage = (e) => {
+      if (!active || !ws || ws.readyState !== WebSocket.OPEN || !transmitting) return;
+      ws.send(e.data);
+      framesSent++;
+
+      // Level meter from the PCM data
+      const pcm = new Int16Array(e.data);
+      let max = 0;
+      for (let i = 0; i < pcm.length; i += 16) max = Math.max(max, Math.abs(pcm[i]));
+      document.getElementById('levelBar').style.width = (max / 32768 * 100) + '%';
+    };
+    source.connect(captureNode);
+    captureNode.connect(audioCtx.destination); // needed to keep worklet alive
+  } else {
+    // Fallback to ScriptProcessorNode (deprecated but widely supported)
+    console.warn('Capture: using ScriptProcessorNode fallback');
+    captureNode = audioCtx.createScriptProcessor(4096, 1, 1);
+    let acc = new Float32Array(0);
+    captureNode.onaudioprocess = (ev) => {
+      if (!active || !ws || ws.readyState !== WebSocket.OPEN || !transmitting) return;
+      const input = ev.inputBuffer.getChannelData(0);
+      const n = new Float32Array(acc.length + input.length);
+      n.set(acc); n.set(input, acc.length); acc = n;
+      while (acc.length >= FRAME_SIZE) {
+        const frame = acc.slice(0, FRAME_SIZE); acc = acc.slice(FRAME_SIZE);
+        const pcm = new Int16Array(FRAME_SIZE);
+        for (let i = 0; i < FRAME_SIZE; i++) pcm[i] = Math.max(-32768, Math.min(32767, Math.round(frame[i] * 32767)));
+        let max = 0;
+        for (let i = 0; i < pcm.length; i += 16) max = Math.max(max, Math.abs(pcm[i]));
+        document.getElementById('levelBar').style.width = (max / 32768 * 100) + '%';
+        ws.send(pcm.buffer);
+        framesSent++;
+      }
+    };
+    source.connect(captureNode);
+    captureNode.connect(audioCtx.destination);
+  }
+}
+
+async function startAudioPlayback() {
+  const hasWorklet = await loadWorkletModule();
+
+  if (hasWorklet) {
+    playbackNode = new AudioWorkletNode(audioCtx, 'wzp-playback-processor');
+    playbackNode.connect(audioCtx.destination);
+  } else {
+    console.warn('Playback: using scheduled BufferSource fallback');
+    playbackNode = null; // will use createBufferSource fallback in playAudio()
+  }
+}
+
+let nextPlayTime = 0;
+
+function playAudio(pcmInt16) {
+  if (!audioCtx) return;
+
+  if (playbackNode && playbackNode.port) {
+    // AudioWorklet path — send Int16 PCM directly to the worklet for conversion
+    playbackNode.port.postMessage(pcmInt16.buffer, [pcmInt16.buffer]);
+  } else {
+    // Fallback: scheduled BufferSource (convert Int16 -> Float32 on main thread)
+    const floatData = new Float32Array(pcmInt16.length);
+    for (let i = 0; i < pcmInt16.length; i++) {
+      floatData[i] = pcmInt16[i] / 32768.0;
+    }
+    const buffer = audioCtx.createBuffer(1, floatData.length, SAMPLE_RATE);
+    buffer.getChannelData(0).set(floatData);
+    const source = audioCtx.createBufferSource();
+    source.buffer = buffer;
+    source.connect(audioCtx.destination);
+    const now = audioCtx.currentTime;
+    if (nextPlayTime < now || nextPlayTime > now + 1.0) {
+      nextPlayTime = now + 0.02;
+    }
+    source.start(nextPlayTime);
+    nextPlayTime += buffer.duration;
+  }
+}
+
+function startStatsUpdate() {
+  statsInterval = setInterval(() => {
+    if (!active) { clearInterval(statsInterval); return; }
+    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
+    setStats(elapsed + 's | sent: ' + framesSent + ' | recv: ' + framesRecv);
+  }, 1000);
+}
+
+// --- Push-to-talk ---
+
+function togglePTT() {
+  pttMode = document.getElementById('pttMode').checked;
+  const btn = document.getElementById('pttBtn');
+  if (pttMode) {
+    transmitting = false;
+    btn.style.display = 'block';
+  } else {
+    transmitting = true;
+    btn.style.display = 'none';
+  }
+}
+
+// PTT button — hold to talk (mouse + touch)
+document.getElementById('pttBtn').addEventListener('mousedown', () => { startTransmit(); });
+document.getElementById('pttBtn').addEventListener('mouseup', () => { stopTransmit(); });
+document.getElementById('pttBtn').addEventListener('mouseleave', () => { stopTransmit(); });
+document.getElementById('pttBtn').addEventListener('touchstart', (e) => { e.preventDefault(); startTransmit(); });
+document.getElementById('pttBtn').addEventListener('touchend', (e) => { e.preventDefault(); stopTransmit(); });
+
+// Spacebar PTT
+document.addEventListener('keydown', (e) => { if (pttMode && active && e.code === 'Space' && !e.repeat) { e.preventDefault(); startTransmit(); } });
+document.addEventListener('keyup', (e) => { if (pttMode && active && e.code === 'Space') { e.preventDefault(); stopTransmit(); } });
+
+function startTransmit() {
+  if (!pttMode || !active) return;
+  transmitting = true;
+  document.getElementById('pttBtn').classList.add('transmitting');
+  document.getElementById('pttBtn').textContent = 'Transmitting...';
+}
+
+function stopTransmit() {
+  if (!pttMode) return;
+  transmitting = false;
+  document.getElementById('pttBtn').classList.remove('transmitting');
+  document.getElementById('pttBtn').textContent = 'Hold to Talk';
+}
+
+// Show controls when connected
+function showControls(show) {
+  document.getElementById('controls').style.display = show ? 'flex' : 'none';
+  if (!show) {
+    document.getElementById('pttBtn').style.display = 'none';
+    pttMode = false;
+    transmitting = true;
+  }
+}
+
+// Set room from URL on load
+window.addEventListener('load', () => {
+  const room = getRoom();
+  if (room && room !== 'default') {
+    document.getElementById('room').value = room;
+  }
+});
 </script>
 </body>
 </html>

crates/wzp-web/static/js/wzp-core.js

@@ -1,379 +0,0 @@
-// WarzonePhone — Shared UI logic for all client variants.
-// Provides: audio context management, mic capture, playback, UI wiring.
-
-'use strict';
-
-const WZP_SAMPLE_RATE = 48000;
-const WZP_FRAME_SIZE = 960; // 20ms @ 48kHz
-
-// ---------------------------------------------------------------------------
-// Variant detection
-// ---------------------------------------------------------------------------
-
-function wzpDetectVariant() {
-  const params = new URLSearchParams(location.search);
-  const v = (params.get('variant') || 'pure').toLowerCase();
-  const valid = ['pure', 'hybrid', 'full', 'ws', 'ws-fec', 'ws-full'];
-  if (valid.includes(v)) return v;
-  return 'pure';
-}
-
-// ---------------------------------------------------------------------------
-// Room helpers
-// ---------------------------------------------------------------------------
-
-function wzpGetRoom() {
-  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
-  if (path && path !== 'index.html') return path;
-  const hash = location.hash.replace('#', '');
-  if (hash) return hash;
-  const el = document.getElementById('room');
-  return (el && el.value.trim()) || 'default';
-}
-
-function wzpPrefillRoom() {
-  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
-  if (path && path !== 'index.html') {
-    const el = document.getElementById('room');
-    if (el) el.value = path;
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Status / stats helpers
-// ---------------------------------------------------------------------------
-
-function wzpUpdateStatus(msg) {
-  const el = document.getElementById('status');
-  if (el) el.textContent = msg;
-}
-
-function wzpUpdateStats(stats) {
-  const el = document.getElementById('stats');
-  if (!el) return;
-  if (typeof stats === 'string') {
-    el.textContent = stats;
-  } else {
-    const parts = [];
-    if (stats.elapsed != null) parts.push(stats.elapsed.toFixed(1) + 's');
-    if (stats.sent != null) parts.push('sent: ' + stats.sent);
-    if (stats.recv != null) parts.push('recv: ' + stats.recv);
-    if (stats.loss != null) parts.push('loss: ' + (stats.loss * 100).toFixed(1) + '%');
-    if (stats.fecRecovered != null && stats.fecRecovered > 0) parts.push('fec: ' + stats.fecRecovered);
-    if (stats.fecReady != null) parts.push(stats.fecReady ? 'FEC:on' : 'FEC:off');
-    el.textContent = parts.join(' | ');
-  }
-}
-
-function wzpUpdateLevel(pcmInt16) {
-  const bar = document.getElementById('levelBar');
-  if (!bar) return;
-  let max = 0;
-  for (let i = 0; i < pcmInt16.length; i += 16) {
-    const v = Math.abs(pcmInt16[i]);
-    if (v > max) max = v;
-  }
-  bar.style.width = (max / 32768 * 100) + '%';
-}
-
-// ---------------------------------------------------------------------------
-// Audio context + worklet
-// ---------------------------------------------------------------------------
-
-let _wzpAudioCtx = null;
-let _wzpWorkletLoaded = false;
-
-async function wzpStartAudioContext() {
-  if (_wzpAudioCtx && _wzpAudioCtx.state !== 'closed') return _wzpAudioCtx;
-  _wzpAudioCtx = new AudioContext({ sampleRate: WZP_SAMPLE_RATE });
-  _wzpWorkletLoaded = false;
-  return _wzpAudioCtx;
-}
-
-function wzpGetAudioContext() {
-  return _wzpAudioCtx;
-}
-
-async function _wzpLoadWorklet(audioCtx) {
-  if (_wzpWorkletLoaded) return true;
-  if (typeof AudioWorkletNode === 'undefined' || !audioCtx.audioWorklet) {
-    console.warn('[wzp-core] AudioWorklet not supported, will use fallback');
-    return false;
-  }
-  try {
-    await audioCtx.audioWorklet.addModule('audio-processor.js');
-    _wzpWorkletLoaded = true;
-    return true;
-  } catch (e) {
-    console.warn('[wzp-core] AudioWorklet load failed:', e);
-    return false;
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Mic capture — returns { node, stop() }
-// onFrame(ArrayBuffer) called for each 960-sample Int16 PCM frame
-// ---------------------------------------------------------------------------
-
-async function wzpConnectCapture(audioCtx, onFrame) {
-  let mediaStream;
-  try {
-    mediaStream = await navigator.mediaDevices.getUserMedia({
-      audio: {
-        sampleRate: WZP_SAMPLE_RATE,
-        channelCount: 1,
-        echoCancellation: true,
-        noiseSuppression: true,
-      },
-    });
-  } catch (e) {
-    throw new Error('Mic access denied: ' + e.message);
-  }
-
-  const source = audioCtx.createMediaStreamSource(mediaStream);
-  const hasWorklet = await _wzpLoadWorklet(audioCtx);
-  let captureNode;
-
-  if (hasWorklet) {
-    captureNode = new AudioWorkletNode(audioCtx, 'wzp-capture-processor');
-    captureNode.port.onmessage = (e) => {
-      onFrame(e.data); // ArrayBuffer of Int16 PCM
-    };
-    source.connect(captureNode);
-    captureNode.connect(audioCtx.destination); // keep worklet alive
-  } else {
-    // ScriptProcessorNode fallback
-    captureNode = audioCtx.createScriptProcessor(4096, 1, 1);
-    let acc = new Float32Array(0);
-    captureNode.onaudioprocess = (ev) => {
-      const input = ev.inputBuffer.getChannelData(0);
-      const n = new Float32Array(acc.length + input.length);
-      n.set(acc);
-      n.set(input, acc.length);
-      acc = n;
-      while (acc.length >= WZP_FRAME_SIZE) {
-        const frame = acc.slice(0, WZP_FRAME_SIZE);
-        acc = acc.slice(WZP_FRAME_SIZE);
-        const pcm = new Int16Array(WZP_FRAME_SIZE);
-        for (let i = 0; i < WZP_FRAME_SIZE; i++) {
-          pcm[i] = Math.max(-32768, Math.min(32767, Math.round(frame[i] * 32767)));
-        }
-        onFrame(pcm.buffer);
-      }
-    };
-    source.connect(captureNode);
-    captureNode.connect(audioCtx.destination);
-  }
-
-  return {
-    node: captureNode,
-    stop() {
-      captureNode.disconnect();
-      mediaStream.getTracks().forEach((t) => t.stop());
-    },
-  };
-}
-
-// ---------------------------------------------------------------------------
-// Playback — returns { node, play(Int16Array), stop() }
-// ---------------------------------------------------------------------------
-
-async function wzpConnectPlayback(audioCtx) {
-  const hasWorklet = await _wzpLoadWorklet(audioCtx);
-  let playbackNode;
-  let nextPlayTime = 0;
-
-  if (hasWorklet) {
-    playbackNode = new AudioWorkletNode(audioCtx, 'wzp-playback-processor');
-    playbackNode.connect(audioCtx.destination);
-    return {
-      node: playbackNode,
-      play(pcmInt16) {
-        // Transfer Int16 buffer to worklet
-        const buf = pcmInt16.buffer.slice(
-          pcmInt16.byteOffset,
-          pcmInt16.byteOffset + pcmInt16.byteLength
-        );
-        playbackNode.port.postMessage(buf, [buf]);
-      },
-      stop() {
-        playbackNode.disconnect();
-      },
-    };
-  }
-
-  // Fallback: scheduled BufferSource
-  return {
-    node: null,
-    play(pcmInt16) {
-      if (!audioCtx || audioCtx.state === 'closed') return;
-      const floatData = new Float32Array(pcmInt16.length);
-      for (let i = 0; i < pcmInt16.length; i++) {
-        floatData[i] = pcmInt16[i] / 32768.0;
-      }
-      const buffer = audioCtx.createBuffer(1, floatData.length, WZP_SAMPLE_RATE);
-      buffer.getChannelData(0).set(floatData);
-      const source = audioCtx.createBufferSource();
-      source.buffer = buffer;
-      source.connect(audioCtx.destination);
-      const now = audioCtx.currentTime;
-      if (nextPlayTime < now || nextPlayTime > now + 1.0) {
-        nextPlayTime = now + 0.02;
-      }
-      source.start(nextPlayTime);
-      nextPlayTime += buffer.duration;
-    },
-    stop() {
-      // nothing to disconnect for fallback
-    },
-  };
-}
-
-// ---------------------------------------------------------------------------
-// UI wiring — call after DOM ready
-// ---------------------------------------------------------------------------
-
-function wzpInitUI(callbacks) {
-  // callbacks: { onConnect(room), onDisconnect() }
-  const btn = document.getElementById('callBtn');
-  const pttBtn = document.getElementById('pttBtn');
-  const pttCheckbox = document.getElementById('pttMode');
-  let connected = false;
-  let pttMode = false;
-
-  wzpPrefillRoom();
-
-  // Variant badge
-  const variant = wzpDetectVariant();
-  const badge = document.getElementById('variantBadge');
-  if (badge) badge.textContent = variant.toUpperCase();
-
-  // Variant selector radio buttons
-  document.querySelectorAll('input[name="variant"]').forEach((radio) => {
-    if (radio.value === variant) radio.checked = true;
-    radio.addEventListener('change', () => {
-      if (radio.checked) {
-        const params = new URLSearchParams(location.search);
-        params.set('variant', radio.value);
-        location.search = params.toString();
-      }
-    });
-  });
-
-  btn.onclick = () => {
-    if (connected) {
-      connected = false;
-      btn.textContent = 'Connect';
-      btn.classList.remove('active');
-      _showControls(false);
-      if (callbacks.onDisconnect) callbacks.onDisconnect();
-    } else {
-      const room = wzpGetRoom();
-      if (!room) {
-        wzpUpdateStatus('Enter a room name');
-        return;
-      }
-      connected = true;
-      btn.disabled = true;
-      if (callbacks.onConnect) callbacks.onConnect(room);
-    }
-  };
-
-  // PTT toggle
-  if (pttCheckbox) {
-    pttCheckbox.onchange = () => {
-      pttMode = pttCheckbox.checked;
-      if (pttMode) {
-        pttBtn.style.display = 'block';
-        if (callbacks.onTransmit) callbacks.onTransmit(false);
-      } else {
-        pttBtn.style.display = 'none';
-        if (callbacks.onTransmit) callbacks.onTransmit(true);
-      }
-    };
-  }
-
-  // PTT button events
-  function startTx() {
-    if (!pttMode || !connected) return;
-    pttBtn.classList.add('transmitting');
-    pttBtn.textContent = 'Transmitting...';
-    if (callbacks.onTransmit) callbacks.onTransmit(true);
-  }
-  function stopTx() {
-    if (!pttMode) return;
-    pttBtn.classList.remove('transmitting');
-    pttBtn.textContent = 'Hold to Talk';
-    if (callbacks.onTransmit) callbacks.onTransmit(false);
-  }
-
-  if (pttBtn) {
-    pttBtn.addEventListener('mousedown', startTx);
-    pttBtn.addEventListener('mouseup', stopTx);
-    pttBtn.addEventListener('mouseleave', stopTx);
-    pttBtn.addEventListener('touchstart', (e) => { e.preventDefault(); startTx(); });
-    pttBtn.addEventListener('touchend', (e) => { e.preventDefault(); stopTx(); });
-  }
-
-  // Spacebar PTT
-  document.addEventListener('keydown', (e) => {
-    if (pttMode && connected && e.code === 'Space' && !e.repeat) {
-      e.preventDefault();
-      startTx();
-    }
-  });
-  document.addEventListener('keyup', (e) => {
-    if (pttMode && connected && e.code === 'Space') {
-      e.preventDefault();
-      stopTx();
-    }
-  });
-
-  function _showControls(show) {
-    const controls = document.getElementById('controls');
-    if (controls) controls.style.display = show ? 'flex' : 'none';
-    if (!show && pttBtn) {
-      pttBtn.style.display = 'none';
-      pttMode = false;
-      if (pttCheckbox) pttCheckbox.checked = false;
-    }
-  }
-
-  return {
-    setConnected(isConnected) {
-      connected = isConnected;
-      btn.disabled = false;
-      if (isConnected) {
-        btn.textContent = 'Disconnect';
-        btn.classList.add('active');
-        _showControls(true);
-      } else {
-        btn.textContent = 'Connect';
-        btn.classList.remove('active');
-        _showControls(false);
-      }
-    },
-    isPTT() {
-      return pttMode;
-    },
-  };
-}
-
-// ---------------------------------------------------------------------------
-// Exports (global)
-// ---------------------------------------------------------------------------
-
-window.WZPCore = {
-  SAMPLE_RATE: WZP_SAMPLE_RATE,
-  FRAME_SIZE: WZP_FRAME_SIZE,
-  detectVariant: wzpDetectVariant,
-  getRoom: wzpGetRoom,
-  updateStatus: wzpUpdateStatus,
-  updateStats: wzpUpdateStats,
-  updateLevel: wzpUpdateLevel,
-  startAudioContext: wzpStartAudioContext,
-  getAudioContext: wzpGetAudioContext,
-  connectCapture: wzpConnectCapture,
-  connectPlayback: wzpConnectPlayback,
-  initUI: wzpInitUI,
-};

crates/wzp-web/static/js/wzp-full.js

@@ -1,579 +0,0 @@
-// WarzonePhone — Full WASM + WebTransport client (Variant 3).
-//
-// Architecture:
-//   - WebTransport for unreliable datagrams (UDP-like, no head-of-line blocking)
-//   - ChaCha20-Poly1305 encryption via WASM (wzp-wasm WzpCryptoSession)
-//   - RaptorQ FEC via WASM (wzp-wasm WzpFecEncoder/WzpFecDecoder)
-//   - X25519 key exchange via WASM (wzp-wasm WzpKeyExchange)
-//
-// NOTE: WebTransport requires the relay to support HTTP/3 (h3-quinn).
-// The current wzp-relay uses raw QUIC. This variant demonstrates the full
-// architecture but will need relay-side HTTP/3 support to work end-to-end.
-// For development / testing, use the hybrid variant (WebSocket + WASM FEC).
-//
-// Relies on wzp-core.js for UI and audio helpers.
-
-'use strict';
-
-const WZP_WASM_PATH = (window.__WZP_BASE_URL || '') + '/wasm/wzp_wasm.js';
-
-// 12-byte MediaHeader size (matches wzp-proto MediaHeader::WIRE_SIZE).
-const MEDIA_HEADER_SIZE = 12;
-
-// FEC wire header: block_id(1) + symbol_idx(1) + is_repair(1) = 3 bytes.
-const FEC_HEADER_SIZE = 3;
-
-class WZPFullClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.url          WebTransport URL (https://host:port)
-   * @param {string} options.room         Room name
-   * @param {Function} options.onAudio    callback(Int16Array) for playback
-   * @param {Function} options.onStatus   callback(string) for UI status
-   * @param {Function} options.onStats    callback(Object) for UI stats
-   */
-  constructor(options) {
-    this.url = options.url;
-    this.wsUrl = options.wsUrl;      // WS fallback URL
-    this.room = options.room;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.wt = null;                  // WebTransport instance
-    this.ws = null;                  // WebSocket fallback
-    this.datagramWriter = null;      // WritableStreamDefaultWriter
-    this.datagramReader = null;      // ReadableStreamDefaultReader
-    this.cryptoSession = null;       // WzpCryptoSession (WASM)
-    this.fecEncoder = null;          // WzpFecEncoder (WASM)
-    this.fecDecoder = null;          // WzpFecDecoder (WASM)
-    this.sequence = 0;
-    this._wasmModule = null;
-    this._connected = false;
-    this._useWebTransport = false;   // true if WT connected, false = WS fallback
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._recvLoopRunning = false;
-    this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
-  }
-
-  /**
-   * Connect: load WASM, open WebTransport, perform key exchange,
-   * initialise FEC, and start the receive loop.
-   */
-  async connect() {
-    if (this._connected) return;
-
-    this._status('Loading WASM module...');
-
-    // 1. Load WASM (FEC + crypto)
-    this._wasmModule = await import(WZP_WASM_PATH);
-    await this._wasmModule.default();
-
-    // 2. Try WebTransport first, fall back to WebSocket
-    let wtSuccess = false;
-    if (typeof WebTransport !== 'undefined' && this.url) {
-      try {
-        this._status('Trying WebTransport...');
-        const wtUrl = this.url + '/' + encodeURIComponent(this.room);
-        this.wt = new WebTransport(wtUrl);
-        await Promise.race([
-          this.wt.ready,
-          new Promise((_, reject) => setTimeout(() => reject(new Error('timeout')), 3000)),
-        ]);
-        this.datagramWriter = this.wt.datagrams.writable.getWriter();
-        this.datagramReader = this.wt.datagrams.readable.getReader();
-        this._status('Performing key exchange...');
-        await this._performKeyExchange();
-        wtSuccess = true;
-        this._useWebTransport = true;
-      } catch (e) {
-        console.warn('[wzp-full] WebTransport failed, falling back to WebSocket:', e.message);
-        if (this.wt) { try { this.wt.close(); } catch (_) {} }
-        this.wt = null;
-        this.datagramWriter = null;
-        this.datagramReader = null;
-      }
-    }
-
-    if (!wtSuccess) {
-      // WebSocket fallback (same as hybrid — WASM loaded but uses WS transport)
-      this._useWebTransport = false;
-      await this._connectWebSocket();
-    }
-
-    // 3. Initialise FEC
-    this.fecEncoder = new this._wasmModule.WzpFecEncoder(5, 256);
-    this.fecDecoder = new this._wasmModule.WzpFecDecoder(5, 256);
-
-    this._connected = true;
-    this.sequence = 0;
-    this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
-    this._startTime = Date.now();
-    this._startStatsTimer();
-
-    // 4. Start receive loop (WebTransport only — WS uses onmessage)
-    if (this._useWebTransport) {
-      this._recvLoop();
-      this._status('Connected to room: ' + this.room + ' (WebTransport, encrypted, FEC active)');
-    } else {
-      this._status('Connected to room: ' + this.room + ' (WebSocket fallback, WASM FEC loaded)');
-    }
-  }
-
-  /**
-   * WebSocket fallback connection (used when WebTransport unavailable).
-   */
-  async _connectWebSocket() {
-    return new Promise((resolve, reject) => {
-      this._status('Connecting via WebSocket (fallback)...');
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        this._status('WebSocket connected to room: ' + this.room);
-        resolve();
-      };
-
-      this.ws.onmessage = (event) => {
-        if (!(event.data instanceof ArrayBuffer)) return;
-        const pcm = new Int16Array(event.data);
-        this.stats.recv++;
-        if (this.onAudio) this.onAudio(pcm);
-      };
-
-      this.ws.onclose = () => {
-        if (this._connected) {
-          this._cleanup();
-          this._status('Disconnected');
-        }
-      };
-
-      this.ws.onerror = () => {
-        if (!this._connected) {
-          this._cleanup();
-          reject(new Error('WebSocket connection failed'));
-        }
-      };
-    });
-  }
-
-  /**
-   * Disconnect and clean up all resources.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.wt) {
-      try { this.wt.close(); } catch (_) { /* ignore */ }
-      this.wt = null;
-    }
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-    this._cleanup();
-  }
-
-  /**
-   * Send a PCM audio frame.
-   *
-   * Pipeline: PCM -> FEC encode -> encrypt -> datagram send.
-   *
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected) return;
-
-    // WebSocket fallback: send raw PCM like pure/hybrid
-    if (!this._useWebTransport) {
-      if (this.ws && this.ws.readyState === WebSocket.OPEN) {
-        this.ws.send(pcmBuffer);
-        this.sequence++;
-        this.stats.sent++;
-      }
-      return;
-    }
-
-    if (!this.datagramWriter || !this.cryptoSession) return;
-
-    const pcmBytes = new Uint8Array(pcmBuffer);
-
-    // Build a minimal 12-byte MediaHeader for AAD.
-    const header = this._buildMediaHeader(this.sequence);
-
-    // FEC encode: feed the frame; when a block completes we get wire packets.
-    const fecOutput = this.fecEncoder.add_symbol(pcmBytes);
-
-    if (fecOutput) {
-      // FEC block completed — send all packets (source + repair).
-      const packetSize = FEC_HEADER_SIZE + 256; // header + symbol_size
-      for (let offset = 0; offset + packetSize <= fecOutput.length; offset += packetSize) {
-        const fecPacket = fecOutput.slice(offset, offset + packetSize);
-
-        // Encrypt: header bytes as AAD, FEC packet as plaintext.
-        const ciphertext = this.cryptoSession.encrypt(header, fecPacket);
-        this.stats.encrypted++;
-
-        // Build wire datagram: header (12) + ciphertext
-        const datagram = new Uint8Array(MEDIA_HEADER_SIZE + ciphertext.length);
-        datagram.set(header, 0);
-        datagram.set(ciphertext, MEDIA_HEADER_SIZE);
-
-        try {
-          await this.datagramWriter.write(datagram);
-        } catch (e) {
-          // Datagram send can fail if the transport is closing.
-          if (this._connected) {
-            console.warn('[wzp-full] datagram write failed:', e);
-          }
-          return;
-        }
-        this.stats.sent++;
-      }
-    }
-    // If FEC block not yet complete, accumulate (no packets sent yet).
-
-    this.sequence = (this.sequence + 1) & 0xFFFF;
-  }
-
-  /**
-   * Test crypto + FEC roundtrip entirely in WASM (no network).
-   * Useful for verifying the WASM module works correctly in the browser.
-   *
-   * @returns {Object} test results
-   */
-  testCryptoFec() {
-    if (!this._wasmModule) {
-      return { success: false, error: 'WASM module not loaded' };
-    }
-
-    const t0 = performance.now();
-    const wasm = this._wasmModule;
-
-    // Key exchange
-    const alice = new wasm.WzpKeyExchange();
-    const bob = new wasm.WzpKeyExchange();
-    const aliceSecret = alice.derive_shared_secret(bob.public_key());
-    const bobSecret = bob.derive_shared_secret(alice.public_key());
-
-    // Verify secrets match
-    let secretsMatch = aliceSecret.length === bobSecret.length;
-    if (secretsMatch) {
-      for (let i = 0; i < aliceSecret.length; i++) {
-        if (aliceSecret[i] !== bobSecret[i]) { secretsMatch = false; break; }
-      }
-    }
-
-    // Encrypt/decrypt
-    const aliceSession = new wasm.WzpCryptoSession(aliceSecret);
-    const bobSession = new wasm.WzpCryptoSession(bobSecret);
-
-    const header = new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF]);
-    const plaintext = new TextEncoder().encode('hello warzone from full variant');
-
-    const ciphertext = aliceSession.encrypt(header, plaintext);
-    const decrypted = bobSession.decrypt(header, ciphertext);
-
-    let cryptoOk = decrypted.length === plaintext.length;
-    if (cryptoOk) {
-      for (let i = 0; i < plaintext.length; i++) {
-        if (decrypted[i] !== plaintext[i]) { cryptoOk = false; break; }
-      }
-    }
-
-    // FEC test (same as hybrid testFec)
-    const encoder = new wasm.WzpFecEncoder(5, 256);
-    const decoder = new wasm.WzpFecDecoder(5, 256);
-
-    const frames = [];
-    for (let i = 0; i < 5; i++) {
-      const frame = new Uint8Array(100);
-      for (let j = 0; j < 100; j++) frame[j] = ((i * 37 + 7) + j) & 0xFF;
-      frames.push(frame);
-    }
-
-    let wireData = null;
-    for (const frame of frames) {
-      const result = encoder.add_symbol(frame);
-      if (result) wireData = result;
-    }
-
-    const PACKET_SIZE = FEC_HEADER_SIZE + 256;
-    const packets = [];
-    if (wireData) {
-      for (let off = 0; off + PACKET_SIZE <= wireData.length; off += PACKET_SIZE) {
-        packets.push({
-          blockId: wireData[off],
-          symbolIdx: wireData[off + 1],
-          isRepair: wireData[off + 2] !== 0,
-          data: wireData.slice(off + FEC_HEADER_SIZE, off + PACKET_SIZE),
-        });
-      }
-    }
-
-    // Drop 2 packets, try to recover
-    let fecDecoded = null;
-    for (let i = 0; i < packets.length; i++) {
-      if (i === 1 || i === 3) continue; // simulate loss
-      const pkt = packets[i];
-      const result = decoder.add_symbol(pkt.blockId, pkt.symbolIdx, pkt.isRepair, pkt.data);
-      if (result) { fecDecoded = result; break; }
-    }
-
-    let fecOk = false;
-    if (fecDecoded) {
-      const expected = new Uint8Array(5 * 100);
-      let off = 0;
-      for (const f of frames) { expected.set(f, off); off += f.length; }
-      fecOk = fecDecoded.length === expected.length;
-      if (fecOk) {
-        for (let i = 0; i < expected.length; i++) {
-          if (fecDecoded[i] !== expected[i]) { fecOk = false; break; }
-        }
-      }
-    }
-
-    // Cleanup WASM objects
-    alice.free();
-    bob.free();
-    aliceSession.free();
-    bobSession.free();
-    encoder.free();
-    decoder.free();
-
-    const elapsed = performance.now() - t0;
-
-    return {
-      success: secretsMatch && cryptoOk && fecOk,
-      secretsMatch,
-      cryptoOk,
-      fecOk,
-      fecPacketsTotal: packets.length,
-      fecDropped: 2,
-      elapsed: elapsed.toFixed(2) + 'ms',
-    };
-  }
-
-  // =========================================================================
-  // Internal
-  // =========================================================================
-
-  /**
-   * Perform X25519 key exchange over a WebTransport bidirectional stream.
-   *
-   * Protocol (simplified DH, not the full SignalMessage handshake):
-   *   1. Open a bidirectional stream.
-   *   2. Send our 32-byte X25519 public key.
-   *   3. Read the peer's 32-byte public key.
-   *   4. Derive shared secret via HKDF.
-   *   5. Create WzpCryptoSession from the shared secret.
-   *
-   * In production this would use the full SignalMessage protocol over the
-   * bidirectional stream (offer/answer/encrypted-session). For now we do
-   * a simple DH swap to prove the architecture.
-   */
-  async _performKeyExchange() {
-    const wasm = this._wasmModule;
-    const kx = new wasm.WzpKeyExchange();
-    const ourPub = kx.public_key(); // Uint8Array(32)
-
-    // Open a bidirectional stream for signaling.
-    const stream = await this.wt.createBidirectionalStream();
-    const writer = stream.writable.getWriter();
-    const reader = stream.readable.getReader();
-
-    // Send our public key.
-    await writer.write(new Uint8Array(ourPub));
-
-    // Read peer's public key (exactly 32 bytes).
-    // WebTransport streams are byte-oriented; we may get it in chunks.
-    let peerPub = new Uint8Array(0);
-    while (peerPub.length < 32) {
-      const { value, done } = await reader.read();
-      if (done) {
-        throw new Error('Key exchange stream closed before receiving peer public key');
-      }
-      const combined = new Uint8Array(peerPub.length + value.length);
-      combined.set(peerPub, 0);
-      combined.set(value, peerPub.length);
-      peerPub = combined;
-    }
-    peerPub = peerPub.slice(0, 32);
-
-    // Derive shared secret and create crypto session.
-    const secret = kx.derive_shared_secret(peerPub);
-    this.cryptoSession = new wasm.WzpCryptoSession(secret);
-
-    // Close the signaling stream (key exchange complete).
-    try {
-      writer.releaseLock();
-      reader.releaseLock();
-      await stream.writable.close();
-    } catch (_) {
-      // Best-effort close.
-    }
-
-    kx.free();
-  }
-
-  /**
-   * Receive loop: read datagrams, decrypt, FEC decode, play audio.
-   *
-   * Runs until the transport closes or disconnect() is called.
-   */
-  async _recvLoop() {
-    if (this._recvLoopRunning) return;
-    this._recvLoopRunning = true;
-
-    try {
-      while (this._connected && this.datagramReader) {
-        const { value, done } = await this.datagramReader.read();
-        if (done) break;
-
-        this.stats.recv++;
-
-        // value is a Uint8Array datagram: header(12) + ciphertext
-        if (value.length <= MEDIA_HEADER_SIZE) continue; // too short
-
-        const headerAad = value.slice(0, MEDIA_HEADER_SIZE);
-        const ciphertext = value.slice(MEDIA_HEADER_SIZE);
-
-        // Decrypt
-        let fecPacket;
-        try {
-          fecPacket = this.cryptoSession.decrypt(headerAad, ciphertext);
-          this.stats.decrypted++;
-        } catch (e) {
-          // Decryption failure — corrupted or out-of-order packet.
-          // In a real implementation we'd handle sequence number gaps.
-          console.warn('[wzp-full] decrypt failed:', e);
-          continue;
-        }
-
-        // FEC decode: parse the FEC wire header and feed to decoder.
-        if (fecPacket.length < FEC_HEADER_SIZE) continue;
-        const blockId = fecPacket[0];
-        const symbolIdx = fecPacket[1];
-        const isRepair = fecPacket[2] !== 0;
-        const symbolData = fecPacket.slice(FEC_HEADER_SIZE);
-
-        const decoded = this.fecDecoder.add_symbol(blockId, symbolIdx, isRepair, symbolData);
-        if (decoded) {
-          this.stats.fecRecovered++;
-          // decoded is concatenated original PCM frames.
-          // Each frame is 1920 bytes (960 Int16 samples @ 48kHz mono).
-          const FRAME_BYTES = 1920;
-          for (let off = 0; off + FRAME_BYTES <= decoded.length; off += FRAME_BYTES) {
-            const pcmSlice = decoded.slice(off, off + FRAME_BYTES);
-            const pcm = new Int16Array(pcmSlice.buffer, pcmSlice.byteOffset, pcmSlice.byteLength / 2);
-            if (this.onAudio) {
-              this.onAudio(pcm);
-            }
-          }
-        }
-      }
-    } catch (e) {
-      if (this._connected) {
-        console.warn('[wzp-full] recv loop error:', e);
-      }
-    } finally {
-      this._recvLoopRunning = false;
-    }
-  }
-
-  /**
-   * Build a minimal 12-byte MediaHeader for use as AAD.
-   *
-   * Wire layout (from wzp-proto::packet::MediaHeader):
-   *   Byte 0:  V(1)|T(1)|CodecID(4)|Q(1)|FecRatioHi(1)
-   *   Byte 1:  FecRatioLo(6)|unused(2)
-   *   Bytes 2-3: Sequence number (BE u16)
-   *   Bytes 4-7: Timestamp ms (BE u32)
-   *   Byte 8:  FEC block ID
-   *   Byte 9:  FEC symbol index
-   *   Byte 10: Reserved
-   *   Byte 11: CSRC count
-   *
-   * @param {number} seq  Sequence number (u16)
-   * @returns {Uint8Array} 12-byte header
-   */
-  _buildMediaHeader(seq) {
-    const buf = new Uint8Array(MEDIA_HEADER_SIZE);
-    // Byte 0: version=0, is_repair=0, codec=0 (Opus), quality_report=0, fec_ratio_hi=0
-    buf[0] = 0x00;
-    // Byte 1: fec_ratio_lo=0
-    buf[1] = 0x00;
-    // Bytes 2-3: sequence (BE u16)
-    buf[2] = (seq >> 8) & 0xFF;
-    buf[3] = seq & 0xFF;
-    // Bytes 4-7: timestamp (BE u32) — ms since session start
-    const ts = Date.now() - this._startTime;
-    buf[4] = (ts >> 24) & 0xFF;
-    buf[5] = (ts >> 16) & 0xFF;
-    buf[6] = (ts >> 8) & 0xFF;
-    buf[7] = ts & 0xFF;
-    // Bytes 8-11: FEC block/symbol/reserved/csrc — filled by FEC layer in production
-    return buf;
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss,
-          elapsed,
-          encrypted: this.stats.encrypted,
-          decrypted: this.stats.decrypted,
-          fecRecovered: this.stats.fecRecovered,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._stopStatsTimer();
-    this.datagramWriter = null;
-    this.datagramReader = null;
-    if (this.cryptoSession) {
-      try { this.cryptoSession.free(); } catch (_) { /* ignore */ }
-      this.cryptoSession = null;
-    }
-    if (this.fecEncoder) {
-      try { this.fecEncoder.free(); } catch (_) { /* ignore */ }
-      this.fecEncoder = null;
-    }
-    if (this.fecDecoder) {
-      try { this.fecDecoder.free(); } catch (_) { /* ignore */ }
-      this.fecDecoder = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPFullClient = WZPFullClient;

crates/wzp-web/static/js/wzp-hybrid.js

@@ -1,345 +0,0 @@
-// WarzonePhone — Hybrid JS + WASM client (Variant 2).
-// WebSocket transport, raw PCM, WASM FEC (RaptorQ) ready for WebTransport.
-// Relies on wzp-core.js for UI and audio helpers.
-//
-// The WASM FEC module is loaded and exposed but not used on the wire yet,
-// because WebSocket is TCP (no packet loss). FEC will activate when
-// WebTransport (UDP) is added. A testFec() method demonstrates FEC
-// encode -> simulate loss -> decode in the browser.
-
-'use strict';
-
-// WASM module path (served from /wasm/ by the wzp-web bridge).
-const WZP_WASM_PATH = (window.__WZP_BASE_URL || '') + '/wasm/wzp_wasm.js';
-
-class WZPHybridClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.wsUrl       WebSocket URL (ws://host/ws/room)
-   * @param {string} options.room        Room name
-   * @param {Function} options.onAudio   callback(Int16Array) for playback
-   * @param {Function} options.onStatus  callback(string) for UI status
-   * @param {Function} options.onStats   callback({sent, recv, loss, elapsed, fecRecovered}) for UI
-   */
-  constructor(options) {
-    this.wsUrl = options.wsUrl;
-    this.room = options.room;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.ws = null;
-    this.sequence = 0;
-    this.stats = { sent: 0, recv: 0, fecRecovered: 0 };
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._connected = false;
-
-    // WASM FEC instances (loaded in connect()).
-    this._wasmModule = null;
-    this.fecEncoder = null;
-    this.fecDecoder = null;
-    this._fecReady = false;
-  }
-
-  /**
-   * Open WebSocket connection and load the WASM FEC module.
-   * @returns {Promise<void>} resolves when connected
-   */
-  async connect() {
-    if (this._connected) return;
-
-    // Load WASM module in parallel with WebSocket connect.
-    const wasmPromise = this._loadWasm();
-
-    const wsPromise = new Promise((resolve, reject) => {
-      this._status('Connecting to room: ' + this.room + '...');
-
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        this._connected = true;
-        this.sequence = 0;
-        this.stats = { sent: 0, recv: 0, fecRecovered: 0 };
-        this._startTime = Date.now();
-        this._startStatsTimer();
-        resolve();
-      };
-
-      this.ws.onmessage = (event) => {
-        this._handleMessage(event);
-      };
-
-      this.ws.onclose = () => {
-        const wasConnected = this._connected;
-        this._cleanup();
-        if (wasConnected) {
-          this._status('Disconnected');
-        }
-      };
-
-      this.ws.onerror = () => {
-        if (!this._connected) {
-          this._cleanup();
-          reject(new Error('WebSocket connection failed'));
-        } else {
-          this._status('Connection error');
-        }
-      };
-    });
-
-    // Wait for both WASM load and WS connect.
-    await Promise.all([wasmPromise, wsPromise]);
-
-    const fecStatus = this._fecReady ? 'FEC ready' : 'FEC unavailable';
-    this._status('Connected to room: ' + this.room + ' (' + fecStatus + ')');
-  }
-
-  /**
-   * Close WebSocket and clean up.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.ws) {
-      this.ws.close();
-      this.ws = null;
-    }
-    this._stopStatsTimer();
-    // Keep WASM module loaded (reusable).
-    this.fecEncoder = null;
-    this.fecDecoder = null;
-  }
-
-  /**
-   * Send a PCM audio frame over the WebSocket.
-   * Currently sends raw PCM (same as pure client) since WebSocket is TCP.
-   * When WebTransport is added, this will FEC-encode before sending.
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected || !this.ws || this.ws.readyState !== WebSocket.OPEN) {
-      return;
-    }
-
-    // Over WebSocket (TCP): send raw PCM, no FEC needed.
-    // Over WebTransport (UDP, future): would call this.fecEncoder.add_symbol()
-    // and send the resulting FEC-protected packets.
-    this.ws.send(pcmBuffer);
-    this.sequence++;
-    this.stats.sent++;
-  }
-
-  /**
-   * Test FEC encode -> simulate loss -> decode in the browser.
-   * Demonstrates that the WASM RaptorQ module works correctly.
-   *
-   * @param {Object} [opts]
-   * @param {number} [opts.blockSize=5]     Source symbols per block
-   * @param {number} [opts.symbolSize=256]  Padded symbol size
-   * @param {number} [opts.frameSize=100]   Bytes per test frame
-   * @param {number} [opts.dropCount=2]     Number of packets to drop
-   * @returns {Object} { success, sourcePackets, repairPackets, dropped, recovered, elapsed }
-   */
-  testFec(opts) {
-    if (!this._fecReady) {
-      return { success: false, error: 'WASM FEC module not loaded' };
-    }
-
-    const blockSize = (opts && opts.blockSize) || 5;
-    const symbolSize = (opts && opts.symbolSize) || 256;
-    const frameSize = (opts && opts.frameSize) || 100;
-    const dropCount = (opts && opts.dropCount) || 2;
-
-    const HEADER_SIZE = 3; // block_id + symbol_idx + is_repair
-    const packetSize = HEADER_SIZE + symbolSize;
-
-    const t0 = performance.now();
-
-    // Create fresh encoder/decoder for the test.
-    const encoder = new this._wasmModule.WzpFecEncoder(blockSize, symbolSize);
-    const decoder = new this._wasmModule.WzpFecDecoder(blockSize, symbolSize);
-
-    // Generate test frames with known data.
-    const frames = [];
-    for (let i = 0; i < blockSize; i++) {
-      const frame = new Uint8Array(frameSize);
-      for (let j = 0; j < frameSize; j++) {
-        frame[j] = ((i * 37 + 7) + j) & 0xFF;
-      }
-      frames.push(frame);
-    }
-
-    // Encode: feed frames to encoder; last one triggers block output.
-    let wireData = null;
-    for (const frame of frames) {
-      const result = encoder.add_symbol(frame);
-      if (result) {
-        wireData = result;
-      }
-    }
-
-    if (!wireData) {
-      // Flush if block didn't complete (shouldn't happen with exact blockSize).
-      wireData = encoder.flush();
-    }
-
-    // Parse wire packets.
-    const packets = [];
-    for (let offset = 0; offset + packetSize <= wireData.length; offset += packetSize) {
-      packets.push({
-        blockId: wireData[offset],
-        symbolIdx: wireData[offset + 1],
-        isRepair: wireData[offset + 2] !== 0,
-        data: wireData.slice(offset + HEADER_SIZE, offset + packetSize),
-      });
-    }
-
-    const sourcePackets = packets.filter(p => !p.isRepair).length;
-    const repairPackets = packets.filter(p => p.isRepair).length;
-
-    // Simulate packet loss: drop `dropCount` packets from the front (source symbols).
-    const dropped = [];
-    const surviving = [];
-    for (let i = 0; i < packets.length; i++) {
-      if (i < dropCount) {
-        dropped.push(i);
-      } else {
-        surviving.push(packets[i]);
-      }
-    }
-
-    // Decode from surviving packets.
-    let decoded = null;
-    for (const pkt of surviving) {
-      const result = decoder.add_symbol(pkt.blockId, pkt.symbolIdx, pkt.isRepair, pkt.data);
-      if (result) {
-        decoded = result;
-        break;
-      }
-    }
-
-    const elapsed = performance.now() - t0;
-
-    // Verify decoded data matches original frames.
-    let success = false;
-    if (decoded) {
-      const expected = new Uint8Array(blockSize * frameSize);
-      let off = 0;
-      for (const frame of frames) {
-        expected.set(frame, off);
-        off += frame.length;
-      }
-
-      success = decoded.length === expected.length;
-      if (success) {
-        for (let i = 0; i < decoded.length; i++) {
-          if (decoded[i] !== expected[i]) {
-            success = false;
-            break;
-          }
-        }
-      }
-    }
-
-    // Free WASM objects.
-    encoder.free();
-    decoder.free();
-
-    return {
-      success,
-      sourcePackets,
-      repairPackets,
-      totalPackets: packets.length,
-      dropped: dropCount,
-      recovered: success,
-      decodedBytes: decoded ? decoded.length : 0,
-      expectedBytes: blockSize * frameSize,
-      elapsed: elapsed.toFixed(2) + 'ms',
-    };
-  }
-
-  // -----------------------------------------------------------------------
-  // Internal
-  // -----------------------------------------------------------------------
-
-  async _loadWasm() {
-    try {
-      // Dynamic import of the wasm-pack generated JS glue.
-      this._wasmModule = await import(WZP_WASM_PATH);
-      // Initialize the WASM module (calls __wbg_init).
-      await this._wasmModule.default();
-
-      // Create FEC encoder/decoder instances.
-      // 5 symbols per block, 256-byte symbols — matches native wzp-fec defaults.
-      this.fecEncoder = new this._wasmModule.WzpFecEncoder(5, 256);
-      this.fecDecoder = new this._wasmModule.WzpFecDecoder(5, 256);
-      this._fecReady = true;
-
-      console.log('[wzp-hybrid] WASM FEC module loaded successfully');
-    } catch (e) {
-      console.warn('[wzp-hybrid] WASM FEC module failed to load:', e);
-      this._fecReady = false;
-      // Non-fatal: client still works without FEC (like pure variant).
-    }
-  }
-
-  _handleMessage(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const pcm = new Int16Array(event.data);
-    this.stats.recv++;
-    if (this.onAudio) {
-      this.onAudio(pcm);
-    }
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss: loss,
-          elapsed: elapsed,
-          fecRecovered: this.stats.fecRecovered,
-          fecReady: this._fecReady,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._stopStatsTimer();
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPHybridClient = WZPHybridClient;

crates/wzp-web/static/js/wzp-pure.js

@@ -1,168 +0,0 @@
-// WarzonePhone — Pure JS client (Variant 1).
-// WebSocket transport, raw PCM, no WASM, no FEC.
-// Relies on wzp-core.js for UI and audio helpers.
-
-'use strict';
-
-class WZPPureClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.wsUrl       WebSocket URL (ws://host/ws/room)
-   * @param {string} options.room        Room name
-   * @param {Function} options.onAudio   callback(Int16Array) for playback
-   * @param {Function} options.onStatus  callback(string) for UI status
-   * @param {Function} options.onStats   callback({sent, recv, loss, elapsed}) for UI
-   */
-  constructor(options) {
-    this.wsUrl = options.wsUrl;
-    this.room = options.room;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.ws = null;
-    this.sequence = 0;
-    this.stats = { sent: 0, recv: 0 };
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._connected = false;
-  }
-
-  /**
-   * Open WebSocket connection to the wzp-web bridge.
-   * @returns {Promise<void>} resolves when connected
-   */
-  async connect() {
-    if (this._connected) return;
-
-    return new Promise((resolve, reject) => {
-      this._status('Connecting to room: ' + this.room + '...');
-
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        this._connected = true;
-        this.sequence = 0;
-        this.stats = { sent: 0, recv: 0 };
-        this._startTime = Date.now();
-        this._status('Connected to room: ' + this.room);
-        this._startStatsTimer();
-        resolve();
-      };
-
-      this.ws.onmessage = (event) => {
-        this._handleMessage(event);
-      };
-
-      this.ws.onclose = () => {
-        const wasConnected = this._connected;
-        this._cleanup();
-        if (wasConnected) {
-          this._status('Disconnected');
-        }
-      };
-
-      this.ws.onerror = (err) => {
-        if (!this._connected) {
-          this._cleanup();
-          reject(new Error('WebSocket connection failed'));
-        } else {
-          this._status('Connection error');
-        }
-      };
-    });
-  }
-
-  /**
-   * Close WebSocket and clean up.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.ws) {
-      this.ws.close();
-      this.ws = null;
-    }
-    this._stopStatsTimer();
-  }
-
-  /**
-   * Send a PCM audio frame over the WebSocket.
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected || !this.ws || this.ws.readyState !== WebSocket.OPEN) {
-      return;
-    }
-
-    // Pure JS variant: send raw PCM directly (no encryption, no header).
-    // The wzp-web bridge handles QUIC-side encryption.
-    this.ws.send(pcmBuffer);
-    this.sequence++;
-    this.stats.sent++;
-  }
-
-  // -----------------------------------------------------------------------
-  // Internal
-  // -----------------------------------------------------------------------
-
-  _handleMessage(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const pcm = new Int16Array(event.data);
-    this.stats.recv++;
-    if (this.onAudio) {
-      this.onAudio(pcm);
-    }
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      // Simple loss estimate: if we sent frames, the other side should
-      // receive roughly the same count. Since we only see our own recv,
-      // we report raw counts and let the UI decide.
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss: loss,
-          elapsed: elapsed,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._stopStatsTimer();
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPPureClient = WZPPureClient;

crates/wzp-web/static/js/wzp-ws-fec.js

@@ -1,592 +0,0 @@
-// WarzonePhone — WZP-WS-FEC client (Variant 5).
-// WebSocket transport, WZP wire protocol, WASM RaptorQ FEC.
-// Application-layer redundancy even over TCP.
-// Sends MediaPacket-formatted frames with FEC encoding.
-// Ready for direct relay WS support (no bridge translation needed).
-
-'use strict';
-
-// WASM module path (served from /wasm/ by the wzp-web bridge).
-const WZP_WS_FEC_WASM_PATH = (window.__WZP_BASE_URL || '') + '/wasm/wzp_wasm.js';
-
-// 12-byte MediaHeader size (matches wzp-proto MediaHeader::WIRE_SIZE).
-const WZP_WS_FEC_HEADER_SIZE = 12;
-
-// FEC wire header: block_id(1) + symbol_idx(1) + is_repair(1) = 3 bytes.
-const WZP_WS_FEC_FEC_HEADER_SIZE = 3;
-
-// FEC parameters.
-// A 960-sample Int16 PCM frame = 1920 bytes. We use symbol_size = 2048
-// (1920 payload + 2-byte length prefix + 126 bytes padding).
-const WZP_WS_FEC_BLOCK_SIZE = 5;
-const WZP_WS_FEC_SYMBOL_SIZE = 2048;
-
-// Length prefix size within each FEC symbol.
-const WZP_WS_FEC_LENGTH_PREFIX = 2;
-
-class WZPWsFecClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.wsUrl       WebSocket URL (ws://host/ws/room)
-   * @param {string} options.room        Room name
-   * @param {Function} options.onAudio   callback(Int16Array) for playback
-   * @param {Function} options.onStatus  callback(string) for UI status
-   * @param {Function} options.onStats   callback(Object) for UI stats
-   */
-  constructor(options) {
-    this.wsUrl = options.wsUrl;
-    this.room = options.room;
-    this.authToken = options.authToken || null;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.ws = null;
-    this.seq = 0;
-    this.startTimestamp = 0;
-    this.stats = { sent: 0, recv: 0, fecRecovered: 0 };
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._connected = false;
-    this._authenticated = false;
-
-    // WASM FEC instances (loaded in loadWasm() / connect()).
-    this._wasmModule = null;
-    this.fecEncoder = null;
-    this.fecDecoder = null;
-    this.wasmReady = false;
-
-    // Current FEC block counter for outgoing packets.
-    this._fecBlockId = 0;
-  }
-
-  /**
-   * Load the WASM FEC module.
-   * Called automatically by connect(), or can be called early.
-   */
-  async loadWasm() {
-    if (this.wasmReady) return;
-    try {
-      this._wasmModule = await import(WZP_WS_FEC_WASM_PATH);
-      await this._wasmModule.default();
-
-      this.fecEncoder = new this._wasmModule.WzpFecEncoder(
-        WZP_WS_FEC_BLOCK_SIZE,
-        WZP_WS_FEC_SYMBOL_SIZE
-      );
-      this.fecDecoder = new this._wasmModule.WzpFecDecoder(
-        WZP_WS_FEC_BLOCK_SIZE,
-        WZP_WS_FEC_SYMBOL_SIZE
-      );
-      this.wasmReady = true;
-      console.log('[wzp-ws-fec] WASM FEC module loaded successfully');
-    } catch (e) {
-      console.error('[wzp-ws-fec] WASM FEC module failed to load:', e);
-      this.wasmReady = false;
-      throw e;
-    }
-  }
-
-  /**
-   * Build a 12-byte WZP MediaHeader.
-   *
-   * @param {number} seq         Sequence number (u16)
-   * @param {number} timestampMs Milliseconds since session start
-   * @param {boolean} isRepair   True if this is a FEC repair symbol
-   * @param {number} codecId     Codec ID (0=RawPcm16, 1=Opus16k, 2=Opus48k)
-   * @param {number} fecBlock    FEC block ID (u8)
-   * @param {number} fecSymbol   FEC symbol index (u8)
-   * @param {number} fecRatio    FEC ratio (0.0 to ~2.0)
-   * @param {boolean} hasQuality Whether a quality report is attached
-   * @returns {Uint8Array} 12-byte header
-   */
-  _buildHeader(seq, timestampMs, isRepair = false, codecId = 0, fecBlock = 0, fecSymbol = 0, fecRatio = 0, hasQuality = false) {
-    const buf = new ArrayBuffer(WZP_WS_FEC_HEADER_SIZE);
-    const view = new DataView(buf);
-
-    const fecRatioEncoded = Math.min(127, Math.round(fecRatio * 63.5));
-    const byte0 = ((0 & 0x01) << 7)           // version=0
-        | ((isRepair ? 1 : 0) << 6)            // T bit
-        | ((codecId & 0x0F) << 2)              // CodecID
-        | ((hasQuality ? 1 : 0) << 1)          // Q bit
-        | ((fecRatioEncoded >> 6) & 0x01);     // FecRatioHi
-    view.setUint8(0, byte0);
-
-    const byte1 = (fecRatioEncoded & 0x3F) << 2;
-    view.setUint8(1, byte1);
-
-    view.setUint16(2, seq & 0xFFFF);           // big-endian (default for DataView)
-    view.setUint32(4, timestampMs & 0xFFFFFFFF); // big-endian
-    view.setUint8(8, fecBlock & 0xFF);
-    view.setUint8(9, fecSymbol & 0xFF);
-    view.setUint8(10, 0);  // reserved
-    view.setUint8(11, 0);  // csrc_count
-    return new Uint8Array(buf);
-  }
-
-  /**
-   * Parse a 12-byte MediaHeader from received binary data.
-   *
-   * @param {Uint8Array} data  At least 12 bytes
-   * @returns {Object|null} Parsed header fields, or null if too short
-   */
-  _parseHeader(data) {
-    if (data.byteLength < WZP_WS_FEC_HEADER_SIZE) return null;
-    const view = new DataView(data.buffer || data, data.byteOffset || 0, 12);
-    const byte0 = view.getUint8(0);
-    const byte1 = view.getUint8(1);
-    const fecRatioEncoded = ((byte0 & 0x01) << 6) | ((byte1 >> 2) & 0x3F);
-    return {
-      version: (byte0 >> 7) & 1,
-      isRepair: !!((byte0 >> 6) & 1),
-      codecId: (byte0 >> 2) & 0x0F,
-      hasQuality: !!((byte0 >> 1) & 1),
-      fecRatio: fecRatioEncoded / 63.5,
-      seq: view.getUint16(2),
-      timestamp: view.getUint32(4),
-      fecBlock: view.getUint8(8),
-      fecSymbol: view.getUint8(9),
-      reserved: view.getUint8(10),
-      csrcCount: view.getUint8(11),
-    };
-  }
-
-  /**
-   * Pad a PCM frame into a FEC symbol with a 2-byte length prefix.
-   * Symbol layout: [len_hi, len_lo, ...pcm_bytes..., ...zero_padding...]
-   *
-   * @param {Uint8Array} pcmBytes  Raw PCM bytes
-   * @returns {Uint8Array} Padded symbol of WZP_WS_FEC_SYMBOL_SIZE bytes
-   */
-  _padToSymbol(pcmBytes) {
-    const symbol = new Uint8Array(WZP_WS_FEC_SYMBOL_SIZE);
-    const len = pcmBytes.length;
-    symbol[0] = (len >> 8) & 0xFF;
-    symbol[1] = len & 0xFF;
-    symbol.set(pcmBytes, WZP_WS_FEC_LENGTH_PREFIX);
-    return symbol;
-  }
-
-  /**
-   * Extract the original PCM payload from a FEC symbol (strip prefix + padding).
-   *
-   * @param {Uint8Array} symbol  Symbol data (WZP_WS_FEC_SYMBOL_SIZE bytes)
-   * @returns {Uint8Array} Original PCM bytes
-   */
-  _unpadSymbol(symbol) {
-    const len = (symbol[0] << 8) | symbol[1];
-    if (len > WZP_WS_FEC_SYMBOL_SIZE - WZP_WS_FEC_LENGTH_PREFIX) {
-      // Sanity check: if length is bogus, return empty.
-      return new Uint8Array(0);
-    }
-    return symbol.slice(WZP_WS_FEC_LENGTH_PREFIX, WZP_WS_FEC_LENGTH_PREFIX + len);
-  }
-
-  /**
-   * Open WebSocket connection and load the WASM FEC module.
-   * @returns {Promise<void>} resolves when connected
-   */
-  async connect() {
-    if (this._connected) return;
-
-    // Load WASM module in parallel with WebSocket connect.
-    const wasmPromise = this.loadWasm();
-
-    const wsPromise = new Promise((resolve, reject) => {
-      this._status('Connecting (WZP-WS-FEC) to room: ' + this.room + '...');
-
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        // Send auth if token provided.
-        if (this.authToken) {
-          this.ws.send(JSON.stringify({ type: 'auth', token: this.authToken }));
-        }
-
-        this._connected = true;
-        this._authenticated = !this.authToken;
-        this.seq = 0;
-        this.startTimestamp = Date.now();
-        this.stats = { sent: 0, recv: 0, fecRecovered: 0 };
-        this._startTime = Date.now();
-        this._fecBlockId = 0;
-        this._startStatsTimer();
-        resolve();
-      };
-
-      this.ws.onmessage = (event) => {
-        // Handle text messages (auth responses).
-        if (typeof event.data === 'string') {
-          try {
-            const msg = JSON.parse(event.data);
-            if (msg.type === 'auth_ok') {
-              this._authenticated = true;
-              this._status('Authenticated (WZP-WS-FEC) to room: ' + this.room);
-            }
-            if (msg.type === 'auth_error') {
-              this._status('Auth failed: ' + (msg.reason || 'unknown'));
-              this.disconnect();
-            }
-          } catch(e) { /* ignore non-JSON text */ }
-          return;
-        }
-        this._handleMessage(event);
-      };
-
-      this.ws.onclose = () => {
-        const was = this._connected;
-        this._cleanup();
-        if (was) this._status('Disconnected');
-      };
-
-      this.ws.onerror = () => {
-        if (!this._connected) {
-          this._cleanup();
-          reject(new Error('WebSocket connection failed'));
-        } else {
-          this._status('Connection error');
-        }
-      };
-    });
-
-    await Promise.all([wasmPromise, wsPromise]);
-
-    const fecStatus = this.wasmReady ? 'FEC ready' : 'FEC unavailable';
-    this._status('Connected (WZP-WS-FEC) to room: ' + this.room + ' (' + fecStatus + ')');
-  }
-
-  /**
-   * Close WebSocket and clean up.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.ws) {
-      this.ws.close();
-      this.ws = null;
-    }
-    this._stopStatsTimer();
-    // Keep WASM module loaded (reusable), but reset encoder/decoder.
-    if (this.fecEncoder) {
-      try { this.fecEncoder.free(); } catch (_) { /* ignore */ }
-      this.fecEncoder = null;
-    }
-    if (this.fecDecoder) {
-      try { this.fecDecoder.free(); } catch (_) { /* ignore */ }
-      this.fecDecoder = null;
-    }
-  }
-
-  /**
-   * Send a PCM audio frame with FEC encoding over the WebSocket.
-   *
-   * Each PCM frame is padded to a FEC symbol (2048 bytes with length prefix)
-   * and fed to the FEC encoder. When a block of 5 symbols completes, the
-   * encoder outputs source + repair symbols. Each is sent as an individual
-   * WZP MediaPacket with the appropriate fecBlock, fecSymbol, and isRepair
-   * fields in the 12-byte header.
-   *
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected || !this.ws || this.ws.readyState !== WebSocket.OPEN) return;
-    if (!this.wasmReady || !this.fecEncoder) return;
-
-    const pcmBytes = new Uint8Array(pcmBuffer);
-
-    // Pad PCM frame to FEC symbol size with length prefix.
-    const symbol = this._padToSymbol(pcmBytes);
-
-    // Feed to FEC encoder. Returns wire data when block completes.
-    const fecOutput = this.fecEncoder.add_symbol(symbol);
-
-    if (fecOutput) {
-      // Block completed — send all packets (source + repair).
-      const packetSize = WZP_WS_FEC_FEC_HEADER_SIZE + WZP_WS_FEC_SYMBOL_SIZE;
-      const timestampMs = Date.now() - this.startTimestamp;
-
-      for (let offset = 0; offset + packetSize <= fecOutput.length; offset += packetSize) {
-        const blockId = fecOutput[offset];
-        const symbolIdx = fecOutput[offset + 1];
-        const isRepair = fecOutput[offset + 2] !== 0;
-        const symbolData = fecOutput.slice(
-          offset + WZP_WS_FEC_FEC_HEADER_SIZE,
-          offset + packetSize
-        );
-
-        // Build WZP MediaHeader for this FEC symbol.
-        // fecRatio ~0.5 for 50% repair overhead: encoded = round(0.5 * 63.5) = 32
-        const header = this._buildHeader(
-          this.seq,
-          timestampMs,
-          isRepair,
-          0,          // codecId = RawPcm16
-          blockId,
-          symbolIdx,
-          0.5,        // fecRatio
-          false       // hasQuality
-        );
-
-        // Wire frame: header(12) + symbol_data(2048)
-        const packet = new Uint8Array(WZP_WS_FEC_HEADER_SIZE + symbolData.length);
-        packet.set(header, 0);
-        packet.set(symbolData, WZP_WS_FEC_HEADER_SIZE);
-
-        this.ws.send(packet.buffer);
-        this.seq = (this.seq + 1) & 0xFFFF;
-        this.stats.sent++;
-      }
-
-      this._fecBlockId++;
-    }
-    // If block not yet complete, accumulate (no packets sent yet).
-  }
-
-  /**
-   * Test FEC encode -> simulate loss -> decode in the browser.
-   * Demonstrates that the WASM RaptorQ module works correctly
-   * with the WZP wire protocol symbol format.
-   *
-   * @param {Object} [opts]
-   * @param {number} [opts.blockSize=5]     Source symbols per block
-   * @param {number} [opts.symbolSize=2048] Padded symbol size
-   * @param {number} [opts.frameSize=1920]  PCM frame size in bytes
-   * @param {number} [opts.dropCount=2]     Number of packets to drop (simulated 30%+ loss)
-   * @returns {Object} Test results
-   */
-  testFec(opts) {
-    if (!this.wasmReady || !this._wasmModule) {
-      return { success: false, error: 'WASM FEC module not loaded' };
-    }
-
-    const blockSize = (opts && opts.blockSize) || 5;
-    const symbolSize = (opts && opts.symbolSize) || WZP_WS_FEC_SYMBOL_SIZE;
-    const frameSize = (opts && opts.frameSize) || 1920;
-    const dropCount = (opts && opts.dropCount) || 2;
-
-    const FEC_HDR = 3; // block_id + symbol_idx + is_repair
-    const packetSize = FEC_HDR + symbolSize;
-
-    const t0 = performance.now();
-
-    // Create fresh encoder/decoder for the test.
-    const encoder = new this._wasmModule.WzpFecEncoder(blockSize, symbolSize);
-    const decoder = new this._wasmModule.WzpFecDecoder(blockSize, symbolSize);
-
-    // Generate test frames with known data, padded to symbol size with length prefix.
-    const originalFrames = [];
-    const paddedSymbols = [];
-    for (let i = 0; i < blockSize; i++) {
-      const frame = new Uint8Array(frameSize);
-      for (let j = 0; j < frameSize; j++) {
-        frame[j] = ((i * 37 + 7) + j) & 0xFF;
-      }
-      originalFrames.push(frame);
-
-      // Pad with length prefix (same as _padToSymbol).
-      const sym = new Uint8Array(symbolSize);
-      sym[0] = (frameSize >> 8) & 0xFF;
-      sym[1] = frameSize & 0xFF;
-      sym.set(frame, 2);
-      paddedSymbols.push(sym);
-    }
-
-    // Encode: feed padded symbols to encoder.
-    let wireData = null;
-    for (const sym of paddedSymbols) {
-      const result = encoder.add_symbol(sym);
-      if (result) wireData = result;
-    }
-
-    if (!wireData) {
-      wireData = encoder.flush();
-    }
-
-    // Parse wire packets.
-    const packets = [];
-    if (wireData) {
-      for (let offset = 0; offset + packetSize <= wireData.length; offset += packetSize) {
-        packets.push({
-          blockId: wireData[offset],
-          symbolIdx: wireData[offset + 1],
-          isRepair: wireData[offset + 2] !== 0,
-          data: wireData.slice(offset + FEC_HDR, offset + packetSize),
-        });
-      }
-    }
-
-    const sourcePackets = packets.filter(p => !p.isRepair).length;
-    const repairPackets = packets.filter(p => p.isRepair).length;
-
-    // Simulate packet loss: drop `dropCount` source packets from the front.
-    const dropped = [];
-    const surviving = [];
-    for (let i = 0; i < packets.length; i++) {
-      if (i < dropCount) {
-        dropped.push(i);
-      } else {
-        surviving.push(packets[i]);
-      }
-    }
-
-    // Decode from surviving packets.
-    let decoded = null;
-    for (const pkt of surviving) {
-      const result = decoder.add_symbol(pkt.blockId, pkt.symbolIdx, pkt.isRepair, pkt.data);
-      if (result) {
-        decoded = result;
-        break;
-      }
-    }
-
-    // Verify decoded data: extract original frames from decoded symbols.
-    let success = false;
-    if (decoded) {
-      // decoded is the concatenated padded symbols. Extract original frames.
-      const recoveredFrames = [];
-      for (let i = 0; i < blockSize; i++) {
-        const symOffset = i * symbolSize;
-        if (symOffset + symbolSize <= decoded.length) {
-          const sym = decoded.slice(symOffset, symOffset + symbolSize);
-          const len = (sym[0] << 8) | sym[1];
-          recoveredFrames.push(sym.slice(2, 2 + len));
-        }
-      }
-
-      success = recoveredFrames.length === blockSize;
-      if (success) {
-        for (let i = 0; i < blockSize && success; i++) {
-          if (recoveredFrames[i].length !== originalFrames[i].length) {
-            success = false;
-            break;
-          }
-          for (let j = 0; j < originalFrames[i].length; j++) {
-            if (recoveredFrames[i][j] !== originalFrames[i][j]) {
-              success = false;
-              break;
-            }
-          }
-        }
-      }
-    }
-
-    // Free WASM objects.
-    encoder.free();
-    decoder.free();
-
-    const elapsed = performance.now() - t0;
-
-    return {
-      success,
-      sourcePackets,
-      repairPackets,
-      totalPackets: packets.length,
-      dropped: dropCount,
-      recovered: !!decoded,
-      symbolSize: symbolSize,
-      frameSize: frameSize,
-      elapsed: elapsed.toFixed(2) + 'ms',
-    };
-  }
-
-  // -----------------------------------------------------------------------
-  // Internal
-  // -----------------------------------------------------------------------
-
-  _handleMessage(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const data = new Uint8Array(event.data);
-    if (data.length < WZP_WS_FEC_HEADER_SIZE) return;
-
-    const header = this._parseHeader(data);
-    if (!header) return;
-
-    this.stats.recv++;
-
-    if (!this.wasmReady || !this.fecDecoder) {
-      // No FEC decoder — cannot process FEC-encoded data.
-      return;
-    }
-
-    // Extract symbol data (everything after 12-byte MediaHeader).
-    const symbolData = data.slice(WZP_WS_FEC_HEADER_SIZE);
-
-    // Feed symbol to FEC decoder using header fields.
-    const decoded = this.fecDecoder.add_symbol(
-      header.fecBlock,
-      header.fecSymbol,
-      header.isRepair,
-      symbolData
-    );
-
-    if (decoded) {
-      this.stats.fecRecovered++;
-
-      // decoded is concatenated padded symbols.
-      // Each symbol is WZP_WS_FEC_SYMBOL_SIZE bytes with a 2-byte length prefix.
-      for (let off = 0; off + WZP_WS_FEC_SYMBOL_SIZE <= decoded.length; off += WZP_WS_FEC_SYMBOL_SIZE) {
-        const symbol = decoded.slice(off, off + WZP_WS_FEC_SYMBOL_SIZE);
-        const pcmBytes = this._unpadSymbol(symbol);
-
-        if (pcmBytes.length > 0 && pcmBytes.length % 2 === 0) {
-          const pcm = new Int16Array(
-            pcmBytes.buffer,
-            pcmBytes.byteOffset,
-            pcmBytes.byteLength / 2
-          );
-          if (this.onAudio) this.onAudio(pcm);
-        }
-      }
-    }
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss: loss,
-          elapsed: elapsed,
-          fecRecovered: this.stats.fecRecovered,
-          fecReady: this.wasmReady,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._stopStatsTimer();
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPWsFecClient = WZPWsFecClient;

crates/wzp-web/static/js/wzp-ws-full.js

@@ -1,749 +0,0 @@
-// WarzonePhone — WZP-WS-Full client (Variant 6).
-// WebSocket transport, WZP wire protocol, WASM FEC + ChaCha20-Poly1305 E2E.
-// Full encryption — relay sees only ciphertext.
-// Sends MediaPacket-formatted frames with FEC + encryption.
-// Ready for direct relay WS support (no bridge translation needed).
-
-'use strict';
-
-// WASM module path (served from /wasm/ by the wzp-web bridge).
-const WZP_WS_FULL_WASM_PATH = (window.__WZP_BASE_URL || '') + '/wasm/wzp_wasm.js';
-
-// 12-byte MediaHeader size (matches wzp-proto MediaHeader::WIRE_SIZE).
-const WZP_WS_FULL_HEADER_SIZE = 12;
-
-// FEC wire header: block_id(1) + symbol_idx(1) + is_repair(1) = 3 bytes.
-const WZP_WS_FULL_FEC_HEADER_SIZE = 3;
-
-// FEC parameters.
-// A 960-sample Int16 PCM frame = 1920 bytes. Symbol size = 2048
-// (1920 payload + 2-byte length prefix + 126 bytes padding).
-const WZP_WS_FULL_BLOCK_SIZE = 5;
-const WZP_WS_FULL_SYMBOL_SIZE = 2048;
-
-// Length prefix size within each FEC symbol.
-const WZP_WS_FULL_LENGTH_PREFIX = 2;
-
-// ChaCha20-Poly1305 tag size (16 bytes).
-const WZP_WS_FULL_TAG_SIZE = 16;
-
-// X25519 public key size (32 bytes).
-const WZP_WS_FULL_PUBKEY_SIZE = 32;
-
-class WZPWsFullClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.wsUrl       WebSocket URL (ws://host/ws/room)
-   * @param {string} options.room        Room name
-   * @param {Function} options.onAudio   callback(Int16Array) for playback
-   * @param {Function} options.onStatus  callback(string) for UI status
-   * @param {Function} options.onStats   callback(Object) for UI stats
-   */
-  constructor(options) {
-    this.wsUrl = options.wsUrl;
-    this.room = options.room;
-    this.authToken = options.authToken || null;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.ws = null;
-    this.seq = 0;
-    this.startTimestamp = 0;
-    this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._connected = false;
-    this._authenticated = false;
-
-    // WASM instances.
-    this._wasmModule = null;
-    this.fecEncoder = null;
-    this.fecDecoder = null;
-    this.cryptoSession = null;
-    this._keyExchange = null;
-    this.wasmReady = false;
-
-    // Key exchange state.
-    this._keyExchangeComplete = false;
-    this._keyExchangeResolve = null;
-    this._keyExchangeReject = null;
-
-    // Current FEC block counter for outgoing packets.
-    this._fecBlockId = 0;
-  }
-
-  /**
-   * Load the WASM module (FEC + Crypto).
-   * Called automatically by connect(), or can be called early.
-   */
-  async loadWasm() {
-    if (this.wasmReady) return;
-    try {
-      this._wasmModule = await import(WZP_WS_FULL_WASM_PATH);
-      await this._wasmModule.default();
-      this.wasmReady = true;
-      console.log('[wzp-ws-full] WASM module loaded successfully');
-    } catch (e) {
-      console.error('[wzp-ws-full] WASM module failed to load:', e);
-      this.wasmReady = false;
-      throw e;
-    }
-  }
-
-  /**
-   * Build a 12-byte WZP MediaHeader.
-   *
-   * @param {number} seq         Sequence number (u16)
-   * @param {number} timestampMs Milliseconds since session start
-   * @param {boolean} isRepair   True if this is a FEC repair symbol
-   * @param {number} codecId     Codec ID (0=RawPcm16, 1=Opus16k, 2=Opus48k)
-   * @param {number} fecBlock    FEC block ID (u8)
-   * @param {number} fecSymbol   FEC symbol index (u8)
-   * @param {number} fecRatio    FEC ratio (0.0 to ~2.0)
-   * @param {boolean} hasQuality Whether a quality report is attached
-   * @returns {Uint8Array} 12-byte header
-   */
-  _buildHeader(seq, timestampMs, isRepair = false, codecId = 0, fecBlock = 0, fecSymbol = 0, fecRatio = 0, hasQuality = false) {
-    const buf = new ArrayBuffer(WZP_WS_FULL_HEADER_SIZE);
-    const view = new DataView(buf);
-
-    const fecRatioEncoded = Math.min(127, Math.round(fecRatio * 63.5));
-    const byte0 = ((0 & 0x01) << 7)           // version=0
-        | ((isRepair ? 1 : 0) << 6)            // T bit
-        | ((codecId & 0x0F) << 2)              // CodecID
-        | ((hasQuality ? 1 : 0) << 1)          // Q bit
-        | ((fecRatioEncoded >> 6) & 0x01);     // FecRatioHi
-    view.setUint8(0, byte0);
-
-    const byte1 = (fecRatioEncoded & 0x3F) << 2;
-    view.setUint8(1, byte1);
-
-    view.setUint16(2, seq & 0xFFFF);           // big-endian (default for DataView)
-    view.setUint32(4, timestampMs & 0xFFFFFFFF); // big-endian
-    view.setUint8(8, fecBlock & 0xFF);
-    view.setUint8(9, fecSymbol & 0xFF);
-    view.setUint8(10, 0);  // reserved
-    view.setUint8(11, 0);  // csrc_count
-    return new Uint8Array(buf);
-  }
-
-  /**
-   * Parse a 12-byte MediaHeader from received binary data.
-   *
-   * @param {Uint8Array} data  At least 12 bytes
-   * @returns {Object|null} Parsed header fields, or null if too short
-   */
-  _parseHeader(data) {
-    if (data.byteLength < WZP_WS_FULL_HEADER_SIZE) return null;
-    const view = new DataView(data.buffer || data, data.byteOffset || 0, 12);
-    const byte0 = view.getUint8(0);
-    const byte1 = view.getUint8(1);
-    const fecRatioEncoded = ((byte0 & 0x01) << 6) | ((byte1 >> 2) & 0x3F);
-    return {
-      version: (byte0 >> 7) & 1,
-      isRepair: !!((byte0 >> 6) & 1),
-      codecId: (byte0 >> 2) & 0x0F,
-      hasQuality: !!((byte0 >> 1) & 1),
-      fecRatio: fecRatioEncoded / 63.5,
-      seq: view.getUint16(2),
-      timestamp: view.getUint32(4),
-      fecBlock: view.getUint8(8),
-      fecSymbol: view.getUint8(9),
-      reserved: view.getUint8(10),
-      csrcCount: view.getUint8(11),
-    };
-  }
-
-  /**
-   * Pad a PCM frame into a FEC symbol with a 2-byte length prefix.
-   *
-   * @param {Uint8Array} pcmBytes  Raw PCM bytes
-   * @returns {Uint8Array} Padded symbol of WZP_WS_FULL_SYMBOL_SIZE bytes
-   */
-  _padToSymbol(pcmBytes) {
-    const symbol = new Uint8Array(WZP_WS_FULL_SYMBOL_SIZE);
-    const len = pcmBytes.length;
-    symbol[0] = (len >> 8) & 0xFF;
-    symbol[1] = len & 0xFF;
-    symbol.set(pcmBytes, WZP_WS_FULL_LENGTH_PREFIX);
-    return symbol;
-  }
-
-  /**
-   * Extract the original PCM payload from a FEC symbol (strip prefix + padding).
-   *
-   * @param {Uint8Array} symbol  Symbol data
-   * @returns {Uint8Array} Original PCM bytes
-   */
-  _unpadSymbol(symbol) {
-    const len = (symbol[0] << 8) | symbol[1];
-    if (len > WZP_WS_FULL_SYMBOL_SIZE - WZP_WS_FULL_LENGTH_PREFIX) {
-      return new Uint8Array(0);
-    }
-    return symbol.slice(WZP_WS_FULL_LENGTH_PREFIX, WZP_WS_FULL_LENGTH_PREFIX + len);
-  }
-
-  /**
-   * Open WebSocket connection, load WASM, and perform key exchange.
-   *
-   * Key exchange protocol over WebSocket:
-   *   1. After WS open, send our 32-byte X25519 public key as first binary message.
-   *   2. First received binary message of exactly 32 bytes = peer's public key.
-   *   3. Derive shared secret, create WzpCryptoSession.
-   *   4. All subsequent binary messages are encrypted MediaPackets.
-   *
-   * @returns {Promise<void>} resolves when connected and key exchange completes
-   */
-  async connect() {
-    if (this._connected) return;
-
-    // Load WASM first (needed for key exchange).
-    await this.loadWasm();
-
-    // Prepare key exchange.
-    this._keyExchange = new this._wasmModule.WzpKeyExchange();
-    this._keyExchangeComplete = false;
-
-    return new Promise((resolve, reject) => {
-      this._status('Connecting (WZP-WS-Full) to room: ' + this.room + '...');
-
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        this.seq = 0;
-        this.startTimestamp = Date.now();
-        this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
-        this._startTime = Date.now();
-        this._fecBlockId = 0;
-
-        // Send auth if token provided.
-        if (this.authToken) {
-          this.ws.send(JSON.stringify({ type: 'auth', token: this.authToken }));
-          this._authenticated = false;
-        } else {
-          this._authenticated = true;
-          // No auth needed — proceed directly to key exchange.
-          this._status('Performing key exchange...');
-          const ourPub = this._keyExchange.public_key();
-          this.ws.send(new Uint8Array(ourPub).buffer);
-        }
-
-        // Store resolve/reject for key exchange completion.
-        this._keyExchangeResolve = resolve;
-        this._keyExchangeReject = reject;
-      };
-
-      this.ws.onmessage = (event) => {
-        // Handle text messages (auth responses).
-        if (typeof event.data === 'string') {
-          try {
-            const msg = JSON.parse(event.data);
-            if (msg.type === 'auth_ok') {
-              this._authenticated = true;
-              this._status('Authenticated, performing key exchange...');
-              // Auth succeeded — now send public key for key exchange.
-              const ourPub = this._keyExchange.public_key();
-              this.ws.send(new Uint8Array(ourPub).buffer);
-            }
-            if (msg.type === 'auth_error') {
-              this._status('Auth failed: ' + (msg.reason || 'unknown'));
-              if (this._keyExchangeReject) {
-                this._keyExchangeReject(new Error('Auth failed: ' + (msg.reason || 'unknown')));
-                this._keyExchangeResolve = null;
-                this._keyExchangeReject = null;
-              }
-              this._cleanup();
-            }
-          } catch(e) { /* ignore non-JSON text */ }
-          return;
-        }
-        if (!this._keyExchangeComplete) {
-          this._handleKeyExchange(event);
-        } else {
-          this._handleMessage(event);
-        }
-      };
-
-      this.ws.onclose = () => {
-        const was = this._connected;
-        this._cleanup();
-        if (was) {
-          this._status('Disconnected');
-        } else if (this._keyExchangeReject) {
-          this._keyExchangeReject(new Error('Connection closed during key exchange'));
-          this._keyExchangeResolve = null;
-          this._keyExchangeReject = null;
-        }
-      };
-
-      this.ws.onerror = () => {
-        if (!this._connected) {
-          this._cleanup();
-          if (this._keyExchangeReject) {
-            this._keyExchangeReject(new Error('WebSocket connection failed'));
-            this._keyExchangeResolve = null;
-            this._keyExchangeReject = null;
-          } else {
-            reject(new Error('WebSocket connection failed'));
-          }
-        } else {
-          this._status('Connection error');
-        }
-      };
-    });
-  }
-
-  /**
-   * Handle the key exchange: first binary message of 32 bytes = peer's public key.
-   */
-  _handleKeyExchange(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const data = new Uint8Array(event.data);
-
-    if (data.length === WZP_WS_FULL_PUBKEY_SIZE) {
-      // Received peer's public key — derive shared secret.
-      try {
-        const peerPub = data;
-        const secret = this._keyExchange.derive_shared_secret(peerPub);
-        this.cryptoSession = new this._wasmModule.WzpCryptoSession(secret);
-
-        // Free key exchange object (no longer needed).
-        this._keyExchange.free();
-        this._keyExchange = null;
-
-        // Initialize FEC encoder/decoder.
-        this.fecEncoder = new this._wasmModule.WzpFecEncoder(
-          WZP_WS_FULL_BLOCK_SIZE,
-          WZP_WS_FULL_SYMBOL_SIZE
-        );
-        this.fecDecoder = new this._wasmModule.WzpFecDecoder(
-          WZP_WS_FULL_BLOCK_SIZE,
-          WZP_WS_FULL_SYMBOL_SIZE
-        );
-
-        this._keyExchangeComplete = true;
-        this._connected = true;
-        this._startStatsTimer();
-        this._status('Connected (WZP-WS-Full) to room: ' + this.room + ' (encrypted, FEC active)');
-
-        if (this._keyExchangeResolve) {
-          this._keyExchangeResolve();
-          this._keyExchangeResolve = null;
-          this._keyExchangeReject = null;
-        }
-      } catch (e) {
-        console.error('[wzp-ws-full] Key exchange failed:', e);
-        if (this._keyExchangeReject) {
-          this._keyExchangeReject(new Error('Key exchange failed: ' + e.message));
-          this._keyExchangeResolve = null;
-          this._keyExchangeReject = null;
-        }
-        this._cleanup();
-      }
-    }
-    // Ignore non-32-byte messages during key exchange.
-  }
-
-  /**
-   * Close WebSocket and clean up all resources.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.ws) {
-      this.ws.close();
-      this.ws = null;
-    }
-    this._stopStatsTimer();
-    if (this.cryptoSession) {
-      try { this.cryptoSession.free(); } catch (_) { /* ignore */ }
-      this.cryptoSession = null;
-    }
-    if (this.fecEncoder) {
-      try { this.fecEncoder.free(); } catch (_) { /* ignore */ }
-      this.fecEncoder = null;
-    }
-    if (this.fecDecoder) {
-      try { this.fecDecoder.free(); } catch (_) { /* ignore */ }
-      this.fecDecoder = null;
-    }
-    if (this._keyExchange) {
-      try { this._keyExchange.free(); } catch (_) { /* ignore */ }
-      this._keyExchange = null;
-    }
-    this._keyExchangeComplete = false;
-  }
-
-  /**
-   * Send a PCM audio frame with FEC encoding + encryption over the WebSocket.
-   *
-   * Pipeline: PCM -> pad to FEC symbol -> FEC encode -> encrypt -> WS send.
-   *
-   * Each FEC symbol is encrypted individually with ChaCha20-Poly1305. The
-   * 12-byte MediaHeader is used as AAD (authenticated but not encrypted),
-   * so the relay can inspect routing fields without decrypting the payload.
-   *
-   * Wire format per packet:
-   *   header(12) + ciphertext(symbol_size) + tag(16)
-   *
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected || !this.ws || this.ws.readyState !== WebSocket.OPEN) return;
-    if (!this.cryptoSession || !this.fecEncoder) return;
-
-    const pcmBytes = new Uint8Array(pcmBuffer);
-
-    // Pad PCM frame to FEC symbol size with length prefix.
-    const symbol = this._padToSymbol(pcmBytes);
-
-    // Feed to FEC encoder. Returns wire data when block completes.
-    const fecOutput = this.fecEncoder.add_symbol(symbol);
-
-    if (fecOutput) {
-      // Block completed — encrypt and send all packets (source + repair).
-      const fecPacketSize = WZP_WS_FULL_FEC_HEADER_SIZE + WZP_WS_FULL_SYMBOL_SIZE;
-      const timestampMs = Date.now() - this.startTimestamp;
-
-      for (let offset = 0; offset + fecPacketSize <= fecOutput.length; offset += fecPacketSize) {
-        const blockId = fecOutput[offset];
-        const symbolIdx = fecOutput[offset + 1];
-        const isRepair = fecOutput[offset + 2] !== 0;
-        const symbolData = fecOutput.slice(
-          offset + WZP_WS_FULL_FEC_HEADER_SIZE,
-          offset + fecPacketSize
-        );
-
-        // Build WZP MediaHeader (used as AAD for encryption).
-        // fecRatio ~0.5 for 50% repair overhead.
-        const header = this._buildHeader(
-          this.seq,
-          timestampMs,
-          isRepair,
-          0,          // codecId = RawPcm16
-          blockId,
-          symbolIdx,
-          0.5,        // fecRatio
-          false       // hasQuality
-        );
-
-        // Encrypt: header as AAD, FEC symbol data as plaintext.
-        // Returns ciphertext + tag (symbol_size + 16 bytes).
-        const ciphertext = this.cryptoSession.encrypt(header, symbolData);
-        this.stats.encrypted++;
-
-        // Wire frame: header(12) + ciphertext_with_tag
-        const packet = new Uint8Array(WZP_WS_FULL_HEADER_SIZE + ciphertext.length);
-        packet.set(header, 0);
-        packet.set(ciphertext, WZP_WS_FULL_HEADER_SIZE);
-
-        this.ws.send(packet.buffer);
-        this.seq = (this.seq + 1) & 0xFFFF;
-        this.stats.sent++;
-      }
-
-      this._fecBlockId++;
-    }
-    // If block not yet complete, accumulate (no packets sent yet).
-  }
-
-  /**
-   * Test crypto + FEC roundtrip entirely in WASM (no network).
-   * Simulates: key exchange -> encrypt -> FEC encode -> simulate loss ->
-   * FEC decode -> decrypt -> verify.
-   *
-   * @returns {Object} Test results
-   */
-  testCryptoFec() {
-    if (!this.wasmReady || !this._wasmModule) {
-      return { success: false, error: 'WASM module not loaded' };
-    }
-
-    const t0 = performance.now();
-    const wasm = this._wasmModule;
-
-    // --- Key exchange ---
-    const alice = new wasm.WzpKeyExchange();
-    const bob = new wasm.WzpKeyExchange();
-    const aliceSecret = alice.derive_shared_secret(bob.public_key());
-    const bobSecret = bob.derive_shared_secret(alice.public_key());
-
-    let secretsMatch = aliceSecret.length === bobSecret.length;
-    if (secretsMatch) {
-      for (let i = 0; i < aliceSecret.length; i++) {
-        if (aliceSecret[i] !== bobSecret[i]) { secretsMatch = false; break; }
-      }
-    }
-
-    // --- Crypto sessions ---
-    const aliceSession = new wasm.WzpCryptoSession(aliceSecret);
-    const bobSession = new wasm.WzpCryptoSession(bobSecret);
-
-    // --- Encrypt + FEC encode ---
-    const encoder = new wasm.WzpFecEncoder(WZP_WS_FULL_BLOCK_SIZE, WZP_WS_FULL_SYMBOL_SIZE);
-    const decoder = new wasm.WzpFecDecoder(WZP_WS_FULL_BLOCK_SIZE, WZP_WS_FULL_SYMBOL_SIZE);
-
-    // Generate test PCM frames (known data).
-    const originalFrames = [];
-    for (let i = 0; i < WZP_WS_FULL_BLOCK_SIZE; i++) {
-      const frame = new Uint8Array(1920);
-      for (let j = 0; j < 1920; j++) {
-        frame[j] = ((i * 37 + 7) + j) & 0xFF;
-      }
-      originalFrames.push(frame);
-    }
-
-    // Pad and FEC-encode.
-    const paddedSymbols = [];
-    let wireData = null;
-    for (const frame of originalFrames) {
-      const sym = new Uint8Array(WZP_WS_FULL_SYMBOL_SIZE);
-      sym[0] = (frame.length >> 8) & 0xFF;
-      sym[1] = frame.length & 0xFF;
-      sym.set(frame, 2);
-      paddedSymbols.push(sym);
-
-      const result = encoder.add_symbol(sym);
-      if (result) wireData = result;
-    }
-
-    if (!wireData) wireData = encoder.flush();
-
-    // Parse FEC packets and encrypt each one.
-    const FEC_HDR = WZP_WS_FULL_FEC_HEADER_SIZE;
-    const fecPacketSize = FEC_HDR + WZP_WS_FULL_SYMBOL_SIZE;
-    const encryptedPackets = [];
-
-    if (wireData) {
-      for (let offset = 0; offset + fecPacketSize <= wireData.length; offset += fecPacketSize) {
-        const blockId = wireData[offset];
-        const symbolIdx = wireData[offset + 1];
-        const isRepair = wireData[offset + 2] !== 0;
-        const symbolData = wireData.slice(offset + FEC_HDR, offset + fecPacketSize);
-
-        // Build header for AAD (match wire protocol bit layout).
-        const header = new Uint8Array(WZP_WS_FULL_HEADER_SIZE);
-        const fecRatioEncoded = Math.min(127, Math.round(0.5 * 63.5)); // 50% FEC
-        header[0] = ((isRepair ? 1 : 0) << 6)
-            | ((0 & 0x0F) << 2)                   // codecId=0
-            | ((fecRatioEncoded >> 6) & 0x01);     // FecRatioHi
-        header[1] = (fecRatioEncoded & 0x3F) << 2; // FecRatioLo
-        header[8] = blockId;
-        header[9] = symbolIdx;
-
-        // Encrypt with Alice's session.
-        const ciphertext = aliceSession.encrypt(header, symbolData);
-
-        encryptedPackets.push({
-          blockId, symbolIdx, isRepair, header, ciphertext,
-        });
-      }
-    }
-
-    const sourcePackets = encryptedPackets.filter(p => !p.isRepair).length;
-    const repairPackets = encryptedPackets.filter(p => p.isRepair).length;
-
-    // --- Simulate 30% loss (drop 2 of ~7 packets) ---
-    const dropIndices = new Set([1, 3]);
-    const surviving = encryptedPackets.filter((_, i) => !dropIndices.has(i));
-
-    // --- Decrypt + FEC decode on Bob's side ---
-    let fecDecoded = null;
-    let decryptOk = true;
-
-    for (const pkt of surviving) {
-      let symbolData;
-      try {
-        symbolData = bobSession.decrypt(pkt.header, pkt.ciphertext);
-      } catch (e) {
-        decryptOk = false;
-        break;
-      }
-
-      const result = decoder.add_symbol(pkt.blockId, pkt.symbolIdx, pkt.isRepair, symbolData);
-      if (result) {
-        fecDecoded = result;
-        break;
-      }
-    }
-
-    // --- Verify recovered frames ---
-    let fecOk = false;
-    if (fecDecoded) {
-      fecOk = true;
-      for (let i = 0; i < WZP_WS_FULL_BLOCK_SIZE && fecOk; i++) {
-        const symOffset = i * WZP_WS_FULL_SYMBOL_SIZE;
-        if (symOffset + WZP_WS_FULL_SYMBOL_SIZE > fecDecoded.length) {
-          fecOk = false;
-          break;
-        }
-        const sym = fecDecoded.slice(symOffset, symOffset + WZP_WS_FULL_SYMBOL_SIZE);
-        const len = (sym[0] << 8) | sym[1];
-        const recovered = sym.slice(2, 2 + len);
-
-        if (recovered.length !== originalFrames[i].length) {
-          fecOk = false;
-          break;
-        }
-        for (let j = 0; j < recovered.length; j++) {
-          if (recovered[j] !== originalFrames[i][j]) {
-            fecOk = false;
-            break;
-          }
-        }
-      }
-    }
-
-    // Cleanup WASM objects.
-    alice.free();
-    bob.free();
-    aliceSession.free();
-    bobSession.free();
-    encoder.free();
-    decoder.free();
-
-    const elapsed = performance.now() - t0;
-
-    return {
-      success: secretsMatch && decryptOk && fecOk,
-      secretsMatch,
-      decryptOk,
-      fecOk,
-      sourcePackets,
-      repairPackets,
-      totalPackets: encryptedPackets.length,
-      dropped: dropIndices.size,
-      surviving: surviving.length,
-      elapsed: elapsed.toFixed(2) + 'ms',
-    };
-  }
-
-  // -----------------------------------------------------------------------
-  // Internal
-  // -----------------------------------------------------------------------
-
-  _handleMessage(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const data = new Uint8Array(event.data);
-    if (data.length < WZP_WS_FULL_HEADER_SIZE) return;
-
-    const header = this._parseHeader(data);
-    if (!header) return;
-
-    this.stats.recv++;
-
-    if (!this.cryptoSession || !this.fecDecoder) return;
-
-    // Extract header bytes (AAD) and ciphertext.
-    const headerBytes = data.slice(0, WZP_WS_FULL_HEADER_SIZE);
-    const ciphertext = data.slice(WZP_WS_FULL_HEADER_SIZE);
-
-    // Decrypt.
-    let symbolData;
-    try {
-      symbolData = this.cryptoSession.decrypt(headerBytes, ciphertext);
-      this.stats.decrypted++;
-    } catch (e) {
-      // Decryption failure — corrupted or replayed packet.
-      console.warn('[wzp-ws-full] decrypt failed:', e);
-      return;
-    }
-
-    // Feed decrypted symbol to FEC decoder.
-    const decoded = this.fecDecoder.add_symbol(
-      header.fecBlock,
-      header.fecSymbol,
-      header.isRepair,
-      symbolData
-    );
-
-    if (decoded) {
-      this.stats.fecRecovered++;
-
-      // decoded is concatenated padded symbols.
-      // Each symbol is WZP_WS_FULL_SYMBOL_SIZE bytes with a 2-byte length prefix.
-      for (let off = 0; off + WZP_WS_FULL_SYMBOL_SIZE <= decoded.length; off += WZP_WS_FULL_SYMBOL_SIZE) {
-        const symbol = decoded.slice(off, off + WZP_WS_FULL_SYMBOL_SIZE);
-        const pcmBytes = this._unpadSymbol(symbol);
-
-        if (pcmBytes.length > 0 && pcmBytes.length % 2 === 0) {
-          const pcm = new Int16Array(
-            pcmBytes.buffer,
-            pcmBytes.byteOffset,
-            pcmBytes.byteLength / 2
-          );
-          if (this.onAudio) this.onAudio(pcm);
-        }
-      }
-    }
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss: loss,
-          elapsed: elapsed,
-          encrypted: this.stats.encrypted,
-          decrypted: this.stats.decrypted,
-          fecRecovered: this.stats.fecRecovered,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._keyExchangeComplete = false;
-    this._stopStatsTimer();
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-    if (this.cryptoSession) {
-      try { this.cryptoSession.free(); } catch (_) { /* ignore */ }
-      this.cryptoSession = null;
-    }
-    if (this.fecEncoder) {
-      try { this.fecEncoder.free(); } catch (_) { /* ignore */ }
-      this.fecEncoder = null;
-    }
-    if (this.fecDecoder) {
-      try { this.fecDecoder.free(); } catch (_) { /* ignore */ }
-      this.fecDecoder = null;
-    }
-    if (this._keyExchange) {
-      try { this._keyExchange.free(); } catch (_) { /* ignore */ }
-      this._keyExchange = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPWsFullClient = WZPWsFullClient;

crates/wzp-web/static/js/wzp-ws.js

@@ -1,289 +0,0 @@
-// WarzonePhone — WZP-WS client (Variant 4).
-// WebSocket transport, WZP wire protocol, no WASM.
-// Sends MediaPacket-formatted frames instead of raw PCM.
-// Ready for direct relay WS support (no bridge translation needed).
-
-'use strict';
-
-// 12-byte MediaHeader size (matches wzp-proto MediaHeader::WIRE_SIZE).
-const WZP_WS_HEADER_SIZE = 12;
-
-class WZPWsClient {
-  /**
-   * @param {Object} options
-   * @param {string} options.wsUrl       WebSocket URL (ws://host/ws/room)
-   * @param {string} options.room        Room name
-   * @param {Function} options.onAudio   callback(Int16Array) for playback
-   * @param {Function} options.onStatus  callback(string) for UI status
-   * @param {Function} options.onStats   callback({sent, recv, loss, elapsed}) for UI
-   */
-  constructor(options) {
-    this.wsUrl = options.wsUrl;
-    this.room = options.room;
-    this.authToken = options.authToken || null;
-    this.onAudio = options.onAudio || null;
-    this.onStatus = options.onStatus || null;
-    this.onStats = options.onStats || null;
-
-    this.ws = null;
-    this.seq = 0;
-    this.startTimestamp = 0;
-    this.stats = { sent: 0, recv: 0 };
-    this._startTime = 0;
-    this._statsInterval = null;
-    this._connected = false;
-    this._authenticated = false;
-  }
-
-  /**
-   * Build a 12-byte WZP MediaHeader.
-   *
-   * Wire layout (from wzp-proto::packet::MediaHeader):
-   *   Byte 0:  V(1)|T(1)|CodecID(4)|Q(1)|FecRatioHi(1)
-   *   Byte 1:  FecRatioLo(6)|Reserved(2)
-   *   Bytes 2-3: Sequence number (BE u16)
-   *   Bytes 4-7: Timestamp ms (BE u32)
-   *   Byte 8:  FEC block ID
-   *   Byte 9:  FEC symbol index
-   *   Byte 10: Reserved
-   *   Byte 11: CSRC count
-   *
-   * @param {number} seq         Sequence number (u16)
-   * @param {number} timestampMs Milliseconds since session start
-   * @param {boolean} isRepair   True if this is a FEC repair symbol
-   * @param {number} codecId     Codec ID (0=RawPcm16, 1=Opus16k, 2=Opus48k)
-   * @param {number} fecBlock    FEC block ID (u8)
-   * @param {number} fecSymbol   FEC symbol index (u8)
-   * @param {number} fecRatio    FEC ratio (0.0 to ~2.0)
-   * @param {boolean} hasQuality Whether a quality report is attached
-   * @returns {Uint8Array} 12-byte header
-   */
-  _buildHeader(seq, timestampMs, isRepair = false, codecId = 0, fecBlock = 0, fecSymbol = 0, fecRatio = 0, hasQuality = false) {
-    const buf = new ArrayBuffer(WZP_WS_HEADER_SIZE);
-    const view = new DataView(buf);
-
-    const fecRatioEncoded = Math.min(127, Math.round(fecRatio * 63.5));
-    const byte0 = ((0 & 0x01) << 7)           // version=0
-        | ((isRepair ? 1 : 0) << 6)            // T bit
-        | ((codecId & 0x0F) << 2)              // CodecID
-        | ((hasQuality ? 1 : 0) << 1)          // Q bit
-        | ((fecRatioEncoded >> 6) & 0x01);     // FecRatioHi
-    view.setUint8(0, byte0);
-
-    const byte1 = (fecRatioEncoded & 0x3F) << 2;
-    view.setUint8(1, byte1);
-
-    view.setUint16(2, seq & 0xFFFF);           // big-endian (default for DataView)
-    view.setUint32(4, timestampMs & 0xFFFFFFFF); // big-endian
-    view.setUint8(8, fecBlock & 0xFF);
-    view.setUint8(9, fecSymbol & 0xFF);
-    view.setUint8(10, 0);  // reserved
-    view.setUint8(11, 0);  // csrc_count
-    return new Uint8Array(buf);
-  }
-
-  /**
-   * Parse a 12-byte MediaHeader from received binary data.
-   *
-   * @param {Uint8Array} data  At least 12 bytes
-   * @returns {Object|null} Parsed header fields, or null if too short
-   */
-  _parseHeader(data) {
-    if (data.byteLength < WZP_WS_HEADER_SIZE) return null;
-    const view = new DataView(data.buffer || data, data.byteOffset || 0, 12);
-    const byte0 = view.getUint8(0);
-    const byte1 = view.getUint8(1);
-    const fecRatioEncoded = ((byte0 & 0x01) << 6) | ((byte1 >> 2) & 0x3F);
-    return {
-      version: (byte0 >> 7) & 1,
-      isRepair: !!((byte0 >> 6) & 1),
-      codecId: (byte0 >> 2) & 0x0F,
-      hasQuality: !!((byte0 >> 1) & 1),
-      fecRatio: fecRatioEncoded / 63.5,
-      seq: view.getUint16(2),
-      timestamp: view.getUint32(4),
-      fecBlock: view.getUint8(8),
-      fecSymbol: view.getUint8(9),
-      reserved: view.getUint8(10),
-      csrcCount: view.getUint8(11),
-    };
-  }
-
-  /**
-   * Open WebSocket connection to the wzp-web bridge.
-   * @returns {Promise<void>} resolves when connected
-   */
-  async connect() {
-    if (this._connected) return;
-
-    return new Promise((resolve, reject) => {
-      this._status('Connecting (WZP-WS) to room: ' + this.room + '...');
-
-      this.ws = new WebSocket(this.wsUrl);
-      this.ws.binaryType = 'arraybuffer';
-
-      this.ws.onopen = () => {
-        // Send auth if token provided.
-        if (this.authToken) {
-          this.ws.send(JSON.stringify({ type: 'auth', token: this.authToken }));
-        }
-
-        this._connected = true;
-        this._authenticated = !this.authToken; // authenticated immediately if no token needed
-        this.seq = 0;
-        this.startTimestamp = Date.now();
-        this.stats = { sent: 0, recv: 0 };
-        this._startTime = Date.now();
-        this._status('Connected (WZP-WS) to room: ' + this.room);
-        this._startStatsTimer();
-        resolve();
-      };
-
-      this.ws.onmessage = (event) => {
-        // Handle text messages (auth responses).
-        if (typeof event.data === 'string') {
-          try {
-            const msg = JSON.parse(event.data);
-            if (msg.type === 'auth_ok') {
-              this._authenticated = true;
-              this._status('Authenticated (WZP-WS) to room: ' + this.room);
-            }
-            if (msg.type === 'auth_error') {
-              this._status('Auth failed: ' + (msg.reason || 'unknown'));
-              this.disconnect();
-            }
-          } catch(e) { /* ignore non-JSON text */ }
-          return;
-        }
-        this._handleMessage(event);
-      };
-
-      this.ws.onclose = () => {
-        const was = this._connected;
-        this._cleanup();
-        if (was) this._status('Disconnected');
-      };
-
-      this.ws.onerror = () => {
-        if (!this._connected) {
-          this._cleanup();
-          reject(new Error('WebSocket connection failed'));
-        } else {
-          this._status('Connection error');
-        }
-      };
-    });
-  }
-
-  /**
-   * Close WebSocket and clean up.
-   */
-  disconnect() {
-    this._connected = false;
-    if (this.ws) {
-      this.ws.close();
-      this.ws = null;
-    }
-    this._stopStatsTimer();
-  }
-
-  /**
-   * Send a PCM audio frame wrapped in a WZP MediaPacket over the WebSocket.
-   *
-   * Wire format: 12-byte MediaHeader + raw PCM payload.
-   * The relay can parse this natively without bridge translation.
-   *
-   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
-   */
-  async sendAudio(pcmBuffer) {
-    if (!this._connected || !this.ws || this.ws.readyState !== WebSocket.OPEN) return;
-
-    const header = this._buildHeader(
-      this.seq,
-      Date.now() - this.startTimestamp,
-      false, 0, 0, 0, 0, false
-    );
-
-    // Combine header + payload into single binary frame.
-    const pcmBytes = new Uint8Array(pcmBuffer);
-    const packet = new Uint8Array(WZP_WS_HEADER_SIZE + pcmBytes.length);
-    packet.set(header, 0);
-    packet.set(pcmBytes, WZP_WS_HEADER_SIZE);
-
-    this.ws.send(packet.buffer);
-    this.seq = (this.seq + 1) & 0xFFFF;
-    this.stats.sent++;
-  }
-
-  // -----------------------------------------------------------------------
-  // Internal
-  // -----------------------------------------------------------------------
-
-  _handleMessage(event) {
-    if (!(event.data instanceof ArrayBuffer)) return;
-    const data = new Uint8Array(event.data);
-    if (data.length < WZP_WS_HEADER_SIZE) return; // too small for header
-
-    const header = this._parseHeader(data);
-    if (!header) return;
-
-    // Extract payload (everything after 12-byte header).
-    // Payload is raw PCM Int16 samples.
-    const payloadBytes = data.slice(WZP_WS_HEADER_SIZE);
-    const pcm = new Int16Array(
-      payloadBytes.buffer,
-      payloadBytes.byteOffset,
-      payloadBytes.byteLength / 2
-    );
-    this.stats.recv++;
-    if (this.onAudio) this.onAudio(pcm);
-  }
-
-  _startStatsTimer() {
-    this._stopStatsTimer();
-    this._statsInterval = setInterval(() => {
-      if (!this._connected) {
-        this._stopStatsTimer();
-        return;
-      }
-      const elapsed = (Date.now() - this._startTime) / 1000;
-      const loss = this.stats.sent > 0
-        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
-        : 0;
-      if (this.onStats) {
-        this.onStats({
-          sent: this.stats.sent,
-          recv: this.stats.recv,
-          loss: loss,
-          elapsed: elapsed,
-        });
-      }
-    }, 1000);
-  }
-
-  _stopStatsTimer() {
-    if (this._statsInterval) {
-      clearInterval(this._statsInterval);
-      this._statsInterval = null;
-    }
-  }
-
-  _status(msg) {
-    if (this.onStatus) this.onStatus(msg);
-  }
-
-  _cleanup() {
-    this._connected = false;
-    this._stopStatsTimer();
-    if (this.ws) {
-      try { this.ws.close(); } catch (_) { /* ignore */ }
-      this.ws = null;
-    }
-  }
-}
-
-// ---------------------------------------------------------------------------
-// Export
-// ---------------------------------------------------------------------------
-
-window.WZPWsClient = WZPWsClient;

crates/wzp-web/static/wasm/.gitignore

@@ -1,2 +0,0 @@
-package.json
-*.d.ts