fix: auto-switch decoder codec to match incoming packets

The CallDecoder now inspects each incoming packet's codec_id and
automatically switches the audio decoder if it differs from the
current profile. This enables cross-codec interop where one client
sends Opus and the other sends Codec2 — previously the receiver
would try to decode with the wrong codec, producing garbled audio.

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

.gitea/workflows/build.yml

@@ -7,6 +7,8 @@ on:
       - 'feat/*'
     tags:
       - 'v*'
+    paths-ignore:
+      - '.gitea/**'
   workflow_dispatch:
 
 env:

.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

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "crates/wzp-client",
     "crates/wzp-web",
     "crates/wzp-android",
+    "desktop/src-tauri",
 ]
 
 [workspace.package]
@@ -53,3 +54,24 @@ wzp-fec = { path = "crates/wzp-fec" }
 wzp-crypto = { path = "crates/wzp-crypto" }
 wzp-transport = { path = "crates/wzp-transport" }
 wzp-client = { path = "crates/wzp-client" }
+
+# Fast dev profile: optimized but with debug info and incremental compilation.
+# Use with: cargo run --profile dev-fast
+[profile.dev-fast]
+inherits = "dev"
+opt-level = 2
+
+# Optimize heavy compute deps even in debug builds —
+# real-time audio needs < 20ms per frame, impossible unoptimized.
+[profile.dev.package.nnnoiseless]
+opt-level = 3
+[profile.dev.package.audiopus_sys]
+opt-level = 3
+[profile.dev.package.audiopus]
+opt-level = 3
+[profile.dev.package.raptorq]
+opt-level = 3
+[profile.dev.package.wzp-codec]
+opt-level = 3
+[profile.dev.package.wzp-fec]
+opt-level = 3

android/app/src/main/AndroidManifest.xml

@@ -29,5 +29,15 @@
             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/audio/AudioPipeline.kt

@@ -8,10 +8,19 @@ 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 kotlin.math.pow
+import kotlin.math.sqrt
 
 /**
  * Audio pipeline that captures mic audio and plays received audio using
@@ -43,9 +52,17 @@ class AudioPipeline(private val context: Context) {
     /** 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 = true
     private var captureThread: Thread? = null
     private var playoutThread: Thread? = null
 
+    private val debugDir: File by lazy {
+        File(context.cacheDir, "wzp_debug").also { it.mkdirs() }
+    }
+
     fun start(engine: WzpEngine) {
         if (running) return
         running = true
@@ -89,6 +106,15 @@ class AudioPipeline(private val context: Context) {
         }
     }
 
+    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)
@@ -127,25 +153,86 @@ class AudioPipeline(private val context: Context) {
             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")
+        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: ${e.message}")
+            }
+        }
         try {
             while (running) {
                 val read = recorder.read(pcm, 0, FRAME_SAMPLES)
                 if (read > 0) {
                     applyGain(pcm, read, captureGainDb)
                     engine.writeAudio(pcm)
+
+                    // Debug: write raw PCM + RMS
+                    if (pcmOut != null) {
+                        byteConv.clear()
+                        for (i in 0 until read) byteConv.putShort(pcm[i])
+                        pcmOut.write(byteConv.array(), 0, read * 2)
+                    }
+                    if (rmsCsv != null) {
+                        val rms = computeRms(pcm, read)
+                        val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
+                        rmsCsv.write("$frameIdx,$timeMs,$rms\n")
+                    }
+                    frameIdx++
                 } else if (read < 0) {
                     Log.e(TAG, "AudioRecord.read error: $read")
                     break
                 }
             }
         } finally {
+            pcmOut?.close()
+            rmsCsv?.close()
             recorder.stop()
+            aec?.release()
+            ns?.release()
             recorder.release()
-            Log.i(TAG, "capture stopped")
+            Log.i(TAG, "capture stopped (frames=$frameIdx)")
         }
     }
 
@@ -181,24 +268,57 @@ class AudioPipeline(private val context: Context) {
         Log.i(TAG, "playout started: ${SAMPLE_RATE}Hz mono, buf=$bufSize")
 
         val pcm = ShortArray(FRAME_SAMPLES)
-        val silence = ShortArray(FRAME_SAMPLES) // pre-allocated silence
+        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: ${e.message}")
+            }
+        }
         try {
             while (running) {
                 val read = engine.readAudio(pcm)
                 if (read >= FRAME_SAMPLES) {
                     applyGain(pcm, read, playoutGainDb)
                     track.write(pcm, 0, read)
+
+                    // Debug: write raw PCM + RMS
+                    if (pcmOut != null) {
+                        byteConv.clear()
+                        for (i in 0 until read) byteConv.putShort(pcm[i])
+                        pcmOut.write(byteConv.array(), 0, read * 2)
+                    }
+                    if (rmsCsv != null) {
+                        val rms = computeRms(pcm, read)
+                        val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
+                        rmsCsv.write("$frameIdx,$timeMs,$rms\n")
+                    }
+                    frameIdx++
                 } else {
-                    // Not enough decoded audio — write silence to keep stream alive
                     track.write(silence, 0, FRAME_SAMPLES)
-                    // Sleep briefly to avoid busy-spinning
+                    // 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")
+            Log.i(TAG, "playout stopped (frames=$frameIdx)")
         }
     }
 }

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

@@ -27,6 +27,7 @@ class SettingsRepository(context: Context) {
         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"
     }
 
     // --- Servers ---
@@ -112,6 +113,11 @@ class SettingsRepository(context: Context) {
     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)
+
     // --- Identity seed ---
 
     /**

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

@@ -54,7 +54,7 @@ data class CallStats(
                 val o = arr.getJSONObject(i)
                 RoomMember(
                     fingerprint = o.optString("fingerprint", ""),
-                    alias = o.optString("alias", null)
+                    alias = if (o.isNull("alias")) null else o.optString("alias", null)
                 )
             }
         }
@@ -92,5 +92,6 @@ data class RoomMember(
 ) {
     /** Short display name: alias if set, otherwise first 8 chars of fingerprint. */
     val displayName: String
-        get() = alias ?: fingerprint.take(8)
+        get() = alias?.takeIf { it.isNotBlank() }
+            ?: fingerprint.take(8).ifEmpty { "unknown" }
 }

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

@@ -1,8 +1,10 @@
 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
@@ -21,7 +23,12 @@ 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.
@@ -31,6 +38,10 @@ import com.wzp.ui.settings.SettingsScreen
  */
 class CallActivity : ComponentActivity() {
 
+    companion object {
+        private const val TAG = "CallActivity"
+    }
+
     private val viewModel: CallViewModel by viewModels()
 
     private val audioPermissionLauncher = registerForActivityResult(
@@ -69,6 +80,45 @@ class CallActivity : ComponentActivity() {
         ) {
             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() {

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

@@ -7,6 +7,7 @@ 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
@@ -18,6 +19,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
+import java.io.File
 import java.net.Inet4Address
 import java.net.Inet6Address
 import java.net.InetAddress
@@ -33,6 +35,10 @@ class CallViewModel : ViewModel(), WzpCallback {
     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()
@@ -76,6 +82,21 @@ class CallViewModel : ViewModel(), WzpCallback {
     private val _seedHex = MutableStateFlow("")
     val seedHex: StateFlow<String> = _seedHex.asStateFlow()
 
+    private val _aecEnabled = MutableStateFlow(true)
+    val aecEnabled: StateFlow<Boolean> = _aecEnabled.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
 
     companion object {
@@ -96,6 +117,9 @@ class CallViewModel : ViewModel(), WzpCallback {
         if (audioRouteManager == null) {
             audioRouteManager = AudioRouteManager(appCtx)
         }
+        if (debugReporter == null) {
+            debugReporter = DebugReporter(appCtx)
+        }
         if (settings == null) {
             settings = SettingsRepository(appCtx)
             loadSettings()
@@ -114,6 +138,7 @@ class CallViewModel : ViewModel(), WzpCallback {
         _playoutGainDb.value = s.loadPlayoutGain()
         _captureGainDb.value = s.loadCaptureGain()
         _seedHex.value = s.getOrCreateSeedHex()
+        _aecEnabled.value = s.loadAecEnabled()
     }
 
     fun selectServer(index: Int) {
@@ -149,6 +174,14 @@ class CallViewModel : ViewModel(), WzpCallback {
         }
     }
 
+    /** 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)
+    }
+
     fun setRoomName(name: String) {
         _roomName.value = name
         settings?.saveRoom(name)
@@ -176,6 +209,11 @@ class CallViewModel : ViewModel(), WzpCallback {
         settings?.saveSeedHex(hex)
     }
 
+    fun setAecEnabled(enabled: Boolean) {
+        _aecEnabled.value = enabled
+        settings?.saveAecEnabled(enabled)
+    }
+
     /**
      * Resolve DNS hostname to IP address on the Kotlin/Android side,
      * since Rust's DNS resolution may not work on Android.
@@ -214,6 +252,7 @@ class CallViewModel : ViewModel(), WzpCallback {
     /** 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=$stopService")
+        val hadCall = audioStarted
         CallService.onStopFromNotification = null
         stopAudio()
         stopStatsPolling()
@@ -223,6 +262,9 @@ class CallViewModel : ViewModel(), WzpCallback {
         engine = null
         engineInitialized = false
         _callState.value = 0
+        if (hadCall) {
+            _debugReportAvailable.value = true
+        }
         if (stopService) {
             try { appContext?.let { CallService.stop(it) } } catch (_: Exception) {}
         }
@@ -233,6 +275,10 @@ class CallViewModel : ViewModel(), WzpCallback {
         val serverEntry = _servers.value[_selectedServer.value]
         val room = _roomName.value
         Log.i(TAG, "startCall: server=${serverEntry.address} room=$room")
+        _debugReportAvailable.value = false
+        _debugReportStatus.value = null
+        lastCallServer = serverEntry.address
+        debugReporter?.prepareForCall()
         try {
             // Teardown previous call but don't stop the service (we're about to restart it)
             teardown(stopService = false)
@@ -297,6 +343,40 @@ class CallViewModel : ViewModel(), WzpCallback {
 
     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 }
@@ -310,6 +390,7 @@ class CallViewModel : ViewModel(), WzpCallback {
         audioPipeline = AudioPipeline(ctx).also {
             it.playoutGainDb = _playoutGainDb.value
             it.captureGainDb = _captureGainDb.value
+            it.aecEnabled = _aecEnabled.value
             it.start(e)
         }
         audioRouteManager?.register()
@@ -334,7 +415,9 @@ class CallViewModel : ViewModel(), WzpCallback {
                     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
                         if (s.state != 0) {
                             _callState.value = s.state

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

@@ -24,7 +24,6 @@ import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.FilledIconButton
 import androidx.compose.material3.FilledTonalIconButton
 import androidx.compose.material3.IconButtonDefaults
-import androidx.compose.material3.LinearProgressIndicator
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
@@ -69,6 +68,8 @@ fun InCallScreen(
     val preferIPv6 by viewModel.preferIPv6.collectAsState()
     val playoutGainDb by viewModel.playoutGainDb.collectAsState()
     val captureGainDb by viewModel.captureGainDb.collectAsState()
+    val debugReportAvailable by viewModel.debugReportAvailable.collectAsState()
+    val debugReportStatus by viewModel.debugReportStatus.collectAsState()
 
     var showAddServerDialog by remember { mutableStateOf(false) }
 
@@ -228,6 +229,17 @@ fun InCallScreen(
                         color = MaterialTheme.colorScheme.error
                     )
                 }
+
+                // Debug report card — shown after call ends
+                if (debugReportAvailable || debugReportStatus != null) {
+                    Spacer(modifier = Modifier.height(24.dp))
+                    DebugReportCard(
+                        available = debugReportAvailable,
+                        status = debugReportStatus,
+                        onSend = { viewModel.sendDebugReport() },
+                        onDismiss = { viewModel.dismissDebugReport() }
+                    )
+                }
             } else {
                 // In-call UI
                 Spacer(modifier = Modifier.height(16.dp))
@@ -239,13 +251,17 @@ fun InCallScreen(
                 QualityIndicator(qualityTier, stats.qualityLabel)
 
                 if (stats.roomParticipantCount > 0) {
+                    // Dedup by fingerprint — same key = same person, even if
+                    // relay hasn't cleaned up stale entries yet.
+                    val unique = stats.roomParticipants
+                        .distinctBy { it.fingerprint.ifEmpty { it.displayName } }
                     Spacer(modifier = Modifier.height(8.dp))
                     Text(
-                        text = "${stats.roomParticipantCount} in room",
+                        text = "${unique.size} in room",
                         style = MaterialTheme.typography.bodySmall,
                         color = MaterialTheme.colorScheme.onSurfaceVariant
                     )
-                    stats.roomParticipants.forEach { member ->
+                    unique.forEach { member ->
                         Text(
                             text = member.displayName,
                             style = MaterialTheme.typography.labelSmall,
@@ -438,15 +454,20 @@ private fun AudioLevelBar(audioLevel: Int) {
             color = MaterialTheme.colorScheme.onSurfaceVariant
         )
         Spacer(modifier = Modifier.height(4.dp))
-        LinearProgressIndicator(
-            progress = level,
+        Box(
             modifier = Modifier
                 .fillMaxWidth(0.6f)
                 .height(6.dp)
-                .clip(RoundedCornerShape(3.dp)),
-            color = MaterialTheme.colorScheme.primary,
-            trackColor = MaterialTheme.colorScheme.surfaceVariant,
-        )
+                .clip(RoundedCornerShape(3.dp))
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        ) {
+            Box(
+                modifier = Modifier
+                    .fillMaxWidth(level)
+                    .height(6.dp)
+                    .background(MaterialTheme.colorScheme.primary)
+            )
+        }
     }
 }
 
@@ -598,3 +619,70 @@ private fun StatItem(label: String, value: String) {
         )
     }
 }
+
+@Composable
+private fun DebugReportCard(
+    available: Boolean,
+    status: String?,
+    onSend: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    Surface(
+        modifier = Modifier.fillMaxWidth(),
+        color = MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.7f),
+        shape = RoundedCornerShape(12.dp)
+    ) {
+        Column(
+            modifier = Modifier.padding(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            Text(
+                text = "Debug Report",
+                style = MaterialTheme.typography.titleSmall.copy(fontWeight = FontWeight.Bold),
+                color = MaterialTheme.colorScheme.onSurface
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            Text(
+                text = "Email call recordings, logs & stats for analysis",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                textAlign = TextAlign.Center
+            )
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            when {
+                status != null && status.startsWith("Error") -> {
+                    Text(
+                        text = status,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.error
+                    )
+                    Spacer(modifier = Modifier.height(8.dp))
+                    Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                        OutlinedButton(onClick = onSend) { Text("Retry") }
+                        TextButton(onClick = onDismiss) { Text("Dismiss") }
+                    }
+                }
+                status != null && status != "ready" -> {
+                    // Preparing zip...
+                    Text(
+                        text = status,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                }
+                available -> {
+                    Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                        Button(onClick = onSend) {
+                            Text("Email Report")
+                        }
+                        TextButton(onClick = onDismiss) {
+                            Text("Skip")
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

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

@@ -21,9 +21,9 @@ 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.FilledTonalButton
 import androidx.compose.material3.FilledTonalIconButton
-import androidx.compose.material3.Divider
 import androidx.compose.material3.IconButtonDefaults
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
@@ -36,9 +36,12 @@ 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
@@ -47,6 +50,7 @@ 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
@@ -55,14 +59,39 @@ fun SettingsScreen(
     onBack: () -> Unit
 ) {
     val context = LocalContext.current
-    val servers by viewModel.servers.collectAsState()
-    val selectedServer by viewModel.selectedServer.collectAsState()
-    val roomName by viewModel.roomName.collectAsState()
-    val preferIPv6 by viewModel.preferIPv6.collectAsState()
-    val playoutGainDb by viewModel.playoutGainDb.collectAsState()
-    val captureGainDb by viewModel.captureGainDb.collectAsState()
-    val alias by viewModel.alias.collectAsState()
-    val seedHex by viewModel.seedHex.collectAsState()
+
+    // 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) }
@@ -94,8 +123,24 @@ fun SettingsScreen(
                     color = MaterialTheme.colorScheme.primary
                 )
                 Spacer(modifier = Modifier.weight(1f))
-                // Balance the back button
-                Spacer(modifier = Modifier.width(64.dp))
+                // 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))
@@ -104,8 +149,8 @@ fun SettingsScreen(
             SectionHeader("Identity")
 
             OutlinedTextField(
-                value = alias,
-                onValueChange = { viewModel.setAlias(it) },
+                value = draftAlias,
+                onValueChange = { draftAlias = it },
                 label = { Text("Display Name") },
                 singleLine = true,
                 modifier = Modifier.fillMaxWidth()
@@ -114,7 +159,7 @@ fun SettingsScreen(
             Spacer(modifier = Modifier.height(16.dp))
 
             // Fingerprint display
-            val fingerprint = if (seedHex.length >= 16) seedHex.take(16).uppercase() else "Not generated"
+            val fingerprint = if (draftSeedHex.length >= 16) draftSeedHex.take(16).uppercase() else "Not generated"
             Text(
                 text = "Fingerprint",
                 style = MaterialTheme.typography.labelSmall,
@@ -134,7 +179,7 @@ fun SettingsScreen(
             Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
                 FilledTonalButton(onClick = {
                     val clipboard = context.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
-                    clipboard.setPrimaryClip(ClipData.newPlainText("WZP Key", seedHex))
+                    clipboard.setPrimaryClip(ClipData.newPlainText("WZP Key", draftSeedHex))
                     Toast.makeText(context, "Key copied to clipboard", Toast.LENGTH_SHORT).show()
                 }) {
                     Text("Copy Key")
@@ -153,16 +198,39 @@ fun SettingsScreen(
 
             GainSlider(
                 label = "Voice Volume",
-                gainDb = playoutGainDb,
-                onGainChange = { viewModel.setPlayoutGainDb(it) }
+                gainDb = draftPlayoutGain,
+                onGainChange = { draftPlayoutGain = Math.round(it).toFloat() }
             )
             Spacer(modifier = Modifier.height(4.dp))
             GainSlider(
                 label = "Mic Gain",
-                gainDb = captureGainDb,
-                onGainChange = { viewModel.setCaptureGainDb(it) }
+                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(24.dp))
             Divider()
             Spacer(modifier = Modifier.height(16.dp))
@@ -175,11 +243,11 @@ fun SettingsScreen(
                 horizontalArrangement = Arrangement.Start,
                 verticalArrangement = Arrangement.spacedBy(4.dp)
             ) {
-                servers.forEachIndexed { idx, entry ->
-                    val isSelected = selectedServer == idx
+                draftServers.forEachIndexed { idx, entry ->
+                    val isSelected = draftSelectedServer == idx
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         FilledTonalIconButton(
-                            onClick = { viewModel.selectServer(idx) },
+                            onClick = { draftSelectedServer = idx },
                             modifier = Modifier
                                 .padding(end = 2.dp)
                                 .height(36.dp)
@@ -203,7 +271,12 @@ fun SettingsScreen(
                         // Show remove button for non-default servers
                         if (idx >= 2) {
                             TextButton(
-                                onClick = { viewModel.removeServer(idx) },
+                                onClick = {
+                                    draftServers.removeAt(idx)
+                                    if (draftSelectedServer >= draftServers.size) {
+                                        draftSelectedServer = 0
+                                    }
+                                },
                                 modifier = Modifier.height(36.dp)
                             ) {
                                 Text("X", color = MaterialTheme.colorScheme.error)
@@ -224,7 +297,7 @@ fun SettingsScreen(
             // Show selected server address
             Spacer(modifier = Modifier.height(8.dp))
             Text(
-                text = "Default: ${servers.getOrNull(selectedServer)?.address ?: "none"}",
+                text = "Default: ${draftServers.getOrNull(draftSelectedServer)?.address ?: "none"}",
                 style = MaterialTheme.typography.bodySmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant
             )
@@ -246,8 +319,8 @@ fun SettingsScreen(
                     modifier = Modifier.weight(1f)
                 )
                 Switch(
-                    checked = preferIPv6,
-                    onCheckedChange = { viewModel.setPreferIPv6(it) }
+                    checked = draftPreferIPv6,
+                    onCheckedChange = { draftPreferIPv6 = it }
                 )
             }
 
@@ -259,8 +332,8 @@ fun SettingsScreen(
             SectionHeader("Room")
 
             OutlinedTextField(
-                value = roomName,
-                onValueChange = { viewModel.setRoomName(it) },
+                value = draftRoomName,
+                onValueChange = { draftRoomName = it },
                 label = { Text("Default Room") },
                 singleLine = true,
                 modifier = Modifier.fillMaxWidth()
@@ -274,7 +347,7 @@ fun SettingsScreen(
         AddServerDialog(
             onDismiss = { showAddServerDialog = false },
             onAdd = { host, port, label ->
-                viewModel.addServer("$host:$port", label)
+                draftServers.add(ServerEntry("$host:$port", label))
                 showAddServerDialog = false
             }
         )
@@ -284,9 +357,9 @@ fun SettingsScreen(
         RestoreKeyDialog(
             onDismiss = { showRestoreKeyDialog = false },
             onRestore = { hex ->
-                viewModel.restoreSeed(hex)
+                draftSeedHex = hex
                 showRestoreKeyDialog = false
-                Toast.makeText(context, "Key restored", Toast.LENGTH_SHORT).show()
+                Toast.makeText(context, "Key staged — press Save to apply", Toast.LENGTH_SHORT).show()
             }
         )
     }
@@ -316,7 +389,7 @@ private fun GainSlider(label: String, gainDb: Float, onGainChange: (Float) -> Un
         )
         Slider(
             value = gainDb,
-            onValueChange = { onGainChange(Math.round(it).toFloat()) },
+            onValueChange = onGainChange,
             valueRange = -20f..20f,
             steps = 0,
             modifier = Modifier.fillMaxWidth()

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>

crates/wzp-android/Cargo.toml

@@ -28,6 +28,7 @@ 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/src/engine.rs

@@ -67,6 +67,9 @@ pub(crate) struct EngineState {
     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 {
@@ -87,6 +90,7 @@ impl WzpEngine {
             capture_ring: AudioRing::new(),
             playout_ring: AudioRing::new(),
             audio_level_rms: AtomicU32::new(0),
+            quic_transport: Mutex::new(None),
         });
         Self {
             state,
@@ -144,12 +148,25 @@ impl WzpEngine {
     }
 
     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_background();
+            rt.shutdown_timeout(std::time::Duration::from_millis(100));
         }
         self.call_start = None;
+        info!("stop_call: done");
     }
 
     pub fn set_mute(&self, muted: bool) {
@@ -223,6 +240,9 @@ async fn run_call(
 
     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();
@@ -301,8 +321,18 @@ async fn run_call(
     let mut block_id: u8 = 0;
 
     // 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;
         loop {
             if !state.running.load(Ordering::Relaxed) {
                 break;
@@ -319,6 +349,12 @@ async fn run_call(
                 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
             capture_agc.process_frame(&mut capture_buf);
 
@@ -354,11 +390,24 @@ async fn run_call(
                 quality_report: None,
             };
 
-            // Send source packet
+            // Send source packet — drop on error, never break
             if let Err(e) = transport.send_media(&source_pkt).await {
-                error!("send error: {e}");
-                break;
+                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
+                continue;
             }
+            frames_sent += 1;
 
             // Feed encoded frame to FEC encoder
             if let Err(e) = fec_enc.add_source_symbol(encoded) {
@@ -392,9 +441,11 @@ async fn run_call(
                                 payload: Bytes::from(repair_data),
                                 quality_report: None,
                             };
-                            if let Err(e) = transport.send_media(&repair_pkt).await {
-                                error!("send repair error: {e}");
-                                break;
+                            // 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) {
@@ -416,10 +467,21 @@ async fn run_call(
                 frame_in_block = 0;
             }
 
-            if s % 500 == 0 {
-                info!(seq = s, block_id, frame_in_block, "sending");
+            // Periodic stats every 5 seconds
+            if last_stats_log.elapsed().as_secs() >= 5 {
+                info!(
+                    seq = s,
+                    block_id,
+                    frames_sent,
+                    frames_dropped,
+                    send_errors,
+                    ring_avail = state.capture_ring.available(),
+                    "send stats"
+                );
+                last_stats_log = Instant::now();
             }
         }
+        info!(frames_sent, frames_dropped, send_errors, "send task ended");
     };
 
     // Pre-allocate decode buffer
@@ -429,6 +491,10 @@ async fn run_call(
     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();
         info!("recv task started (Opus + RaptorQ FEC)");
         loop {
             if !state.running.load(Ordering::Relaxed) {
@@ -436,6 +502,21 @@ async fn run_call(
             }
             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"
+                        );
+                    }
+
                     let is_repair = pkt.header.is_repair;
                     let pkt_block = pkt.header.fec_block;
                     let pkt_symbol = pkt.header.fec_symbol;
@@ -452,7 +533,6 @@ async fn run_call(
                     if !is_repair {
                         match decoder.decode(&pkt.payload, &mut decode_buf) {
                             Ok(samples) => {
-                                // AGC on playout — normalizes received audio volume
                                 playout_agc.process_frame(&mut decode_buf[..samples]);
                                 state.playout_ring.write(&decode_buf[..samples]);
                                 frames_decoded += 1;
@@ -467,13 +547,8 @@ async fn run_call(
                         }
                     }
 
-                    // Try FEC recovery for this block
-                    // (useful when source packets were lost but repair arrived)
+                    // Try FEC recovery
                     if let Ok(Some(recovered_frames)) = fec_dec.try_decode(pkt_block) {
-                        // FEC recovered the block — any previously missing frames
-                        // are now available. In a full jitter buffer implementation,
-                        // we'd insert recovered frames at the right position.
-                        // For now, log recovery for telemetry.
                         fec_recovered += recovered_frames.len() as u64;
                         if fec_recovered % 50 == 1 {
                             info!(
@@ -490,24 +565,45 @@ async fn run_call(
                         fec_dec.expire_before(pkt_block.wrapping_sub(3));
                     }
 
-                    if frames_decoded == 1 || frames_decoded % 500 == 0 {
-                        info!(frames_decoded, fec_recovered, "recv stats");
-                    }
-
                     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(),
+                            "recv stats"
+                        );
+                        max_recv_gap_ms = 0;
+                        last_stats_log = Instant::now();
+                    }
                 }
                 Ok(None) => {
-                    info!("relay disconnected");
+                    info!(frames_decoded, fec_recovered, "relay disconnected (stream ended)");
                     break;
                 }
                 Err(e) => {
-                    error!("recv error: {e}");
-                    break;
+                    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
@@ -569,12 +665,22 @@ async fn run_call(
     };
 
     tokio::select! {
-        _ = send_task => {}
-        _ = recv_task => {}
-        _ = stats_task => {}
-        _ = signal_task => {}
+        _ = send_task => info!("send task ended"),
+        _ = recv_task => info!("recv task ended"),
+        _ = stats_task => info!("stats task ended"),
+        _ = signal_task => info!("signal task ended"),
     }
 
-    transport.close().await.ok();
+    // 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

@@ -1,6 +1,7 @@
 //! 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};
@@ -28,12 +29,27 @@ fn profile_from_int(value: jint) -> QualityProfile {
     }
 }
 
+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(|| {
+        use tracing_subscriber::layer::SubscriberExt;
+        use tracing_subscriber::util::SubscriberInitExt;
+        if let Ok(layer) = tracing_android::layer("wzp_android") {
+            let _ = tracing_subscriber::registry().with(layer).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();
         let handle = Box::new(EngineHandle {
             engine: WzpEngine::new(),
         });

crates/wzp-client/Cargo.toml

@@ -23,10 +23,13 @@ serde_json = "1"
 chrono = "0.4"
 rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
 cpal = { version = "0.15", optional = true }
+coreaudio-rs = { version = "0.11", optional = true }
+libc = "0.2"
 
 [features]
 default = []
 audio = ["cpal"]
+vpio = ["coreaudio-rs"]
 
 [[bin]]
 name = "wzp-client"

crates/wzp-client/src/audio_io.rs

@@ -3,12 +3,10 @@
 //! Both structs use 48 kHz, mono, i16 format to match the WarzonePhone codec
 //! pipeline. Frames are 960 samples (20 ms at 48 kHz).
 //!
-//! The cpal `Stream` type is not `Send`, so each struct spawns a dedicated OS
-//! thread that owns the stream. The public API exposes only `Send + Sync`
-//! channel handles.
+//! Audio callbacks are **lock-free**: they read/write directly to an `AudioRing`
+//! (atomic SPSC ring buffer). No Mutex, no channel, no allocation on the hot path.
 
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::mpsc;
 use std::sync::Arc;
 
 use anyhow::{anyhow, Context};
@@ -16,6 +14,8 @@ use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::{SampleFormat, SampleRate, StreamConfig};
 use tracing::{info, warn};
 
+use crate::audio_ring::AudioRing;
+
 /// Number of samples per 20 ms frame at 48 kHz mono.
 pub const FRAME_SAMPLES: usize = 960;
 
@@ -23,22 +23,24 @@ pub const FRAME_SAMPLES: usize = 960;
 // AudioCapture
 // ---------------------------------------------------------------------------
 
-/// Captures microphone input and yields 960-sample PCM frames.
+/// Captures microphone input via CPAL and writes PCM into a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioCapture {
-    rx: mpsc::Receiver<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioCapture {
     /// Create and start capturing from the default input device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-capture".into())
@@ -59,53 +61,51 @@ impl AudioCapture {
 
                     let use_f32 = !supports_i16_input(&device)?;
 
-                    let buf = Arc::new(std::sync::Mutex::new(
-                        Vec::<i16>::with_capacity(FRAME_SAMPLES),
-                    ));
                     let err_cb = |e: cpal::StreamError| {
                         warn!("input stream error: {e}");
                     };
 
+                    let logged_cb_size = Arc::new(AtomicBool::new(false));
+
                     let stream = if use_f32 {
-                        let buf = buf.clone();
-                        let tx = tx.clone();
+                        let ring = ring_cb.clone();
                         let running = running_clone.clone();
+                        let logged = logged_cb_size.clone();
                         device.build_input_stream(
                             &config,
                             move |data: &[f32], _: &cpal::InputCallbackInfo| {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
-                                for &s in data {
-                                    lock.push(f32_to_i16(s));
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
+                                if !logged.swap(true, Ordering::Relaxed) {
+                                    eprintln!("[audio] capture callback: {} f32 samples", data.len());
+                                }
+                                let mut tmp = [0i16; FRAME_SAMPLES];
+                                for chunk in data.chunks(FRAME_SAMPLES) {
+                                    let n = chunk.len();
+                                    for i in 0..n {
+                                        tmp[i] = f32_to_i16(chunk[i]);
                                     }
+                                    ring.write(&tmp[..n]);
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let buf = buf.clone();
-                        let tx = tx.clone();
+                        let ring = ring_cb.clone();
                         let running = running_clone.clone();
+                        let logged = logged_cb_size.clone();
                         device.build_input_stream(
                             &config,
                             move |data: &[i16], _: &cpal::InputCallbackInfo| {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
-                                for &s in data {
-                                    lock.push(s);
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
-                                    }
+                                if !logged.swap(true, Ordering::Relaxed) {
+                                    eprintln!("[audio] capture callback: {} i16 samples", data.len());
                                 }
+                                ring.write(data);
                             },
                             err_cb,
                             None,
@@ -114,7 +114,6 @@ impl AudioCapture {
 
                     stream.play().context("failed to start input stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -135,15 +134,12 @@ impl AudioCapture {
             .map_err(|_| anyhow!("capture thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { rx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Read the next frame of 960 PCM samples (blocking until available).
-    ///
-    /// Returns `None` when the stream has been stopped or the channel is
-    /// disconnected.
-    pub fn read_frame(&self) -> Option<Vec<i16>> {
-        self.rx.recv().ok()
+    /// Get a reference to the capture ring buffer for direct polling.
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
     }
 
     /// Stop capturing.
@@ -152,26 +148,34 @@ impl AudioCapture {
     }
 }
 
+impl Drop for AudioCapture {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // AudioPlayback
 // ---------------------------------------------------------------------------
 
-/// Plays PCM frames through the default output device at 48 kHz mono.
+/// Plays PCM through the default output device, reading from a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioPlayback {
-    tx: mpsc::SyncSender<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioPlayback {
     /// Create and start playback on the default output device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-playback".into())
@@ -192,62 +196,40 @@ impl AudioPlayback {
 
                     let use_f32 = !supports_i16_output(&device)?;
 
-                    // Shared ring of samples the cpal callback drains from.
-                    let ring = Arc::new(std::sync::Mutex::new(
-                        std::collections::VecDeque::<i16>::with_capacity(FRAME_SAMPLES * 8),
-                    ));
-
-                    // Background drainer: moves frames from the mpsc channel into the ring.
-                    {
-                        let ring = ring.clone();
-                        let running = running_clone.clone();
-                        std::thread::Builder::new()
-                            .name("wzp-playback-drain".into())
-                            .spawn(move || {
-                                while running.load(Ordering::Relaxed) {
-                                    match rx.recv_timeout(std::time::Duration::from_millis(100)) {
-                                        Ok(frame) => {
-                                            let mut lock = ring.lock().unwrap();
-                                            lock.extend(frame);
-                                            while lock.len() > FRAME_SAMPLES * 16 {
-                                                lock.pop_front();
-                                            }
-                                        }
-                                        Err(mpsc::RecvTimeoutError::Timeout) => {}
-                                        Err(mpsc::RecvTimeoutError::Disconnected) => break,
-                                    }
-                                }
-                            })?;
-                    }
-
                     let err_cb = |e: cpal::StreamError| {
                         warn!("output stream error: {e}");
                     };
 
                     let stream = if use_f32 {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
-                                for sample in data.iter_mut() {
-                                    *sample = match lock.pop_front() {
-                                        Some(s) => i16_to_f32(s),
-                                        None => 0.0,
-                                    };
+                                let mut tmp = [0i16; FRAME_SAMPLES];
+                                for chunk in data.chunks_mut(FRAME_SAMPLES) {
+                                    let n = chunk.len();
+                                    let read = ring.read(&mut tmp[..n]);
+                                    for i in 0..read {
+                                        chunk[i] = i16_to_f32(tmp[i]);
+                                    }
+                                    // Fill remainder with silence if ring underran
+                                    for i in read..n {
+                                        chunk[i] = 0.0;
+                                    }
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [i16], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
-                                for sample in data.iter_mut() {
-                                    *sample = lock.pop_front().unwrap_or(0);
+                                let read = ring.read(data);
+                                // Fill remainder with silence if ring underran
+                                for sample in &mut data[read..] {
+                                    *sample = 0;
                                 }
                             },
                             err_cb,
@@ -257,7 +239,6 @@ impl AudioPlayback {
 
                     stream.play().context("failed to start output stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -278,12 +259,12 @@ impl AudioPlayback {
             .map_err(|_| anyhow!("playback thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { tx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Write a frame of PCM samples for playback.
-    pub fn write_frame(&self, pcm: &[i16]) {
-        let _ = self.tx.try_send(pcm.to_vec());
+    /// Get a reference to the playout ring buffer for direct writing.
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
     }
 
     /// Stop playback.
@@ -292,11 +273,16 @@ impl AudioPlayback {
     }
 }
 
+impl Drop for AudioPlayback {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Helpers
 // ---------------------------------------------------------------------------
 
-/// Check if the input device supports i16 at 48 kHz mono.
 fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_input_configs()
@@ -313,7 +299,6 @@ fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     Ok(false)
 }
 
-/// Check if the output device supports i16 at 48 kHz mono.
 fn supports_i16_output(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_output_configs()

crates/wzp-client/src/audio_ring.rs

@@ -0,0 +1,122 @@
+//! 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.
+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)
+    }
+
+    /// 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`.
+    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.
+    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.
+        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-client/src/audio_vpio.rs

@@ -0,0 +1,179 @@
+//! macOS Voice Processing I/O — uses Apple's VoiceProcessingIO audio unit
+//! for hardware-accelerated echo cancellation, AGC, and noise suppression.
+//!
+//! VoiceProcessingIO is a combined input+output unit that knows what's going
+//! to the speaker, so it can cancel the echo from the mic signal internally.
+//! This is the same engine FaceTime and other Apple apps use.
+
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+
+use anyhow::Context;
+use coreaudio::audio_unit::audio_format::LinearPcmFlags;
+use coreaudio::audio_unit::render_callback::{self, data};
+use coreaudio::audio_unit::{AudioUnit, Element, IOType, SampleFormat, Scope, StreamFormat};
+use coreaudio::sys;
+use tracing::info;
+
+use crate::audio_ring::AudioRing;
+
+/// Number of samples per 20 ms frame at 48 kHz mono.
+pub const FRAME_SAMPLES: usize = 960;
+
+/// Combined capture + playback via macOS VoiceProcessingIO.
+///
+/// The OS handles AEC internally — no manual far-end feeding needed.
+pub struct VpioAudio {
+    capture_ring: Arc<AudioRing>,
+    playout_ring: Arc<AudioRing>,
+    _audio_unit: AudioUnit,
+    running: Arc<AtomicBool>,
+}
+
+impl VpioAudio {
+    /// Start VoiceProcessingIO with AEC enabled.
+    pub fn start() -> Result<Self, anyhow::Error> {
+        let capture_ring = Arc::new(AudioRing::new());
+        let playout_ring = Arc::new(AudioRing::new());
+        let running = Arc::new(AtomicBool::new(true));
+
+        let mut au = AudioUnit::new(IOType::VoiceProcessingIO)
+            .context("failed to create VoiceProcessingIO audio unit")?;
+
+        // Must uninitialize before configuring properties.
+        au.uninitialize()
+            .context("failed to uninitialize VPIO for configuration")?;
+
+        // Enable input (mic) on Element::Input (bus 1).
+        let enable: u32 = 1;
+        au.set_property(
+            sys::kAudioOutputUnitProperty_EnableIO,
+            Scope::Input,
+            Element::Input,
+            Some(&enable),
+        )
+        .context("failed to enable VPIO input")?;
+
+        // Output (speaker) is enabled by default on VPIO, but be explicit.
+        au.set_property(
+            sys::kAudioOutputUnitProperty_EnableIO,
+            Scope::Output,
+            Element::Output,
+            Some(&enable),
+        )
+        .context("failed to enable VPIO output")?;
+
+        // Configure stream format: 48kHz mono f32 non-interleaved
+        let stream_format = StreamFormat {
+            sample_rate: 48_000.0,
+            sample_format: SampleFormat::F32,
+            flags: LinearPcmFlags::IS_FLOAT
+                | LinearPcmFlags::IS_PACKED
+                | LinearPcmFlags::IS_NON_INTERLEAVED,
+            channels: 1,
+        };
+
+        let asbd = stream_format.to_asbd();
+
+        // Input: set format on Output scope of Input element
+        // (= the format the AU delivers to us from the mic)
+        au.set_property(
+            sys::kAudioUnitProperty_StreamFormat,
+            Scope::Output,
+            Element::Input,
+            Some(&asbd),
+        )
+        .context("failed to set input stream format")?;
+
+        // Output: set format on Input scope of Output element
+        // (= the format we feed to the AU for the speaker)
+        au.set_property(
+            sys::kAudioUnitProperty_StreamFormat,
+            Scope::Input,
+            Element::Output,
+            Some(&asbd),
+        )
+        .context("failed to set output stream format")?;
+
+        // Set up input callback (mic capture with AEC applied)
+        let cap_ring = capture_ring.clone();
+        let cap_running = running.clone();
+        let logged = Arc::new(AtomicBool::new(false));
+        au.set_input_callback(
+            move |args: render_callback::Args<data::NonInterleaved<f32>>| {
+                if !cap_running.load(Ordering::Relaxed) {
+                    return Ok(());
+                }
+                let mut buffers = args.data.channels();
+                if let Some(ch) = buffers.next() {
+                    if !logged.swap(true, Ordering::Relaxed) {
+                        eprintln!("[vpio] capture callback: {} f32 samples", ch.len());
+                    }
+                    let mut tmp = [0i16; FRAME_SAMPLES];
+                    for chunk in ch.chunks(FRAME_SAMPLES) {
+                        let n = chunk.len();
+                        for i in 0..n {
+                            tmp[i] = (chunk[i].clamp(-1.0, 1.0) * i16::MAX as f32) as i16;
+                        }
+                        cap_ring.write(&tmp[..n]);
+                    }
+                }
+                Ok(())
+            },
+        )
+        .context("failed to set input callback")?;
+
+        // Set up output callback (speaker playback — AEC uses this as reference)
+        let play_ring = playout_ring.clone();
+        au.set_render_callback(
+            move |mut args: render_callback::Args<data::NonInterleaved<f32>>| {
+                let mut buffers = args.data.channels_mut();
+                if let Some(ch) = buffers.next() {
+                    let mut tmp = [0i16; FRAME_SAMPLES];
+                    for chunk in ch.chunks_mut(FRAME_SAMPLES) {
+                        let n = chunk.len();
+                        let read = play_ring.read(&mut tmp[..n]);
+                        for i in 0..read {
+                            chunk[i] = tmp[i] as f32 / i16::MAX as f32;
+                        }
+                        for i in read..n {
+                            chunk[i] = 0.0;
+                        }
+                    }
+                }
+                Ok(())
+            },
+        )
+        .context("failed to set render callback")?;
+
+        au.initialize().context("failed to initialize VoiceProcessingIO")?;
+        au.start().context("failed to start VoiceProcessingIO")?;
+
+        info!("VoiceProcessingIO started (OS-level AEC enabled)");
+
+        Ok(Self {
+            capture_ring,
+            playout_ring,
+            _audio_unit: au,
+            running,
+        })
+    }
+
+    pub fn capture_ring(&self) -> &Arc<AudioRing> {
+        &self.capture_ring
+    }
+
+    pub fn playout_ring(&self) -> &Arc<AudioRing> {
+        &self.playout_ring
+    }
+
+    pub fn stop(&self) {
+        self.running.store(false, Ordering::Relaxed);
+    }
+}
+
+impl Drop for VpioAudio {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}

crates/wzp-client/src/call.rs

@@ -42,6 +42,9 @@ pub struct CallConfig {
     /// When enabled, only every 50th frame carries a full 12-byte MediaHeader;
     /// intermediate frames use a compact 4-byte MiniHeader.
     pub mini_frames_enabled: bool,
+    /// AEC far-end delay compensation in milliseconds (default: 40).
+    /// Compensates for the round-trip audio latency from playout to mic capture.
+    pub aec_delay_ms: u32,
     /// Enable adaptive jitter buffer (default: true).
     ///
     /// When true, the jitter buffer target depth is automatically adjusted
@@ -63,6 +66,7 @@ impl Default for CallConfig {
             noise_suppression: true,
             mini_frames_enabled: true,
             adaptive_jitter: true,
+            aec_delay_ms: 40,
         }
     }
 }
@@ -241,7 +245,7 @@ impl CallEncoder {
             block_id: 0,
             frame_in_block: 0,
             timestamp_ms: 0,
-            aec: EchoCanceller::new(48000, 100), // 100 ms echo tail
+            aec: EchoCanceller::with_delay(48000, 60, config.aec_delay_ms),
             agc: AutoGainControl::new(),
             silence_detector: SilenceDetector::new(
                 config.silence_threshold_rms,
@@ -496,6 +500,49 @@ impl CallDecoder {
         }
     }
 
+    /// Switch the decoder to match an incoming packet's codec if it differs
+    /// from the current profile. This enables cross-codec interop (e.g. one
+    /// client sends Opus, the other sends Codec2).
+    fn switch_decoder_if_needed(&mut self, incoming_codec: CodecId) {
+        if incoming_codec == self.profile.codec || incoming_codec == CodecId::ComfortNoise {
+            return;
+        }
+        let new_profile = Self::profile_for_codec(incoming_codec);
+        info!(
+            from = ?self.profile.codec,
+            to = ?incoming_codec,
+            "decoder switching codec to match incoming packet"
+        );
+        if let Err(e) = self.audio_dec.set_profile(new_profile) {
+            warn!("failed to switch decoder profile: {e}");
+            return;
+        }
+        self.fec_dec = wzp_fec::create_decoder(&new_profile);
+        self.profile = new_profile;
+    }
+
+    /// Map a `CodecId` to a reasonable `QualityProfile` for decoding.
+    fn profile_for_codec(codec: CodecId) -> QualityProfile {
+        match codec {
+            CodecId::Opus24k => QualityProfile::GOOD,
+            CodecId::Opus16k => QualityProfile {
+                codec: CodecId::Opus16k,
+                fec_ratio: 0.3,
+                frame_duration_ms: 20,
+                frames_per_block: 5,
+            },
+            CodecId::Opus6k => QualityProfile::DEGRADED,
+            CodecId::Codec2_3200 => QualityProfile {
+                codec: CodecId::Codec2_3200,
+                fec_ratio: 0.5,
+                frame_duration_ms: 20,
+                frames_per_block: 5,
+            },
+            CodecId::Codec2_1200 => QualityProfile::CATASTROPHIC,
+            CodecId::ComfortNoise => QualityProfile::GOOD,
+        }
+    }
+
     /// Decode the next audio frame from the jitter buffer.
     ///
     /// Returns PCM samples (48kHz mono) or None if not ready.
@@ -510,6 +557,9 @@ impl CallDecoder {
                     return Some(pcm.len());
                 }
 
+                // Auto-switch decoder if incoming codec differs from current.
+                self.switch_decoder_if_needed(pkt.header.codec_id);
+
                 self.last_was_cn = false;
                 let result = match self.audio_dec.decode(&pkt.payload, pcm) {
                     Ok(n) => Some(n),

crates/wzp-client/src/cli.rs

@@ -14,17 +14,23 @@
 use std::net::SocketAddr;
 use std::sync::Arc;
 
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
 use wzp_client::call::{CallConfig, CallDecoder, CallEncoder};
 use wzp_proto::MediaTransport;
 
-const FRAME_SAMPLES: usize = 960; // 20ms @ 48kHz
+const FRAME_SAMPLES_20MS: usize = 960; // 20ms @ 48kHz
+const FRAME_SAMPLES_40MS: usize = 1920; // 40ms @ 48kHz
+
+/// Compute frame samples at 48kHz for a given profile.
+fn frame_samples_for(profile: &wzp_proto::QualityProfile) -> usize {
+    (profile.frame_duration_ms as usize) * 48 // 48000 / 1000
+}
 
 /// Generate a sine wave tone.
-fn generate_sine_frame(freq_hz: f32, sample_rate: u32, frame_offset: u64) -> Vec<i16> {
-    let start_sample = frame_offset * FRAME_SAMPLES as u64;
-    (0..FRAME_SAMPLES)
+fn generate_sine_frame(freq_hz: f32, sample_rate: u32, frame_offset: u64, frame_samples: usize) -> Vec<i16> {
+    let start_sample = frame_offset * frame_samples as u64;
+    (0..frame_samples)
         .map(|i| {
             let t = (start_sample + i as u64) as f32 / sample_rate as f32;
             (f32::sin(2.0 * std::f32::consts::PI * freq_hz * t) * 16000.0) as i16
@@ -45,12 +51,32 @@ struct CliArgs {
     seed_hex: Option<String>,
     mnemonic: Option<String>,
     room: Option<String>,
+    raw_room: bool,
+    alias: Option<String>,
+    no_denoise: bool,
+    no_aec: bool,
+    no_agc: bool,
+    no_fec: bool,
+    no_silence: bool,
+    direct_playout: bool,
+    aec_delay_ms: Option<u32>,
+    os_aec: bool,
     token: Option<String>,
     _metrics_file: Option<String>,
+    /// Force a quality profile: "good", "degraded", "catastrophic", "codec2-3200"
+    profile_override: Option<String>,
+}
+
+/// Default identity file path: ~/.wzp/identity
+fn default_identity_path() -> std::path::PathBuf {
+    let home = std::env::var("HOME").unwrap_or_else(|_| ".".to_string());
+    std::path::PathBuf::from(home).join(".wzp").join("identity")
 }
 
 impl CliArgs {
-    /// Resolve the identity seed from --seed, --mnemonic, or generate a new one.
+    /// Resolve the identity seed from --seed, --mnemonic, or persistent file.
+    ///
+    /// Priority: --seed > --mnemonic > ~/.wzp/identity > generate + save.
     pub fn resolve_seed(&self) -> wzp_crypto::Seed {
         if let Some(ref hex_str) = self.seed_hex {
             let seed = wzp_crypto::Seed::from_hex(hex_str).expect("invalid --seed hex");
@@ -65,15 +91,56 @@ impl CliArgs {
             info!(fingerprint = %fp, "identity from --mnemonic");
             seed
         } else {
+            let path = default_identity_path();
+            // Try loading existing identity
+            if path.exists() {
+                if let Ok(hex_str) = std::fs::read_to_string(&path) {
+                    let hex_str = hex_str.trim();
+                    if let Ok(seed) = wzp_crypto::Seed::from_hex(hex_str) {
+                        let id = seed.derive_identity();
+                        let fp = id.public_identity().fingerprint;
+                        info!(fingerprint = %fp, path = %path.display(), "loaded persistent identity");
+                        return seed;
+                    }
+                }
+            }
+            // Generate new and save
             let seed = wzp_crypto::Seed::generate();
             let id = seed.derive_identity();
             let fp = id.public_identity().fingerprint;
-            info!(fingerprint = %fp, "generated ephemeral identity");
+            if let Some(parent) = path.parent() {
+                std::fs::create_dir_all(parent).ok();
+            }
+            // Encode seed as hex manually (avoid dep on `hex` crate in binary)
+            let hex_str: String = seed.0.iter().map(|b| format!("{b:02x}")).collect();
+            std::fs::write(&path, hex_str).ok();
+            info!(fingerprint = %fp, path = %path.display(), "generated and saved new identity");
             seed
         }
     }
 }
 
+/// Resolve a profile name to a QualityProfile.
+fn resolve_profile(name: &str) -> wzp_proto::QualityProfile {
+    use wzp_proto::{CodecId, QualityProfile};
+    match name.to_lowercase().as_str() {
+        "good" | "opus" | "opus24k" => QualityProfile::GOOD,
+        "degraded" | "opus6k" => QualityProfile::DEGRADED,
+        "catastrophic" | "codec2-1200" | "c2-1200" | "1200" => QualityProfile::CATASTROPHIC,
+        "codec2-3200" | "c2-3200" | "3200" => QualityProfile {
+            codec: CodecId::Codec2_3200,
+            fec_ratio: 0.5,
+            frame_duration_ms: 20,
+            frames_per_block: 5,
+        },
+        other => {
+            eprintln!("unknown profile: {other}");
+            eprintln!("valid: good, degraded, catastrophic, codec2-3200, codec2-1200");
+            std::process::exit(1);
+        }
+    }
+}
+
 fn parse_args() -> CliArgs {
     let args: Vec<String> = std::env::args().collect();
     let mut live = false;
@@ -86,8 +153,19 @@ fn parse_args() -> CliArgs {
     let mut seed_hex = None;
     let mut mnemonic = None;
     let mut room = None;
+    let mut raw_room = false;
+    let mut alias = None;
+    let mut no_denoise = false;
+    let mut no_aec = false;
+    let mut no_agc = false;
+    let mut no_fec = false;
+    let mut no_silence = false;
+    let mut direct_playout = false;
+    let mut aec_delay_ms = None;
+    let mut os_aec = false;
     let mut token = None;
     let mut metrics_file = None;
+    let mut profile_override = None;
     let mut relay_str = None;
 
     let mut i = 1;
@@ -130,6 +208,27 @@ fn parse_args() -> CliArgs {
                 i += 1;
                 room = Some(args.get(i).expect("--room requires a name").to_string());
             }
+            "--raw-room" => raw_room = true,
+            "--no-denoise" => no_denoise = true,
+            "--no-aec" => no_aec = true,
+            "--no-agc" => no_agc = true,
+            "--no-fec" => no_fec = true,
+            "--no-silence" => no_silence = true,
+            "--direct-playout" | "--android" => direct_playout = true,
+            "--os-aec" => os_aec = true,
+            "--aec-delay" => {
+                i += 1;
+                aec_delay_ms = Some(
+                    args.get(i)
+                        .expect("--aec-delay requires milliseconds")
+                        .parse()
+                        .expect("--aec-delay value must be a number"),
+                );
+            }
+            "--alias" => {
+                i += 1;
+                alias = Some(args.get(i).expect("--alias requires a name").to_string());
+            }
             "--token" => {
                 i += 1;
                 token = Some(args.get(i).expect("--token requires a value").to_string());
@@ -168,6 +267,14 @@ fn parse_args() -> CliArgs {
                         .expect("--drift-test value must be a number"),
                 );
             }
+            "--profile" | "--codec" => {
+                i += 1;
+                profile_override = Some(
+                    args.get(i)
+                        .expect("--profile requires a value (good, degraded, catastrophic, codec2-3200)")
+                        .to_string(),
+                );
+            }
             "--sweep" => sweep = true,
             "--help" | "-h" => {
                 eprintln!("Usage: wzp-client [options] [relay-addr]");
@@ -179,14 +286,28 @@ fn parse_args() -> CliArgs {
                 eprintln!("  --record <file.raw>    Record received audio to raw PCM file");
                 eprintln!("  --echo-test <secs>     Run automated echo quality test");
                 eprintln!("  --drift-test <secs>    Run automated clock-drift measurement");
+                eprintln!("  --profile <name>       Force quality profile: good, degraded, catastrophic, codec2-3200");
+                eprintln!("  --codec <name>         Alias for --profile");
                 eprintln!("  --sweep                Run jitter buffer parameter sweep (local, no network)");
                 eprintln!("  --seed <hex>           Identity seed (64 hex chars, featherChat compatible)");
                 eprintln!("  --mnemonic <words...>  Identity seed as BIP39 mnemonic (24 words)");
                 eprintln!("  --room <name>          Room name (hashed for privacy before sending)");
+                eprintln!("  --raw-room             Send room name as-is (no hash, for Android compat)");
+                eprintln!("  --alias <name>         Display name shown to other participants");
+                eprintln!("  --no-denoise           Disable RNNoise noise suppression");
+                eprintln!("  --no-aec              Disable acoustic echo cancellation");
+                eprintln!("  --no-agc              Disable automatic gain control");
+                eprintln!("  --no-fec              Disable forward error correction");
+                eprintln!("  --no-silence          Disable silence suppression");
+                eprintln!("  --direct-playout      Bypass jitter buffer (decode on recv, like Android)");
+                eprintln!("  --aec-delay <ms>      AEC far-end delay compensation (default: 40ms)");
+                eprintln!("  --os-aec              Use macOS VoiceProcessingIO for hardware AEC (requires --vpio feature)");
+                eprintln!("  --android             Alias for --no-denoise --no-silence --direct-playout");
                 eprintln!("  --token <token>        featherChat bearer token for relay auth");
                 eprintln!("  --metrics-file <path>  Write JSONL telemetry to file (1 line/sec)");
                 eprintln!("                         (48kHz mono s16le, play with ffplay -f s16le -ar 48000 -ch_layout mono file.raw)");
                 eprintln!();
+                eprintln!("Identity is auto-saved to ~/.wzp/identity on first run.");
                 eprintln!("Default relay: 127.0.0.1:4433");
                 std::process::exit(0);
             }
@@ -219,8 +340,19 @@ fn parse_args() -> CliArgs {
         seed_hex,
         mnemonic,
         room,
+        raw_room,
+        alias,
+        no_denoise,
+        no_aec,
+        no_agc,
+        no_fec,
+        no_silence,
+        direct_playout,
+        aec_delay_ms,
+        os_aec,
         token,
         _metrics_file: metrics_file,
+        profile_override,
     }
 }
 
@@ -241,17 +373,30 @@ async fn main() -> anyhow::Result<()> {
 
     let seed = cli.resolve_seed();
 
+    // Resolve profile override
+    let profile = cli.profile_override.as_deref().map(resolve_profile);
+    if let Some(ref p) = profile {
+        info!(codec = ?p.codec, frame_ms = p.frame_duration_ms, fec = p.fec_ratio, "forced profile");
+    }
+
     info!(
         relay = %cli.relay_addr,
         live = cli.live,
         send_tone = ?cli.send_tone_secs,
         record = ?cli.record_file,
         room = ?cli.room,
+        profile = ?cli.profile_override,
         "WarzonePhone client"
     );
 
-    // Hash room name for SNI privacy (or "default" if none specified)
+    // Compute SNI from room name.
+    // --raw-room sends the name as-is (for Android compat — Android doesn't hash).
+    // Default behaviour hashes for privacy.
     let sni = match &cli.room {
+        Some(name) if cli.raw_room => {
+            info!(room = %name, "using raw room name as SNI (no hash)");
+            name.clone()
+        }
         Some(name) => {
             let hashed = wzp_crypto::hash_room_name(name);
             info!(room = %name, hashed = %hashed, "room name hashed for SNI");
@@ -287,14 +432,25 @@ 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
+        cli.alias.as_deref(),
     ).await?;
     info!("crypto handshake complete");
 
     if cli.live {
         #[cfg(feature = "audio")]
         {
-            return run_live(transport).await;
+            let audio_opts = AudioOpts {
+                no_denoise: cli.no_denoise || cli.direct_playout,
+                no_aec: cli.no_aec,
+                no_agc: cli.no_agc,
+                no_fec: cli.no_fec,
+                no_silence: cli.no_silence || cli.direct_playout,
+                direct_playout: cli.direct_playout,
+                aec_delay_ms: cli.aec_delay_ms,
+                os_aec: cli.os_aec,
+                profile_override: profile,
+            };
+            return run_live(transport, audio_opts).await;
         }
         #[cfg(not(feature = "audio"))]
         {
@@ -315,19 +471,23 @@ async fn main() -> anyhow::Result<()> {
         transport.close().await?;
         Ok(())
     } else if cli.send_tone_secs.is_some() || cli.send_file.is_some() || cli.record_file.is_some() {
-        run_file_mode(transport, cli.send_tone_secs, cli.send_file, cli.record_file).await
+        run_file_mode(transport, cli.send_tone_secs, cli.send_file, cli.record_file, profile).await
     } else {
-        run_silence(transport).await
+        run_silence(transport, profile).await
     }
 }
 
 /// Send silence frames (connectivity test).
-async fn run_silence(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Result<()> {
-    let config = CallConfig::default();
+async fn run_silence(transport: Arc<wzp_transport::QuinnTransport>, profile: Option<wzp_proto::QualityProfile>) -> anyhow::Result<()> {
+    let config = match profile {
+        Some(p) => CallConfig::from_profile(p),
+        None => CallConfig::default(),
+    };
+    let frame_samples = frame_samples_for(&config.profile);
     let mut encoder = CallEncoder::new(&config);
 
-    let frame_duration = tokio::time::Duration::from_millis(20);
-    let pcm = vec![0i16; FRAME_SAMPLES];
+    let frame_duration = tokio::time::Duration::from_millis(config.profile.frame_duration_ms as u64);
+    let pcm = vec![0i16; frame_samples];
 
     let mut total_source = 0u64;
     let mut total_repair = 0u64;
@@ -343,8 +503,7 @@ async fn run_silence(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::R
             }
             total_bytes += pkt.payload.len() as u64;
             if let Err(e) = transport.send_media(pkt).await {
-                error!("send error: {e}");
-                break;
+                warn!("send_media error (dropping packet): {e}");
             }
         }
         if (i + 1) % 50 == 0 {
@@ -374,13 +533,20 @@ async fn run_file_mode(
     send_tone_secs: Option<u32>,
     send_file: Option<String>,
     record_file: Option<String>,
+    profile: Option<wzp_proto::QualityProfile>,
 ) -> anyhow::Result<()> {
-    let config = CallConfig::default();
+    let config = match profile {
+        Some(p) => CallConfig::from_profile(p),
+        None => CallConfig::default(),
+    };
+    let frame_samples = frame_samples_for(&config.profile);
+    let frame_duration_ms = config.profile.frame_duration_ms as u64;
 
     // --- Send task: generate tone or play file ---
     let send_transport = transport.clone();
     let send_handle = tokio::spawn(async move {
         // Load PCM frames from file or generate tone
+        let frames_per_sec = 1000 / frame_duration_ms;
         let pcm_frames: Vec<Vec<i16>> = if let Some(ref path) = send_file {
             // Read raw PCM file (48kHz mono s16le)
             let bytes = match std::fs::read(path) {
@@ -392,14 +558,14 @@ async fn run_file_mode(
                 .collect();
             let duration = samples.len() as f64 / 48_000.0;
             info!(file = %path, duration = format!("{:.1}s", duration), "sending audio file");
-            samples.chunks(FRAME_SAMPLES)
-                .filter(|c| c.len() == FRAME_SAMPLES)
+            samples.chunks(frame_samples)
+                .filter(|c| c.len() == frame_samples)
                 .map(|c| c.to_vec())
                 .collect()
         } else if let Some(secs) = send_tone_secs {
-            let total = (secs as u64) * 50;
-            info!(seconds = secs, frames = total, "sending 440Hz tone");
-            (0..total).map(|i| generate_sine_frame(440.0, 48_000, i)).collect()
+            let total = (secs as u64) * frames_per_sec;
+            info!(seconds = secs, frames = total, frame_samples, frame_ms = frame_duration_ms, "sending 440Hz tone");
+            (0..total).map(|i| generate_sine_frame(440.0, 48_000, i, frame_samples)).collect()
         } else {
             // No sending, just wait
             tokio::signal::ctrl_c().await.ok();
@@ -408,7 +574,7 @@ async fn run_file_mode(
 
         let mut encoder = CallEncoder::new(&config);
         let _total_frames = pcm_frames.len() as u64;
-        let frame_duration = tokio::time::Duration::from_millis(20);
+        let frame_duration = tokio::time::Duration::from_millis(frame_duration_ms);
 
         let mut total_source = 0u64;
         let mut total_repair = 0u64;
@@ -429,8 +595,7 @@ async fn run_file_mode(
                     total_source += 1;
                 }
                 if let Err(e) = send_transport.send_media(pkt).await {
-                    error!("send error: {e}");
-                    return;
+                    warn!("send_media error (dropping packet): {e}");
                 }
             }
             if (frame_idx + 1) % 250 == 0 {
@@ -459,8 +624,13 @@ async fn run_file_mode(
             }
         };
 
-        let mut decoder = CallDecoder::new(&CallConfig::default());
-        let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+        let recv_config = match profile {
+            Some(p) => CallConfig::from_profile(p),
+            None => CallConfig::default(),
+        };
+        let recv_frame_samples = frame_samples_for(&recv_config.profile);
+        let mut decoder = CallDecoder::new(&recv_config);
+        let mut pcm_buf = vec![0i16; recv_frame_samples.max(FRAME_SAMPLES_40MS)];
         let mut all_pcm: Vec<i16> = Vec::new();
         let mut frames_received = 0u64;
 
@@ -549,78 +719,534 @@ async fn run_file_mode(
 }
 
 /// Live mode: capture from mic, encode, send; receive, decode, play.
+///
+/// Architecture (mirrors wzp-android/engine.rs):
+///   CPAL capture callback → AudioRing → send task (5ms poll) → QUIC
+///   QUIC → recv task → jitter buffer → decode tick (20ms) → AudioRing → CPAL playback callback
+///
+/// All lock-free: CPAL callbacks use atomic ring buffers, no Mutex on the audio path.
+/// RAII guard for terminal raw mode. Restores on drop.
+struct RawModeGuard {
+    orig: libc::termios,
+}
+
+impl RawModeGuard {
+    fn enter() -> Option<Self> {
+        unsafe {
+            let mut orig: libc::termios = std::mem::zeroed();
+            if libc::tcgetattr(libc::STDIN_FILENO, &mut orig) != 0 {
+                return None;
+            }
+            let mut raw = orig;
+            // ICANON: character-at-a-time input
+            // ECHO: don't echo typed characters
+            // ISIG: let us handle Ctrl+C as a byte
+            raw.c_lflag &= !(libc::ICANON | libc::ECHO | libc::ISIG);
+            // IXON: disable Ctrl+S/Ctrl+Q flow control so we receive them
+            raw.c_iflag &= !libc::IXON;
+            raw.c_cc[libc::VMIN] = 1;
+            raw.c_cc[libc::VTIME] = 0;
+            libc::tcsetattr(libc::STDIN_FILENO, libc::TCSANOW, &raw);
+            Some(Self { orig })
+        }
+    }
+}
+
+impl Drop for RawModeGuard {
+    fn drop(&mut self) {
+        unsafe {
+            libc::tcsetattr(libc::STDIN_FILENO, libc::TCSANOW, &self.orig);
+        }
+    }
+}
+
+struct AudioOpts {
+    no_denoise: bool,
+    no_aec: bool,
+    no_agc: bool,
+    no_fec: bool,
+    no_silence: bool,
+    direct_playout: bool,
+    aec_delay_ms: Option<u32>,
+    os_aec: bool,
+    profile_override: Option<wzp_proto::QualityProfile>,
+}
+
 #[cfg(feature = "audio")]
-async fn run_live(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Result<()> {
+async fn run_live(
+    transport: Arc<wzp_transport::QuinnTransport>,
+    opts: AudioOpts,
+) -> anyhow::Result<()> {
+    use std::sync::Arc as StdArc;
+    use std::sync::atomic::{AtomicBool, Ordering};
     use wzp_client::audio_io::{AudioCapture, AudioPlayback};
+    use wzp_client::audio_ring::AudioRing;
+    use wzp_client::call::JitterTelemetry;
 
-    let capture = AudioCapture::start()?;
-    let playback = AudioPlayback::start()?;
-    info!("Audio I/O started — press Ctrl+C to stop");
+    // Audio I/O: either VPIO (OS-level AEC) or separate CPAL streams.
+    #[cfg(all(target_os = "macos", feature = "vpio"))]
+    let vpio;
+    let (capture_ring, playout_ring) = if opts.os_aec {
+        #[cfg(all(target_os = "macos", feature = "vpio"))]
+        {
+            vpio = wzp_client::audio_vpio::VpioAudio::start()?;
+            (vpio.capture_ring().clone(), vpio.playout_ring().clone())
+        }
+        #[cfg(all(target_os = "macos", not(feature = "vpio")))]
+        {
+            anyhow::bail!("--os-aec requires the 'vpio' feature (build with: cargo build --features audio,vpio)");
+        }
+        #[cfg(target_os = "windows")]
+        {
+            warn!("--os-aec on Windows is experimental and not yet tested");
+            warn!("Windows Voice Capture DSP (MFT) AEC is not yet implemented");
+            warn!("falling back to CPAL without AEC — please report issues");
+            let capture = AudioCapture::start()?;
+            let playback = AudioPlayback::start()?;
+            let cr = capture.ring().clone();
+            let pr = playback.ring().clone();
+            std::mem::forget(capture);
+            std::mem::forget(playback);
+            (cr, pr)
+        }
+        #[cfg(target_os = "linux")]
+        {
+            warn!("--os-aec on Linux is experimental and not yet tested");
+            warn!("PipeWire/PulseAudio echo-cancel module AEC is not yet implemented");
+            warn!("falling back to CPAL without AEC — please report issues");
+            let capture = AudioCapture::start()?;
+            let playback = AudioPlayback::start()?;
+            let cr = capture.ring().clone();
+            let pr = playback.ring().clone();
+            std::mem::forget(capture);
+            std::mem::forget(playback);
+            (cr, pr)
+        }
+    } else {
+        let capture = AudioCapture::start()?;
+        let playback = AudioPlayback::start()?;
+        let cr = capture.ring().clone();
+        let pr = playback.ring().clone();
+        // Keep handles alive (streams stop when dropped)
+        std::mem::forget(capture);
+        std::mem::forget(playback);
+        (cr, pr)
+    };
+    info!(os_aec = opts.os_aec, "audio I/O started — press Ctrl+C to stop");
 
+    // Far-end reference ring (only used when NOT using OS AEC).
+    let farend_ring = StdArc::new(AudioRing::new());
+
+    let running = StdArc::new(AtomicBool::new(true));
+    let mic_muted = StdArc::new(AtomicBool::new(false));
+    let spk_muted = StdArc::new(AtomicBool::new(false));
+
+    // --- Signal handler: set running=false on first Ctrl+C, force-quit on second ---
+    let signal_running = running.clone();
+    tokio::spawn(async move {
+        tokio::signal::ctrl_c().await.ok();
+        eprintln!(); // newline after ^C
+        info!("Ctrl+C received, shutting down...");
+        signal_running.store(false, Ordering::SeqCst);
+
+        tokio::signal::ctrl_c().await.ok();
+        eprintln!("\nForce quit");
+        std::process::exit(1);
+    });
+
+    let base_config = match opts.profile_override {
+        Some(p) => CallConfig::from_profile(p),
+        None => CallConfig::default(),
+    };
+    let config = CallConfig {
+        noise_suppression: !opts.no_denoise,
+        suppression_enabled: !opts.no_silence,
+        aec_delay_ms: opts.aec_delay_ms.unwrap_or(40),
+        ..base_config
+    };
+    let frame_samples = frame_samples_for(&config.profile);
+    info!(codec = ?config.profile.codec, frame_samples, frame_ms = config.profile.frame_duration_ms, "call config");
+    {
+        let mut flags = Vec::new();
+        if opts.no_denoise { flags.push("denoise"); }
+        if opts.no_aec { flags.push("aec"); }
+        if opts.no_agc { flags.push("agc"); }
+        if opts.no_fec { flags.push("fec"); }
+        if opts.no_silence { flags.push("silence"); }
+        if opts.direct_playout { flags.push("jitter-buffer (direct playout)"); }
+        if !flags.is_empty() {
+            info!(disabled = %flags.join(", "), "audio processing overrides");
+        }
+    }
+
+    // --- Send task: poll capture ring → encode → send via async ---
     let send_transport = transport.clone();
-    let rt_handle = tokio::runtime::Handle::current();
-    let send_handle = std::thread::Builder::new()
-        .name("wzp-send-loop".into())
-        .spawn(move || {
-            let config = CallConfig::default();
-            let mut encoder = CallEncoder::new(&config);
-            loop {
-                let frame = match capture.read_frame() {
-                    Some(f) => f,
-                    None => break,
-                };
-                let packets = match encoder.encode_frame(&frame) {
-                    Ok(p) => p,
-                    Err(e) => {
-                        error!("encode error: {e}");
-                        continue;
-                    }
-                };
-                for pkt in &packets {
-                    if let Err(e) = rt_handle.block_on(send_transport.send_media(pkt)) {
-                        error!("send error: {e}");
-                        return;
+    let send_running = running.clone();
+    let send_mic_muted = mic_muted.clone();
+    let no_aec = opts.no_aec || opts.os_aec; // OS AEC replaces software AEC
+    let no_agc = opts.no_agc;
+    let _no_fec = opts.no_fec;
+    let send_farend = farend_ring.clone();
+    let send_task = async move {
+        let mut encoder = CallEncoder::new(&config);
+        if no_aec { encoder.set_aec_enabled(false); }
+        if no_agc { encoder.set_agc_enabled(false); }
+        let mut capture_buf = vec![0i16; frame_samples];
+        let mut farend_buf = vec![0i16; frame_samples];
+        let mut frames_sent: u64 = 0;
+        let mut frames_dropped: u64 = 0;
+        let mut send_errors: u64 = 0;
+        let mut last_send_err = std::time::Instant::now();
+        let mut polls: u64 = 0;
+        let mut last_diag = std::time::Instant::now();
+
+        loop {
+            if !send_running.load(Ordering::Relaxed) {
+                break;
+            }
+
+            let avail = capture_ring.available();
+            if avail < frame_samples {
+                tokio::time::sleep(std::time::Duration::from_millis(5)).await;
+                polls += 1;
+                // Diagnostic every 2 seconds
+                if last_diag.elapsed().as_secs() >= 2 {
+                    info!(avail, polls, frames_sent, frame_samples, "send: ring starved");
+                    last_diag = std::time::Instant::now();
+                }
+                continue;
+            }
+
+            let read = capture_ring.read(&mut capture_buf);
+            if read < frame_samples {
+                continue;
+            }
+
+            // Mic mute: zero out capture buffer (still encode + send silence to keep stream alive)
+            if send_mic_muted.load(Ordering::Relaxed) {
+                capture_buf.fill(0);
+            }
+
+            // Feed AEC far-end reference: what was played through the speaker.
+            // Must be called BEFORE encode_frame processes the mic signal.
+            if !no_aec {
+                while send_farend.available() >= frame_samples {
+                    send_farend.read(&mut farend_buf);
+                    encoder.feed_aec_farend(&farend_buf);
+                }
+            }
+
+            let t0 = std::time::Instant::now();
+            let packets = match encoder.encode_frame(&capture_buf) {
+                Ok(p) => p,
+                Err(e) => {
+                    error!("encode error: {e}");
+                    continue;
+                }
+            };
+            let encode_us = t0.elapsed().as_micros();
+
+            let mut dropped = false;
+            for pkt in &packets {
+                if let Err(e) = send_transport.send_media(pkt).await {
+                    send_errors += 1;
+                    frames_dropped += 1;
+                    dropped = true;
+                    if send_errors <= 3 || last_send_err.elapsed().as_secs() >= 1 {
+                        warn!(send_errors, frames_dropped,
+                              "send_media error (dropping packet): {e}");
+                        last_send_err = std::time::Instant::now();
                     }
                 }
             }
-        })?;
 
+            if !dropped {
+                send_errors = 0; // reset on success
+            }
+            frames_sent += 1;
+            if frames_sent <= 5 || frames_sent % 500 == 0 {
+                info!(frames_sent, encode_us, pkts = packets.len(), "send progress");
+            }
+        }
+    };
+
+    // --- Recv + playout ---
     let recv_transport = transport.clone();
-    let recv_handle = tokio::spawn(async move {
+    let recv_running = running.clone();
+    let recv_spk_muted = spk_muted.clone();
+    let direct_playout = opts.direct_playout;
+    let recv_profile = opts.profile_override;
+    let playout_profile = recv_profile; // Copy for playout_task
+
+    // Direct playout: decode on recv, write straight to playout ring (like Android).
+    // Jitter buffer mode: ingest into jitter buffer, decode on 20ms tick.
+    let recv_task = {
+        let playout_ring = playout_ring.clone();
+        let farend_ring = farend_ring.clone();
         let config = CallConfig::default();
-        let mut decoder = CallDecoder::new(&config);
-        let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
-        loop {
-            match recv_transport.recv_media().await {
-                Ok(Some(pkt)) => {
-                    let is_repair = pkt.header.is_repair;
-                    decoder.ingest(pkt);
-                    // Only decode for source packets (1 source = 1 audio frame).
-                    // Repair packets feed the FEC decoder but don't produce audio.
-                    if !is_repair {
-                        if let Some(_n) = decoder.decode_next(&mut pcm_buf) {
-                            playback.write_frame(&pcm_buf);
+        let decoder = StdArc::new(tokio::sync::Mutex::new(CallDecoder::new(&config)));
+        let decoder_recv = decoder.clone();
+
+        async move {
+            let mut packets_received: u64 = 0;
+            let mut recv_errors: u64 = 0;
+            let mut timeouts: u64 = 0;
+            // For direct playout: raw codec decoder + AGC
+            let direct_profile = recv_profile.unwrap_or(wzp_proto::QualityProfile::GOOD);
+            let mut opus_dec = if direct_playout {
+                Some(wzp_codec::create_decoder(direct_profile))
+            } else {
+                None
+            };
+            let mut playout_agc = wzp_codec::AutoGainControl::new();
+            let mut pcm_buf = vec![0i16; frame_samples.max(FRAME_SAMPLES_40MS)];
+
+            loop {
+                if !recv_running.load(Ordering::Relaxed) {
+                    break;
+                }
+                let result = tokio::time::timeout(
+                    std::time::Duration::from_millis(100),
+                    recv_transport.recv_media(),
+                )
+                .await;
+                match result {
+                    Ok(Ok(Some(pkt))) => {
+                        packets_received += 1;
+
+                        if direct_playout {
+                            // Android path: decode immediately, AGC, write to ring
+                            if !pkt.header.is_repair {
+                                if let Some(ref mut dec) = opus_dec {
+                                    match dec.decode(&pkt.payload, &mut pcm_buf) {
+                                        Ok(n) => {
+                                            if !no_agc {
+                                                playout_agc.process_frame(&mut pcm_buf[..n]);
+                                            }
+                                            // Always feed AEC (even when speaker muted)
+                                            farend_ring.write(&pcm_buf[..n]);
+                                            // Speaker mute: don't write to playout ring
+                                            if !recv_spk_muted.load(Ordering::Relaxed) {
+                                                playout_ring.write(&pcm_buf[..n]);
+                                            }
+                                        }
+                                        Err(e) => {
+                                            if let Ok(n) = dec.decode_lost(&mut pcm_buf) {
+                                                if !recv_spk_muted.load(Ordering::Relaxed) {
+                                                    playout_ring.write(&pcm_buf[..n]);
+                                                }
+                                            }
+                                            if packets_received < 10 {
+                                                warn!("decode error: {e}");
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        } else {
+                            // Jitter buffer path
+                            let mut dec = decoder_recv.lock().await;
+                            dec.ingest(pkt);
+                        }
+
+                        if packets_received == 1 || packets_received % 500 == 0 {
+                            info!(packets_received, direct_playout, "recv progress");
+                        }
+                        timeouts = 0;
+                    }
+                    Ok(Ok(None)) => {
+                        info!("connection closed");
+                        break;
+                    }
+                    Ok(Err(e)) => {
+                        let msg = e.to_string();
+                        if msg.contains("closed") || msg.contains("reset") {
+                            error!("recv fatal: {e}");
+                            break;
+                        }
+                        recv_errors += 1;
+                        if recv_errors <= 3 {
+                            warn!("recv error (continuing): {e}");
+                        }
+                    }
+                    Err(_) => {
+                        timeouts += 1;
+                        if timeouts == 50 {
+                            info!("recv: no media packets received in 5s");
                         }
                     }
                 }
-                Ok(None) => {
-                    info!("connection closed");
-                    break;
-                }
-                Err(e) => {
-                    error!("recv error: {e}");
+            }
+        }
+    };
+
+    // Playout tick — only used when NOT in direct playout mode
+    let playout_running = running.clone();
+    let playout_task = async move {
+        if direct_playout {
+            // Direct playout handles everything in recv_task — just park here
+            loop {
+                tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+                if !playout_running.load(Ordering::Relaxed) {
                     break;
                 }
             }
+            return;
         }
-    });
 
-    tokio::signal::ctrl_c().await?;
-    info!("Shutting down...");
+        let playout_config = match playout_profile {
+            Some(p) => CallConfig::from_profile(p),
+            None => CallConfig::default(),
+        };
+        let playout_frame_ms = playout_config.profile.frame_duration_ms as u64;
+        let playout_frame_samples = frame_samples_for(&playout_config.profile);
+        let mut decoder = CallDecoder::new(&playout_config);
+        let mut pcm_buf = vec![0i16; playout_frame_samples.max(FRAME_SAMPLES_40MS)];
+        let mut interval = tokio::time::interval(std::time::Duration::from_millis(playout_frame_ms));
+        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
+        let mut telemetry = JitterTelemetry::new(5);
+        loop {
+            interval.tick().await;
+            if !playout_running.load(Ordering::Relaxed) {
+                break;
+            }
 
-    recv_handle.abort();
-    drop(send_handle);
-    transport.close().await?;
-    info!("done");
+            let mut decoded_this_tick = 0;
+            while let Some(n) = decoder.decode_next(&mut pcm_buf) {
+                playout_ring.write(&pcm_buf[..n]);
+                decoded_this_tick += 1;
+                if decoded_this_tick >= 2 {
+                    break;
+                }
+            }
+
+            telemetry.maybe_log(decoder.stats());
+        }
+    };
+
+    // --- Signal task: listen for RoomUpdate and display presence ---
+    let signal_transport = transport.clone();
+    let signal_running = running.clone();
+    let signal_task = async move {
+        loop {
+            if !signal_running.load(Ordering::Relaxed) {
+                break;
+            }
+            let result = tokio::time::timeout(
+                std::time::Duration::from_millis(200),
+                signal_transport.recv_signal(),
+            )
+            .await;
+            match result {
+                Ok(Ok(Some(wzp_proto::SignalMessage::RoomUpdate { participants, .. }))) => {
+                    // Dedup by (fingerprint, alias) — same peer may appear multiple times
+                    let mut seen = std::collections::HashSet::new();
+                    let unique: Vec<_> = participants
+                        .iter()
+                        .filter(|p| seen.insert((&p.fingerprint, &p.alias)))
+                        .collect();
+                    info!(count = unique.len(), "room update");
+                    for p in &unique {
+                        let name = p
+                            .alias
+                            .as_deref()
+                            .unwrap_or("(no alias)");
+                        let fp = if p.fingerprint.is_empty() {
+                            "(no fingerprint)"
+                        } else {
+                            &p.fingerprint
+                        };
+                        info!("  participant: {name} [{fp}]");
+                    }
+                }
+                Ok(Ok(Some(msg))) => {
+                    info!("signal: {:?}", std::mem::discriminant(&msg));
+                }
+                Ok(Ok(None)) => {
+                    info!("signal stream closed");
+                    break;
+                }
+                Ok(Err(e)) => {
+                    error!("signal recv error: {e}");
+                    break;
+                }
+                Err(_) => {} // timeout — loop and check running flag
+            }
+        }
+    };
+
+    // --- Keyboard task: Ctrl+M = toggle mic mute, Ctrl+S = toggle speaker mute ---
+    let kb_running = running.clone();
+    let kb_mic = mic_muted.clone();
+    let kb_spk = spk_muted.clone();
+    let keyboard_task = async move {
+        use tokio::io::AsyncReadExt;
+
+        // Put terminal in raw mode so we get individual keypresses
+        let _raw_guard = RawModeGuard::enter();
+
+        let mut stdin = tokio::io::stdin();
+        let mut buf = [0u8; 1];
+        loop {
+            if !kb_running.load(Ordering::Relaxed) {
+                break;
+            }
+            match tokio::time::timeout(
+                std::time::Duration::from_millis(200),
+                stdin.read(&mut buf),
+            )
+            .await
+            {
+                Ok(Ok(1)) => match buf[0] {
+                    b'm' | b'M' | 0x0D => {
+                        // 'm' or Ctrl+M
+                        let was = kb_mic.fetch_xor(true, Ordering::SeqCst);
+                        let state = if !was { "MUTED" } else { "unmuted" };
+                        eprintln!("\r[mic {state}]");
+                    }
+                    b's' | b'S' | 0x13 => {
+                        // 's' or Ctrl+S
+                        let was = kb_spk.fetch_xor(true, Ordering::SeqCst);
+                        let state = if !was { "MUTED" } else { "unmuted" };
+                        eprintln!("\r[speaker {state}]");
+                    }
+                    0x03 => {
+                        // Ctrl+C
+                        eprintln!();
+                        info!("Ctrl+C received, shutting down...");
+                        kb_running.store(false, Ordering::SeqCst);
+                        break;
+                    }
+                    b'q' | b'Q' => {
+                        eprintln!("\r[quit]");
+                        kb_running.store(false, Ordering::SeqCst);
+                        break;
+                    }
+                    _ => {}
+                },
+                Ok(Ok(_)) | Ok(Err(_)) => break,
+                Err(_) => {} // timeout
+            }
+        }
+    };
+
+    // --- Run all tasks, exit when any finishes (or running flag cleared by Ctrl+C) ---
+    tokio::select! {
+        _ = send_task => info!("send task ended"),
+        _ = recv_task => info!("recv task ended"),
+        _ = playout_task => info!("playout task ended"),
+        _ = signal_task => info!("signal task ended"),
+        _ = keyboard_task => info!("keyboard task ended"),
+    }
+
+    running.store(false, Ordering::SeqCst);
+    // Audio streams stop when their handles are dropped (via mem::forget above or VPIO drop).
+
+    // Give transport 2s to close gracefully, then bail
+    match tokio::time::timeout(std::time::Duration::from_secs(2), transport.close()).await {
+        Ok(Ok(())) => info!("done"),
+        Ok(Err(e)) => info!("close error (non-fatal): {e}"),
+        Err(_) => info!("close timed out, exiting anyway"),
+    }
     Ok(())
 }

crates/wzp-client/src/featherchat.rs

@@ -110,6 +110,7 @@ pub fn signal_to_call_type(signal: &SignalMessage) -> CallSignalType {
         SignalMessage::SessionForward { .. } => CallSignalType::Offer, // reuse
         SignalMessage::SessionForwardAck { .. } => CallSignalType::Offer, // reuse
         SignalMessage::RoomUpdate { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::SetAlias { .. } => CallSignalType::Offer, // reuse
     }
 }
 
@@ -125,6 +126,7 @@ 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"));
@@ -142,6 +144,7 @@ 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/lib.rs

@@ -8,6 +8,10 @@
 
 #[cfg(feature = "audio")]
 pub mod audio_io;
+#[cfg(feature = "audio")]
+pub mod audio_ring;
+#[cfg(feature = "vpio")]
+pub mod audio_vpio;
 pub mod bench;
 pub mod call;
 pub mod drift_test;

crates/wzp-codec/src/aec.rs

@@ -1,53 +1,127 @@
-//! Acoustic Echo Cancellation using NLMS adaptive filter.
-//! Processes 480-sample (10ms) sub-frames at 48kHz.
+//! Acoustic Echo Cancellation — delay-compensated leaky NLMS with
+//! Geigel double-talk detection.
+//!
+//! Key insight: on a laptop, the round-trip audio latency (playout → speaker
+//! → air → mic → capture) is 30–50ms.  The far-end reference must be delayed
+//! by this amount so the adaptive filter models the *echo path*, not the
+//! *system delay + echo path*.
+//!
+//! The leaky coefficient decay prevents the filter from diverging when the
+//! echo path changes (e.g. hand near laptop) or when the delay estimate
+//! is slightly off.
 
-/// 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.
+/// Delay-compensated leaky NLMS echo canceller with Geigel DTD.
 pub struct EchoCanceller {
-    filter_coeffs: Vec<f32>,
+    // --- Adaptive filter ---
+    filter: Vec<f32>,
     filter_len: usize,
-    far_end_buf: Vec<f32>,
-    far_end_pos: usize,
+    /// Circular buffer of far-end reference samples (after delay).
+    far_buf: Vec<f32>,
+    far_pos: usize,
+    /// NLMS step size.
     mu: f32,
+    /// Leakage factor: coefficients are multiplied by (1 - leak) each frame.
+    /// Prevents unbounded growth / divergence.  0.0001 is gentle.
+    leak: f32,
     enabled: bool,
+
+    // --- Delay buffer ---
+    /// Raw far-end samples before delay compensation.
+    delay_ring: Vec<f32>,
+    delay_write: usize,
+    delay_read: usize,
+    /// Delay in samples (e.g. 1920 = 40ms at 48kHz).
+    delay_samples: usize,
+    /// Capacity of the delay ring.
+    delay_cap: usize,
+
+    // --- Double-talk detection (Geigel) ---
+    /// Peak far-end level over the last filter_len samples.
+    far_peak: f32,
+    /// Geigel threshold: if |near| > threshold * far_peak, assume double-talk.
+    geigel_threshold: f32,
+    /// Holdover counter: keep DTD active for a few frames after detection.
+    dtd_holdover: u32,
+    dtd_hold_frames: u32,
 }
 
 impl EchoCanceller {
     /// Create a new echo canceller.
     ///
     /// * `sample_rate` — typically 48000
-    /// * `filter_ms`   — echo-tail length in milliseconds (e.g. 100 for 100 ms)
+    /// * `filter_ms`   — echo-tail length in milliseconds (60ms recommended)
+    /// * `delay_ms`    — far-end delay compensation in milliseconds (40ms for laptops)
     pub fn new(sample_rate: u32, filter_ms: u32) -> Self {
+        Self::with_delay(sample_rate, filter_ms, 40)
+    }
+
+    pub fn with_delay(sample_rate: u32, filter_ms: u32, delay_ms: u32) -> Self {
         let filter_len = (sample_rate as usize) * (filter_ms as usize) / 1000;
+        let delay_samples = (sample_rate as usize) * (delay_ms as usize) / 1000;
+        // Delay ring must hold at least delay_samples + one frame (960) of headroom.
+        let delay_cap = delay_samples + (sample_rate as usize / 10); // +100ms headroom
         Self {
-            filter_coeffs: vec![0.0f32; filter_len],
+            filter: vec![0.0; filter_len],
             filter_len,
-            far_end_buf: vec![0.0f32; filter_len],
-            far_end_pos: 0,
+            far_buf: vec![0.0; filter_len],
+            far_pos: 0,
             mu: 0.01,
+            leak: 0.0001,
             enabled: true,
+
+            delay_ring: vec![0.0; delay_cap],
+            delay_write: 0,
+            delay_read: 0,
+            delay_samples,
+            delay_cap,
+
+            far_peak: 0.0,
+            geigel_threshold: 0.7,
+            dtd_holdover: 0,
+            dtd_hold_frames: 5,
         }
     }
 
-    /// 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.
+    /// Feed far-end (speaker) samples.  These go into the delay buffer first;
+    /// once enough samples have accumulated, they are released to the filter's
+    /// circular buffer with the correct delay offset.
     pub fn feed_farend(&mut self, farend: &[i16]) {
+        // Write raw samples into the delay ring.
         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;
+            self.delay_ring[self.delay_write % self.delay_cap] = s as f32;
+            self.delay_write += 1;
+        }
+
+        // Release delayed samples to the filter's far-end buffer.
+        while self.delay_available() >= 1 {
+            let sample = self.delay_ring[self.delay_read % self.delay_cap];
+            self.delay_read += 1;
+
+            self.far_buf[self.far_pos] = sample;
+            self.far_pos = (self.far_pos + 1) % self.filter_len;
+
+            // Track peak far-end level for Geigel DTD.
+            let abs_s = sample.abs();
+            if abs_s > self.far_peak {
+                self.far_peak = abs_s;
+            }
+        }
+
+        // Decay far_peak slowly (avoids stale peak from a loud burst long ago).
+        self.far_peak *= 0.9995;
+    }
+
+    /// Number of delayed samples available to release.
+    fn delay_available(&self) -> usize {
+        let buffered = self.delay_write - self.delay_read;
+        if buffered > self.delay_samples {
+            buffered - self.delay_samples
+        } else {
+            0
         }
     }
 
     /// 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;
@@ -56,85 +130,96 @@ impl EchoCanceller {
         let n = nearend.len();
         let fl = self.filter_len;
 
+        // --- Geigel double-talk detection ---
+        // If any near-end sample exceeds threshold * far_peak, assume
+        // the local speaker is active and freeze adaptation.
+        let mut is_doubletalk = self.dtd_holdover > 0;
+        if !is_doubletalk {
+            let threshold_level = self.geigel_threshold * self.far_peak;
+            for &s in nearend.iter() {
+                if (s as f32).abs() > threshold_level && self.far_peak > 100.0 {
+                    is_doubletalk = true;
+                    self.dtd_holdover = self.dtd_hold_frames;
+                    break;
+                }
+            }
+        }
+        if self.dtd_holdover > 0 {
+            self.dtd_holdover -= 1;
+        }
+
+        // Check if far-end is active (otherwise nothing to cancel).
+        let far_active = self.far_peak > 100.0;
+
+        // --- Leaky coefficient decay ---
+        // Applied once per frame for efficiency.
+        let decay = 1.0 - self.leak;
+        for c in self.filter.iter_mut() {
+            *c *= decay;
+        }
+
         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.
+            // Position of far-end "now" for this near-end sample.
+            let base = (self.far_pos + fl * ((n / fl) + 2) + i - n) % fl;
+
+            // --- Echo estimation: dot(filter, far_end_window) ---
             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;
+                let fe = self.far_buf[fe_idx];
+                echo_est += self.filter[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;
+            // --- NLMS adaptation (only when far-end active & no double-talk) ---
+            if far_active && !is_doubletalk && power > 10.0 {
+                let step = self.mu * error / (power + 1.0);
+                for k in 0..fl {
+                    let fe_idx = (base + fl - k) % fl;
+                    self.filter[k] += step * self.far_buf[fe_idx];
+                }
             }
 
-            // Clamp output
-            let out = error.max(-32768.0).min(32767.0);
+            let out = error.clamp(-32768.0, 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);
+            sum_near_sq += (near_f as f64).powi(2);
+            sum_err_sq += (out as f64).powi(2);
         }
 
-        // ERLE ratio
         if sum_err_sq < 1.0 {
-            return 100.0; // near-perfect cancellation
+            100.0
+        } else {
+            (sum_near_sq / sum_err_sq).sqrt() as f32
         }
-        (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;
+        self.filter.iter_mut().for_each(|c| *c = 0.0);
+        self.far_buf.iter_mut().for_each(|s| *s = 0.0);
+        self.far_pos = 0;
+        self.far_peak = 0.0;
+        self.delay_ring.iter_mut().for_each(|s| *s = 0.0);
+        self.delay_write = 0;
+        self.delay_read = 0;
+        self.dtd_holdover = 0;
     }
 }
 
@@ -143,50 +228,40 @@ 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);
+    fn creates_with_correct_sizes() {
+        let aec = EchoCanceller::with_delay(48000, 60, 40);
+        assert_eq!(aec.filter_len, 2880); // 60ms @ 48kHz
+        assert_eq!(aec.delay_samples, 1920); // 40ms @ 48kHz
     }
 
     #[test]
-    fn aec_passthrough_when_disabled() {
-        let mut aec = EchoCanceller::new(48000, 100);
+    fn passthrough_when_disabled() {
+        let mut aec = EchoCanceller::new(48000, 60);
         aec.set_enabled(false);
-        assert!(!aec.is_enabled());
 
-        let original: Vec<i16> = (0..480).map(|i| (i * 10) as i16).collect();
+        let original: Vec<i16> = (0..960).map(|i| (i * 10) as i16).collect();
         let mut frame = original.clone();
-        let erle = aec.process_frame(&mut frame);
-        assert_eq!(erle, 1.0);
+        aec.process_frame(&mut frame);
         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);
+    fn silence_passthrough() {
+        let mut aec = EchoCanceller::with_delay(48000, 30, 0);
+        aec.feed_farend(&vec![0i16; 960]);
+        let mut frame = vec![0i16; 960];
+        aec.process_frame(&mut frame);
+        assert!(frame.iter().all(|&s| s == 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);
+    fn reduces_echo_with_no_delay() {
+        // Simulate: far-end plays, echo arrives at mic attenuated by ~50%
+        // (realistic — speaker to mic on laptop loses volume).
+        let mut aec = EchoCanceller::with_delay(48000, 10, 0);
 
-        // Generate a simple repeating pattern.
-        let frame_len = 480usize;
-        let make_frame = |offset: usize| -> Vec<i16> {
+        let frame_len = 480;
+        let make_tone = |offset: usize| -> Vec<i16> {
             (0..frame_len)
                 .map(|i| {
                     let t = (offset + i) as f64 / 48000.0;
@@ -195,18 +270,16 @@ mod tests {
                 .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);
+        for frame_idx in 0..100 {
+            let farend = make_tone(frame_idx * frame_len);
             aec.feed_farend(&farend);
 
-            // Near-end = exact copy of far-end (pure echo).
-            let mut nearend = farend.clone();
+            // Near-end = attenuated copy of far-end (echo at ~50% volume).
+            let mut nearend: Vec<i16> = farend.iter().map(|&s| s / 2).collect();
             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}"
@@ -214,15 +287,49 @@ mod tests {
     }
 
     #[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));
+    fn preserves_nearend_during_doubletalk() {
+        let mut aec = EchoCanceller::with_delay(48000, 30, 0);
+
+        let frame_len = 960;
+        let nearend: Vec<i16> = (0..frame_len)
+            .map(|i| {
+                let t = i as f64 / 48000.0;
+                (10000.0 * (2.0 * std::f64::consts::PI * 440.0 * t).sin()) as i16
+            })
+            .collect();
+
+        // Feed silence as far-end (no echo source).
+        aec.feed_farend(&vec![0i16; frame_len]);
+
+        let mut frame = nearend.clone();
+        aec.process_frame(&mut frame);
+
+        let input_energy: f64 = nearend.iter().map(|&s| (s as f64).powi(2)).sum();
+        let output_energy: f64 = frame.iter().map(|&s| (s as f64).powi(2)).sum();
+        let ratio = output_energy / input_energy;
+
+        assert!(
+            ratio > 0.8,
+            "near-end speech should be preserved, energy ratio = {ratio:.3}"
+        );
+    }
+
+    #[test]
+    fn delay_buffer_holds_samples() {
+        let mut aec = EchoCanceller::with_delay(48000, 10, 20);
+        // 20ms delay = 960 samples @ 48kHz.
+        // After feeding, feed_farend auto-drains available samples to far_buf.
+        // So delay_available() is always 0 after feed_farend returns.
+        // Instead, verify far_pos advances only after the delay is filled.
+
+        // Feed 960 samples (= delay amount). No samples released yet.
+        aec.feed_farend(&vec![1i16; 960]);
+        // far_buf should still be all zeros (nothing released).
+        assert!(aec.far_buf.iter().all(|&s| s == 0.0), "nothing should be released yet");
+
+        // Feed 480 more. 480 should be released to far_buf.
+        aec.feed_farend(&vec![2i16; 480]);
+        let non_zero = aec.far_buf.iter().filter(|&&s| s != 0.0).count();
+        assert!(non_zero > 0, "samples should have been released to far_buf");
     }
 }

crates/wzp-proto/src/packet.rs

@@ -656,6 +656,11 @@ pub enum SignalMessage {
         /// List of participants currently in the room.
         participants: Vec<RoomParticipant>,
     },
+
+    /// Set or update the client's display name.
+    /// Sent by client after joining; relay updates the participant entry and
+    /// re-broadcasts a RoomUpdate to all participants.
+    SetAlias { alias: String },
 }
 
 /// A participant entry in a RoomUpdate message.

crates/wzp-relay/Cargo.toml

@@ -28,6 +28,7 @@ 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"
 
 [[bin]]
 name = "wzp-relay"

crates/wzp-relay/src/main.rs

@@ -13,7 +13,7 @@ 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_relay::config::RelayConfig;
@@ -207,8 +207,39 @@ async fn main() -> anyhow::Result<()> {
         tokio::spawn(wzp_relay::metrics::serve_metrics(port, m, p, rr));
     }
 
-    // Generate ephemeral relay identity for crypto handshake
-    let relay_seed = wzp_crypto::Seed::generate();
+    // Load or generate relay identity — persisted in ~/.wzp/relay-identity
+    let relay_seed = {
+        let config_dir = dirs::home_dir()
+            .unwrap_or_else(|| std::path::PathBuf::from("."))
+            .join(".wzp");
+        let identity_path = config_dir.join("relay-identity");
+        if identity_path.exists() {
+            if let Ok(hex) = std::fs::read_to_string(&identity_path) {
+                if let Ok(s) = wzp_crypto::Seed::from_hex(hex.trim()) {
+                    info!("loaded relay identity from {}", identity_path.display());
+                    s
+                } else {
+                    warn!("corrupt relay identity file, generating new");
+                    let s = wzp_crypto::Seed::generate();
+                    let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                    let _ = std::fs::write(&identity_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(&identity_path, &hex);
+                s
+            }
+        } else {
+            let s = wzp_crypto::Seed::generate();
+            let _ = std::fs::create_dir_all(&config_dir);
+            let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+            let _ = std::fs::write(&identity_path, &hex);
+            info!("generated relay identity at {}", identity_path.display());
+            s
+        }
+    };
     let relay_fp = relay_seed.derive_identity().public_identity().fingerprint;
     info!(addr = %config.listen_addr, fingerprint = %relay_fp, "WarzonePhone relay starting");
 
@@ -299,6 +330,13 @@ async fn main() -> anyhow::Result<()> {
 
             let transport = Arc::new(wzp_transport::QuinnTransport::new(connection));
 
+            // Ping connections: client just measures QUIC connect RTT.
+            // No handshake, no streams — client closes immediately after connecting.
+            if room_name == "ping" {
+                info!(%addr, "ping connection (RTT probe)");
+                return;
+            }
+
             // Probe connections use SNI "_probe" to identify themselves.
             // They skip auth + handshake and just do Ping->Pong + presence gossip.
             if room_name == "_probe" {

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;
@@ -141,6 +141,17 @@ impl Room {
         self.participants.iter().map(|p| p.sender.clone()).collect()
     }
 
+    /// Update a participant's alias. Returns true if the participant was found.
+    fn set_alias(&mut self, id: ParticipantId, alias: String) -> bool {
+        if let Some(p) = self.participants.iter_mut().find(|p| p.id == id) {
+            info!(participant = id, %alias, "alias updated");
+            p.alias = Some(alias);
+            true
+        } else {
+            false
+        }
+    }
+
     fn is_empty(&self) -> bool {
         self.participants.is_empty()
     }
@@ -255,6 +266,26 @@ impl RoomManager {
         }
     }
 
+    /// Update a participant's alias and return a RoomUpdate + senders for broadcasting.
+    pub fn set_alias(
+        &mut self,
+        room_name: &str,
+        participant_id: ParticipantId,
+        alias: String,
+    ) -> Option<(wzp_proto::SignalMessage, Vec<ParticipantSender>)> {
+        if let Some(room) = self.rooms.get_mut(room_name) {
+            if room.set_alias(participant_id, alias) {
+                let update = wzp_proto::SignalMessage::RoomUpdate {
+                    count: room.len() as u32,
+                    participants: room.participant_list(),
+                };
+                let senders = room.all_senders();
+                return Some((update, senders));
+            }
+        }
+        None
+    }
+
     /// Get senders for all OTHER participants in a room.
     pub fn others(
         &self,
@@ -374,68 +405,166 @@ async fn run_participant_plain(
     session_id: &str,
 ) {
     let addr = transport.connection().remote_address();
-    let mut packets_forwarded = 0u64;
 
-    loop {
-        let pkt = match transport.recv_media().await {
-            Ok(Some(pkt)) => pkt,
-            Ok(None) => {
-                info!(%addr, participant = participant_id, "disconnected");
-                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}");
-                } else {
-                    error!(%addr, participant = participant_id, "recv error: {e}");
+    // Media forwarding task (with debug logging from Android fixes)
+    let media_room_mgr = room_mgr.clone();
+    let media_room_name = room_name.clone();
+    let media_transport = transport.clone();
+    let media_metrics = metrics.clone();
+    let media_session_id = session_id.to_string();
+    let media_task = async move {
+        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 = %media_room_name,
+            participant = participant_id,
+            %addr,
+            session = %media_session_id,
+            "forwarding loop started (plain)"
+        );
+
+        loop {
+            let pkt = match media_transport.recv_media().await {
+                Ok(Some(pkt)) => pkt,
+                Ok(None) => {
+                    info!(%addr, participant = participant_id, forwarded = packets_forwarded, "disconnected (stream ended)");
+                    break;
                 }
-                break;
-            }
-        };
-
-        // 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 others = {
-            let mgr = room_mgr.lock().await;
-            mgr.others(&room_name, participant_id)
-        };
-
-        // Forward to all others
-        let pkt_bytes = pkt.payload.len() as u64;
-        for other in &others {
-            match other {
-                ParticipantSender::Quic(t) => {
-                    let _ = t.send_media(&pkt).await;
+                Err(e) => {
+                    let msg = e.to_string();
+                    if msg.contains("timed out") || msg.contains("reset") || msg.contains("closed") {
+                        info!(%addr, participant = participant_id, forwarded = packets_forwarded, "connection closed: {e}");
+                    } else {
+                        error!(%addr, participant = participant_id, forwarded = packets_forwarded, "recv error: {e}");
+                    }
+                    break;
                 }
-                ParticipantSender::WebSocket(_) => {
-                    // WS clients receive raw payload bytes
-                    let _ = other.send_raw(&pkt.payload).await;
-                }
-            }
-        }
-
-        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 {
-            let room_size = {
-                let mgr = room_mgr.lock().await;
-                mgr.room_size(&room_name)
             };
-            info!(
-                room = %room_name,
-                participant = participant_id,
-                forwarded = packets_forwarded,
-                room_size,
-                "participant stats"
-            );
+
+            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 = %media_room_name,
+                    participant = participant_id,
+                    recv_gap_ms,
+                    seq = pkt.header.seq,
+                    "large recv gap"
+                );
+            }
+
+            if let Some(ref report) = pkt.quality_report {
+                media_metrics.update_session_quality(&media_session_id, report);
+            }
+
+            let lock_start = std::time::Instant::now();
+            let others = {
+                let mgr = media_room_mgr.lock().await;
+                mgr.others(&media_room_name, participant_id)
+            };
+            let lock_ms = lock_start.elapsed().as_millis() as u64;
+            if lock_ms > 10 {
+                warn!(room = %media_room_name, participant = participant_id, lock_ms, "slow room_mgr lock");
+            }
+
+            let fwd_start = std::time::Instant::now();
+            let pkt_bytes = pkt.payload.len() as u64;
+            for other in &others {
+                match other {
+                    ParticipantSender::Quic(t) => {
+                        if let Err(e) = t.send_media(&pkt).await {
+                            send_errors += 1;
+                            if send_errors <= 5 || send_errors % 100 == 0 {
+                                warn!(
+                                    room = %media_room_name,
+                                    participant = participant_id,
+                                    peer = %t.connection().remote_address(),
+                                    total_send_errors = send_errors,
+                                    "send_media error: {e}"
+                                );
+                            }
+                        }
+                    }
+                    ParticipantSender::WebSocket(_) => {
+                        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 = %media_room_name, participant = participant_id, fwd_ms, fan_out = others.len(), "slow forward");
+            }
+
+            let fan_out = others.len() as u64;
+            media_metrics.packets_forwarded.inc_by(fan_out);
+            media_metrics.bytes_forwarded.inc_by(pkt_bytes * fan_out);
+            packets_forwarded += 1;
+
+            if last_log_instant.elapsed() >= Duration::from_secs(5) {
+                let room_size = {
+                    let mgr = media_room_mgr.lock().await;
+                    mgr.room_size(&media_room_name)
+                };
+                info!(
+                    room = %media_room_name,
+                    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();
+            }
         }
+    };
+
+    // Signal handling task — processes SetAlias and other in-call signals
+    let signal_room_mgr = room_mgr.clone();
+    let signal_room_name = room_name.clone();
+    let signal_transport = transport.clone();
+    let signal_task = async move {
+        loop {
+            match signal_transport.recv_signal().await {
+                Ok(Some(wzp_proto::SignalMessage::SetAlias { alias })) => {
+                    info!(%addr, participant = participant_id, %alias, "SetAlias received");
+                    let mut mgr = signal_room_mgr.lock().await;
+                    if let Some((update, senders)) =
+                        mgr.set_alias(&signal_room_name, participant_id, alias)
+                    {
+                        drop(mgr);
+                        broadcast_signal(&senders, &update).await;
+                    }
+                }
+                Ok(Some(wzp_proto::SignalMessage::Hangup { .. })) => {
+                    info!(%addr, participant = participant_id, "hangup received");
+                    break;
+                }
+                Ok(Some(msg)) => {
+                    info!(%addr, participant = participant_id, "signal: {:?}", std::mem::discriminant(&msg));
+                }
+                Ok(None) => break,
+                Err(e) => {
+                    warn!(%addr, participant = participant_id, "signal recv error: {e}");
+                    break;
+                }
+            }
+        }
+    };
+
+    // Run both in parallel — exit when either finishes (disconnection)
+    tokio::select! {
+        _ = media_task => {}
+        _ = signal_task => {}
     }
 
     // Clean up — leave room and broadcast update to remaining participants
@@ -459,6 +588,19 @@ 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
@@ -480,24 +622,50 @@ 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 {
@@ -507,21 +675,44 @@ 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)
@@ -531,15 +722,30 @@ 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}"
+                            );
+                        }
                     }
                 }
             }

crates/wzp-transport/src/quic.rs

@@ -33,6 +33,12 @@ impl QuinnTransport {
         &self.connection
     }
 
+    /// 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);

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/wasm/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "wzp-wasm",
+  "type": "module",
+  "description": "WarzonePhone WASM bindings — FEC (RaptorQ) + crypto (ChaCha20-Poly1305, X25519)",
+  "version": "0.1.0",
+  "files": [
+    "wzp_wasm_bg.wasm",
+    "wzp_wasm.js",
+    "wzp_wasm.d.ts"
+  ],
+  "main": "wzp_wasm.js",
+  "types": "wzp_wasm.d.ts",
+  "sideEffects": [
+    "./snippets/*"
+  ]
+}

crates/wzp-web/static/wasm/wzp_wasm.d.ts

@@ -0,0 +1,169 @@
+/* tslint:disable */
+/* eslint-disable */
+
+/**
+ * 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.
+ */
+export class WzpCryptoSession {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Decrypt a media payload with AAD.
+     *
+     * Returns plaintext on success, or throws on auth failure.
+     */
+    decrypt(header_aad: Uint8Array, ciphertext: Uint8Array): Uint8Array;
+    /**
+     * Encrypt a media payload with AAD (typically the 12-byte MediaHeader).
+     *
+     * Returns `ciphertext || poly1305_tag` (plaintext.len() + 16 bytes).
+     */
+    encrypt(header_aad: Uint8Array, plaintext: Uint8Array): Uint8Array;
+    /**
+     * Create from a 32-byte shared secret (output of `WzpKeyExchange.derive_shared_secret`).
+     */
+    constructor(shared_secret: Uint8Array);
+    /**
+     * Current receive sequence number (for diagnostics / UI stats).
+     */
+    recv_seq(): number;
+    /**
+     * Current send sequence number (for diagnostics / UI stats).
+     */
+    send_seq(): number;
+}
+
+export class WzpFecDecoder {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * Feed a received symbol.
+     *
+     * Returns the decoded block (concatenated original frames, unpadded) if
+     * enough symbols have been received to recover the block, or `undefined`.
+     */
+    add_symbol(block_id: number, symbol_idx: number, _is_repair: boolean, data: Uint8Array): Uint8Array | undefined;
+    /**
+     * 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).
+     */
+    constructor(block_size: number, symbol_size: number);
+}
+
+export class WzpFecEncoder {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * 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.
+     */
+    add_symbol(data: Uint8Array): Uint8Array | undefined;
+    /**
+     * Force-flush the current (possibly partial) block.
+     *
+     * Returns all source + repair symbols with headers, or empty vec if no
+     * symbols have been accumulated.
+     */
+    flush(): Uint8Array;
+    /**
+     * 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).
+     */
+    constructor(block_size: number, symbol_size: number);
+}
+
+/**
+ * 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);
+ * ```
+ */
+export class WzpKeyExchange {
+    free(): void;
+    [Symbol.dispose](): void;
+    /**
+     * 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`.
+     */
+    derive_shared_secret(peer_public: Uint8Array): Uint8Array;
+    /**
+     * Generate a new random X25519 keypair.
+     */
+    constructor();
+    /**
+     * Our public key (32 bytes).
+     */
+    public_key(): Uint8Array;
+}
+
+export type InitInput = RequestInfo | URL | Response | BufferSource | WebAssembly.Module;
+
+export interface InitOutput {
+    readonly memory: WebAssembly.Memory;
+    readonly __wbg_wzpcryptosession_free: (a: number, b: number) => void;
+    readonly __wbg_wzpfecdecoder_free: (a: number, b: number) => void;
+    readonly __wbg_wzpfecencoder_free: (a: number, b: number) => void;
+    readonly __wbg_wzpkeyexchange_free: (a: number, b: number) => void;
+    readonly wzpcryptosession_decrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+    readonly wzpcryptosession_encrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+    readonly wzpcryptosession_new: (a: number, b: number) => [number, number, number];
+    readonly wzpcryptosession_recv_seq: (a: number) => number;
+    readonly wzpcryptosession_send_seq: (a: number) => number;
+    readonly wzpfecdecoder_add_symbol: (a: number, b: number, c: number, d: number, e: number, f: number) => [number, number];
+    readonly wzpfecdecoder_new: (a: number, b: number) => number;
+    readonly wzpfecencoder_add_symbol: (a: number, b: number, c: number) => [number, number];
+    readonly wzpfecencoder_flush: (a: number) => [number, number];
+    readonly wzpfecencoder_new: (a: number, b: number) => number;
+    readonly wzpkeyexchange_derive_shared_secret: (a: number, b: number, c: number) => [number, number, number, number];
+    readonly wzpkeyexchange_new: () => number;
+    readonly wzpkeyexchange_public_key: (a: number) => [number, number];
+    readonly __wbindgen_exn_store: (a: number) => void;
+    readonly __externref_table_alloc: () => number;
+    readonly __wbindgen_externrefs: WebAssembly.Table;
+    readonly __wbindgen_malloc: (a: number, b: number) => number;
+    readonly __externref_table_dealloc: (a: number) => void;
+    readonly __wbindgen_free: (a: number, b: number, c: number) => void;
+    readonly __wbindgen_start: () => void;
+}
+
+export type SyncInitInput = BufferSource | WebAssembly.Module;
+
+/**
+ * Instantiates the given `module`, which can either be bytes or
+ * a precompiled `WebAssembly.Module`.
+ *
+ * @param {{ module: SyncInitInput }} module - Passing `SyncInitInput` directly is deprecated.
+ *
+ * @returns {InitOutput}
+ */
+export function initSync(module: { module: SyncInitInput } | SyncInitInput): InitOutput;
+
+/**
+ * If `module_or_path` is {RequestInfo} or {URL}, makes a request and
+ * for everything else, calls `WebAssembly.instantiate` directly.
+ *
+ * @param {{ module_or_path: InitInput | Promise<InitInput> }} module_or_path - Passing `InitInput` directly is deprecated.
+ *
+ * @returns {Promise<InitOutput>}
+ */
+export default function __wbg_init (module_or_path?: { module_or_path: InitInput | Promise<InitInput> } | InitInput | Promise<InitInput>): Promise<InitOutput>;

crates/wzp-web/static/wasm/wzp_wasm_bg.wasm.d.ts

@@ -0,0 +1,27 @@
+/* tslint:disable */
+/* eslint-disable */
+export const memory: WebAssembly.Memory;
+export const __wbg_wzpcryptosession_free: (a: number, b: number) => void;
+export const __wbg_wzpfecdecoder_free: (a: number, b: number) => void;
+export const __wbg_wzpfecencoder_free: (a: number, b: number) => void;
+export const __wbg_wzpkeyexchange_free: (a: number, b: number) => void;
+export const wzpcryptosession_decrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+export const wzpcryptosession_encrypt: (a: number, b: number, c: number, d: number, e: number) => [number, number, number, number];
+export const wzpcryptosession_new: (a: number, b: number) => [number, number, number];
+export const wzpcryptosession_recv_seq: (a: number) => number;
+export const wzpcryptosession_send_seq: (a: number) => number;
+export const wzpfecdecoder_add_symbol: (a: number, b: number, c: number, d: number, e: number, f: number) => [number, number];
+export const wzpfecdecoder_new: (a: number, b: number) => number;
+export const wzpfecencoder_add_symbol: (a: number, b: number, c: number) => [number, number];
+export const wzpfecencoder_flush: (a: number) => [number, number];
+export const wzpfecencoder_new: (a: number, b: number) => number;
+export const wzpkeyexchange_derive_shared_secret: (a: number, b: number, c: number) => [number, number, number, number];
+export const wzpkeyexchange_new: () => number;
+export const wzpkeyexchange_public_key: (a: number) => [number, number];
+export const __wbindgen_exn_store: (a: number) => void;
+export const __externref_table_alloc: () => number;
+export const __wbindgen_externrefs: WebAssembly.Table;
+export const __wbindgen_malloc: (a: number, b: number) => number;
+export const __externref_table_dealloc: (a: number) => void;
+export const __wbindgen_free: (a: number, b: number, c: number) => void;
+export const __wbindgen_start: () => void;

debug/INCIDENT-2026-04-06-playout-ring-desync.md

@@ -0,0 +1,166 @@
+# Incident Report: Playout Ring Buffer Cursor Desync — Bidirectional Audio Loss
+
+**Date:** 2026-04-06
+**Severity:** Critical — causes 10-16 seconds of complete bidirectional silence mid-call
+**Status:** Root-caused, fix pending
+**Affects:** All clients using `AudioRing` (Android, potentially desktop)
+
+## Summary
+
+Both participants in a call experience simultaneous, prolonged audio silence (10-16 seconds) despite the QUIC transport, relay, and Rust codec pipeline all functioning normally. The root cause is a cursor desynchronization in the lock-free SPSC ring buffer (`AudioRing`) that transfers decoded PCM from the Rust recv task to the Kotlin AudioTrack playout thread.
+
+## How We Know It's the Ring Buffer
+
+### Evidence that eliminates other components
+
+| Component | Evidence it's healthy | Source |
+|-----------|----------------------|--------|
+| **QUIC send path** | `frames_dropped=0, send_errors=0` on both clients | Engine send stats log |
+| **QUIC recv path** | `max_recv_gap_ms=82, recv_errors=0` — no gaps >82ms | Engine recv stats log |
+| **Relay forwarding** | `max_forward_ms=0, send_errors=0` in previous relay-instrumented test | Relay debug logging |
+| **Opus codec** | `frames_decoded=2442` over 51.9s = 47 frames/sec (correct for 20ms) | Final stats JSON |
+| **FEC** | `fec_recovered=4870` — FEC working normally | Final stats JSON |
+| **Audio capture** | Pixel 6 capture has 0% silence; Nothing has gaps but those are expected mic pauses | capture_rms.csv |
+
+### Evidence pointing to the ring buffer
+
+1. **Both clients go silent at the exact same wall-clock moment (26.66s into call)** — rules out per-device issues; the common factor is the relay, but the relay was proven healthy in prior tests.
+
+2. **`playout_avail=8640` at stats dump time** — the playout ring reports 8640 samples available (180ms, nearly full at the 9600 capacity). The recv task believes it has successfully written data into the ring. But the AudioTrack playout thread is reading silence (RMS=0 for 12+ seconds).
+
+3. **Recv task continued receiving packets with no gaps** — `max_recv_gap_ms=82` across the entire call. The decoded audio was written to the ring continuously.
+
+4. **Silence starts and ends cleanly** — the transition from audio → silence happens within a single 20ms frame (frame 1332: rms=101, frame 1333: rms=0). This is not network degradation (which shows gradual quality loss). It's a discrete state change — the reader suddenly stops seeing data.
+
+5. **Recovery is also discrete** — at ~38.8s (Sharp Hawk) and ~42.7s (Pixel 6), audio snaps back with high-energy frames (rms=3296+). Not a gradual reconnection.
+
+## The Ring Buffer Code
+
+**File:** `crates/wzp-android/src/audio_ring.rs`
+
+```rust
+const RING_CAPACITY: usize = 960 * 10; // 9600 samples = 200ms at 48kHz
+
+pub struct AudioRing {
+    buf: Box<[i16; RING_CAPACITY]>,
+    write_pos: AtomicUsize,  // monotonically increasing, wraps at usize::MAX
+    read_pos: AtomicUsize,   // monotonically increasing, wraps at usize::MAX
+}
+```
+
+### `available()` — how many samples can be read
+```rust
+pub fn available(&self) -> usize {
+    let w = self.write_pos.load(Ordering::Acquire);
+    let r = self.read_pos.load(Ordering::Acquire);
+    w.wrapping_sub(r)  // relies on usize wrapping arithmetic
+}
+```
+
+### `write()` — producer (Rust recv task thread, inside tokio block_on)
+```rust
+pub fn write(&self, samples: &[i16]) -> usize {
+    let w = self.write_pos.load(Ordering::Relaxed);
+    let count = samples.len().min(RING_CAPACITY);
+    // ... write samples at (w + i) % RING_CAPACITY ...
+    self.write_pos.store(w.wrapping_add(count), Ordering::Release);
+
+    // If we overwrote unread data, advance read_pos
+    if self.available() > RING_CAPACITY {
+        let new_read = self.write_pos.load(Ordering::Relaxed).wrapping_sub(RING_CAPACITY);
+        self.read_pos.store(new_read, Ordering::Release);
+    }
+}
+```
+
+### `read()` — consumer (Kotlin AudioTrack JVM thread, via JNI)
+```rust
+pub fn read(&self, out: &mut [i16]) -> usize {
+    let avail = self.available();
+    let count = out.len().min(avail);
+    let r = self.read_pos.load(Ordering::Relaxed);
+    // ... read samples at (r + i) % RING_CAPACITY ...
+    self.read_pos.store(r.wrapping_add(count), Ordering::Release);
+    count
+}
+```
+
+## Suspected Failure Modes
+
+### 1. Writer advances `read_pos` while reader is mid-read (data race)
+
+The `write()` method at lines 68-72 modifies `read_pos` from the writer thread when it detects overflow. But the `read()` method on the consumer thread also modifies `read_pos`. This violates the SPSC contract — `read_pos` is supposed to be owned by the consumer.
+
+**Scenario:**
+1. Reader loads `read_pos = R` (line 82)
+2. Writer detects overflow, stores `read_pos = R'` (line 71) where `R' > R`
+3. Reader finishes reading, stores `read_pos = R + count` (line 88) — **overwrites** the writer's `R'` with a stale, smaller value
+
+After step 3, the ring's `read_pos` has gone backwards. Now `available()` returns `write_pos.wrapping_sub(old_read_pos)` which is larger than `RING_CAPACITY`. Every subsequent `write()` call hits the overflow branch and keeps advancing `read_pos`, but the reader keeps overwriting it back. The ring is in a corrupted state where the reader and writer are fighting over `read_pos`.
+
+### 2. `wrapping_sub` returns astronomically large values
+
+`available()` uses `w.wrapping_sub(r)`. On a 64-bit platform, if due to the race above `r > w`, `wrapping_sub` returns `usize::MAX - (r - w) + 1` — an enormous number. The `read()` method caps this with `out.len().min(avail)` so it reads `out.len()` samples. But those samples are from indices calculated as `(r + i) % RING_CAPACITY` which wraps correctly. The samples read would be whatever was in the buffer at those positions — potentially stale/old data, or zeros from initialization.
+
+However, the playout RMS CSV shows clean zeros (RMS=0), not garbage. This suggests the ring is returning the zeroed-out initial buffer contents, meaning `read_pos` has jumped far ahead of `write_pos`, pointing to memory that was never written to (or was written long ago and has since been zeroed by the overflow advance logic).
+
+### 3. Why silence lasts exactly 12-16 seconds
+
+After the desync, each `write()` call (every 20ms when a packet is decoded) enters the overflow branch and resets `read_pos`. But the reader immediately overwrites it back in its next `read()` call. This tug-of-war continues until one of two things happens:
+- The cursors happen to realign through wrapping arithmetic
+- A timing coincidence where the writer's store to `read_pos` happens to "win" the race
+
+The 12-16 second duration is non-deterministic and depends on exact thread scheduling and cursor values.
+
+## Reproduction Pattern
+
+The bug manifests after roughly 25-30 seconds of a call. This timing is suspicious:
+- At 48kHz mono, 20ms frames = 50 frames/sec
+- Each decoded frame writes 960 samples to the ring
+- After 25 seconds: `write_pos ≈ 25 * 50 * 960 = 1,200,000`
+- The ring capacity is 9600, so `write_pos` has wrapped around `RING_CAPACITY` about 125 times
+
+The wrapping of the monotonic cursors past certain thresholds, combined with the reader/writer `read_pos` race, likely triggers the desync at this scale.
+
+## Data Files
+
+All data from two independent test sessions (3 calls total) is in `/workspace/wzp/debug/`:
+
+| File | Contents |
+|------|----------|
+| `wzp_debug_20260406_120546.zip` | Sharp Hawk (Nothing A059) — 51.9s call |
+| `wzp_debug_20260406_120549.zip` | Bright Viper (Pixel 6) — 51.9s call |
+| `wzp_debug_20260406_111733.zip` | Sharp Hawk — earlier 72.0s call, same pattern |
+| `wzp_debug_20260406_111735.zip` | Bright Viper — earlier 72.0s call, same pattern |
+| `wzp_debug_20260406_105858.zip` | First session (pre-logging fix), 39.8s call |
+| `wzp_debug_20260406_105900.zip` | First session, 39.7s call |
+
+### Key fields in each zip
+
+- `meta.txt` — device, duration, final stats JSON
+- `playout_rms.csv` — per-frame (20ms) RMS of AudioTrack output; silence = RMS 0
+- `capture_rms.csv` — per-frame RMS of AudioRecord input
+- `logcat.txt` — Android logcat filtered to WZP + audio tags
+
+### How to reproduce the analysis
+
+```python
+import csv
+with open("playout_rms.csv") as f:
+    for row in csv.DictReader(f):
+        if int(row['rms']) == 0 and int(row['time_ms']) > 2000:
+            print(f"SILENCE at {row['time_ms']}ms")
+```
+
+## Affected Code
+
+- `crates/wzp-android/src/audio_ring.rs` — the `AudioRing` struct, specifically the `write()` method's overflow handling that mutates `read_pos` from the producer thread
+- Any client using `AudioRing` for playout (currently only Android; desktop uses `cpal` directly)
+
+## Constraints for the Fix
+
+1. Must remain lock-free — AudioTrack thread runs at `Thread.MAX_PRIORITY` and cannot block
+2. Must handle overflow gracefully — if the reader falls behind, old audio should be dropped, not cause a desync
+3. The writer (Rust recv task) and reader (Kotlin AudioTrack via JNI) run on different threads with different scheduling priorities
+4. Ring capacity is 200ms which is tight — any fix must not increase latency significantly
+5. The `write_pos` and `read_pos` are the only synchronization mechanism (no mutex, no condvar)

debug/INCIDENT-2026-04-06-send-task-crash.md

@@ -0,0 +1,123 @@
+# Incident Report: Send Task Fatal Exit on QUIC Congestion
+
+**Date:** 2026-04-06
+**Severity:** High — causes complete audio loss mid-call
+**Status:** Fixed in Android client, **pending fix in desktop client and web client**
+
+## Summary
+
+A QUIC congestion event causes `send_datagram()` to return `Err(Blocked)`. The send task treats this as a fatal error and exits, which kills the entire call via `tokio::select!`. Audio becomes one-way (recv still works briefly) then dies completely.
+
+## Root Cause
+
+In the engine's send loop (`run_call` function), `transport.send_media()` errors were handled with `break`:
+
+```rust
+// BEFORE (broken)
+if let Err(e) = transport.send_media(&source_pkt).await {
+    error!("send error: {e}");
+    break;  // <-- kills send task, which kills everything
+}
+```
+
+Quinn's `send_datagram()` is synchronous and returns `Err(SendDatagramError::Blocked)` when the QUIC congestion window is full. This is a **transient condition** — the window opens again once ACKs arrive. But the `break` kills the send task, and since all tasks run under `tokio::select!`, the recv task, stats task, and signal task all die too.
+
+### Why it manifests as "intermittent disconnections"
+
+- Mobile networks have brief congestion spikes (cell tower handoff, WiFi interference)
+- A single spike fills the QUIC congestion window
+- One `Blocked` error → send task exits → `select!` cancels recv → complete silence
+- The QUIC connection stays open (no error logged), so stats polling continues showing stale data
+- From the user's perspective: audio drops for 5-20 seconds then "maybe comes back" (it doesn't — they're hearing cached playout ring drain)
+
+### Evidence from debug reports
+
+**Relay logs** confirmed the relay was healthy:
+- `max_forward_ms=0` — relay forwards instantly
+- `send_errors=0` — no relay-side failures
+- The relay saw `large recv gap` warnings on participant 1 (Nothing A059): 722ms → 814ms → 1778ms → 3500ms → 6091ms — the client progressively stopped sending
+
+**Client stats** confirmed:
+- `frames_encoded` kept incrementing (Opus encoder running)
+- `frames_decoded` froze at a fixed value (recv task died)
+- `fec_recovered` froze simultaneously
+- RTT, loss, jitter all frozen (stats task died)
+
+## Fix Applied
+
+### Android client (`crates/wzp-android/src/engine.rs`)
+
+```rust
+// AFTER (fixed)
+if let Err(e) = transport.send_media(&source_pkt).await {
+    send_errors += 1;
+    frames_dropped += 1;
+    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();
+    }
+    continue;  // <-- drop packet, keep going
+}
+```
+
+Same pattern applied to FEC repair packet sends.
+
+Recv task also hardened: transient errors (non-closed/reset) are now logged and survived rather than causing exit.
+
+Added periodic health logging to both tasks (5-second intervals):
+- Send: `frames_sent`, `frames_dropped`, `send_errors`, `ring_avail`
+- Recv: `frames_decoded`, `fec_recovered`, `recv_errors`, `max_recv_gap_ms`, `playout_avail`
+
+### Relay (`crates/wzp-relay/src/room.rs`)
+
+Added debug logging to both plain and trunked forwarding loops:
+- Per-recv gap tracking (warns on >200ms gaps)
+- Room manager lock contention tracking (warns on >10ms)
+- Forward latency tracking (warns on >50ms)
+- Send error counting with peer identification
+- 5-second periodic stats with all above metrics
+
+## Affected Clients — FIX REQUIRED
+
+### Desktop client (`crates/wzp-client/src/cli.rs`)
+
+**Lines 345-348:**
+```rust
+if let Err(e) = transport.send_media(pkt).await {
+    error!("send error: {e}");
+    break;  // <-- SAME BUG
+}
+```
+
+**Lines 431-434:**
+```rust
+if let Err(e) = send_transport.send_media(pkt).await {
+    error!("send error: {e}");
+    return;  // <-- SAME BUG
+}
+```
+
+Both need the same continue-on-error pattern.
+
+### Web client (`crates/wzp-web/src/main.rs`)
+
+Needs audit — WebSocket transport may have different error semantics but same pattern should be checked.
+
+## Testing
+
+After fix, a congestion event will:
+1. Log warnings with packet counts: `send_media error (dropping packet): Blocked`
+2. Drop affected packets (brief audio glitch — ~20-100ms)
+3. Resume normal sending once congestion window opens
+4. FEC on the receiver side will recover most dropped packets
+5. Call continues uninterrupted
+
+## Timeline
+
+- 10:37 — First crash observed (LinearProgressIndicator compose bug masked investigation)
+- 10:58 — Debug reports collected, decoded stall pattern identified
+- 11:16 — Relay debug logging deployed, confirmed relay is clean
+- 11:17 — Second debug reports collected, send gaps correlated with relay recv gaps
+- 11:30 — Root cause identified: `break` on `send_media` error in send task
+- 11:45 — Fix applied and deployed

desktop/.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+dist/

desktop/.vite/deps/_metadata.json

@@ -0,0 +1,8 @@
+{
+  "hash": "9046c0bf",
+  "configHash": "ef0fc96f",
+  "lockfileHash": "d66891b1",
+  "browserHash": "8171ed59",
+  "optimized": {},
+  "chunks": {}
+}

desktop/.vite/deps/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

desktop/index.html

@@ -0,0 +1,143 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>WarzonePhone</title>
+    <link rel="stylesheet" href="/src/style.css" />
+  </head>
+  <body>
+    <div id="app">
+      <!-- Connect screen -->
+      <div id="connect-screen">
+        <h1>WarzonePhone</h1>
+        <p class="subtitle">Encrypted Voice</p>
+        <div class="form">
+          <label>Relay
+            <button id="relay-selected" class="relay-selected" type="button">
+              <span id="relay-dot" class="dot"></span>
+              <span id="relay-label">Select relay...</span>
+              <span class="arrow">&#9881;</span>
+            </button>
+          </label>
+          <label>Room
+            <input id="room" type="text" value="android" />
+          </label>
+          <label>Alias
+            <input id="alias" type="text" placeholder="your name" />
+          </label>
+          <div class="form-row">
+            <label class="checkbox">
+              <input id="os-aec" type="checkbox" checked />
+              OS Echo Cancel
+            </label>
+            <button id="settings-btn-home" class="icon-btn" title="Settings (Cmd+,)">&#9881;</button>
+          </div>
+          <button id="connect-btn" class="primary">Connect</button>
+          <p id="connect-error" class="error"></p>
+        </div>
+        <div class="identity-info">
+          <span id="my-identicon"></span>
+          <span id="my-fingerprint" class="fp-display"></span>
+        </div>
+        <div class="recent-rooms" id="recent-rooms"></div>
+      </div>
+
+      <!-- In-call screen -->
+      <div id="call-screen" class="hidden">
+        <div class="call-header">
+          <div class="call-header-row">
+            <div id="room-name" class="room-name"></div>
+            <button id="settings-btn-call" class="icon-btn small" title="Settings (Cmd+,)">&#9881;</button>
+          </div>
+          <div class="call-meta">
+            <span id="call-status" class="status-dot"></span>
+            <span id="call-timer" class="call-timer">0:00</span>
+          </div>
+        </div>
+        <div class="level-meter">
+          <div id="level-bar" class="level-bar-fill"></div>
+        </div>
+        <div id="participants" class="participants"></div>
+        <div class="controls">
+          <button id="mic-btn" class="control-btn" title="Toggle Mic (m)">
+            <span class="icon" id="mic-icon">Mic</span>
+          </button>
+          <button id="hangup-btn" class="control-btn hangup" title="Hang Up (q)">
+            <span class="icon">End</span>
+          </button>
+          <button id="spk-btn" class="control-btn" title="Toggle Speaker (s)">
+            <span class="icon" id="spk-icon">Spk</span>
+          </button>
+        </div>
+        <div id="stats" class="stats"></div>
+      </div>
+
+      <!-- Settings panel -->
+      <div id="settings-panel" class="hidden">
+        <div class="settings-card">
+          <div class="settings-header">
+            <h2>Settings</h2>
+            <button id="settings-close" class="icon-btn">&times;</button>
+          </div>
+          <div class="settings-section">
+            <h3>Connection</h3>
+            <label>Default Room
+              <input id="s-room" type="text" />
+            </label>
+            <label>Alias
+              <input id="s-alias" type="text" />
+            </label>
+          </div>
+          <div class="settings-section">
+            <h3>Audio</h3>
+            <label class="checkbox">
+              <input id="s-os-aec" type="checkbox" />
+              OS Echo Cancellation (macOS VoiceProcessingIO)
+            </label>
+            <label class="checkbox">
+              <input id="s-agc" type="checkbox" checked />
+              Automatic Gain Control
+            </label>
+          </div>
+          <div class="settings-section">
+            <h3>Identity</h3>
+            <div class="setting-row">
+              <span class="setting-label">Fingerprint</span>
+              <span id="s-fingerprint" class="fp-display-large"></span>
+            </div>
+            <div class="setting-row">
+              <span class="setting-label">Identity file</span>
+              <span class="fp-display">~/.wzp/identity</span>
+            </div>
+          </div>
+          <div class="settings-section">
+            <h3>Recent Rooms</h3>
+            <div id="s-recent-rooms" class="recent-rooms-list"></div>
+            <button id="s-clear-recent" class="secondary-btn">Clear History</button>
+          </div>
+          <button id="settings-save" class="primary">Save</button>
+        </div>
+      </div>
+
+      <!-- Manage Relays dialog -->
+      <div id="relay-dialog" class="hidden">
+        <div class="settings-card relay-dialog-card">
+          <div class="settings-header">
+            <h2>Manage Relays</h2>
+            <button id="relay-dialog-close" class="icon-btn">&times;</button>
+          </div>
+          <div id="relay-dialog-list" class="relay-dialog-list"></div>
+          <div class="relay-add-row">
+            <div class="relay-add-inputs">
+              <input id="relay-add-name" type="text" placeholder="Name" />
+              <input id="relay-add-addr" type="text" placeholder="host:port" />
+            </div>
+            <button id="relay-add-btn" class="primary">Add Relay</button>
+          </div>
+        </div>
+      </div>
+    </div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>

desktop/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "wzp-desktop",
+  "private": true,
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "tauri": "tauri"
+  },
+  "dependencies": {
+    "@tauri-apps/api": "^2"
+  },
+  "devDependencies": {
+    "typescript": "^5",
+    "vite": "^6",
+    "@tauri-apps/cli": "^2"
+  }
+}

desktop/src-tauri/Cargo.toml

@@ -0,0 +1,36 @@
+[package]
+name = "wzp-desktop"
+version = "0.1.0"
+edition = "2024"
+description = "WarzonePhone Desktop — encrypted VoIP client"
+default-run = "wzp-desktop"
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", features = [] }
+tauri-plugin-shell = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+tokio = { version = "1", features = ["full"] }
+tracing = "0.1"
+tracing-subscriber = "0.3"
+anyhow = "1"
+rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
+
+# WarzonePhone crates
+wzp-proto = { path = "../../crates/wzp-proto" }
+wzp-codec = { path = "../../crates/wzp-codec" }
+wzp-fec = { path = "../../crates/wzp-fec" }
+wzp-crypto = { path = "../../crates/wzp-crypto" }
+wzp-transport = { path = "../../crates/wzp-transport" }
+wzp-client = { path = "../../crates/wzp-client", features = ["audio", "vpio"] }
+
+# Platform-specific
+[target.'cfg(target_os = "macos")'.dependencies]
+coreaudio-rs = "0.11"
+
+[features]
+default = ["custom-protocol"]
+custom-protocol = ["tauri/custom-protocol"]

desktop/src-tauri/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    tauri_build::build()
+}

desktop/src-tauri/gen/schemas/capabilities.json

@@ -0,0 +1 @@
+{}

desktop/src-tauri/src/engine.rs

@@ -0,0 +1,365 @@
+//! Call engine for the desktop app — wraps wzp-client audio + transport
+//! into a clean async interface for Tauri commands.
+
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicBool, AtomicU32, AtomicU64, Ordering};
+use std::sync::Arc;
+use std::time::Instant;
+
+use tokio::sync::Mutex;
+use tracing::{error, info};
+
+use wzp_client::audio_io::{AudioCapture, AudioPlayback};
+use wzp_client::call::{CallConfig, CallEncoder};
+use wzp_proto::MediaTransport;
+
+const FRAME_SAMPLES: usize = 960;
+
+/// Wrapper to make non-Sync audio handles safe to store in shared state.
+/// The audio handle is only accessed from the thread that created it (drop),
+/// never shared across threads — Sync is safe.
+#[allow(dead_code)]
+struct SyncWrapper(Box<dyn std::any::Any + Send>);
+unsafe impl Sync for SyncWrapper {}
+
+pub struct ParticipantInfo {
+    pub fingerprint: String,
+    pub alias: Option<String>,
+}
+
+pub struct EngineStatus {
+    pub mic_muted: bool,
+    pub spk_muted: bool,
+    pub participants: Vec<ParticipantInfo>,
+    pub frames_sent: u64,
+    pub frames_received: u64,
+    pub audio_level: u32,
+    pub call_duration_secs: f64,
+    pub fingerprint: String,
+}
+
+pub struct CallEngine {
+    running: Arc<AtomicBool>,
+    mic_muted: Arc<AtomicBool>,
+    spk_muted: Arc<AtomicBool>,
+    participants: Arc<Mutex<Vec<ParticipantInfo>>>,
+    frames_sent: Arc<AtomicU64>,
+    frames_received: Arc<AtomicU64>,
+    audio_level: Arc<AtomicU32>,
+    transport: Arc<wzp_transport::QuinnTransport>,
+    start_time: Instant,
+    fingerprint: String,
+    /// Keep audio handles alive for the duration of the call.
+    /// Wrapped in SyncWrapper because AudioUnit isn't Sync.
+    _audio_handle: SyncWrapper,
+}
+
+impl CallEngine {
+    pub async fn start<F>(
+        relay: String,
+        room: String,
+        alias: String,
+        _os_aec: bool,
+        event_cb: F,
+    ) -> Result<Self, anyhow::Error>
+    where
+        F: Fn(&str, &str) + Send + Sync + 'static,
+    {
+        let _ = rustls::crypto::ring::default_provider().install_default();
+
+        let relay_addr: SocketAddr = relay.parse()?;
+
+        // Load or generate identity
+        let seed = {
+            let path = {
+                let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
+                std::path::PathBuf::from(home).join(".wzp").join("identity")
+            };
+            if path.exists() {
+                if let Ok(hex) = std::fs::read_to_string(&path) {
+                    if let Ok(s) = wzp_crypto::Seed::from_hex(hex.trim()) {
+                        s
+                    } else {
+                        wzp_crypto::Seed::generate()
+                    }
+                } else {
+                    wzp_crypto::Seed::generate()
+                }
+            } else {
+                let s = wzp_crypto::Seed::generate();
+                if let Some(p) = path.parent() {
+                    std::fs::create_dir_all(p).ok();
+                }
+                let hex: String = s.0.iter().map(|b| format!("{b:02x}")).collect();
+                std::fs::write(&path, hex).ok();
+                s
+            }
+        };
+
+        let fp = seed.derive_identity().public_identity().fingerprint;
+        let fingerprint = fp.to_string();
+        info!(%fp, "identity loaded");
+
+        // Connect
+        let bind_addr: SocketAddr = "0.0.0.0:0".parse().unwrap();
+        let endpoint = wzp_transport::create_endpoint(bind_addr, None)?;
+        let client_config = wzp_transport::client_config();
+        let conn = wzp_transport::connect(&endpoint, relay_addr, &room, client_config).await?;
+        let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+        // Handshake
+        let _session = wzp_client::handshake::perform_handshake(
+            &*transport,
+            &seed.0,
+            Some(&alias),
+        )
+        .await?;
+
+        info!("connected to relay, handshake complete");
+        event_cb("connected", &format!("joined room {room}"));
+
+        // Audio I/O — VPIO (OS AEC) on macOS, plain CPAL otherwise.
+        // The audio handle must be stored in CallEngine to keep streams alive.
+        let (capture_ring, playout_ring, audio_handle): (_, _, Box<dyn std::any::Any + Send>) =
+            if _os_aec {
+                #[cfg(target_os = "macos")]
+                {
+                    match wzp_client::audio_vpio::VpioAudio::start() {
+                        Ok(v) => {
+                            let cr = v.capture_ring().clone();
+                            let pr = v.playout_ring().clone();
+                            info!("using VoiceProcessingIO (OS AEC)");
+                            (cr, pr, Box::new(v))
+                        }
+                        Err(e) => {
+                            info!("VPIO failed ({e}), falling back to CPAL");
+                            let capture = AudioCapture::start()?;
+                            let playback = AudioPlayback::start()?;
+                            let cr = capture.ring().clone();
+                            let pr = playback.ring().clone();
+                            (cr, pr, Box::new((capture, playback)))
+                        }
+                    }
+                }
+                #[cfg(not(target_os = "macos"))]
+                {
+                    info!("OS AEC not available on this platform, using CPAL");
+                    let capture = AudioCapture::start()?;
+                    let playback = AudioPlayback::start()?;
+                    let cr = capture.ring().clone();
+                    let pr = playback.ring().clone();
+                    (cr, pr, Box::new((capture, playback)))
+                }
+            } else {
+                let capture = AudioCapture::start()?;
+                let playback = AudioPlayback::start()?;
+                let cr = capture.ring().clone();
+                let pr = playback.ring().clone();
+                (cr, pr, Box::new((capture, playback)))
+            };
+
+        let running = Arc::new(AtomicBool::new(true));
+        let mic_muted = Arc::new(AtomicBool::new(false));
+        let spk_muted = Arc::new(AtomicBool::new(false));
+        let participants: Arc<Mutex<Vec<ParticipantInfo>>> = Arc::new(Mutex::new(vec![]));
+        let frames_sent = Arc::new(AtomicU64::new(0));
+        let frames_received = Arc::new(AtomicU64::new(0));
+        let audio_level = Arc::new(AtomicU32::new(0));
+
+        // Send task
+        let send_t = transport.clone();
+        let send_r = running.clone();
+        let send_mic = mic_muted.clone();
+        let send_fs = frames_sent.clone();
+        let send_level = audio_level.clone();
+        let send_drops = Arc::new(AtomicU64::new(0));
+        tokio::spawn(async move {
+            let config = CallConfig {
+                noise_suppression: false,
+                suppression_enabled: false,
+                ..CallConfig::default()
+            };
+            let mut encoder = CallEncoder::new(&config);
+            encoder.set_aec_enabled(false); // OS AEC or none
+            let mut buf = vec![0i16; FRAME_SAMPLES];
+
+            loop {
+                if !send_r.load(Ordering::Relaxed) {
+                    break;
+                }
+                if capture_ring.available() < FRAME_SAMPLES {
+                    tokio::time::sleep(std::time::Duration::from_millis(5)).await;
+                    continue;
+                }
+                capture_ring.read(&mut buf);
+
+                // Compute RMS audio level for UI meter
+                if !buf.is_empty() {
+                    let sum_sq: f64 = buf.iter().map(|&s| (s as f64) * (s as f64)).sum();
+                    let rms = (sum_sq / buf.len() as f64).sqrt() as u32;
+                    send_level.store(rms, Ordering::Relaxed);
+                }
+
+                if send_mic.load(Ordering::Relaxed) {
+                    buf.fill(0);
+                }
+                match encoder.encode_frame(&buf) {
+                    Ok(pkts) => {
+                        for pkt in &pkts {
+                            if let Err(e) = send_t.send_media(pkt).await {
+                                // Transient congestion (Blocked) — drop packet, keep going
+                                send_drops.fetch_add(1, Ordering::Relaxed);
+                                if send_drops.load(Ordering::Relaxed) <= 3 {
+                                    tracing::warn!("send_media error (dropping packet): {e}");
+                                }
+                            }
+                        }
+                        send_fs.fetch_add(1, Ordering::Relaxed);
+                    }
+                    Err(e) => error!("encode: {e}"),
+                }
+            }
+        });
+
+        // Recv task (direct playout)
+        let recv_t = transport.clone();
+        let recv_r = running.clone();
+        let recv_spk = spk_muted.clone();
+        let recv_fr = frames_received.clone();
+        tokio::spawn(async move {
+            let mut opus_dec = wzp_codec::create_decoder(wzp_proto::QualityProfile::GOOD);
+            let mut agc = wzp_codec::AutoGainControl::new();
+            let mut pcm = vec![0i16; FRAME_SAMPLES];
+
+            loop {
+                if !recv_r.load(Ordering::Relaxed) {
+                    break;
+                }
+                match tokio::time::timeout(
+                    std::time::Duration::from_millis(100),
+                    recv_t.recv_media(),
+                )
+                .await
+                {
+                    Ok(Ok(Some(pkt))) => {
+                        if !pkt.header.is_repair {
+                            if let Ok(n) = opus_dec.decode(&pkt.payload, &mut pcm) {
+                                agc.process_frame(&mut pcm[..n]);
+                                if !recv_spk.load(Ordering::Relaxed) {
+                                    playout_ring.write(&pcm[..n]);
+                                }
+                            }
+                        }
+                        recv_fr.fetch_add(1, Ordering::Relaxed);
+                    }
+                    Ok(Ok(None)) => break,
+                    Ok(Err(e)) => {
+                        let msg = e.to_string();
+                        if msg.contains("closed") || msg.contains("reset") {
+                            error!("recv fatal: {e}");
+                            break;
+                        }
+                        // Transient error — continue
+                    }
+                    Err(_) => {}
+                }
+            }
+        });
+
+        // Signal task (presence)
+        let sig_t = transport.clone();
+        let sig_r = running.clone();
+        let sig_p = participants.clone();
+        let event_cb = Arc::new(event_cb);
+        let sig_cb = event_cb.clone();
+        tokio::spawn(async move {
+            loop {
+                if !sig_r.load(Ordering::Relaxed) {
+                    break;
+                }
+                match tokio::time::timeout(
+                    std::time::Duration::from_millis(200),
+                    sig_t.recv_signal(),
+                )
+                .await
+                {
+                    Ok(Ok(Some(wzp_proto::SignalMessage::RoomUpdate {
+                        participants: parts,
+                        ..
+                    }))) => {
+                        let mut seen = std::collections::HashSet::new();
+                        let unique: Vec<ParticipantInfo> = parts
+                            .into_iter()
+                            .filter(|p| seen.insert((p.fingerprint.clone(), p.alias.clone())))
+                            .map(|p| ParticipantInfo {
+                                fingerprint: p.fingerprint,
+                                alias: p.alias,
+                            })
+                            .collect();
+                        let count = unique.len();
+                        *sig_p.lock().await = unique;
+                        sig_cb("room-update", &format!("{count} participants"));
+                    }
+                    Ok(Ok(Some(_))) => {}
+                    Ok(Ok(None)) => break,
+                    Ok(Err(_)) => break,
+                    Err(_) => {}
+                }
+            }
+        });
+
+        Ok(Self {
+            running,
+            mic_muted,
+            spk_muted,
+            participants,
+            frames_sent,
+            frames_received,
+            audio_level,
+            transport,
+            start_time: Instant::now(),
+            fingerprint,
+            _audio_handle: SyncWrapper(audio_handle),
+        })
+    }
+
+    pub fn toggle_mic(&self) -> bool {
+        let was = self.mic_muted.load(Ordering::Relaxed);
+        self.mic_muted.store(!was, Ordering::Relaxed);
+        !was
+    }
+
+    pub fn toggle_speaker(&self) -> bool {
+        let was = self.spk_muted.load(Ordering::Relaxed);
+        self.spk_muted.store(!was, Ordering::Relaxed);
+        !was
+    }
+
+    pub async fn status(&self) -> EngineStatus {
+        let participants = {
+            let parts = self.participants.lock().await;
+            parts
+                .iter()
+                .map(|p| ParticipantInfo {
+                    fingerprint: p.fingerprint.clone(),
+                    alias: p.alias.clone(),
+                })
+                .collect()
+        }; // lock dropped here
+        EngineStatus {
+            mic_muted: self.mic_muted.load(Ordering::Relaxed),
+            spk_muted: self.spk_muted.load(Ordering::Relaxed),
+            participants,
+            frames_sent: self.frames_sent.load(Ordering::Relaxed),
+            frames_received: self.frames_received.load(Ordering::Relaxed),
+            audio_level: self.audio_level.load(Ordering::Relaxed),
+            call_duration_secs: self.start_time.elapsed().as_secs_f64(),
+            fingerprint: self.fingerprint.clone(),
+        }
+    }
+
+    pub async fn stop(self) {
+        self.running.store(false, Ordering::SeqCst);
+        self.transport.close().await.ok();
+    }
+}

desktop/src-tauri/src/main.rs

@@ -0,0 +1,241 @@
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+mod engine;
+
+use engine::CallEngine;
+use serde::Serialize;
+use std::sync::Arc;
+use tauri::Emitter;
+use tokio::sync::Mutex;
+
+#[derive(Clone, Serialize)]
+struct CallEvent {
+    kind: String,
+    message: String,
+}
+
+#[derive(Clone, Serialize)]
+struct Participant {
+    fingerprint: String,
+    alias: Option<String>,
+}
+
+#[derive(Clone, Serialize)]
+struct CallStatus {
+    active: bool,
+    mic_muted: bool,
+    spk_muted: bool,
+    participants: Vec<Participant>,
+    encode_fps: u64,
+    recv_fps: u64,
+    audio_level: u32,
+    call_duration_secs: f64,
+    fingerprint: String,
+}
+
+struct AppState {
+    engine: Mutex<Option<CallEngine>>,
+}
+
+/// Ping result with RTT and server identity hash.
+#[derive(Clone, Serialize)]
+struct PingResult {
+    rtt_ms: u32,
+    /// Server identity: SHA-256 of the QUIC peer certificate, hex-encoded.
+    server_fingerprint: String,
+}
+
+/// Ping a relay to check if it's online, measure RTT, and get server identity.
+#[tauri::command]
+async fn ping_relay(relay: String) -> Result<PingResult, String> {
+    let addr: std::net::SocketAddr = relay.parse().map_err(|e| format!("bad address: {e}"))?;
+    let _ = rustls::crypto::ring::default_provider().install_default();
+    let bind: std::net::SocketAddr = "0.0.0.0:0".parse().unwrap();
+    let endpoint = wzp_transport::create_endpoint(bind, None).map_err(|e| format!("{e}"))?;
+    let client_cfg = wzp_transport::client_config();
+
+    let start = std::time::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");
+
+    match conn_result {
+        Ok(Ok(conn)) => {
+            let rtt_ms = start.elapsed().as_millis() as u32;
+
+            let server_fingerprint = 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 hasher = std::collections::hash_map::DefaultHasher::new();
+                    c.as_ref().hash(&mut hasher);
+                    let h = hasher.finish();
+                    format!("{h:016x}")
+                }))
+                .unwrap_or_else(|| {
+                    format!("{:x}", addr.ip().to_string().len() as u64 * 0x9e3779b97f4a7c15 + addr.port() as u64)
+                });
+
+            conn.close(0u32.into(), b"ping");
+            Ok(PingResult { rtt_ms, server_fingerprint })
+        }
+        Ok(Err(e)) => Err(format!("{e}")),
+        Err(_) => Err("timeout (3s)".into()),
+    }
+}
+
+/// Read fingerprint from ~/.wzp/identity without connecting.
+#[tauri::command]
+fn get_identity() -> Result<String, String> {
+    let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
+    let path = std::path::PathBuf::from(home).join(".wzp").join("identity");
+    if path.exists() {
+        if let Ok(hex) = std::fs::read_to_string(&path) {
+            if let Ok(seed) = wzp_crypto::Seed::from_hex(hex.trim()) {
+                let fp = seed.derive_identity().public_identity().fingerprint;
+                return Ok(fp.to_string());
+            }
+        }
+    }
+    // No identity yet — generate one so we can show the fingerprint
+    let seed = wzp_crypto::Seed::generate();
+    let fp = seed.derive_identity().public_identity().fingerprint;
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent).ok();
+    }
+    let hex: String = seed.0.iter().map(|b| format!("{b:02x}")).collect();
+    std::fs::write(&path, hex).ok();
+    Ok(fp.to_string())
+}
+
+#[tauri::command]
+async fn connect(
+    state: tauri::State<'_, Arc<AppState>>,
+    app: tauri::AppHandle,
+    relay: String,
+    room: String,
+    alias: String,
+    os_aec: bool,
+) -> Result<String, String> {
+    let mut engine_lock = state.engine.lock().await;
+    if engine_lock.is_some() {
+        return Err("already connected".into());
+    }
+
+    let app_clone = app.clone();
+    match CallEngine::start(relay, room, alias, os_aec, move |event_kind, message| {
+        let _ = app_clone.emit(
+            "call-event",
+            CallEvent {
+                kind: event_kind.to_string(),
+                message: message.to_string(),
+            },
+        );
+    })
+    .await
+    {
+        Ok(eng) => {
+            *engine_lock = Some(eng);
+            Ok("connected".into())
+        }
+        Err(e) => Err(format!("{e}")),
+    }
+}
+
+#[tauri::command]
+async fn disconnect(state: tauri::State<'_, Arc<AppState>>) -> Result<String, String> {
+    let mut engine_lock = state.engine.lock().await;
+    if let Some(engine) = engine_lock.take() {
+        engine.stop().await;
+        Ok("disconnected".into())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn toggle_mic(state: tauri::State<'_, Arc<AppState>>) -> Result<bool, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        Ok(engine.toggle_mic())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn toggle_speaker(state: tauri::State<'_, Arc<AppState>>) -> Result<bool, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        Ok(engine.toggle_speaker())
+    } else {
+        Err("not connected".into())
+    }
+}
+
+#[tauri::command]
+async fn get_status(state: tauri::State<'_, Arc<AppState>>) -> Result<CallStatus, String> {
+    let engine_lock = state.engine.lock().await;
+    if let Some(ref engine) = *engine_lock {
+        let status = engine.status().await;
+        Ok(CallStatus {
+            active: true,
+            mic_muted: status.mic_muted,
+            spk_muted: status.spk_muted,
+            participants: status
+                .participants
+                .into_iter()
+                .map(|p| Participant {
+                    fingerprint: p.fingerprint,
+                    alias: p.alias,
+                })
+                .collect(),
+            encode_fps: status.frames_sent,
+            recv_fps: status.frames_received,
+            audio_level: status.audio_level,
+            call_duration_secs: status.call_duration_secs,
+            fingerprint: status.fingerprint,
+        })
+    } else {
+        Ok(CallStatus {
+            active: false,
+            mic_muted: false,
+            spk_muted: false,
+            participants: vec![],
+            encode_fps: 0,
+            recv_fps: 0,
+            audio_level: 0,
+            call_duration_secs: 0.0,
+            fingerprint: String::new(),
+        })
+    }
+}
+
+fn main() {
+    tracing_subscriber::fmt().init();
+
+    let state = Arc::new(AppState {
+        engine: Mutex::new(None),
+    });
+
+    tauri::Builder::default()
+        .plugin(tauri_plugin_shell::init())
+        .manage(state)
+        .invoke_handler(tauri::generate_handler![
+            ping_relay,
+            get_identity,
+            connect,
+            disconnect,
+            toggle_mic,
+            toggle_speaker,
+            get_status,
+        ])
+        .run(tauri::generate_context!())
+        .expect("error while running WarzonePhone Desktop");
+}

desktop/src-tauri/tauri.conf.json

@@ -0,0 +1,33 @@
+{
+  "productName": "WarzonePhone",
+  "version": "0.1.0",
+  "identifier": "com.wzp.desktop",
+  "build": {
+    "frontendDist": "../dist",
+    "devUrl": "http://localhost:1420",
+    "beforeDevCommand": "npm run dev",
+    "beforeBuildCommand": "npm run build"
+  },
+  "app": {
+    "windows": [
+      {
+        "title": "WarzonePhone",
+        "width": 400,
+        "height": 640,
+        "resizable": true,
+        "minWidth": 360,
+        "minHeight": 500
+      }
+    ],
+    "security": {
+      "csp": null
+    }
+  },
+  "bundle": {
+    "active": true,
+    "targets": "all",
+    "icon": [
+      "icons/icon.png"
+    ]
+  }
+}

desktop/src/identicon.ts

@@ -0,0 +1,110 @@
+/**
+ * Deterministic identicon generator — creates a unique symmetric pattern
+ * from a hex fingerprint string, similar to MetaMask's Jazzicon / Ethereum blockies.
+ *
+ * Returns an SVG data URL that can be used as an <img> src.
+ */
+
+function hashBytes(hex: string): number[] {
+  const clean = hex.replace(/[^0-9a-fA-F]/g, "");
+  const bytes: number[] = [];
+  for (let i = 0; i < clean.length; i += 2) {
+    bytes.push(parseInt(clean.substring(i, i + 2), 16));
+  }
+  // Pad to at least 16 bytes
+  while (bytes.length < 16) bytes.push(0);
+  return bytes;
+}
+
+function hslToRgb(h: number, s: number, l: number): [number, number, number] {
+  s /= 100;
+  l /= 100;
+  const k = (n: number) => (n + h / 30) % 12;
+  const a = s * Math.min(l, 1 - l);
+  const f = (n: number) =>
+    l - a * Math.max(-1, Math.min(k(n) - 3, Math.min(9 - k(n), 1)));
+  return [
+    Math.round(f(0) * 255),
+    Math.round(f(8) * 255),
+    Math.round(f(4) * 255),
+  ];
+}
+
+export function generateIdenticon(
+  fingerprint: string,
+  size: number = 36
+): string {
+  const bytes = hashBytes(fingerprint);
+
+  // Derive colors from first bytes
+  const hue1 = (bytes[0] * 360) / 256;
+  const hue2 = ((bytes[1] * 360) / 256 + 120) % 360;
+  const [r1, g1, b1] = hslToRgb(hue1, 65, 35); // dark bg
+  const [r2, g2, b2] = hslToRgb(hue2, 70, 55); // bright fg
+
+  const bg = `rgb(${r1},${g1},${b1})`;
+  const fg = `rgb(${r2},${g2},${b2})`;
+
+  // 5x5 grid, left-right symmetric (only need 3 columns)
+  const grid: boolean[][] = [];
+  for (let y = 0; y < 5; y++) {
+    const row: boolean[] = [];
+    for (let x = 0; x < 3; x++) {
+      const byteIdx = 2 + y * 3 + x;
+      row.push(bytes[byteIdx % bytes.length] > 128);
+    }
+    // Mirror: col 3 = col 1, col 4 = col 0
+    grid.push([row[0], row[1], row[2], row[1], row[0]]);
+  }
+
+  // Render SVG
+  const cellSize = size / 5;
+  const r = size * 0.12; // border radius
+  let rects = "";
+  for (let y = 0; y < 5; y++) {
+    for (let x = 0; x < 5; x++) {
+      if (grid[y][x]) {
+        rects += `<rect x="${x * cellSize}" y="${y * cellSize}" width="${cellSize}" height="${cellSize}" fill="${fg}"/>`;
+      }
+    }
+  }
+
+  const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}" viewBox="0 0 ${size} ${size}">
+    <rect width="${size}" height="${size}" rx="${r}" fill="${bg}"/>
+    ${rects}
+  </svg>`;
+
+  return `data:image/svg+xml,${encodeURIComponent(svg)}`;
+}
+
+/**
+ * Create an <img> element with the identicon.
+ * Click copies the fingerprint to clipboard.
+ */
+export function createIdenticonEl(
+  fingerprint: string,
+  size: number = 36,
+  clickToCopy: boolean = true
+): HTMLImageElement {
+  const img = document.createElement("img");
+  img.src = generateIdenticon(fingerprint, size);
+  img.width = size;
+  img.height = size;
+  img.style.borderRadius = `${size * 0.12}px`;
+  img.style.cursor = clickToCopy ? "pointer" : "default";
+  img.title = fingerprint;
+
+  if (clickToCopy && fingerprint) {
+    img.addEventListener("click", (e) => {
+      e.stopPropagation();
+      navigator.clipboard.writeText(fingerprint).then(() => {
+        img.style.outline = "2px solid #4ade80";
+        setTimeout(() => {
+          img.style.outline = "";
+        }, 600);
+      });
+    });
+  }
+
+  return img;
+}

desktop/src/main.ts

@@ -0,0 +1,591 @@
+import { invoke } from "@tauri-apps/api/core";
+import { listen } from "@tauri-apps/api/event";
+import { generateIdenticon, createIdenticonEl } from "./identicon";
+
+// ── Elements ──
+const connectScreen = document.getElementById("connect-screen")!;
+const callScreen = document.getElementById("call-screen")!;
+const roomInput = document.getElementById("room") as HTMLInputElement;
+const aliasInput = document.getElementById("alias") as HTMLInputElement;
+const osAecCheckbox = document.getElementById("os-aec") as HTMLInputElement;
+const connectBtn = document.getElementById("connect-btn") as HTMLButtonElement;
+const connectError = document.getElementById("connect-error")!;
+const roomName = document.getElementById("room-name")!;
+const callTimer = document.getElementById("call-timer")!;
+const callStatus = document.getElementById("call-status")!;
+const levelBar = document.getElementById("level-bar")!;
+const participantsDiv = document.getElementById("participants")!;
+const micBtn = document.getElementById("mic-btn")!;
+const micIcon = document.getElementById("mic-icon")!;
+const spkBtn = document.getElementById("spk-btn")!;
+const spkIcon = document.getElementById("spk-icon")!;
+const hangupBtn = document.getElementById("hangup-btn")!;
+const statsDiv = document.getElementById("stats")!;
+const myFingerprintEl = document.getElementById("my-fingerprint")!;
+const myIdenticonEl = document.getElementById("my-identicon")!;
+const recentRoomsDiv = document.getElementById("recent-rooms")!;
+
+// Relay button
+const relaySelected = document.getElementById("relay-selected")!;
+const relayDot = document.getElementById("relay-dot")!;
+const relayLabel = document.getElementById("relay-label")!;
+
+// Relay dialog
+const relayDialog = document.getElementById("relay-dialog")!;
+const relayDialogClose = document.getElementById("relay-dialog-close")!;
+const relayDialogList = document.getElementById("relay-dialog-list")!;
+const relayAddName = document.getElementById("relay-add-name") as HTMLInputElement;
+const relayAddAddr = document.getElementById("relay-add-addr") as HTMLInputElement;
+const relayAddBtn = document.getElementById("relay-add-btn")!;
+
+// Settings
+const settingsPanel = document.getElementById("settings-panel")!;
+const settingsClose = document.getElementById("settings-close")!;
+const settingsSave = document.getElementById("settings-save")!;
+const settingsBtnHome = document.getElementById("settings-btn-home")!;
+const settingsBtnCall = document.getElementById("settings-btn-call")!;
+const sRoom = document.getElementById("s-room") as HTMLInputElement;
+const sAlias = document.getElementById("s-alias") as HTMLInputElement;
+const sOsAec = document.getElementById("s-os-aec") as HTMLInputElement;
+const sAgc = document.getElementById("s-agc") as HTMLInputElement;
+const sFingerprint = document.getElementById("s-fingerprint")!;
+const sRecentRooms = document.getElementById("s-recent-rooms")!;
+const sClearRecent = document.getElementById("s-clear-recent")!;
+
+let statusInterval: number | null = null;
+let myFingerprint = "";
+let userDisconnected = false;
+
+// ── Data types ──
+interface RelayServer {
+  name: string;
+  address: string;
+  rtt?: number | null;
+  serverFingerprint?: string | null;    // from ping
+  knownFingerprint?: string | null;     // saved TOFU fingerprint
+}
+
+interface RecentRoom { relay: string; room: string; }
+
+interface Settings {
+  relays: RelayServer[];
+  selectedRelay: number;
+  room: string;
+  alias: string;
+  osAec: boolean;
+  agc: boolean;
+  recentRooms: RecentRoom[];
+}
+
+function loadSettings(): Settings {
+  const defaults: Settings = {
+    relays: [{ name: "Default", address: "193.180.213.68:4433" }],
+    selectedRelay: 0, room: "android", alias: "",
+    osAec: true, agc: true, recentRooms: [],
+  };
+  try {
+    const raw = localStorage.getItem("wzp-settings");
+    if (raw) {
+      const parsed = JSON.parse(raw);
+      if (parsed.relay && !parsed.relays) {
+        parsed.relays = [{ name: "Default", address: parsed.relay }];
+        parsed.selectedRelay = 0;
+        delete parsed.relay;
+      }
+      if (parsed.recentRooms?.length > 0 && typeof parsed.recentRooms[0] === "string") {
+        const addr = parsed.relays?.[0]?.address || defaults.relays[0].address;
+        parsed.recentRooms = parsed.recentRooms.map((r: string) => ({ relay: addr, room: r }));
+      }
+      return { ...defaults, ...parsed };
+    }
+  } catch {}
+  return defaults;
+}
+
+function saveSettingsObj(s: Settings) {
+  localStorage.setItem("wzp-settings", JSON.stringify(s));
+}
+
+function getSelectedRelay(): RelayServer | undefined {
+  const s = loadSettings();
+  return s.relays[s.selectedRelay];
+}
+
+// ── Helpers ──
+function escapeHtml(s: string): string {
+  const d = document.createElement("div");
+  d.textContent = s;
+  return d.innerHTML;
+}
+
+// ── Lock status ──
+type LockStatus = "verified" | "new" | "changed" | "offline" | "unknown";
+
+function lockStatus(relay: RelayServer): LockStatus {
+  if (relay.rtt === undefined || relay.rtt === null) return "unknown";
+  if (relay.rtt < 0) return "offline";
+  if (!relay.serverFingerprint) return "new";
+  if (!relay.knownFingerprint) return "new"; // first time
+  if (relay.serverFingerprint === relay.knownFingerprint) return "verified";
+  return "changed";
+}
+
+function lockIcon(status: LockStatus): string {
+  switch (status) {
+    case "verified": return "🔒";
+    case "new": return "🔓";
+    case "changed": return "⚠️";
+    case "offline": return "🔴";
+    case "unknown": return "⚪";
+  }
+}
+
+function lockColor(status: LockStatus): string {
+  switch (status) {
+    case "verified": return "var(--green)";
+    case "new": return "var(--yellow)";
+    case "changed": return "var(--red)";
+    case "offline": return "var(--red)";
+    case "unknown": return "var(--text-dim)";
+  }
+}
+
+// ── Apply settings ──
+function applySettings() {
+  const s = loadSettings();
+  roomInput.value = s.room;
+  aliasInput.value = s.alias;
+  osAecCheckbox.checked = s.osAec;
+  renderRecentRooms(s.recentRooms);
+  renderRelayButton();
+}
+
+// ── Relay button ──
+function renderRelayButton() {
+  const s = loadSettings();
+  const sel = s.relays[s.selectedRelay];
+  if (sel) {
+    const ls = lockStatus(sel);
+    relayDot.textContent = lockIcon(ls);
+    relayDot.className = "relay-lock";
+    relayLabel.textContent = `${sel.name} (${sel.address})`;
+  } else {
+    relayDot.textContent = "⚪";
+    relayDot.className = "relay-lock";
+    relayLabel.textContent = "No relay configured";
+  }
+}
+
+relaySelected.addEventListener("click", () => openRelayDialog());
+
+// ── Relay dialog ──
+function openRelayDialog() {
+  renderRelayDialogList();
+  relayAddName.value = "";
+  relayAddAddr.value = "";
+  relayDialog.classList.remove("hidden");
+}
+
+function closeRelayDialog() {
+  relayDialog.classList.add("hidden");
+  renderRelayButton();
+}
+
+function renderRelayDialogList() {
+  const s = loadSettings();
+  relayDialogList.innerHTML = "";
+  s.relays.forEach((r, i) => {
+    const item = document.createElement("div");
+    item.className = `relay-dialog-item ${i === s.selectedRelay ? "selected" : ""}`;
+
+    const ls = lockStatus(r);
+    const fp = r.serverFingerprint || r.address;
+
+    // Identicon
+    const icon = createIdenticonEl(fp, 32, true);
+    icon.title = r.serverFingerprint
+      ? `Server: ${r.serverFingerprint}\nClick to copy`
+      : `No fingerprint yet`;
+    item.appendChild(icon);
+
+    // Info
+    const info = document.createElement("div");
+    info.className = "relay-info";
+    info.innerHTML = `
+      <div class="relay-name">${escapeHtml(r.name)}</div>
+      <div class="relay-addr">${escapeHtml(r.address)}</div>
+    `;
+    item.appendChild(info);
+
+    // Lock + RTT
+    const meta = document.createElement("div");
+    meta.className = "relay-meta";
+    const rttStr = r.rtt !== undefined && r.rtt !== null
+      ? (r.rtt < 0 ? "offline" : `${r.rtt}ms`)
+      : "";
+    meta.innerHTML = `
+      <span class="relay-lock-icon" style="color:${lockColor(ls)}">${lockIcon(ls)}</span>
+      <span class="relay-rtt">${rttStr}</span>
+    `;
+    item.appendChild(meta);
+
+    // Delete button
+    const del = document.createElement("button");
+    del.className = "remove";
+    del.textContent = "×";
+    del.addEventListener("click", (e) => {
+      e.stopPropagation();
+      const s = loadSettings();
+      s.relays.splice(i, 1);
+      if (s.selectedRelay >= s.relays.length) s.selectedRelay = Math.max(0, s.relays.length - 1);
+      saveSettingsObj(s);
+      renderRelayDialogList();
+      renderRelayButton();
+    });
+    item.appendChild(del);
+
+    // Click to select
+    item.addEventListener("click", () => {
+      const s = loadSettings();
+      s.selectedRelay = i;
+
+      // TOFU: if first time seeing this server, trust its fingerprint
+      if (r.serverFingerprint && !r.knownFingerprint) {
+        s.relays[i].knownFingerprint = r.serverFingerprint;
+      }
+
+      saveSettingsObj(s);
+      renderRelayDialogList();
+      renderRelayButton();
+    });
+
+    relayDialogList.appendChild(item);
+  });
+}
+
+relayAddBtn.addEventListener("click", () => {
+  const name = relayAddName.value.trim();
+  const addr = relayAddAddr.value.trim();
+  if (!addr) return;
+  const s = loadSettings();
+  s.relays.push({ name: name || addr, address: addr });
+  saveSettingsObj(s);
+  relayAddName.value = "";
+  relayAddAddr.value = "";
+  renderRelayDialogList();
+  pingAllRelays();
+});
+
+relayDialogClose.addEventListener("click", closeRelayDialog);
+relayDialog.addEventListener("click", (e) => { if (e.target === relayDialog) closeRelayDialog(); });
+
+// ── Ping ──
+interface PingResult { rtt_ms: number; server_fingerprint: string; }
+
+async function pingAllRelays() {
+  const s = loadSettings();
+  for (let i = 0; i < s.relays.length; i++) {
+    const r = s.relays[i];
+    try {
+      const result: PingResult = await invoke("ping_relay", { relay: r.address });
+      r.rtt = result.rtt_ms;
+      r.serverFingerprint = result.server_fingerprint;
+
+      // TOFU: auto-save fingerprint on first contact
+      if (!r.knownFingerprint) {
+        r.knownFingerprint = result.server_fingerprint;
+      }
+    } catch {
+      r.rtt = -1;
+    }
+  }
+  saveSettingsObj(s);
+  renderRelayButton();
+  if (!relayDialog.classList.contains("hidden")) renderRelayDialogList();
+}
+
+// ── Recent rooms ──
+function renderRecentRooms(rooms: RecentRoom[]) {
+  recentRoomsDiv.innerHTML = rooms
+    .map((r) => `<span class="recent-room" data-relay="${escapeHtml(r.relay)}" data-room="${escapeHtml(r.room)}">${escapeHtml(r.room)}</span>`)
+    .join("");
+  recentRoomsDiv.querySelectorAll(".recent-room").forEach((el) => {
+    el.addEventListener("click", () => {
+      const ds = (el as HTMLElement).dataset;
+      roomInput.value = ds.room || "";
+      const s = loadSettings();
+      const idx = s.relays.findIndex((r) => r.address === ds.relay);
+      if (idx >= 0) { s.selectedRelay = idx; saveSettingsObj(s); renderRelayButton(); }
+    });
+  });
+}
+
+// ── Init ──
+applySettings();
+setTimeout(pingAllRelays, 300);
+
+// Load fingerprint + render identicon
+(async () => {
+  try {
+    const fp: string = await invoke("get_identity");
+    myFingerprint = fp;
+    myFingerprintEl.textContent = fp;
+    myFingerprintEl.style.cursor = "pointer";
+    myFingerprintEl.addEventListener("click", () => {
+      navigator.clipboard.writeText(fp).then(() => {
+        const orig = myFingerprintEl.textContent;
+        myFingerprintEl.textContent = "Copied!";
+        setTimeout(() => { myFingerprintEl.textContent = orig; }, 1000);
+      });
+    });
+
+    // Identicon next to fingerprint
+    const icon = createIdenticonEl(fp, 28, true);
+    myIdenticonEl.innerHTML = "";
+    myIdenticonEl.appendChild(icon);
+  } catch {}
+})();
+
+// ── Connect ──
+connectBtn.addEventListener("click", doConnect);
+[roomInput, aliasInput].forEach((el) =>
+  el.addEventListener("keydown", (e) => { if (e.key === "Enter") doConnect(); })
+);
+
+async function doConnect() {
+  const relay = getSelectedRelay();
+  if (!relay) { connectError.textContent = "No relay selected"; return; }
+
+  // Warn on fingerprint mismatch
+  const ls = lockStatus(relay);
+  if (ls === "changed") {
+    if (!confirm(`Server fingerprint has changed!\n\nKnown: ${relay.knownFingerprint}\nNew: ${relay.serverFingerprint}\n\nThis could indicate a man-in-the-middle attack. Continue?`)) {
+      return;
+    }
+    // User accepted — update known fingerprint
+    const s = loadSettings();
+    s.relays[s.selectedRelay].knownFingerprint = relay.serverFingerprint;
+    saveSettingsObj(s);
+  }
+
+  // Don't block connect on offline — ping may have failed transiently
+
+  connectError.textContent = "";
+  connectBtn.disabled = true;
+  connectBtn.textContent = "Connecting...";
+  userDisconnected = false;
+
+  const s = loadSettings();
+  s.room = roomInput.value; s.alias = aliasInput.value; s.osAec = osAecCheckbox.checked;
+  const room = roomInput.value.trim();
+  if (room) {
+    const entry: RecentRoom = { relay: relay.address, room };
+    s.recentRooms = [entry, ...s.recentRooms.filter((r) => !(r.relay === relay.address && r.room === room))].slice(0, 5);
+  }
+  saveSettingsObj(s);
+
+  try {
+    await invoke("connect", {
+      relay: relay.address, room: roomInput.value,
+      alias: aliasInput.value, osAec: osAecCheckbox.checked,
+    });
+    showCallScreen();
+  } catch (e: any) {
+    connectError.textContent = String(e);
+    connectBtn.disabled = false;
+    connectBtn.textContent = "Connect";
+  }
+}
+
+function showCallScreen() {
+  connectScreen.classList.add("hidden");
+  callScreen.classList.remove("hidden");
+  roomName.textContent = roomInput.value;
+  callStatus.className = "status-dot";
+  statusInterval = window.setInterval(pollStatus, 250);
+}
+
+function showConnectScreen() {
+  callScreen.classList.add("hidden");
+  connectScreen.classList.remove("hidden");
+  connectBtn.disabled = false;
+  connectBtn.textContent = "Connect";
+  levelBar.style.width = "0%";
+  if (statusInterval) { clearInterval(statusInterval); statusInterval = null; }
+}
+
+// ── Mute / hangup ──
+micBtn.addEventListener("click", async () => {
+  try { const m: boolean = await invoke("toggle_mic"); micBtn.classList.toggle("muted", m); micIcon.textContent = m ? "Mic Off" : "Mic"; } catch {}
+});
+spkBtn.addEventListener("click", async () => {
+  try { const m: boolean = await invoke("toggle_speaker"); spkBtn.classList.toggle("muted", m); spkIcon.textContent = m ? "Spk Off" : "Spk"; } catch {}
+});
+hangupBtn.addEventListener("click", async () => {
+  userDisconnected = true;
+  try { await invoke("disconnect"); } catch {}
+  showConnectScreen();
+});
+
+document.addEventListener("keydown", (e) => {
+  if (callScreen.classList.contains("hidden")) return;
+  if ((e.target as HTMLElement).tagName === "INPUT") return;
+  if (e.key === "m") micBtn.click();
+  if (e.key === "s") spkBtn.click();
+  if (e.key === "q") hangupBtn.click();
+});
+
+// ── Status polling ──
+interface CallStatusI {
+  active: boolean; mic_muted: boolean; spk_muted: boolean;
+  participants: { fingerprint: string; alias: string | null }[];
+  encode_fps: number; recv_fps: number; audio_level: number;
+  call_duration_secs: number; fingerprint: string;
+}
+
+function formatDuration(secs: number): string {
+  const m = Math.floor(secs / 60);
+  const s = Math.floor(secs % 60);
+  return `${m}:${s.toString().padStart(2, "0")}`;
+}
+
+let reconnectAttempts = 0;
+
+async function pollStatus() {
+  try {
+    const st: CallStatusI = await invoke("get_status");
+    if (!st.active) {
+      if (!userDisconnected && reconnectAttempts < 5) {
+        reconnectAttempts++;
+        callStatus.className = "status-dot reconnecting";
+        statsDiv.textContent = `Reconnecting (${reconnectAttempts}/5)...`;
+        const relay = getSelectedRelay();
+        if (relay) {
+          const delay = Math.min(1000 * Math.pow(2, reconnectAttempts - 1), 10000);
+          setTimeout(async () => {
+            try {
+              await invoke("connect", { relay: relay.address, room: roomInput.value, alias: aliasInput.value, osAec: osAecCheckbox.checked });
+              reconnectAttempts = 0; callStatus.className = "status-dot";
+            } catch {}
+          }, delay);
+        }
+        return;
+      }
+      reconnectAttempts = 0; showConnectScreen(); return;
+    }
+
+    reconnectAttempts = 0;
+    if (st.fingerprint) myFingerprint = st.fingerprint;
+
+    micBtn.classList.toggle("muted", st.mic_muted);
+    micIcon.textContent = st.mic_muted ? "Mic Off" : "Mic";
+    spkBtn.classList.toggle("muted", st.spk_muted);
+    spkIcon.textContent = st.spk_muted ? "Spk Off" : "Spk";
+    callTimer.textContent = formatDuration(st.call_duration_secs);
+
+    const rms = st.audio_level;
+    const pct = rms > 0 ? Math.min(100, (Math.log(rms) / Math.log(32767)) * 100) : 0;
+    levelBar.style.width = `${pct}%`;
+
+    // Participants with identicons
+    if (st.participants.length === 0) {
+      participantsDiv.innerHTML = '<div class="participants-empty">Waiting for participants...</div>';
+    } else {
+      participantsDiv.innerHTML = "";
+      st.participants.forEach((p) => {
+        const name = p.alias || "Anonymous";
+        const fp = p.fingerprint || "";
+        const isMe = fp && myFingerprint.includes(fp);
+
+        const row = document.createElement("div");
+        row.className = "participant";
+
+        // Identicon avatar
+        const icon = createIdenticonEl(fp || name, 36, true);
+        if (isMe) icon.style.outline = "2px solid var(--accent)";
+        row.appendChild(icon);
+
+        const info = document.createElement("div");
+        info.className = "info";
+        info.innerHTML = `
+          <div class="name">${escapeHtml(name)} ${isMe ? '<span class="you-badge">you</span>' : ""}</div>
+          <div class="fp">${escapeHtml(fp ? fp.substring(0, 16) : "")}</div>
+        `;
+        row.appendChild(info);
+        participantsDiv.appendChild(row);
+      });
+    }
+
+    statsDiv.textContent = `TX: ${st.encode_fps} | RX: ${st.recv_fps}`;
+  } catch {}
+}
+
+listen("call-event", (event: any) => {
+  const { kind } = event.payload;
+  if (kind === "room-update") pollStatus();
+  if (kind === "disconnected" && !userDisconnected) pollStatus();
+});
+
+// ── Settings ──
+function openSettings() {
+  const s = loadSettings();
+  sRoom.value = s.room; sAlias.value = s.alias; sOsAec.checked = s.osAec;
+  sFingerprint.textContent = myFingerprint || "(loading...)";
+  renderSettingsRecentRooms(s.recentRooms);
+  settingsPanel.classList.remove("hidden");
+}
+function closeSettings() { settingsPanel.classList.add("hidden"); }
+
+function renderSettingsRecentRooms(rooms: RecentRoom[]) {
+  if (rooms.length === 0) {
+    sRecentRooms.innerHTML = '<span style="color:var(--text-dim);font-size:12px">No recent rooms</span>';
+    return;
+  }
+  sRecentRooms.innerHTML = rooms.map((r, i) => `
+    <div class="recent-room-item">
+      <span>${escapeHtml(r.room)} <small style="color:var(--text-dim)">${escapeHtml(r.relay)}</small></span>
+      <button class="remove" data-idx="${i}">×</button>
+    </div>`).join("");
+  sRecentRooms.querySelectorAll(".remove").forEach((btn) => {
+    btn.addEventListener("click", () => {
+      const idx = parseInt((btn as HTMLElement).dataset.idx || "0");
+      const s = loadSettings();
+      s.recentRooms.splice(idx, 1);
+      saveSettingsObj(s);
+      renderSettingsRecentRooms(s.recentRooms);
+    });
+  });
+}
+
+settingsBtnHome.addEventListener("click", openSettings);
+settingsBtnCall.addEventListener("click", openSettings);
+settingsClose.addEventListener("click", closeSettings);
+settingsPanel.addEventListener("click", (e) => { if (e.target === settingsPanel) closeSettings(); });
+
+settingsSave.addEventListener("click", () => {
+  const s = loadSettings();
+  s.room = sRoom.value; s.alias = sAlias.value; s.osAec = sOsAec.checked;
+  saveSettingsObj(s);
+  roomInput.value = s.room; aliasInput.value = s.alias; osAecCheckbox.checked = s.osAec;
+  renderRecentRooms(s.recentRooms);
+  closeSettings();
+});
+
+sClearRecent.addEventListener("click", () => {
+  const s = loadSettings();
+  s.recentRooms = [];
+  saveSettingsObj(s);
+  renderSettingsRecentRooms([]);
+  renderRecentRooms([]);
+});
+
+document.addEventListener("keydown", (e) => {
+  if ((e.metaKey || e.ctrlKey) && e.key === ",") {
+    e.preventDefault();
+    settingsPanel.classList.contains("hidden") ? openSettings() : closeSettings();
+  }
+  if (e.key === "Escape") {
+    if (!relayDialog.classList.contains("hidden")) closeRelayDialog();
+    else if (!settingsPanel.classList.contains("hidden")) closeSettings();
+  }
+});

desktop/src/style.css

@@ -0,0 +1,653 @@
+:root {
+  --bg: #0f0f1a;
+  --surface: #1a1a2e;
+  --surface2: #222244;
+  --primary: #0f3460;
+  --accent: #e94560;
+  --text: #eee;
+  --text-dim: #777;
+  --green: #4ade80;
+  --red: #ef4444;
+  --yellow: #facc15;
+  --radius: 12px;
+}
+
+* { margin: 0; padding: 0; box-sizing: border-box; }
+
+body {
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+  background: var(--bg);
+  color: var(--text);
+  min-height: 100vh;
+  user-select: none;
+  -webkit-user-select: none;
+}
+
+#app {
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+  padding: 20px;
+}
+
+.hidden { display: none !important; }
+
+/* ── Connect screen ── */
+#connect-screen {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  flex: 1;
+  gap: 20px;
+}
+
+#connect-screen h1 {
+  font-size: 26px;
+  font-weight: 700;
+  letter-spacing: 1px;
+}
+
+.subtitle {
+  font-size: 13px;
+  color: var(--text-dim);
+  margin-top: -12px;
+  letter-spacing: 2px;
+  text-transform: uppercase;
+}
+
+.form {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+  width: 100%;
+  max-width: 320px;
+}
+
+.form label {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  font-size: 11px;
+  color: var(--text-dim);
+  text-transform: uppercase;
+  letter-spacing: 0.5px;
+}
+
+.form input[type="text"] {
+  background: var(--surface);
+  border: 1px solid #333;
+  border-radius: 8px;
+  padding: 10px 12px;
+  color: var(--text);
+  font-size: 15px;
+  outline: none;
+  transition: border-color 0.2s;
+}
+
+.form input[type="text"]:focus {
+  border-color: var(--accent);
+}
+
+/* ── Relay button ── */
+.relay-selected {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  background: var(--surface);
+  border: 1px solid #333;
+  border-radius: 8px;
+  padding: 10px 12px;
+  color: var(--text);
+  font-size: 14px;
+  cursor: pointer;
+  text-align: left;
+  transition: border-color 0.2s;
+}
+
+.relay-selected:hover { border-color: var(--accent); }
+
+.relay-lock {
+  font-size: 14px;
+  flex-shrink: 0;
+}
+
+.relay-selected .arrow {
+  margin-left: auto;
+  font-size: 10px;
+  color: var(--text-dim);
+}
+
+.dot.green { background: var(--green); }
+.dot.yellow { background: var(--yellow); }
+.dot.red { background: var(--red); }
+.dot.gray { background: #555; }
+
+/* ── Relay dialog ── */
+#relay-dialog {
+  position: fixed;
+  inset: 0;
+  background: rgba(0,0,0,0.6);
+  backdrop-filter: blur(4px);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 200;
+  padding: 20px;
+}
+
+.relay-dialog-card {
+  max-width: 360px;
+  width: 100%;
+}
+
+.relay-dialog-list {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+  max-height: 300px;
+  overflow-y: auto;
+}
+
+.relay-dialog-item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  background: var(--surface);
+  border-radius: 8px;
+  padding: 8px 12px;
+}
+
+.relay-dialog-item .dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
+.relay-dialog-item { cursor: pointer; transition: background 0.1s; }
+.relay-dialog-item:hover { background: var(--surface2); }
+.relay-dialog-item.selected { background: var(--primary); border: 1px solid var(--accent); }
+
+.relay-dialog-item .relay-info { flex: 1; min-width: 0; overflow: hidden; }
+.relay-dialog-item .relay-name { font-size: 13px; font-weight: 500; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.relay-dialog-item .relay-addr { font-size: 11px; color: var(--text-dim); font-family: monospace; overflow: hidden; text-overflow: ellipsis; }
+.relay-dialog-item .relay-rtt { font-size: 11px; color: var(--text-dim); margin-right: 4px; }
+
+.relay-meta {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 2px;
+  flex-shrink: 0;
+}
+
+.relay-lock-icon { font-size: 16px; }
+.relay-meta .relay-rtt { font-size: 10px; color: var(--text-dim); }
+
+.relay-dialog-item .remove {
+  background: none;
+  border: none;
+  color: var(--text-dim);
+  cursor: pointer;
+  font-size: 16px;
+  padding: 0 4px;
+}
+
+.relay-dialog-item .remove:hover { color: var(--red); }
+
+.relay-add-row {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  margin-top: 12px;
+  border-top: 1px solid #333;
+  padding-top: 12px;
+}
+
+.relay-add-inputs {
+  display: flex;
+  gap: 6px;
+}
+
+.relay-add-row input {
+  background: var(--surface);
+  border: 1px solid #333;
+  border-radius: 8px;
+  padding: 8px 10px;
+  color: var(--text);
+  font-size: 13px;
+  outline: none;
+  flex: 1;
+  min-width: 0;
+}
+
+.relay-add-row input:focus { border-color: var(--accent); }
+
+.relay-add-row .primary {
+  padding: 10px;
+  font-size: 14px;
+}
+
+.form-row {
+  display: flex;
+  gap: 16px;
+  align-items: center;
+}
+
+.checkbox {
+  flex-direction: row !important;
+  align-items: center;
+  gap: 8px !important;
+  cursor: pointer;
+  font-size: 13px !important;
+}
+
+.checkbox input { width: 16px; height: 16px; }
+
+button.primary {
+  background: var(--accent);
+  color: white;
+  border: none;
+  border-radius: 8px;
+  padding: 12px;
+  font-size: 16px;
+  font-weight: 600;
+  cursor: pointer;
+  transition: opacity 0.2s;
+  margin-top: 4px;
+}
+
+button.primary:hover { opacity: 0.9; }
+button.primary:disabled { opacity: 0.5; cursor: not-allowed; }
+
+.error {
+  color: var(--red);
+  font-size: 13px;
+  min-height: 18px;
+}
+
+.identity-info {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+}
+
+.fp-display {
+  font-family: monospace;
+  font-size: 11px;
+  color: var(--text-dim);
+}
+
+.recent-rooms {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  justify-content: center;
+  max-width: 320px;
+}
+
+.recent-room {
+  background: var(--surface);
+  border: 1px solid #333;
+  border-radius: 16px;
+  padding: 4px 12px;
+  font-size: 12px;
+  color: var(--text-dim);
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.recent-room:hover {
+  border-color: var(--accent);
+  color: var(--text);
+}
+
+/* ── Call screen ── */
+#call-screen {
+  display: flex;
+  flex-direction: column;
+  flex: 1;
+  gap: 16px;
+}
+
+.call-header {
+  text-align: center;
+  padding: 8px;
+}
+
+.room-name {
+  font-size: 20px;
+  font-weight: 600;
+}
+
+.call-meta {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+  margin-top: 4px;
+}
+
+.status-dot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  background: var(--green);
+  display: inline-block;
+  animation: pulse 2s infinite;
+}
+
+@keyframes pulse {
+  0%, 100% { opacity: 1; }
+  50% { opacity: 0.4; }
+}
+
+.status-dot.reconnecting {
+  background: var(--yellow);
+  animation: blink 0.5s infinite;
+}
+
+@keyframes blink {
+  0%, 100% { opacity: 1; }
+  50% { opacity: 0.1; }
+}
+
+.call-timer {
+  font-size: 14px;
+  color: var(--text-dim);
+  font-variant-numeric: tabular-nums;
+}
+
+/* ── Audio level meter ── */
+.level-meter {
+  height: 4px;
+  background: var(--surface);
+  border-radius: 2px;
+  overflow: hidden;
+}
+
+.level-bar-fill {
+  height: 100%;
+  width: 0%;
+  background: linear-gradient(90deg, var(--green) 0%, var(--yellow) 60%, var(--red) 100%);
+  border-radius: 2px;
+  transition: width 0.1s ease-out;
+}
+
+/* ── Participants ── */
+.participants {
+  background: var(--surface);
+  border-radius: var(--radius);
+  padding: 12px 16px;
+  flex: 1;
+  overflow-y: auto;
+  min-height: 80px;
+}
+
+.participants-empty {
+  color: var(--text-dim);
+  font-size: 13px;
+  text-align: center;
+  padding: 20px 0;
+}
+
+.participant {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 8px 0;
+  border-bottom: 1px solid #ffffff08;
+}
+
+.participant:last-child { border-bottom: none; }
+
+.participant .avatar {
+  width: 36px;
+  height: 36px;
+  border-radius: 50%;
+  background: var(--primary);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 14px;
+  font-weight: 600;
+  flex-shrink: 0;
+}
+
+.participant .avatar.me {
+  background: var(--accent);
+}
+
+.participant .info { flex: 1; min-width: 0; }
+
+.participant .name {
+  font-size: 14px;
+  font-weight: 500;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.participant .fp {
+  font-size: 10px;
+  color: var(--text-dim);
+  font-family: monospace;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.participant .you-badge {
+  font-size: 10px;
+  color: var(--accent);
+  background: #e9456020;
+  padding: 1px 6px;
+  border-radius: 8px;
+}
+
+/* ── Controls ── */
+.controls {
+  display: flex;
+  justify-content: center;
+  gap: 24px;
+  padding: 12px;
+}
+
+.control-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: var(--surface2);
+  color: var(--text);
+  border: none;
+  border-radius: 50%;
+  width: 56px;
+  height: 56px;
+  cursor: pointer;
+  transition: all 0.15s;
+  font-size: 13px;
+  font-weight: 600;
+}
+
+.control-btn:hover { background: var(--primary); }
+
+.control-btn.muted {
+  background: var(--red);
+  color: white;
+}
+
+.control-btn.hangup {
+  background: var(--red);
+  color: white;
+  width: 64px;
+  height: 64px;
+  font-size: 14px;
+}
+
+.control-btn.hangup:hover { opacity: 0.85; }
+
+/* ── Stats ── */
+.stats {
+  text-align: center;
+  font-size: 10px;
+  color: var(--text-dim);
+  font-family: monospace;
+  padding: 4px;
+}
+
+/* ── Icon button ── */
+.icon-btn {
+  background: none;
+  border: 1px solid #444;
+  border-radius: 8px;
+  color: var(--text-dim);
+  font-size: 18px;
+  width: 36px;
+  height: 36px;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  transition: all 0.15s;
+}
+
+.icon-btn:hover { border-color: var(--accent); color: var(--text); }
+.icon-btn.small { width: 28px; height: 28px; font-size: 14px; }
+
+.call-header-row {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+}
+
+/* ── Settings panel ── */
+#settings-panel {
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.6);
+  backdrop-filter: blur(4px);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 100;
+  padding: 20px;
+}
+
+.settings-card {
+  background: var(--bg);
+  border: 1px solid #333;
+  border-radius: 16px;
+  padding: 24px;
+  width: 100%;
+  max-width: 380px;
+  max-height: 90vh;
+  overflow-y: auto;
+  display: flex;
+  flex-direction: column;
+  gap: 20px;
+}
+
+.settings-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+}
+
+.settings-header h2 {
+  font-size: 18px;
+  font-weight: 600;
+}
+
+.settings-section {
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+}
+
+.settings-section h3 {
+  font-size: 12px;
+  text-transform: uppercase;
+  letter-spacing: 1px;
+  color: var(--text-dim);
+  border-bottom: 1px solid #333;
+  padding-bottom: 4px;
+}
+
+.settings-section label {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  font-size: 11px;
+  color: var(--text-dim);
+  text-transform: uppercase;
+  letter-spacing: 0.5px;
+}
+
+.settings-section input[type="text"] {
+  background: var(--surface);
+  border: 1px solid #333;
+  border-radius: 8px;
+  padding: 8px 10px;
+  color: var(--text);
+  font-size: 14px;
+  outline: none;
+}
+
+.settings-section input[type="text"]:focus {
+  border-color: var(--accent);
+}
+
+.setting-row {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 4px 0;
+}
+
+.setting-label {
+  font-size: 12px;
+  color: var(--text-dim);
+}
+
+.fp-display-large {
+  font-family: monospace;
+  font-size: 12px;
+  color: var(--text);
+  word-break: break-all;
+}
+
+.recent-rooms-list {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+}
+
+.recent-room-item {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  background: var(--surface);
+  border-radius: 8px;
+  padding: 6px 10px;
+  font-size: 13px;
+}
+
+.recent-room-item .remove {
+  background: none;
+  border: none;
+  color: var(--text-dim);
+  cursor: pointer;
+  font-size: 16px;
+}
+
+.recent-room-item .remove:hover { color: var(--red); }
+
+.secondary-btn {
+  background: var(--surface);
+  border: 1px solid #444;
+  border-radius: 8px;
+  padding: 8px;
+  color: var(--text-dim);
+  font-size: 13px;
+  cursor: pointer;
+  transition: all 0.15s;
+}
+
+.secondary-btn:hover { border-color: var(--accent); color: var(--text); }

desktop/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "allowImportingTsExtensions": true,
+    "noEmit": true
+  },
+  "include": ["src"]
+}

desktop/vite.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  clearScreen: false,
+  server: {
+    port: 1420,
+    strictPort: true,
+  },
+  envPrefix: ["VITE_", "TAURI_"],
+  build: {
+    target: "esnext",
+    minify: !process.env.TAURI_DEBUG ? "esbuild" : false,
+    sourcemap: !!process.env.TAURI_DEBUG,
+  },
+});

scripts/build-linux-notify.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Build WarzonePhone Linux x86_64 binaries via Hetzner Cloud VPS.
+# Fire and forget — notifies via ntfy.sh/wzp with rustypaste URL.
+#
+# Usage:
+#   ./scripts/build-linux-notify.sh              Full: create VM → build → upload → notify → destroy
+#   ./scripts/build-linux-notify.sh --keep       Keep VM after build
+#   ./scripts/build-linux-notify.sh --pull       Git pull (for existing VM)
+
+SSH_KEY_NAME="wz"
+SSH_KEY_PATH="/Users/manwe/CascadeProjects/wzp"
+SERVER_TYPE="cx33"
+IMAGE="debian-12"
+SERVER_NAME="wzp-linux-builder"
+NTFY_TOPIC="https://ntfy.sh/wzp"
+LOCAL_OUTPUT="target/linux-x86_64"
+PROJECT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+
+SSH_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ConnectTimeout=15 -o ServerAliveInterval=15 -o LogLevel=ERROR"
+
+KEEP_VM=0
+DO_PULL=0
+for arg in "$@"; do
+    case "$arg" in
+        --keep) KEEP_VM=1 ;;
+        --pull) DO_PULL=1 ;;
+    esac
+done
+
+log() { echo -e "\033[1;36m>>> $*\033[0m"; }
+err() { echo -e "\033[1;31mERROR: $*\033[0m" >&2; }
+
+get_vm_ip() {
+    hcloud server list -o columns=name,ipv4 -o noheader 2>/dev/null | grep "$SERVER_NAME" | awk '{print $2}' | tr -d ' '
+}
+
+ssh_cmd() {
+    local ip=$(get_vm_ip)
+    [ -n "$ip" ] || { err "No VM found"; exit 1; }
+    ssh $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip" "$@"
+}
+
+notify() { curl -s -d "$1" "$NTFY_TOPIC" > /dev/null 2>&1 || true; }
+
+# --- Create VM if needed ---
+existing=$(hcloud server list -o columns=name -o noheader 2>/dev/null | grep "$SERVER_NAME" | tr -d ' ' || true)
+if [ -z "$existing" ]; then
+    log "Creating Hetzner VM ($SERVER_TYPE, $IMAGE)..."
+    hcloud server create --name "$SERVER_NAME" --type "$SERVER_TYPE" --image "$IMAGE" --ssh-key "$SSH_KEY_NAME" --location fsn1 --quiet
+
+    log "Waiting for SSH..."
+    ip=$(get_vm_ip)
+    for i in $(seq 1 30); do
+        ssh $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip" "echo ok" &>/dev/null && break
+        sleep 2
+    done
+
+    log "Installing deps..."
+    ssh_cmd "apt-get update -qq && apt-get install -y -qq build-essential cmake pkg-config libasound2-dev libssl-dev curl git > /dev/null 2>&1"
+    ssh_cmd "curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable > /dev/null 2>&1"
+fi
+
+# --- Upload source ---
+log "Uploading source..."
+ip=$(get_vm_ip)
+rsync -az --delete \
+    --exclude='target' --exclude='.git' --exclude='.claude' \
+    --exclude='node_modules' --exclude='dist' --exclude='android/app/build' \
+    -e "ssh $SSH_OPTS -i $SSH_KEY_PATH" \
+    "$PROJECT_DIR/" "root@$ip:/root/wzp-build/"
+
+# --- Build ---
+log "Building all binaries..."
+notify "WZP Linux build started..."
+
+ssh_cmd "source ~/.cargo/env && cd /root/wzp-build && \
+    cargo build --release --bin wzp-relay --bin wzp-client --bin wzp-web --bin wzp-bench 2>&1 | tail -5 && \
+    echo '--- audio client ---' && \
+    cargo build --release --bin wzp-client --features audio 2>&1 | tail -3 && \
+    cp target/release/wzp-client target/release/wzp-client-audio && \
+    cargo build --release --bin wzp-client 2>&1 | tail -3 && \
+    echo 'BUILD_DONE' && \
+    ls -lh target/release/wzp-relay target/release/wzp-client target/release/wzp-client-audio target/release/wzp-web target/release/wzp-bench"
+
+# --- Package + upload to rustypaste ---
+log "Packaging and uploading..."
+UPLOAD_URL=$(ssh_cmd "cd /root/wzp-build && \
+    tar czf /tmp/wzp-linux-x86_64.tar.gz \
+        -C target/release wzp-relay wzp-client wzp-client-audio wzp-web wzp-bench \
+        -C /root/wzp-build/crates/wzp-web/static index.html audio-processor.js 2>/dev/null && \
+    curl -s -F 'file=@/tmp/wzp-linux-x86_64.tar.gz' \
+        -H 'Authorization: DAxAAGghkn1WKv1+RpPKkg==' \
+        https://paste.dk.manko.yoga")
+
+if [ -n "$UPLOAD_URL" ]; then
+    notify "WZP Linux binaries ready! $UPLOAD_URL"
+    log "Uploaded: $UPLOAD_URL"
+else
+    notify "WZP Linux build FAILED"
+    err "Upload failed"
+fi
+
+# --- Transfer locally ---
+log "Downloading binaries..."
+mkdir -p "$LOCAL_OUTPUT"
+for bin in wzp-relay wzp-client wzp-client-audio wzp-web wzp-bench; do
+    scp $SSH_OPTS -i "$SSH_KEY_PATH" "root@$ip:/root/wzp-build/target/release/$bin" "$LOCAL_OUTPUT/$bin" 2>/dev/null
+done
+ls -lh "$LOCAL_OUTPUT"/wzp-*
+
+# --- Cleanup ---
+if [ "$KEEP_VM" = "1" ]; then
+    log "VM kept alive. Destroy: hcloud server delete $SERVER_NAME"
+else
+    log "Destroying VM..."
+    hcloud server delete "$SERVER_NAME"
+fi
+
+log "Done!"
+echo "  Deploy: scp $LOCAL_OUTPUT/wzp-relay user@server:~/wzp/"