chore: include WASM blob + JS glue in git for deployment

wasm-pack generated .gitignore was excluding all build output.
The WASM (337KB) and JS glue need to be in the repo so the
wzp-web static server can serve them without a build step.

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

Cargo.lock

@@ -3507,7 +3507,7 @@ dependencies = [
 
 [[package]]
 name = "warzone-protocol"
-version = "0.0.21"
+version = "0.0.38"
 dependencies = [
  "base64",
  "bincode",
@@ -4261,6 +4261,21 @@ dependencies = [
  "wzp-proto",
 ]
 
+[[package]]
+name = "wzp-wasm"
+version = "0.1.0"
+dependencies = [
+ "chacha20poly1305",
+ "getrandom 0.2.17",
+ "hkdf",
+ "js-sys",
+ "rand 0.8.5",
+ "raptorq",
+ "sha2",
+ "wasm-bindgen",
+ "x25519-dalek",
+]
+
 [[package]]
 name = "wzp-web"
 version = "0.1.0"

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "crates/wzp-relay",
     "crates/wzp-client",
     "crates/wzp-web",
+    "crates/wzp-wasm",
 ]
 
 [workspace.package]

README.md

@@ -0,0 +1,87 @@
+# WarzonePhone
+
+Custom lossy VoIP protocol built in Rust. E2E encrypted, FEC-protected, adaptive quality, designed for hostile network conditions.
+
+## Quick Start
+
+```bash
+# Build
+cargo build --release
+
+# Run relay
+./target/release/wzp-relay --listen 0.0.0.0:4433
+
+# Send a test tone
+./target/release/wzp-client --send-tone 5 relay-addr:4433
+
+# Web bridge (browser calls)
+./target/release/wzp-web --port 8080 --relay 127.0.0.1:4433 --tls
+# Open https://localhost:8080/room-name in two browser tabs
+```
+
+## Architecture
+
+See [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md) for the full system architecture with Mermaid diagrams covering:
+
+- System overview and data flow
+- Crate dependency graph (8 crates)
+- Wire formats (MediaHeader, MiniHeader, TrunkFrame, SignalMessage)
+- Cryptographic handshake (X25519 + Ed25519 + ChaCha20-Poly1305)
+- Identity model (BIP39 seed, featherChat compatible)
+- Quality profiles (GOOD/DEGRADED/CATASTROPHIC)
+- FEC protection (RaptorQ with interleaving)
+- Adaptive jitter buffer (NetEq-inspired)
+- Telemetry stack (Prometheus + Grafana)
+- Deployment topology
+
+## Features
+
+- **3 quality tiers**: Opus 24k (28.8 kbps) / Opus 6k (9 kbps) / Codec2 1200 (2.4 kbps)
+- **RaptorQ FEC**: Recovers from 20-100% packet loss depending on tier
+- **E2E encryption**: ChaCha20-Poly1305 with X25519 key exchange
+- **Adaptive jitter buffer**: EMA-based playout delay tracking
+- **Silence suppression**: VAD + comfort noise (~50% bandwidth savings)
+- **ML noise removal**: RNNoise (nnnoiseless pure Rust port)
+- **Mini-frames**: 67% header compression for steady-state packets
+- **Trunking**: Multiplex sessions into batched datagrams
+- **featherChat integration**: Shared BIP39 identity, token auth, call signaling
+- **Prometheus metrics**: Relay, web bridge, inter-relay probes
+- **Grafana dashboard**: Pre-built JSON with 18 panels
+
+## Documentation
+
+| Document | Description |
+|----------|-------------|
+| [ARCHITECTURE.md](docs/ARCHITECTURE.md) | Full system architecture with diagrams |
+| [TELEMETRY.md](docs/TELEMETRY.md) | Prometheus metrics specification |
+| [INTEGRATION_TASKS.md](docs/INTEGRATION_TASKS.md) | featherChat integration tracker |
+| [WZP-FC-SHARED-CRATES.md](docs/WZP-FC-SHARED-CRATES.md) | Shared crate strategy |
+| [grafana-dashboard.json](docs/grafana-dashboard.json) | Importable Grafana dashboard |
+
+## Binaries
+
+| Binary | Description |
+|--------|-------------|
+| `wzp-relay` | Relay daemon (SFU room mode, forward mode, probes) |
+| `wzp-client` | CLI client (send-tone, record, live mic, echo-test, drift-test, sweep) |
+| `wzp-web` | Browser bridge (HTTPS + WebSocket + AudioWorklet) |
+| `wzp-bench` | Component benchmarks |
+
+## Linux Build
+
+```bash
+./scripts/build-linux.sh --prepare   # Create Hetzner VM + install deps
+./scripts/build-linux.sh --build     # Build release binaries
+./scripts/build-linux.sh --transfer  # Download to target/linux-x86_64/
+./scripts/build-linux.sh --destroy   # Delete VM
+```
+
+## Tests
+
+```bash
+cargo test --workspace   # 272 tests
+```
+
+## License
+
+MIT OR Apache-2.0

crates/wzp-client/src/featherchat.rs

@@ -104,6 +104,11 @@ pub fn signal_to_call_type(signal: &SignalMessage) -> CallSignalType {
         SignalMessage::Unmute => CallSignalType::Unmute,
         SignalMessage::Transfer { .. } => CallSignalType::Transfer,
         SignalMessage::TransferAck => CallSignalType::Offer, // reuse
+        SignalMessage::PresenceUpdate { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::RouteQuery { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::RouteResponse { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::SessionForward { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::SessionForwardAck { .. } => CallSignalType::Offer, // reuse
     }
 }
 

crates/wzp-client/tests/long_session.rs

@@ -0,0 +1,190 @@
+//! WZP-P2-T1-S5: 60-second long-session regression tests.
+//!
+//! Verifies that the full codec + FEC + jitter buffer pipeline does not drift
+//! or degrade over a sustained 60-second (3000-frame) session. Runs entirely
+//! in-process with no network — packets flow directly from encoder to decoder.
+
+use wzp_client::call::{CallConfig, CallDecoder, CallEncoder};
+use wzp_proto::QualityProfile;
+
+const FRAME_SAMPLES: usize = 960; // 20ms @ 48kHz
+const SAMPLE_RATE: f32 = 48_000.0;
+const TOTAL_FRAMES: u64 = 3_000; // 60 seconds at 50 fps
+
+/// Build a CallConfig tuned for direct-loopback testing (no network).
+///
+/// Disables silence suppression and noise suppression (which would mangle
+/// or squelch the synthetic tone), uses a fixed (non-adaptive) jitter buffer
+/// with min_depth=1 so that packets are played out as soon as they arrive.
+fn test_config() -> CallConfig {
+    CallConfig {
+        profile: QualityProfile::GOOD,
+        jitter_target: 4,
+        jitter_max: 500,
+        jitter_min: 1,
+        suppression_enabled: false,
+        noise_suppression: false,
+        adaptive_jitter: false,
+        ..Default::default()
+    }
+}
+
+/// Generate a 20ms frame of 440 Hz sine tone.
+fn sine_frame(frame_offset: u64) -> 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;
+            (f32::sin(2.0 * std::f32::consts::PI * 440.0 * t) * 16000.0) as i16
+        })
+        .collect()
+}
+
+/// 60-second session with a perfect (lossless, in-order) channel.
+///
+/// Encodes 3000 frames of 440 Hz tone, feeds every packet directly into the
+/// decoder, and verifies:
+///   - frame loss < 5%  (>2850 of 3000 source frames decoded or PLC'd)
+///   - no panics
+///
+/// Note: the encoder shares a single sequence counter between source and
+/// repair packets.  Since repair packets are NOT pushed into the jitter
+/// buffer, each FEC block creates a gap in the playout sequence.  GOOD
+/// profile (5 frames/block, fec_ratio=0.2) generates 1 repair per block,
+/// so every 6th seq number is a "phantom" Missing in the jitter buffer.
+/// The jitter buffer correctly fills these gaps with PLC.  We call
+/// `decode_next` once per encode tick; the buffer stays shallow because
+/// PLC frames consume the phantom seqs at the same rate they're created.
+#[test]
+fn long_session_no_drift() {
+    let config = test_config();
+    let mut encoder = CallEncoder::new(&config);
+    let mut decoder = CallDecoder::new(&config);
+
+    let mut frames_decoded = 0u64;
+    let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+
+    for i in 0..TOTAL_FRAMES {
+        let pcm = sine_frame(i);
+        let packets = encoder.encode_frame(&pcm).expect("encode should not fail");
+
+        for pkt in packets {
+            decoder.ingest(pkt);
+        }
+
+        // Decode one frame per tick (mirrors real-time 50 fps cadence).
+        if decoder.decode_next(&mut pcm_buf).is_some() {
+            frames_decoded += 1;
+        }
+    }
+
+    let stats = decoder.stats();
+
+    println!(
+        "long_session_no_drift: decoded={frames_decoded}/{TOTAL_FRAMES}, \
+         underruns={}, overruns={}, depth={}, max_depth={}, late={}, lost={}",
+        stats.underruns, stats.overruns, stats.current_depth, stats.max_depth_seen,
+        stats.packets_late, stats.packets_lost,
+    );
+
+    // With 1 decode per tick over 3000 ticks, we expect ~3000 decoded frames
+    // (some via PLC for repair-seq gaps).  Allow up to 5% gap.
+    assert!(
+        frames_decoded > 2850,
+        "frame loss too high: decoded {frames_decoded}/3000 (need >2850 = <5% loss)"
+    );
+}
+
+/// 60-second session with simulated 5% packet loss and reordering.
+///
+/// Every 20th source packet is dropped; pairs of adjacent packets are swapped
+/// every 7 frames.  Verifies that FEC + jitter buffer recover gracefully:
+///   - frame loss < 10% (FEC should recover some of the 5% artificial loss)
+///   - no panics
+#[test]
+fn long_session_with_simulated_loss() {
+    let config = test_config();
+    let mut encoder = CallEncoder::new(&config);
+    let mut decoder = CallDecoder::new(&config);
+
+    let mut frames_decoded = 0u64;
+    let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+
+    for i in 0..TOTAL_FRAMES {
+        let pcm = sine_frame(i);
+        let packets = encoder.encode_frame(&pcm).expect("encode should not fail");
+
+        let mut batch: Vec<_> = packets.into_iter().collect();
+
+        // Simulate reordering: swap first two packets in the batch every 7 frames.
+        if i % 7 == 0 && batch.len() >= 2 {
+            batch.swap(0, 1);
+        }
+
+        for (j, pkt) in batch.into_iter().enumerate() {
+            // Drop every 20th *source* (non-repair) packet to simulate ~5% loss.
+            if !pkt.header.is_repair && i % 20 == 0 && j == 0 {
+                continue; // drop this packet
+            }
+            decoder.ingest(pkt);
+        }
+
+        if decoder.decode_next(&mut pcm_buf).is_some() {
+            frames_decoded += 1;
+        }
+    }
+
+    let stats = decoder.stats();
+
+    println!(
+        "long_session_with_simulated_loss: decoded={frames_decoded}/{TOTAL_FRAMES}, \
+         underruns={}, overruns={}, depth={}, max_depth={}, late={}, lost={}",
+        stats.underruns, stats.overruns, stats.current_depth, stats.max_depth_seen,
+        stats.packets_late, stats.packets_lost,
+    );
+
+    // With 5% artificial loss + FEC recovery + PLC, we should still get >90% decoded.
+    assert!(
+        frames_decoded > 2700,
+        "frame loss too high under simulated loss: decoded {frames_decoded}/3000 (need >2700 = <10%)"
+    );
+}
+
+/// Verify that the jitter buffer's decoded-frame count is consistent with its
+/// own internal statistics over a long session.
+#[test]
+fn long_session_stats_consistency() {
+    let config = test_config();
+    let mut encoder = CallEncoder::new(&config);
+    let mut decoder = CallDecoder::new(&config);
+
+    let mut frames_decoded = 0u64;
+    let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+
+    for i in 0..TOTAL_FRAMES {
+        let pcm = sine_frame(i);
+        let packets = encoder.encode_frame(&pcm).expect("encode");
+
+        for pkt in packets {
+            decoder.ingest(pkt);
+        }
+        if decoder.decode_next(&mut pcm_buf).is_some() {
+            frames_decoded += 1;
+        }
+    }
+
+    let stats = decoder.stats();
+
+    // total_decoded should match our manual counter.
+    assert_eq!(
+        stats.total_decoded, frames_decoded,
+        "stats.total_decoded ({}) != manually counted frames_decoded ({frames_decoded})",
+        stats.total_decoded,
+    );
+
+    // packets_received should be > 0.
+    assert!(
+        stats.packets_received > 0,
+        "stats.packets_received should be > 0"
+    );
+}

crates/wzp-proto/src/bandwidth.rs

@@ -0,0 +1,454 @@
+//! GCC-style bandwidth estimation and congestion control.
+//!
+//! Tracks available bandwidth using delay-based and loss-based signals,
+//! then adjusts the sending bitrate to avoid congestion. The estimator
+//! uses multiplicative decrease (15%) on congestion and additive increase
+//! (5%) during underuse, following the general shape of Google Congestion
+//! Control (GCC).
+
+use std::collections::VecDeque;
+use std::time::Instant;
+
+use crate::packet::QualityReport;
+use crate::QualityProfile;
+
+/// Network congestion state derived from delay and loss signals.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum CongestionState {
+    /// Network is fine, can increase bandwidth.
+    Underuse,
+    /// Normal operation.
+    Normal,
+    /// Congestion detected, should decrease bandwidth.
+    Overuse,
+}
+
+/// Detects congestion from increasing RTT using an exponential moving average.
+///
+/// Maintains a baseline RTT (minimum observed) and compares the smoothed RTT
+/// against it. If `rtt_ema > baseline * threshold_ratio`, congestion is detected.
+/// The baseline slowly drifts upward to handle route changes.
+struct DelayBasedDetector {
+    /// Baseline RTT (minimum observed).
+    baseline_rtt_ms: f64,
+    /// EMA of recent RTT.
+    rtt_ema: f64,
+    /// EMA smoothing factor.
+    alpha: f64,
+    /// Threshold: if rtt_ema > baseline * threshold_ratio, congestion detected.
+    threshold_ratio: f64,
+    /// Current state.
+    state: CongestionState,
+    /// Whether we have received any RTT sample yet.
+    initialized: bool,
+    /// Drift factor: baseline slowly increases each update to track route changes.
+    baseline_drift: f64,
+}
+
+impl DelayBasedDetector {
+    fn new() -> Self {
+        Self {
+            baseline_rtt_ms: f64::MAX,
+            rtt_ema: 0.0,
+            alpha: 0.3,
+            threshold_ratio: 1.5,
+            state: CongestionState::Normal,
+            initialized: false,
+            baseline_drift: 0.001,
+        }
+    }
+
+    /// Update the detector with a new RTT sample.
+    fn update(&mut self, rtt_ms: f64) {
+        if !self.initialized {
+            self.baseline_rtt_ms = rtt_ms;
+            self.rtt_ema = rtt_ms;
+            self.initialized = true;
+            self.state = CongestionState::Normal;
+            return;
+        }
+
+        // Track minimum RTT as baseline.
+        if rtt_ms < self.baseline_rtt_ms {
+            self.baseline_rtt_ms = rtt_ms;
+        } else {
+            // Slowly drift baseline upward to handle route changes.
+            self.baseline_rtt_ms += self.baseline_drift * (rtt_ms - self.baseline_rtt_ms);
+        }
+
+        // Update EMA.
+        self.rtt_ema = self.alpha * rtt_ms + (1.0 - self.alpha) * self.rtt_ema;
+
+        // Determine state.
+        let overuse_threshold = self.baseline_rtt_ms * self.threshold_ratio;
+        let underuse_threshold = self.baseline_rtt_ms * 1.1;
+
+        if self.rtt_ema > overuse_threshold {
+            self.state = CongestionState::Overuse;
+        } else if self.rtt_ema < underuse_threshold {
+            self.state = CongestionState::Underuse;
+        } else {
+            self.state = CongestionState::Normal;
+        }
+    }
+
+    fn state(&self) -> CongestionState {
+        self.state
+    }
+}
+
+/// Detects congestion from packet loss using a sliding window average.
+struct LossBasedDetector {
+    /// Recent loss percentages (sliding window).
+    loss_window: VecDeque<f64>,
+    /// Maximum window size.
+    window_size: usize,
+    /// Loss threshold for congestion (default 5%).
+    threshold_pct: f64,
+}
+
+impl LossBasedDetector {
+    fn new() -> Self {
+        Self {
+            loss_window: VecDeque::with_capacity(10),
+            window_size: 10,
+            threshold_pct: 5.0,
+        }
+    }
+
+    /// Add a loss percentage sample to the window.
+    fn update(&mut self, loss_pct: f64) {
+        if self.loss_window.len() >= self.window_size {
+            self.loss_window.pop_front();
+        }
+        self.loss_window.push_back(loss_pct);
+    }
+
+    /// Returns true if the average loss in the window exceeds the threshold.
+    fn is_congested(&self) -> bool {
+        if self.loss_window.is_empty() {
+            return false;
+        }
+        let avg = self.loss_window.iter().sum::<f64>() / self.loss_window.len() as f64;
+        avg > self.threshold_pct
+    }
+}
+
+// ─── BandwidthEstimator ─────────────────────────────────────────────────────
+
+/// GCC-style bandwidth estimator that tracks available bandwidth using
+/// delay-based and loss-based congestion signals.
+///
+/// # Algorithm
+///
+/// - **Overuse** (delay or loss): multiplicative decrease by 15%.
+/// - **Underuse** (delay) with no loss congestion: additive increase by 5%.
+/// - **Normal**: hold steady.
+/// - Result is always clamped to `[min_bw_kbps, max_bw_kbps]`.
+pub struct BandwidthEstimator {
+    /// Current estimated bandwidth in kbps.
+    estimated_bw_kbps: f64,
+    /// Minimum bandwidth floor (don't go below this).
+    min_bw_kbps: f64,
+    /// Maximum bandwidth ceiling.
+    max_bw_kbps: f64,
+    /// Delay-based detector state.
+    delay_detector: DelayBasedDetector,
+    /// Loss-based detector state.
+    loss_detector: LossBasedDetector,
+    /// Last update timestamp.
+    last_update: Option<Instant>,
+}
+
+/// Multiplicative decrease factor applied on congestion (15% reduction).
+const DECREASE_FACTOR: f64 = 0.85;
+/// Additive increase factor applied during underuse (5% of current estimate).
+const INCREASE_FACTOR: f64 = 0.05;
+
+impl BandwidthEstimator {
+    /// Create a new bandwidth estimator.
+    ///
+    /// - `initial_bw_kbps`: starting bandwidth estimate.
+    /// - `min`: minimum bandwidth floor in kbps.
+    /// - `max`: maximum bandwidth ceiling in kbps.
+    pub fn new(initial_bw_kbps: f64, min: f64, max: f64) -> Self {
+        Self {
+            estimated_bw_kbps: initial_bw_kbps,
+            min_bw_kbps: min,
+            max_bw_kbps: max,
+            delay_detector: DelayBasedDetector::new(),
+            loss_detector: LossBasedDetector::new(),
+            last_update: None,
+        }
+    }
+
+    /// Update the estimator with new network observations.
+    ///
+    /// Returns the new estimated bandwidth in kbps.
+    ///
+    /// - If delay overuse OR loss congested: decrease by 15% (multiplicative decrease).
+    /// - If delay underuse AND not loss congested: increase by 5% (additive increase).
+    /// - If normal: hold steady.
+    /// - Result is clamped to `[min, max]`.
+    pub fn update(&mut self, rtt_ms: f64, loss_pct: f64, _jitter_ms: f64) -> f64 {
+        self.delay_detector.update(rtt_ms);
+        self.loss_detector.update(loss_pct);
+        self.last_update = Some(Instant::now());
+
+        let delay_state = self.delay_detector.state();
+        let loss_congested = self.loss_detector.is_congested();
+
+        if delay_state == CongestionState::Overuse || loss_congested {
+            // Multiplicative decrease.
+            self.estimated_bw_kbps *= DECREASE_FACTOR;
+        } else if delay_state == CongestionState::Underuse && !loss_congested {
+            // Additive increase.
+            self.estimated_bw_kbps += self.estimated_bw_kbps * INCREASE_FACTOR;
+        }
+        // Normal: hold steady — no change.
+
+        // Clamp to [min, max].
+        self.estimated_bw_kbps = self
+            .estimated_bw_kbps
+            .clamp(self.min_bw_kbps, self.max_bw_kbps);
+
+        self.estimated_bw_kbps
+    }
+
+    /// Current estimated bandwidth in kbps.
+    pub fn estimated_kbps(&self) -> f64 {
+        self.estimated_bw_kbps
+    }
+
+    /// Current congestion state (derived from delay detector).
+    pub fn congestion_state(&self) -> CongestionState {
+        self.delay_detector.state()
+    }
+
+    /// Convenience method: update from a `QualityReport`.
+    ///
+    /// Extracts RTT, loss, and jitter from the report and feeds them into
+    /// the estimator.
+    pub fn from_quality_report(&mut self, report: &QualityReport) -> f64 {
+        let rtt_ms = report.rtt_ms() as f64;
+        let loss_pct = report.loss_percent() as f64;
+        let jitter_ms = report.jitter_ms as f64;
+        self.update(rtt_ms, loss_pct, jitter_ms)
+    }
+
+    /// Recommend a `QualityProfile` based on the current bandwidth estimate.
+    ///
+    /// - bw >= 25 kbps -> GOOD (Opus 24k + 20% FEC = ~28.8 kbps total)
+    /// - bw >= 8 kbps  -> DEGRADED (Opus 6k + 50% FEC = ~9.0 kbps)
+    /// - bw < 8 kbps   -> CATASTROPHIC (Codec2 1.2k + 100% FEC = ~2.4 kbps)
+    pub fn recommended_profile(&self) -> QualityProfile {
+        if self.estimated_bw_kbps >= 25.0 {
+            QualityProfile::GOOD
+        } else if self.estimated_bw_kbps >= 8.0 {
+            QualityProfile::DEGRADED
+        } else {
+            QualityProfile::CATASTROPHIC
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn initial_bandwidth() {
+        let bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+        assert!((bwe.estimated_kbps() - 50.0).abs() < f64::EPSILON);
+    }
+
+    #[test]
+    fn stable_network_holds_bandwidth() {
+        let mut bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+        // Feed stable, low RTT and 0% loss — after initial sample sets baseline,
+        // subsequent identical RTT should be underuse (rtt_ema < baseline * 1.1),
+        // causing slow increases. The bandwidth should stay near initial or grow slightly.
+        let initial = bwe.estimated_kbps();
+        for _ in 0..20 {
+            bwe.update(30.0, 0.0, 5.0);
+        }
+        // Should not have decreased significantly.
+        assert!(
+            bwe.estimated_kbps() >= initial,
+            "bandwidth should not decrease on stable network: got {} vs initial {}",
+            bwe.estimated_kbps(),
+            initial
+        );
+    }
+
+    #[test]
+    fn high_rtt_decreases_bandwidth() {
+        let mut bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+        // Establish a low baseline.
+        for _ in 0..5 {
+            bwe.update(20.0, 0.0, 2.0);
+        }
+        let before = bwe.estimated_kbps();
+
+        // Now feed high RTT to trigger overuse.
+        for _ in 0..10 {
+            bwe.update(200.0, 0.0, 10.0);
+        }
+        assert!(
+            bwe.estimated_kbps() < before,
+            "bandwidth should decrease on high RTT: got {} vs before {}",
+            bwe.estimated_kbps(),
+            before
+        );
+    }
+
+    #[test]
+    fn high_loss_decreases_bandwidth() {
+        let mut bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+        let before = bwe.estimated_kbps();
+
+        // Feed 10% loss repeatedly (above the 5% threshold).
+        for _ in 0..15 {
+            bwe.update(20.0, 10.0, 2.0);
+        }
+        assert!(
+            bwe.estimated_kbps() < before,
+            "bandwidth should decrease on high loss: got {} vs before {}",
+            bwe.estimated_kbps(),
+            before
+        );
+    }
+
+    #[test]
+    fn recovery_increases_bandwidth() {
+        let mut bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+
+        // Drive bandwidth down with high RTT.
+        for _ in 0..5 {
+            bwe.update(20.0, 0.0, 2.0);
+        }
+        for _ in 0..20 {
+            bwe.update(200.0, 0.0, 10.0);
+        }
+        let low_bw = bwe.estimated_kbps();
+        assert!(low_bw < 50.0, "should have decreased");
+
+        // Now feed good conditions — low RTT should be underuse, causing increase.
+        // Reset the baseline by feeding very low RTT.
+        for _ in 0..30 {
+            bwe.update(10.0, 0.0, 1.0);
+        }
+        assert!(
+            bwe.estimated_kbps() > low_bw,
+            "bandwidth should recover: got {} vs low {}",
+            bwe.estimated_kbps(),
+            low_bw
+        );
+    }
+
+    #[test]
+    fn bandwidth_clamped_to_min() {
+        let mut bwe = BandwidthEstimator::new(10.0, 5.0, 100.0);
+        // Keep feeding congestion to drive bandwidth down.
+        for _ in 0..5 {
+            bwe.update(20.0, 0.0, 2.0);
+        }
+        for _ in 0..100 {
+            bwe.update(500.0, 50.0, 100.0);
+        }
+        assert!(
+            (bwe.estimated_kbps() - 5.0).abs() < f64::EPSILON,
+            "bandwidth should be clamped to min: got {}",
+            bwe.estimated_kbps()
+        );
+    }
+
+    #[test]
+    fn bandwidth_clamped_to_max() {
+        let mut bwe = BandwidthEstimator::new(90.0, 2.0, 100.0);
+        // Keep feeding great conditions to drive bandwidth up.
+        for _ in 0..200 {
+            bwe.update(5.0, 0.0, 1.0);
+        }
+        assert!(
+            bwe.estimated_kbps() <= 100.0,
+            "bandwidth should be clamped to max: got {}",
+            bwe.estimated_kbps()
+        );
+    }
+
+    #[test]
+    fn recommended_profile_thresholds() {
+        // At boundary: >= 25 kbps => GOOD
+        let bwe_good = BandwidthEstimator::new(25.0, 2.0, 100.0);
+        assert_eq!(bwe_good.recommended_profile(), QualityProfile::GOOD);
+
+        // Just below 25 => DEGRADED
+        let bwe_degraded = BandwidthEstimator::new(24.9, 2.0, 100.0);
+        assert_eq!(bwe_degraded.recommended_profile(), QualityProfile::DEGRADED);
+
+        // At boundary: >= 8 kbps => DEGRADED
+        let bwe_degraded2 = BandwidthEstimator::new(8.0, 2.0, 100.0);
+        assert_eq!(
+            bwe_degraded2.recommended_profile(),
+            QualityProfile::DEGRADED
+        );
+
+        // Below 8 => CATASTROPHIC
+        let bwe_cat = BandwidthEstimator::new(7.9, 2.0, 100.0);
+        assert_eq!(
+            bwe_cat.recommended_profile(),
+            QualityProfile::CATASTROPHIC
+        );
+
+        // High bandwidth
+        let bwe_high = BandwidthEstimator::new(80.0, 2.0, 100.0);
+        assert_eq!(bwe_high.recommended_profile(), QualityProfile::GOOD);
+    }
+
+    #[test]
+    fn from_quality_report_integration() {
+        let mut bwe = BandwidthEstimator::new(50.0, 2.0, 100.0);
+
+        // Build a QualityReport with moderate loss and RTT.
+        let report = QualityReport {
+            loss_pct: (10.0_f32 / 100.0 * 255.0) as u8, // ~10% loss
+            rtt_4ms: 25,                                   // 100ms RTT
+            jitter_ms: 10,
+            bitrate_cap_kbps: 200,
+        };
+
+        let new_bw = bwe.from_quality_report(&report);
+        // Should return a valid bandwidth value.
+        assert!(new_bw > 0.0);
+        assert!(new_bw <= 100.0);
+        // The estimator should have been updated.
+        assert!((bwe.estimated_kbps() - new_bw).abs() < f64::EPSILON);
+    }
+
+    // ── Additional detector unit tests ──────────────────────────────────
+
+    #[test]
+    fn delay_detector_starts_normal() {
+        let det = DelayBasedDetector::new();
+        assert_eq!(det.state(), CongestionState::Normal);
+    }
+
+    #[test]
+    fn loss_detector_below_threshold() {
+        let mut det = LossBasedDetector::new();
+        for _ in 0..10 {
+            det.update(2.0); // 2% loss, well below 5% threshold
+        }
+        assert!(!det.is_congested());
+    }
+
+    #[test]
+    fn loss_detector_above_threshold() {
+        let mut det = LossBasedDetector::new();
+        for _ in 0..10 {
+            det.update(8.0); // 8% loss, above 5% threshold
+        }
+        assert!(det.is_congested());
+    }
+}

crates/wzp-proto/src/lib.rs

@@ -12,6 +12,7 @@
 //! - Identity = 32-byte seed → HKDF → Ed25519 (signing) + X25519 (encryption)
 //! - Fingerprint = SHA-256(Ed25519 pub)[:16]
 
+pub mod bandwidth;
 pub mod codec_id;
 pub mod error;
 pub mod jitter;
@@ -27,6 +28,7 @@ pub use packet::{
     HangupReason, MediaHeader, MediaPacket, MiniFrameContext, MiniHeader, QualityReport,
     SignalMessage, TrunkEntry, TrunkFrame, FRAME_TYPE_FULL, FRAME_TYPE_MINI,
 };
+pub use bandwidth::{BandwidthEstimator, CongestionState};
 pub use quality::{AdaptiveQualityController, Tier};
 pub use session::{Session, SessionEvent, SessionState};
 pub use traits::*;

crates/wzp-proto/src/packet.rs

@@ -591,6 +591,43 @@ pub enum SignalMessage {
     },
     /// Acknowledge a transfer request.
     TransferAck,
+
+    /// Presence update from a peer relay (gossip protocol).
+    /// Sent periodically over probe connections to share which fingerprints
+    /// are connected to the sending relay.
+    PresenceUpdate {
+        /// Fingerprints currently connected to the sending relay.
+        fingerprints: Vec<String>,
+        /// Address of the sending relay (e.g., "192.168.1.10:4433").
+        relay_addr: String,
+    },
+
+    /// Ask a peer relay to look up a fingerprint in its registry.
+    RouteQuery {
+        fingerprint: String,
+        ttl: u8,
+    },
+    /// Response to a route query.
+    RouteResponse {
+        fingerprint: String,
+        found: bool,
+        relay_chain: Vec<String>,
+    },
+
+    /// Request to set up a forwarding session for a specific fingerprint.
+    /// Sent over a relay link (`_relay` SNI) to ask the peer relay to
+    /// create a room and forward media for the given session.
+    SessionForward {
+        session_id: String,
+        target_fingerprint: String,
+        source_relay: String,
+    },
+    /// Confirm that the forwarding session has been set up on the peer relay.
+    /// The `room_name` tells the source relay which room to address media to.
+    SessionForwardAck {
+        session_id: String,
+        room_name: String,
+    },
 }
 
 /// Reasons for ending a call.
@@ -776,6 +813,40 @@ mod tests {
         assert!(matches!(decoded, SignalMessage::TransferAck));
     }
 
+    #[test]
+    fn presence_update_signal_roundtrip() {
+        let msg = SignalMessage::PresenceUpdate {
+            fingerprints: vec!["aabb".to_string(), "ccdd".to_string()],
+            relay_addr: "10.0.0.1:4433".to_string(),
+        };
+        let json = serde_json::to_string(&msg).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        match decoded {
+            SignalMessage::PresenceUpdate { fingerprints, relay_addr } => {
+                assert_eq!(fingerprints.len(), 2);
+                assert!(fingerprints.contains(&"aabb".to_string()));
+                assert!(fingerprints.contains(&"ccdd".to_string()));
+                assert_eq!(relay_addr, "10.0.0.1:4433");
+            }
+            _ => panic!("expected PresenceUpdate variant"),
+        }
+
+        // Empty fingerprints list
+        let msg_empty = SignalMessage::PresenceUpdate {
+            fingerprints: vec![],
+            relay_addr: "10.0.0.2:4433".to_string(),
+        };
+        let json = serde_json::to_string(&msg_empty).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        match decoded {
+            SignalMessage::PresenceUpdate { fingerprints, relay_addr } => {
+                assert!(fingerprints.is_empty());
+                assert_eq!(relay_addr, "10.0.0.2:4433");
+            }
+            _ => panic!("expected PresenceUpdate variant"),
+        }
+    }
+
     #[test]
     fn fec_ratio_encode_decode() {
         let ratio = 0.5;

crates/wzp-relay/src/lib.rs

@@ -12,8 +12,11 @@ pub mod config;
 pub mod handshake;
 pub mod metrics;
 pub mod pipeline;
+pub mod presence;
 pub mod probe;
+pub mod relay_link;
 pub mod room;
+pub mod route;
 pub mod session_mgr;
 pub mod trunk;
 

crates/wzp-relay/src/main.rs

@@ -19,6 +19,7 @@ use wzp_proto::MediaTransport;
 use wzp_relay::config::RelayConfig;
 use wzp_relay::metrics::RelayMetrics;
 use wzp_relay::pipeline::{PipelineConfig, RelayPipeline};
+use wzp_relay::presence::PresenceRegistry;
 use wzp_relay::room::{self, RoomManager};
 use wzp_relay::session_mgr::SessionManager;
 
@@ -176,11 +177,19 @@ async fn main() -> anyhow::Result<()> {
         .install_default()
         .expect("failed to install rustls crypto provider");
 
+    // Presence registry
+    let presence = Arc::new(Mutex::new(PresenceRegistry::new()));
+
+    // Route resolver
+    let route_resolver = Arc::new(wzp_relay::route::RouteResolver::new(config.listen_addr));
+
     // Prometheus metrics
     let metrics = Arc::new(RelayMetrics::new());
     if let Some(port) = config.metrics_port {
         let m = metrics.clone();
-        tokio::spawn(wzp_relay::metrics::serve_metrics(port, m));
+        let p = Some(presence.clone());
+        let rr = Some(route_resolver.clone());
+        tokio::spawn(wzp_relay::metrics::serve_metrics(port, m, p, rr));
     }
 
     // Generate ephemeral relay identity for crypto handshake
@@ -214,6 +223,7 @@ async fn main() -> anyhow::Result<()> {
         let mesh = wzp_relay::probe::ProbeMesh::new(
             config.probe_targets.clone(),
             metrics.registry(),
+            Some(presence.clone()),
         );
         info!(
             targets = mesh.target_count(),
@@ -244,6 +254,8 @@ async fn main() -> anyhow::Result<()> {
         let relay_seed_bytes = relay_seed.0;
         let metrics = metrics.clone();
         let trunking_enabled = config.trunking_enabled;
+        let presence = presence.clone();
+        let route_resolver = route_resolver.clone();
 
         tokio::spawn(async move {
             let addr = connection.remote_address();
@@ -259,9 +271,9 @@ async fn main() -> anyhow::Result<()> {
             let transport = Arc::new(wzp_transport::QuinnTransport::new(connection));
 
             // Probe connections use SNI "_probe" to identify themselves.
-            // They skip auth + handshake and just do Ping->Pong.
+            // They skip auth + handshake and just do Ping->Pong + presence gossip.
             if room_name == "_probe" {
-                info!(%addr, "probe connection detected, entering Ping/Pong responder");
+                info!(%addr, "probe connection detected, entering Ping/Pong + presence responder");
                 loop {
                     match transport.recv_signal().await {
                         Ok(Some(wzp_proto::SignalMessage::Ping { timestamp_ms })) => {
@@ -272,8 +284,63 @@ async fn main() -> anyhow::Result<()> {
                                 break;
                             }
                         }
+                        Ok(Some(wzp_proto::SignalMessage::PresenceUpdate { fingerprints, relay_addr })) => {
+                            // A peer relay is telling us which fingerprints it has
+                            let peer_addr: std::net::SocketAddr = relay_addr.parse().unwrap_or(addr);
+                            let fps: std::collections::HashSet<String> = fingerprints.into_iter().collect();
+                            {
+                                let mut reg = presence.lock().await;
+                                reg.update_peer(peer_addr, fps);
+                            }
+                            // Reply with our own local fingerprints
+                            let local_fps: Vec<String> = {
+                                let reg = presence.lock().await;
+                                reg.local_fingerprints().into_iter().collect()
+                            };
+                            let reply = wzp_proto::SignalMessage::PresenceUpdate {
+                                fingerprints: local_fps,
+                                relay_addr: addr.to_string(),
+                            };
+                            if let Err(e) = transport.send_signal(&reply).await {
+                                error!(%addr, "presence reply send error: {e}");
+                                break;
+                            }
+                        }
+                        Ok(Some(wzp_proto::SignalMessage::RouteQuery { fingerprint, ttl })) => {
+                            // Look up the fingerprint in our local registry
+                            let reg = presence.lock().await;
+                            let route = route_resolver.resolve(&reg, &fingerprint);
+                            drop(reg);
+
+                            let (found, relay_chain) = match route {
+                                wzp_relay::route::Route::Local => {
+                                    (true, vec![route_resolver.local_addr().to_string()])
+                                }
+                                wzp_relay::route::Route::DirectPeer(peer_addr) => {
+                                    (true, vec![route_resolver.local_addr().to_string(), peer_addr.to_string()])
+                                }
+                                _ => {
+                                    // Not found locally; if ttl > 0 we could forward
+                                    // to other peers (future multi-hop). For now, reply not found.
+                                    if ttl > 0 {
+                                        // TODO: forward RouteQuery to other peers with ttl-1
+                                    }
+                                    (false, vec![])
+                                }
+                            };
+
+                            let reply = wzp_proto::SignalMessage::RouteResponse {
+                                fingerprint,
+                                found,
+                                relay_chain,
+                            };
+                            if let Err(e) = transport.send_signal(&reply).await {
+                                error!(%addr, "route response send error: {e}");
+                                break;
+                            }
+                        }
                         Ok(Some(_)) => {
-                            // Ignore non-Ping signals on probe connections
+                            // Ignore other signals on probe connections
                         }
                         Ok(None) => {
                             info!(%addr, "probe connection closed");
@@ -352,6 +419,12 @@ async fn main() -> anyhow::Result<()> {
                 }
             };
 
+            // Register in presence registry
+            if let Some(ref fp) = authenticated_fp {
+                let mut reg = presence.lock().await;
+                reg.register_local(fp, None, Some(room_name.clone()));
+            }
+
             info!(%addr, room = %room_name, "client joining");
 
             if let Some(remote) = remote_transport {
@@ -431,7 +504,11 @@ async fn main() -> anyhow::Result<()> {
                     trunking_enabled,
                 ).await;
 
-                // Participant disconnected — clean up per-session metrics
+                // Participant disconnected — clean up presence + per-session metrics
+                if let Some(ref fp) = authenticated_fp {
+                    let mut reg = presence.lock().await;
+                    reg.unregister_local(fp);
+                }
                 metrics.remove_session_metrics(&session_id_str);
                 metrics.active_sessions.dec();
                 {

crates/wzp-relay/src/metrics.rs

@@ -201,11 +201,21 @@ impl RelayMetrics {
     }
 }
 
-/// Start an HTTP server serving GET /metrics and GET /mesh on the given port.
+/// Start an HTTP server serving GET /metrics, GET /mesh, presence, and route endpoints on the given port.
-pub async fn serve_metrics(port: u16, metrics: Arc<RelayMetrics>) {
+pub async fn serve_metrics(
-    use axum::{routing::get, Router};
+    port: u16,
+    metrics: Arc<RelayMetrics>,
+    presence: Option<Arc<tokio::sync::Mutex<crate::presence::PresenceRegistry>>>,
+    route_resolver: Option<Arc<crate::route::RouteResolver>>,
+) {
+    use axum::{extract::Path, routing::get, Router};
 
     let metrics_clone = metrics.clone();
+    let presence_all = presence.clone();
+    let presence_lookup = presence.clone();
+    let presence_peers = presence.clone();
+    let presence_route = presence;
+
     let app = Router::new()
         .route(
             "/metrics",
@@ -220,6 +230,92 @@ pub async fn serve_metrics(port: u16, metrics: Arc<RelayMetrics>) {
                 let m = metrics_clone.clone();
                 async move { crate::probe::mesh_summary(m.registry()) }
             }),
+        )
+        .route(
+            "/presence",
+            get(move || {
+                let reg = presence_all.clone();
+                async move {
+                    match reg {
+                        Some(r) => {
+                            let r = r.lock().await;
+                            let entries: Vec<serde_json::Value> = r.all_known().into_iter().map(|(fp, loc)| {
+                                serde_json::json!({ "fingerprint": fp, "location": loc })
+                            }).collect();
+                            serde_json::to_string_pretty(&entries).unwrap_or_else(|_| "[]".to_string())
+                        }
+                        None => "[]".to_string(),
+                    }
+                }
+            }),
+        )
+        .route(
+            "/presence/:fingerprint",
+            get(move |Path(fingerprint): Path<String>| {
+                let reg = presence_lookup.clone();
+                async move {
+                    match reg {
+                        Some(r) => {
+                            let r = r.lock().await;
+                            match r.lookup(&fingerprint) {
+                                Some(loc) => serde_json::to_string_pretty(
+                                    &serde_json::json!({ "fingerprint": fingerprint, "location": loc })
+                                ).unwrap_or_else(|_| "{}".to_string()),
+                                None => serde_json::json!({ "fingerprint": fingerprint, "location": null }).to_string(),
+                            }
+                        }
+                        None => serde_json::json!({ "fingerprint": fingerprint, "location": null }).to_string(),
+                    }
+                }
+            }),
+        )
+        .route(
+            "/peers",
+            get(move || {
+                let reg = presence_peers.clone();
+                async move {
+                    match reg {
+                        Some(r) => {
+                            let r = r.lock().await;
+                            let peers: Vec<serde_json::Value> = r.peers().iter().map(|(addr, peer)| {
+                                serde_json::json!({
+                                    "addr": addr.to_string(),
+                                    "fingerprints": peer.fingerprints.iter().collect::<Vec<_>>(),
+                                    "rtt_ms": peer.rtt_ms,
+                                })
+                            }).collect();
+                            serde_json::to_string_pretty(&peers).unwrap_or_else(|_| "[]".to_string())
+                        }
+                        None => "[]".to_string(),
+                    }
+                }
+            }),
+        )
+        .route(
+            "/route/:fingerprint",
+            get(move |Path(fingerprint): Path<String>| {
+                let reg = presence_route.clone();
+                let resolver = route_resolver.clone();
+                async move {
+                    match (reg, resolver) {
+                        (Some(r), Some(res)) => {
+                            let r = r.lock().await;
+                            let route = res.resolve(&r, &fingerprint);
+                            let json = res.route_json(&fingerprint, &route);
+                            serde_json::to_string_pretty(&json)
+                                .unwrap_or_else(|_| "{}".to_string())
+                        }
+                        _ => {
+                            serde_json::json!({
+                                "fingerprint": fingerprint,
+                                "route": "not_found",
+                                "relay_chain": [],
+                            })
+                            .to_string()
+                        }
+                    }
+                }
+            }),
         );
 
     let addr = std::net::SocketAddr::from(([0, 0, 0, 0], port));

crates/wzp-relay/src/presence.rs

@@ -0,0 +1,333 @@
+//! Presence registry — tracks which fingerprints are connected to this relay
+//! and to peer relays (via gossip over probe connections).
+//!
+//! This enables route resolution: given a fingerprint, determine whether the
+//! user is local, on a known peer relay, or unknown.
+
+use std::collections::{HashMap, HashSet};
+use std::net::SocketAddr;
+use std::time::{Duration, Instant};
+
+use serde::Serialize;
+
+// ---------------------------------------------------------------------------
+// Data structures
+// ---------------------------------------------------------------------------
+
+/// Where a fingerprint is connected.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
+pub enum PresenceLocation {
+    /// Connected directly to this relay.
+    Local,
+    /// Connected to a peer relay at the given address.
+    Remote(SocketAddr),
+}
+
+/// Presence entry for a fingerprint connected directly to this relay.
+#[derive(Clone, Debug)]
+pub struct LocalPresence {
+    pub fingerprint: String,
+    pub alias: Option<String>,
+    pub connected_at: Instant,
+    pub room: Option<String>,
+}
+
+/// Presence entry for a fingerprint reported by a peer relay.
+#[derive(Clone, Debug)]
+pub struct RemotePresence {
+    pub fingerprint: String,
+    pub relay_addr: SocketAddr,
+    pub last_seen: Instant,
+}
+
+/// Known peer relay and its reported fingerprints.
+#[derive(Clone, Debug)]
+pub struct PeerRelay {
+    pub addr: SocketAddr,
+    pub fingerprints: HashSet<String>,
+    pub last_update: Instant,
+    pub rtt_ms: Option<f64>,
+}
+
+// ---------------------------------------------------------------------------
+// Registry
+// ---------------------------------------------------------------------------
+
+/// Central presence registry tracking local and remote fingerprints.
+pub struct PresenceRegistry {
+    /// Fingerprints connected directly to THIS relay.
+    local: HashMap<String, LocalPresence>,
+    /// Fingerprints reported by peer relays (via gossip).
+    remote: HashMap<String, RemotePresence>,
+    /// Known peer relays and their status.
+    peers: HashMap<SocketAddr, PeerRelay>,
+}
+
+impl PresenceRegistry {
+    /// Create an empty registry.
+    pub fn new() -> Self {
+        Self {
+            local: HashMap::new(),
+            remote: HashMap::new(),
+            peers: HashMap::new(),
+        }
+    }
+
+    /// Register a fingerprint as locally connected (called after auth + handshake).
+    pub fn register_local(&mut self, fingerprint: &str, alias: Option<String>, room: Option<String>) {
+        self.local.insert(fingerprint.to_string(), LocalPresence {
+            fingerprint: fingerprint.to_string(),
+            alias,
+            connected_at: Instant::now(),
+            room,
+        });
+    }
+
+    /// Unregister a locally connected fingerprint (called on disconnect).
+    pub fn unregister_local(&mut self, fingerprint: &str) {
+        self.local.remove(fingerprint);
+    }
+
+    /// Update the fingerprints reported by a peer relay.
+    /// Replaces the previous set for that peer.
+    pub fn update_peer(&mut self, addr: SocketAddr, fingerprints: HashSet<String>) {
+        let now = Instant::now();
+
+        // Remove old remote entries that belonged to this peer
+        self.remote.retain(|_, rp| rp.relay_addr != addr);
+
+        // Insert new remote entries
+        for fp in &fingerprints {
+            self.remote.insert(fp.clone(), RemotePresence {
+                fingerprint: fp.clone(),
+                relay_addr: addr,
+                last_seen: now,
+            });
+        }
+
+        // Update the peer record
+        let peer = self.peers.entry(addr).or_insert_with(|| PeerRelay {
+            addr,
+            fingerprints: HashSet::new(),
+            last_update: now,
+            rtt_ms: None,
+        });
+        peer.fingerprints = fingerprints;
+        peer.last_update = now;
+    }
+
+    /// Look up where a fingerprint is connected.
+    /// Local presence takes priority over remote.
+    pub fn lookup(&self, fingerprint: &str) -> Option<PresenceLocation> {
+        if self.local.contains_key(fingerprint) {
+            return Some(PresenceLocation::Local);
+        }
+        if let Some(rp) = self.remote.get(fingerprint) {
+            return Some(PresenceLocation::Remote(rp.relay_addr));
+        }
+        None
+    }
+
+    /// Return all fingerprints connected directly to this relay.
+    pub fn local_fingerprints(&self) -> HashSet<String> {
+        self.local.keys().cloned().collect()
+    }
+
+    /// Return a full dump of every known fingerprint and its location.
+    pub fn all_known(&self) -> Vec<(String, PresenceLocation)> {
+        let mut out = Vec::new();
+        for fp in self.local.keys() {
+            out.push((fp.clone(), PresenceLocation::Local));
+        }
+        for (fp, rp) in &self.remote {
+            // Skip if also local (local wins)
+            if !self.local.contains_key(fp) {
+                out.push((fp.clone(), PresenceLocation::Remote(rp.relay_addr)));
+            }
+        }
+        out
+    }
+
+    /// Remove remote entries older than `timeout`.
+    pub fn expire_stale(&mut self, timeout: Duration) {
+        let cutoff = Instant::now() - timeout;
+
+        // Expire remote presence entries
+        self.remote.retain(|_, rp| rp.last_seen > cutoff);
+
+        // Expire peer relay records and their fingerprint sets
+        let stale_peers: Vec<SocketAddr> = self.peers
+            .iter()
+            .filter(|(_, p)| p.last_update <= cutoff)
+            .map(|(addr, _)| *addr)
+            .collect();
+
+        for addr in stale_peers {
+            self.peers.remove(&addr);
+        }
+    }
+
+    /// Return a reference to the peer relay map (for HTTP API).
+    pub fn peers(&self) -> &HashMap<SocketAddr, PeerRelay> {
+        &self.peers
+    }
+
+    /// Return a reference to the local presence map (for HTTP API).
+    pub fn local_entries(&self) -> &HashMap<String, LocalPresence> {
+        &self.local
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::net::SocketAddr;
+
+    fn addr(s: &str) -> SocketAddr {
+        s.parse().unwrap()
+    }
+
+    #[test]
+    fn register_and_lookup_local() {
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("aabbccdd", Some("alice".into()), Some("room1".into()));
+
+        assert_eq!(reg.lookup("aabbccdd"), Some(PresenceLocation::Local));
+        // Unknown fingerprint returns None
+        assert_eq!(reg.lookup("00000000"), None);
+    }
+
+    #[test]
+    fn unregister_removes() {
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("aabbccdd", None, None);
+        assert_eq!(reg.lookup("aabbccdd"), Some(PresenceLocation::Local));
+
+        reg.unregister_local("aabbccdd");
+        assert_eq!(reg.lookup("aabbccdd"), None);
+    }
+
+    #[test]
+    fn update_peer_and_lookup() {
+        let mut reg = PresenceRegistry::new();
+        let peer = addr("10.0.0.2:4433");
+        let mut fps = HashSet::new();
+        fps.insert("deadbeef".to_string());
+        fps.insert("cafebabe".to_string());
+
+        reg.update_peer(peer, fps);
+
+        assert_eq!(reg.lookup("deadbeef"), Some(PresenceLocation::Remote(peer)));
+        assert_eq!(reg.lookup("cafebabe"), Some(PresenceLocation::Remote(peer)));
+        assert_eq!(reg.lookup("unknown"), None);
+    }
+
+    #[test]
+    fn expire_stale_removes_old() {
+        let mut reg = PresenceRegistry::new();
+        let peer = addr("10.0.0.3:4433");
+
+        let mut fps = HashSet::new();
+        fps.insert("olduser".to_string());
+        reg.update_peer(peer, fps);
+
+        // Verify it's there
+        assert_eq!(reg.lookup("olduser"), Some(PresenceLocation::Remote(peer)));
+
+        // Manually backdate the last_seen and last_update
+        if let Some(rp) = reg.remote.get_mut("olduser") {
+            rp.last_seen = Instant::now() - Duration::from_secs(120);
+        }
+        if let Some(p) = reg.peers.get_mut(&peer) {
+            p.last_update = Instant::now() - Duration::from_secs(120);
+        }
+
+        // Expire with 60s timeout — should remove the 120s-old entries
+        reg.expire_stale(Duration::from_secs(60));
+
+        assert_eq!(reg.lookup("olduser"), None);
+        assert!(reg.peers.get(&peer).is_none());
+    }
+
+    #[test]
+    fn local_fingerprints_list() {
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("fp1", None, None);
+        reg.register_local("fp2", Some("bob".into()), Some("room-a".into()));
+        reg.register_local("fp3", None, None);
+
+        let fps = reg.local_fingerprints();
+        assert_eq!(fps.len(), 3);
+        assert!(fps.contains("fp1"));
+        assert!(fps.contains("fp2"));
+        assert!(fps.contains("fp3"));
+    }
+
+    #[test]
+    fn all_known_includes_local_and_remote() {
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("local1", None, None);
+
+        let peer = addr("10.0.0.5:4433");
+        let mut fps = HashSet::new();
+        fps.insert("remote1".to_string());
+        reg.update_peer(peer, fps);
+
+        let all = reg.all_known();
+        assert_eq!(all.len(), 2);
+
+        let local_entries: Vec<_> = all.iter()
+            .filter(|(_, loc)| *loc == PresenceLocation::Local)
+            .collect();
+        assert_eq!(local_entries.len(), 1);
+        assert_eq!(local_entries[0].0, "local1");
+
+        let remote_entries: Vec<_> = all.iter()
+            .filter(|(_, loc)| matches!(loc, PresenceLocation::Remote(_)))
+            .collect();
+        assert_eq!(remote_entries.len(), 1);
+        assert_eq!(remote_entries[0].0, "remote1");
+    }
+
+    #[test]
+    fn local_overrides_remote_in_lookup() {
+        let mut reg = PresenceRegistry::new();
+        let peer = addr("10.0.0.6:4433");
+
+        // Register as remote first
+        let mut fps = HashSet::new();
+        fps.insert("dupfp".to_string());
+        reg.update_peer(peer, fps);
+        assert_eq!(reg.lookup("dupfp"), Some(PresenceLocation::Remote(peer)));
+
+        // Now register locally — local should win
+        reg.register_local("dupfp", None, None);
+        assert_eq!(reg.lookup("dupfp"), Some(PresenceLocation::Local));
+    }
+
+    #[test]
+    fn update_peer_replaces_old_fingerprints() {
+        let mut reg = PresenceRegistry::new();
+        let peer = addr("10.0.0.7:4433");
+
+        let mut fps1 = HashSet::new();
+        fps1.insert("user_a".to_string());
+        fps1.insert("user_b".to_string());
+        reg.update_peer(peer, fps1);
+
+        assert_eq!(reg.lookup("user_a"), Some(PresenceLocation::Remote(peer)));
+        assert_eq!(reg.lookup("user_b"), Some(PresenceLocation::Remote(peer)));
+
+        // Update with only user_b — user_a should be gone
+        let mut fps2 = HashSet::new();
+        fps2.insert("user_b".to_string());
+        reg.update_peer(peer, fps2);
+
+        assert_eq!(reg.lookup("user_a"), None);
+        assert_eq!(reg.lookup("user_b"), Some(PresenceLocation::Remote(peer)));
+    }
+}

crates/wzp-relay/src/probe.rs

@@ -156,14 +156,19 @@ impl SlidingWindow {
 pub struct ProbeRunner {
     config: ProbeConfig,
     metrics: ProbeMetrics,
+    presence: Option<Arc<tokio::sync::Mutex<crate::presence::PresenceRegistry>>>,
 }
 
 impl ProbeRunner {
     /// Create a new probe runner, registering metrics with the given registry.
-    pub fn new(config: ProbeConfig, registry: &Registry) -> Self {
+    pub fn new(
+        config: ProbeConfig,
+        registry: &Registry,
+        presence: Option<Arc<tokio::sync::Mutex<crate::presence::PresenceRegistry>>>,
+    ) -> Self {
         let target_str = config.target.to_string();
         let metrics = ProbeMetrics::register(&target_str, registry);
-        Self { config, metrics }
+        Self { config, metrics, presence }
     }
 
     /// Run the probe forever. This function never returns under normal operation.
@@ -215,6 +220,8 @@ impl ProbeRunner {
         let jitter_gauge = self.metrics.jitter_ms.clone();
         let up_gauge = self.metrics.up.clone();
 
+        let recv_presence = self.presence.clone();
+        let recv_target = self.config.target;
         let recv_handle = tokio::spawn(async move {
             loop {
                 match recv_transport.recv_signal().await {
@@ -230,8 +237,17 @@ impl ProbeRunner {
                         loss_gauge.set(w.loss_pct());
                         jitter_gauge.set(w.jitter_ms());
                     }
+                    Ok(Some(SignalMessage::PresenceUpdate { fingerprints, relay_addr })) => {
+                        if let Some(ref reg) = recv_presence {
+                            // Parse the relay_addr; fall back to the connection target
+                            let addr = relay_addr.parse().unwrap_or(recv_target);
+                            let fps: std::collections::HashSet<String> = fingerprints.into_iter().collect();
+                            let mut r = reg.lock().await;
+                            r.update_peer(addr, fps);
+                        }
+                    }
                     Ok(Some(_)) => {
-                        // Ignore non-Pong signals
+                        // Ignore other signals
                     }
                     Ok(None) => {
                         info!("probe recv: connection closed");
@@ -247,8 +263,9 @@ impl ProbeRunner {
             }
         });
 
-        // Send ping loop
+        // Send ping loop (+ presence gossip every 10 pings)
         let mut interval = tokio::time::interval(self.config.interval);
+        let mut ping_count: u64 = 0;
         loop {
             interval.tick().await;
 
@@ -275,6 +292,24 @@ impl ProbeRunner {
                 recv_handle.abort();
                 return Err(e.into());
             }
+
+            // Send presence update every 10 pings (~10 seconds)
+            ping_count += 1;
+            if ping_count % 10 == 0 {
+                if let Some(ref reg) = self.presence {
+                    let fps: Vec<String> = {
+                        let r = reg.lock().await;
+                        r.local_fingerprints().into_iter().collect()
+                    };
+                    let msg = SignalMessage::PresenceUpdate {
+                        fingerprints: fps,
+                        relay_addr: self.config.target.to_string(),
+                    };
+                    if let Err(e) = transport.send_signal(&msg).await {
+                        warn!(target = %self.config.target, "presence update send error: {e}");
+                    }
+                }
+            }
         }
     }
 }
@@ -289,12 +324,16 @@ pub struct ProbeMesh {
 
 impl ProbeMesh {
     /// Create a new mesh coordinator, registering metrics for every target.
-    pub fn new(targets: Vec<SocketAddr>, registry: &Registry) -> Self {
+    pub fn new(
+        targets: Vec<SocketAddr>,
+        registry: &Registry,
+        presence: Option<Arc<tokio::sync::Mutex<crate::presence::PresenceRegistry>>>,
+    ) -> Self {
         let runners = targets
             .into_iter()
             .map(|addr| {
                 let config = ProbeConfig::new(addr);
-                ProbeRunner::new(config, registry)
+                ProbeRunner::new(config, registry, presence.clone())
             })
             .collect();
         Self { runners }
@@ -409,6 +448,7 @@ mod tests {
     fn probe_metrics_register() {
         let registry = Registry::new();
         let _metrics = ProbeMetrics::register("127.0.0.1:4433", &registry);
+        // (ProbeRunner::new signature changed but this test only checks ProbeMetrics)
 
         let encoder = prometheus::TextEncoder::new();
         let families = registry.gather();
@@ -526,7 +566,7 @@ mod tests {
             "127.0.0.2:4433".parse().unwrap(),
             "127.0.0.3:4433".parse().unwrap(),
         ];
-        let mesh = ProbeMesh::new(targets, &registry);
+        let mesh = ProbeMesh::new(targets, &registry, None);
         assert_eq!(mesh.target_count(), 3);
 
         // Verify metrics were registered for each target
@@ -586,7 +626,7 @@ mod tests {
     #[test]
     fn mesh_zero_targets() {
         let registry = Registry::new();
-        let mesh = ProbeMesh::new(vec![], &registry);
+        let mesh = ProbeMesh::new(vec![], &registry, None);
         assert_eq!(mesh.target_count(), 0);
     }
 }

crates/wzp-relay/src/relay_link.rs

@@ -0,0 +1,483 @@
+//! Per-session relay forwarding — connect to a peer relay and forward only
+//! specific sessions' media packets there.
+//!
+//! This is the building block for relay chaining (multi-hop calls). Instead
+//! of forwarding ALL traffic to a single hardcoded relay (forward mode) or
+//! to everyone in a room (SFU mode), a `RelayLink` represents a QUIC
+//! connection to one peer relay used for forwarding a specific set of
+//! sessions.
+//!
+//! `RelayLinkManager` tracks all active relay links and their session
+//! assignments, providing get-or-connect semantics and idle cleanup.
+
+use std::collections::{HashMap, HashSet};
+use std::net::SocketAddr;
+use std::sync::Arc;
+
+use tracing::{debug, info, warn};
+
+use wzp_proto::MediaPacket;
+use wzp_proto::MediaTransport;
+
+/// A connection to a peer relay for forwarding specific sessions.
+///
+/// Each `RelayLink` holds a QUIC transport to one peer relay and tracks
+/// which session IDs are being forwarded through it. When all sessions
+/// are removed the link is considered idle and can be cleaned up.
+pub struct RelayLink {
+    target_addr: SocketAddr,
+    /// The underlying QUIC transport. `None` only in unit-test stubs where
+    /// no real connection is established.
+    transport: Option<Arc<wzp_transport::QuinnTransport>>,
+    active_sessions: HashSet<String>,
+}
+
+impl RelayLink {
+    /// Connect to a peer relay at `target`.
+    ///
+    /// Uses the `"_relay"` SNI to signal that this is a relay-to-relay
+    /// connection (similar to `"_probe"` for health checks). The peer
+    /// should skip normal client auth/handshake for relay-SNI connections.
+    pub async fn connect(target: SocketAddr) -> Result<Self, anyhow::Error> {
+        // Create a client-only endpoint on an OS-assigned port.
+        let endpoint = wzp_transport::create_endpoint(
+            "0.0.0.0:0".parse().unwrap(),
+            None,
+        )?;
+
+        let client_cfg = wzp_transport::client_config();
+        let conn = wzp_transport::connect(&endpoint, target, "_relay", client_cfg).await?;
+        let transport = Arc::new(wzp_transport::QuinnTransport::new(conn));
+
+        info!(%target, "relay link established");
+
+        Ok(Self {
+            target_addr: target,
+            transport: Some(transport),
+            active_sessions: HashSet::new(),
+        })
+    }
+
+    /// Create a `RelayLink` from an existing transport (useful when the
+    /// connection was established through other means).
+    pub fn from_transport(
+        target_addr: SocketAddr,
+        transport: Arc<wzp_transport::QuinnTransport>,
+    ) -> Self {
+        Self {
+            target_addr,
+            transport: Some(transport),
+            active_sessions: HashSet::new(),
+        }
+    }
+
+    /// Create a stub `RelayLink` with no transport — for unit tests that
+    /// only exercise session-tracking / management logic.
+    #[cfg(test)]
+    fn stub(target_addr: SocketAddr) -> Self {
+        Self {
+            target_addr,
+            transport: None,
+            active_sessions: HashSet::new(),
+        }
+    }
+
+    /// Forward a media packet to this peer relay.
+    pub async fn forward(&self, pkt: &MediaPacket) -> Result<(), anyhow::Error> {
+        match &self.transport {
+            Some(t) => t
+                .send_media(pkt)
+                .await
+                .map_err(|e| anyhow::anyhow!("relay link forward to {}: {e}", self.target_addr)),
+            None => Err(anyhow::anyhow!(
+                "relay link to {} has no transport (stub)",
+                self.target_addr
+            )),
+        }
+    }
+
+    /// The address of the peer relay this link connects to.
+    pub fn target_addr(&self) -> SocketAddr {
+        self.target_addr
+    }
+
+    /// A reference to the underlying QUIC transport (if connected).
+    pub fn transport(&self) -> Option<&Arc<wzp_transport::QuinnTransport>> {
+        self.transport.as_ref()
+    }
+
+    /// Add a session to be forwarded through this link.
+    pub fn add_session(&mut self, session_id: &str) {
+        if self.active_sessions.insert(session_id.to_string()) {
+            debug!(
+                target_relay = %self.target_addr,
+                session = session_id,
+                count = self.active_sessions.len(),
+                "session added to relay link"
+            );
+        }
+    }
+
+    /// Remove a session from this link.
+    pub fn remove_session(&mut self, session_id: &str) {
+        if self.active_sessions.remove(session_id) {
+            debug!(
+                target_relay = %self.target_addr,
+                session = session_id,
+                count = self.active_sessions.len(),
+                "session removed from relay link"
+            );
+        }
+    }
+
+    /// Check if this link is forwarding any sessions.
+    pub fn is_idle(&self) -> bool {
+        self.active_sessions.is_empty()
+    }
+
+    /// Number of sessions being forwarded through this link.
+    pub fn session_count(&self) -> usize {
+        self.active_sessions.len()
+    }
+
+    /// Check if a specific session is being forwarded through this link.
+    pub fn has_session(&self, session_id: &str) -> bool {
+        self.active_sessions.contains(session_id)
+    }
+
+    /// Close the underlying QUIC connection (no-op if no transport).
+    pub async fn close(&self) {
+        info!(target_relay = %self.target_addr, "closing relay link");
+        if let Some(ref t) = self.transport {
+            let _ = t.close().await;
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// RelayLinkManager
+// ---------------------------------------------------------------------------
+
+/// Manages connections to multiple peer relays for per-session forwarding.
+///
+/// Each peer relay gets at most one `RelayLink`. Sessions are registered
+/// on specific links, and idle links (no sessions) can be cleaned up.
+pub struct RelayLinkManager {
+    links: HashMap<SocketAddr, RelayLink>,
+}
+
+impl RelayLinkManager {
+    /// Create an empty link manager.
+    pub fn new() -> Self {
+        Self {
+            links: HashMap::new(),
+        }
+    }
+
+    /// Get or create a link to a peer relay.
+    ///
+    /// If a link already exists it is returned. Otherwise a new QUIC
+    /// connection is established using `RelayLink::connect`.
+    pub async fn get_or_connect(
+        &mut self,
+        target: SocketAddr,
+    ) -> Result<&RelayLink, anyhow::Error> {
+        if !self.links.contains_key(&target) {
+            let link = RelayLink::connect(target).await?;
+            self.links.insert(target, link);
+        }
+        Ok(self.links.get(&target).unwrap())
+    }
+
+    /// Get a mutable reference to an existing link (if any).
+    pub fn get_mut(&mut self, target: &SocketAddr) -> Option<&mut RelayLink> {
+        self.links.get_mut(target)
+    }
+
+    /// Get a reference to an existing link (if any).
+    pub fn get(&self, target: &SocketAddr) -> Option<&RelayLink> {
+        self.links.get(target)
+    }
+
+    /// Forward a packet for a specific session to the appropriate relay.
+    ///
+    /// The link must already exist (created via `get_or_connect`).
+    pub async fn forward_to(
+        &self,
+        target: SocketAddr,
+        pkt: &MediaPacket,
+    ) -> Result<(), anyhow::Error> {
+        match self.links.get(&target) {
+            Some(link) => link.forward(pkt).await,
+            None => Err(anyhow::anyhow!(
+                "no relay link to {target} — call get_or_connect first"
+            )),
+        }
+    }
+
+    /// Register a session on a specific link.
+    ///
+    /// The link must already exist. If it does not, a warning is logged
+    /// and the registration is silently skipped.
+    pub fn register_session(&mut self, target: SocketAddr, session_id: &str) {
+        match self.links.get_mut(&target) {
+            Some(link) => link.add_session(session_id),
+            None => {
+                warn!(
+                    %target,
+                    session = session_id,
+                    "cannot register session — no link to target"
+                );
+            }
+        }
+    }
+
+    /// Unregister a session. If the link becomes idle, close and remove it.
+    pub async fn unregister_session(&mut self, target: SocketAddr, session_id: &str) {
+        let should_remove = if let Some(link) = self.links.get_mut(&target) {
+            link.remove_session(session_id);
+            if link.is_idle() {
+                link.close().await;
+                true
+            } else {
+                false
+            }
+        } else {
+            false
+        };
+
+        if should_remove {
+            self.links.remove(&target);
+            info!(%target, "idle relay link removed");
+        }
+    }
+
+    /// Close all links and clear the manager.
+    pub async fn close_all(&mut self) {
+        for (addr, link) in self.links.drain() {
+            info!(%addr, "closing relay link (shutdown)");
+            link.close().await;
+        }
+    }
+
+    /// Number of active links.
+    pub fn link_count(&self) -> usize {
+        self.links.len()
+    }
+
+    /// Total number of sessions being forwarded across all links.
+    pub fn session_count(&self) -> usize {
+        self.links.values().map(|l| l.session_count()).sum()
+    }
+
+    /// Insert a pre-built relay link (for testing or manual setup).
+    pub fn insert(&mut self, link: RelayLink) {
+        self.links.insert(link.target_addr(), link);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn addr(s: &str) -> SocketAddr {
+        s.parse().unwrap()
+    }
+
+    // ---------- RelayLink session tracking ----------
+
+    #[test]
+    fn link_manager_tracks_sessions() {
+        let mut mgr = RelayLinkManager::new();
+        let target1 = addr("10.0.0.2:4433");
+
+        let mut link = RelayLink::stub(target1);
+        link.add_session("session-aaa");
+        link.add_session("session-bbb");
+        mgr.insert(link);
+
+        assert_eq!(mgr.link_count(), 1);
+        assert_eq!(mgr.session_count(), 2);
+
+        // Register another session on the same link
+        mgr.register_session(target1, "session-ccc");
+        assert_eq!(mgr.session_count(), 3);
+
+        // Verify individual link
+        let link_ref = mgr.get(&target1).unwrap();
+        assert!(link_ref.has_session("session-aaa"));
+        assert!(link_ref.has_session("session-bbb"));
+        assert!(link_ref.has_session("session-ccc"));
+        assert!(!link_ref.has_session("unknown"));
+    }
+
+    #[test]
+    fn link_manager_idle_detection() {
+        let mut link = RelayLink::stub(addr("10.0.0.3:4433"));
+
+        // Empty link is idle
+        assert!(link.is_idle());
+        assert_eq!(link.session_count(), 0);
+
+        // Add a session — no longer idle
+        link.add_session("sess-1");
+        assert!(!link.is_idle());
+        assert_eq!(link.session_count(), 1);
+
+        // Remove it — idle again
+        link.remove_session("sess-1");
+        assert!(link.is_idle());
+        assert_eq!(link.session_count(), 0);
+    }
+
+    #[test]
+    fn session_forward_signal_roundtrip() {
+        use wzp_proto::SignalMessage;
+
+        // SessionForward roundtrip
+        let msg = SignalMessage::SessionForward {
+            session_id: "abcd1234".to_string(),
+            target_fingerprint: "deadbeef".to_string(),
+            source_relay: "10.0.0.1:4433".to_string(),
+        };
+        let json = serde_json::to_string(&msg).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        match decoded {
+            SignalMessage::SessionForward {
+                session_id,
+                target_fingerprint,
+                source_relay,
+            } => {
+                assert_eq!(session_id, "abcd1234");
+                assert_eq!(target_fingerprint, "deadbeef");
+                assert_eq!(source_relay, "10.0.0.1:4433");
+            }
+            _ => panic!("expected SessionForward variant"),
+        }
+
+        // SessionForwardAck roundtrip
+        let ack = SignalMessage::SessionForwardAck {
+            session_id: "abcd1234".to_string(),
+            room_name: "relay-room-42".to_string(),
+        };
+        let json = serde_json::to_string(&ack).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        match decoded {
+            SignalMessage::SessionForwardAck {
+                session_id,
+                room_name,
+            } => {
+                assert_eq!(session_id, "abcd1234");
+                assert_eq!(room_name, "relay-room-42");
+            }
+            _ => panic!("expected SessionForwardAck variant"),
+        }
+    }
+
+    #[test]
+    fn link_manager_multi_target() {
+        let mut mgr = RelayLinkManager::new();
+        let target_a = addr("10.0.0.2:4433");
+        let target_b = addr("10.0.0.3:4433");
+        let target_c = addr("10.0.0.4:4433");
+
+        for (target, sessions) in [
+            (target_a, vec!["s1", "s2"]),
+            (target_b, vec!["s3"]),
+            (target_c, vec!["s4", "s5", "s6"]),
+        ] {
+            let mut link = RelayLink::stub(target);
+            for s in sessions {
+                link.add_session(s);
+            }
+            mgr.insert(link);
+        }
+
+        assert_eq!(mgr.link_count(), 3);
+        assert_eq!(mgr.session_count(), 6); // 2 + 1 + 3
+
+        assert_eq!(mgr.get(&target_a).unwrap().session_count(), 2);
+        assert_eq!(mgr.get(&target_b).unwrap().session_count(), 1);
+        assert_eq!(mgr.get(&target_c).unwrap().session_count(), 3);
+    }
+
+    #[test]
+    fn link_manager_cleanup() {
+        let mut mgr = RelayLinkManager::new();
+        let target = addr("10.0.0.5:4433");
+
+        let mut link = RelayLink::stub(target);
+        link.add_session("s1");
+        link.add_session("s2");
+        link.add_session("s3");
+        mgr.insert(link);
+
+        assert_eq!(mgr.link_count(), 1);
+        assert_eq!(mgr.session_count(), 3);
+
+        // Remove sessions one by one via the manager's mutable access.
+        // We cannot call the async unregister_session with stub links here,
+        // so we exercise the synchronous management path directly.
+        {
+            let link = mgr.get_mut(&target).unwrap();
+            link.remove_session("s1");
+            assert!(!link.is_idle());
+            link.remove_session("s2");
+            assert!(!link.is_idle());
+            link.remove_session("s3");
+            assert!(link.is_idle());
+        }
+
+        // All sessions removed — link is idle
+        assert_eq!(mgr.session_count(), 0);
+        assert!(mgr.get(&target).unwrap().is_idle());
+
+        // Simulate what unregister_session does: remove the idle link
+        mgr.links.remove(&target);
+        assert_eq!(mgr.link_count(), 0);
+    }
+
+    #[test]
+    fn register_session_on_nonexistent_link_is_noop() {
+        let mut mgr = RelayLinkManager::new();
+        // Should not panic, just warn
+        mgr.register_session(addr("10.0.0.99:4433"), "orphan-session");
+        assert_eq!(mgr.link_count(), 0);
+        assert_eq!(mgr.session_count(), 0);
+    }
+
+    #[test]
+    fn forward_to_nonexistent_link_errors() {
+        let mgr = RelayLinkManager::new();
+        let target = addr("10.0.0.99:4433");
+
+        let pkt = MediaPacket {
+            header: wzp_proto::packet::MediaHeader {
+                version: 0,
+                is_repair: false,
+                codec_id: wzp_proto::CodecId::Opus16k,
+                has_quality_report: false,
+                fec_ratio_encoded: 0,
+                seq: 1,
+                timestamp: 100,
+                fec_block: 0,
+                fec_symbol: 0,
+                reserved: 0,
+                csrc_count: 0,
+            },
+            payload: bytes::Bytes::from_static(b"test"),
+            quality_report: None,
+        };
+
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .build()
+            .unwrap();
+        let result = rt.block_on(mgr.forward_to(target, &pkt));
+        assert!(result.is_err());
+        assert!(result.unwrap_err().to_string().contains("no relay link"));
+    }
+}

crates/wzp-relay/src/route.rs

@@ -0,0 +1,265 @@
+//! Route resolution — given a target fingerprint, find the relay chain
+//! needed to reach that user.
+//!
+//! Uses the [`PresenceRegistry`] as its data source. Currently supports
+//! single-hop resolution (local or direct peer). The `resolve_multi_hop`
+//! method has the signature for future multi-hop expansion but falls back
+//! to single-hop for now.
+
+use std::net::SocketAddr;
+
+use serde::Serialize;
+
+use crate::presence::{PresenceLocation, PresenceRegistry};
+
+// ---------------------------------------------------------------------------
+// Route type
+// ---------------------------------------------------------------------------
+
+/// The resolved route to a target fingerprint.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
+pub enum Route {
+    /// Target is connected to this relay directly.
+    Local,
+    /// Target is on a directly connected peer relay.
+    DirectPeer(SocketAddr),
+    /// Target is reachable via a chain of relays (multi-hop).
+    Chain(Vec<SocketAddr>),
+    /// Target not found in any known relay.
+    NotFound,
+}
+
+impl std::fmt::Display for Route {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Route::Local => write!(f, "local"),
+            Route::DirectPeer(addr) => write!(f, "direct_peer({})", addr),
+            Route::Chain(chain) => {
+                let addrs: Vec<String> = chain.iter().map(|a| a.to_string()).collect();
+                write!(f, "chain({})", addrs.join(" -> "))
+            }
+            Route::NotFound => write!(f, "not_found"),
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// RouteResolver
+// ---------------------------------------------------------------------------
+
+/// Resolves fingerprints to relay routes using the presence registry.
+pub struct RouteResolver {
+    /// Our own relay address (how peers know us).
+    local_addr: SocketAddr,
+}
+
+impl RouteResolver {
+    /// Create a new route resolver for the relay at `local_addr`.
+    pub fn new(local_addr: SocketAddr) -> Self {
+        Self { local_addr }
+    }
+
+    /// Our local relay address.
+    pub fn local_addr(&self) -> SocketAddr {
+        self.local_addr
+    }
+
+    /// Look up a fingerprint in the registry and return the route.
+    ///
+    /// - If `registry.lookup()` returns `Local` -> `Route::Local`
+    /// - If returns `Remote(addr)` -> `Route::DirectPeer(addr)`
+    /// - If not found -> `Route::NotFound`
+    pub fn resolve(&self, registry: &PresenceRegistry, target_fingerprint: &str) -> Route {
+        match registry.lookup(target_fingerprint) {
+            Some(PresenceLocation::Local) => Route::Local,
+            Some(PresenceLocation::Remote(addr)) => Route::DirectPeer(addr),
+            None => Route::NotFound,
+        }
+    }
+
+    /// Multi-hop route resolution (future expansion).
+    ///
+    /// For now this is equivalent to `resolve()` — single-hop only.
+    /// When multi-hop is implemented, this will query peers transitively
+    /// up to `max_hops` relays deep, using `RouteQuery` / `RouteResponse`
+    /// signals over probe connections.
+    pub fn resolve_multi_hop(
+        &self,
+        registry: &PresenceRegistry,
+        target: &str,
+        _max_hops: usize,
+    ) -> Route {
+        // Phase 1: single-hop only (same as resolve).
+        // Future: if resolve returns NotFound and max_hops > 0,
+        // send RouteQuery to each known peer with ttl = max_hops - 1,
+        // collect RouteResponse, and build a Chain.
+        self.resolve(registry, target)
+    }
+
+    /// Build a JSON-serializable route response for the HTTP API.
+    pub fn route_json(
+        &self,
+        fingerprint: &str,
+        route: &Route,
+    ) -> serde_json::Value {
+        let (route_type, relay_chain) = match route {
+            Route::Local => ("local", vec![self.local_addr.to_string()]),
+            Route::DirectPeer(addr) => ("direct_peer", vec![self.local_addr.to_string(), addr.to_string()]),
+            Route::Chain(chain) => {
+                let mut addrs = vec![self.local_addr.to_string()];
+                addrs.extend(chain.iter().map(|a| a.to_string()));
+                ("chain", addrs)
+            }
+            Route::NotFound => ("not_found", vec![]),
+        };
+
+        serde_json::json!({
+            "fingerprint": fingerprint,
+            "route": route_type,
+            "relay_chain": relay_chain,
+        })
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::collections::HashSet;
+    use std::net::SocketAddr;
+
+    fn addr(s: &str) -> SocketAddr {
+        s.parse().unwrap()
+    }
+
+    fn make_resolver() -> RouteResolver {
+        RouteResolver::new(addr("10.0.0.1:4433"))
+    }
+
+    #[test]
+    fn resolve_local() {
+        let resolver = make_resolver();
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("aabbccdd", Some("alice".into()), Some("room1".into()));
+
+        let route = resolver.resolve(&reg, "aabbccdd");
+        assert_eq!(route, Route::Local);
+    }
+
+    #[test]
+    fn resolve_direct_peer() {
+        let resolver = make_resolver();
+        let mut reg = PresenceRegistry::new();
+        let peer = addr("10.0.0.2:4433");
+        let mut fps = HashSet::new();
+        fps.insert("deadbeef".to_string());
+        reg.update_peer(peer, fps);
+
+        let route = resolver.resolve(&reg, "deadbeef");
+        assert_eq!(route, Route::DirectPeer(peer));
+    }
+
+    #[test]
+    fn resolve_not_found() {
+        let resolver = make_resolver();
+        let reg = PresenceRegistry::new();
+
+        let route = resolver.resolve(&reg, "unknown_fp");
+        assert_eq!(route, Route::NotFound);
+    }
+
+    #[test]
+    fn resolve_multi_hop_fallback() {
+        // multi-hop currently falls back to single-hop behavior
+        let resolver = make_resolver();
+        let mut reg = PresenceRegistry::new();
+        reg.register_local("local_fp", None, None);
+
+        let peer = addr("10.0.0.3:4433");
+        let mut fps = HashSet::new();
+        fps.insert("remote_fp".to_string());
+        reg.update_peer(peer, fps);
+
+        // Local lookup works via multi-hop
+        assert_eq!(resolver.resolve_multi_hop(&reg, "local_fp", 3), Route::Local);
+        // Remote lookup works via multi-hop
+        assert_eq!(
+            resolver.resolve_multi_hop(&reg, "remote_fp", 3),
+            Route::DirectPeer(peer)
+        );
+        // Not-found works via multi-hop
+        assert_eq!(
+            resolver.resolve_multi_hop(&reg, "nobody", 3),
+            Route::NotFound
+        );
+    }
+
+    #[test]
+    fn route_query_signal_roundtrip() {
+        use wzp_proto::SignalMessage;
+
+        let query = SignalMessage::RouteQuery {
+            fingerprint: "aabbccdd".to_string(),
+            ttl: 3,
+        };
+        let json = serde_json::to_string(&query).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        assert!(matches!(
+            decoded,
+            SignalMessage::RouteQuery { ref fingerprint, ttl }
+            if fingerprint == "aabbccdd" && ttl == 3
+        ));
+
+        let response = SignalMessage::RouteResponse {
+            fingerprint: "aabbccdd".to_string(),
+            found: true,
+            relay_chain: vec!["10.0.0.1:4433".to_string(), "10.0.0.2:4433".to_string()],
+        };
+        let json = serde_json::to_string(&response).unwrap();
+        let decoded: SignalMessage = serde_json::from_str(&json).unwrap();
+        assert!(matches!(
+            decoded,
+            SignalMessage::RouteResponse { ref fingerprint, found, ref relay_chain }
+            if fingerprint == "aabbccdd" && found && relay_chain.len() == 2
+        ));
+    }
+
+    #[test]
+    fn route_display() {
+        assert_eq!(Route::Local.to_string(), "local");
+        assert_eq!(
+            Route::DirectPeer(addr("10.0.0.2:4433")).to_string(),
+            "direct_peer(10.0.0.2:4433)"
+        );
+        assert_eq!(
+            Route::Chain(vec![addr("10.0.0.2:4433"), addr("10.0.0.3:4433")]).to_string(),
+            "chain(10.0.0.2:4433 -> 10.0.0.3:4433)"
+        );
+        assert_eq!(Route::NotFound.to_string(), "not_found");
+
+        // Debug is also useful
+        let debug = format!("{:?}", Route::Local);
+        assert!(debug.contains("Local"));
+    }
+
+    #[test]
+    fn route_json_output() {
+        let resolver = make_resolver();
+
+        let json = resolver.route_json("fp1", &Route::Local);
+        assert_eq!(json["route"], "local");
+        assert_eq!(json["fingerprint"], "fp1");
+        assert_eq!(json["relay_chain"].as_array().unwrap().len(), 1);
+
+        let json = resolver.route_json("fp2", &Route::DirectPeer(addr("10.0.0.2:4433")));
+        assert_eq!(json["route"], "direct_peer");
+        assert_eq!(json["relay_chain"].as_array().unwrap().len(), 2);
+
+        let json = resolver.route_json("fp3", &Route::NotFound);
+        assert_eq!(json["route"], "not_found");
+        assert_eq!(json["relay_chain"].as_array().unwrap().len(), 0);
+    }
+}

crates/wzp-wasm/Cargo.toml

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

crates/wzp-wasm/src/lib.rs

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

crates/wzp-web/static/index.html

@@ -10,6 +10,10 @@
   .container { text-align: center; max-width: 420px; padding: 2rem; }
   h1 { font-size: 1.5rem; margin-bottom: 0.5rem; color: #00d4ff; }
   .subtitle { color: #888; font-size: 0.85rem; margin-bottom: 1.5rem; }
+  .variant-badge { display: inline-block; background: #2a2a4a; border: 1px solid #444; color: #00d4ff; font-size: 0.65rem; padding: 0.15rem 0.5rem; border-radius: 4px; margin-left: 0.4rem; vertical-align: middle; font-family: monospace; letter-spacing: 0.05em; }
+  .variant-selector { margin-bottom: 1.2rem; display: flex; gap: 0.8rem; justify-content: center; flex-wrap: wrap; }
+  .variant-selector label { font-size: 0.75rem; color: #888; cursor: pointer; display: flex; align-items: center; gap: 0.25rem; }
+  .variant-selector input[type="radio"] { accent-color: #00d4ff; }
   .room-input { margin-bottom: 1.5rem; }
   .room-input input { background: #2a2a4a; border: 1px solid #444; color: #e0e0e0; padding: 0.6rem 1rem; font-size: 1rem; border-radius: 8px; width: 200px; text-align: center; }
   .room-input input:focus { outline: none; border-color: #00d4ff; }
@@ -31,15 +35,22 @@
 </head>
 <body>
 <div class="container">
-  <h1>WarzonePhone</h1>
+  <h1>WarzonePhone <span class="variant-badge" id="variantBadge">PURE</span></h1>
   <p class="subtitle">Lossy VoIP Protocol</p>
+
+  <div class="variant-selector">
+    <label><input type="radio" name="variant" value="pure"> Pure JS</label>
+    <label><input type="radio" name="variant" value="hybrid"> Hybrid</label>
+    <label><input type="radio" name="variant" value="full"> Full WASM</label>
+  </div>
+
   <div class="room-input">
     <label for="room">Room</label>
     <input type="text" id="room" placeholder="enter room name" value="">
   </div>
-  <button id="callBtn" onclick="toggleCall()">Connect</button>
+  <button id="callBtn">Connect</button>
   <div class="controls" id="controls" style="display:none;">
-    <label><input type="checkbox" id="pttMode" onchange="togglePTT()"> Radio mode (push-to-talk)</label>
+    <label><input type="checkbox" id="pttMode"> Radio mode (push-to-talk)</label>
   </div>
   <button id="pttBtn">Hold to Talk</button>
   <div class="level"><div class="level-bar" id="levelBar"></div></div>
@@ -47,302 +58,126 @@
   <div class="stats" id="stats"></div>
 </div>
 
+<script src="js/wzp-core.js"></script>
 <script>
-const SAMPLE_RATE = 48000;
+// ---------------------------------------------------------------------------
-const FRAME_SIZE = 960;
+// Load the selected variant script dynamically
-
+// ---------------------------------------------------------------------------
-let ws = null;
-let audioCtx = null;
-let mediaStream = null;
-let captureNode = null;
-let playbackNode = null;
-let active = false;
-let transmitting = true; // in open-mic mode, always transmitting
-let pttMode = false;
-let framesSent = 0;
-let framesRecv = 0;
-let startTime = 0;
-let statsInterval = null;
-
-// Use room from URL path or input field
-function getRoom() {
-  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
-  if (path && path !== 'index.html') return path;
-  const hash = location.hash.replace('#', '');
-  if (hash) return hash;
-  return document.getElementById('room').value.trim() || 'default';
-}
-
-// Pre-fill room input from URL on page load
 (function() {
-  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
+  var variant = WZPCore.detectVariant();
-  if (path && path !== 'index.html') {
+  var scriptMap = {
-    document.getElementById('room').value = path;
+    pure:   'js/wzp-pure.js',
-  }
+    hybrid: 'js/wzp-hybrid.js',
+    full:   'js/wzp-full.js',
+  };
+  var src = scriptMap[variant] || scriptMap.pure;
+  var s = document.createElement('script');
+  s.src = src;
+  s.onload = function() { wzpBoot(); };
+  s.onerror = function() {
+    WZPCore.updateStatus('Failed to load variant: ' + variant);
+  };
+  document.body.appendChild(s);
 })();
 
-function setStatus(msg) { document.getElementById('status').textContent = msg; }
+// ---------------------------------------------------------------------------
-function setStats(msg) { document.getElementById('stats').textContent = msg; }
+// Boot: wire UI to the loaded client variant
+// ---------------------------------------------------------------------------
+function wzpBoot() {
+  var client = null;
+  var capture = null;
+  var playback = null;
+  var transmitting = true;
 
-function toggleCall() {
+  var ui = WZPCore.initUI({
-  if (active) stopCall();
+    onConnect: function(room) {
-  else startCall();
+      doConnect(room);
-}
+    },
+    onDisconnect: function() {
+      doDisconnect();
+    },
+    onTransmit: function(tx) {
+      transmitting = tx;
+    },
+  });
 
-async function startCall() {
+  async function doConnect(room) {
-  const btn = document.getElementById('callBtn');
+    WZPCore.updateStatus('Requesting microphone...');
-  const room = getRoom();
-  if (!room) { setStatus('Enter a room name'); return; }
 
-  btn.disabled = true;
+    var audioCtx;
-  setStatus('Requesting microphone...');
+    try {
+      audioCtx = await WZPCore.startAudioContext();
+    } catch (e) {
+      WZPCore.updateStatus('Audio init failed: ' + e.message);
+      ui.setConnected(false);
+      return;
+    }
 
-  try {
+    // Build WebSocket URL
-    mediaStream = await navigator.mediaDevices.getUserMedia({
+    var proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
-      audio: { sampleRate: SAMPLE_RATE, channelCount: 1, echoCancellation: true, noiseSuppression: true }
+    var wsUrl = proto + '//' + location.host + '/ws/' + encodeURIComponent(room);
+
+    // Create client (currently always WZPPureClient; future: switch on variant)
+    client = new WZPPureClient({
+      wsUrl: wsUrl,
+      room: room,
+      onAudio: function(pcm) {
+        if (playback) playback.play(pcm);
+      },
+      onStatus: function(msg) {
+        WZPCore.updateStatus(msg);
+      },
+      onStats: function(stats) {
+        WZPCore.updateStats(stats);
+      },
     });
-  } catch(e) {
-    setStatus('Mic access denied: ' + e.message);
-    btn.disabled = false;
-    return;
-  }
 
-  audioCtx = new AudioContext({ sampleRate: SAMPLE_RATE });
+    try {
-
+      await client.connect();
-  // Connect WebSocket with room name
+    } catch (e) {
-  const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
+      WZPCore.updateStatus('Connection failed: ' + e.message);
-  const wsUrl = proto + '//' + location.host + '/ws/' + encodeURIComponent(room);
+      ui.setConnected(false);
-  setStatus('Connecting to room: ' + room + '...');
+      return;
-
-  ws = new WebSocket(wsUrl);
-  ws.binaryType = 'arraybuffer';
-
-  ws.onopen = async () => {
-    setStatus('Connected to room: ' + room);
-    btn.textContent = 'Disconnect';
-    btn.classList.add('active');
-    btn.disabled = false;
-    active = true;
-    framesSent = 0;
-    framesRecv = 0;
-    startTime = Date.now();
-    showControls(true);
-    await startAudioCapture();
-    await startAudioPlayback();
-    startStatsUpdate();
-  };
-
-  ws.onmessage = (event) => {
-    const pcmData = new Int16Array(event.data);
-    framesRecv++;
-    playAudio(pcmData);
-  };
-
-  ws.onclose = () => {
-    if (active) {
-      setStatus('Disconnected — reconnecting to ' + room + '...');
-      setTimeout(() => { if (active) { cleanupAudio(); startCall(); } }, 1000);
-    } else {
-      setStatus('Disconnected');
     }
-  };
 
-  ws.onerror = () => {
+    // Start audio capture and playback
-    if (active) {
+    try {
-      setStatus('Error — reconnecting...');
+      capture = await WZPCore.connectCapture(audioCtx, function(pcmBuffer) {
-      setTimeout(() => { if (active) { cleanupAudio(); startCall(); } }, 1000);
+        if (!transmitting) return;
+        var pcm = new Int16Array(pcmBuffer);
+        WZPCore.updateLevel(pcm);
+        if (client) client.sendAudio(pcmBuffer);
+      });
+
+      playback = await WZPCore.connectPlayback(audioCtx);
+    } catch (e) {
+      WZPCore.updateStatus('Audio error: ' + e.message);
+      if (client) client.disconnect();
+      client = null;
+      ui.setConnected(false);
+      return;
     }
-  };
-}
 
-function stopCall() {
+    ui.setConnected(true);
-  active = false;
-  const btn = document.getElementById('callBtn');
-  btn.textContent = 'Connect';
-  btn.classList.remove('active');
-  btn.disabled = false;
-  showControls(false);
-  cleanupAudio();
-  if (ws) { ws.close(); ws = null; }
-  if (statsInterval) { clearInterval(statsInterval); statsInterval = null; }
-  setStatus('');
-  setStats('');
-}
-
-function cleanupAudio() {
-  if (captureNode) { captureNode.disconnect(); captureNode = null; }
-  if (playbackNode) { playbackNode.disconnect(); playbackNode = null; }
-  if (audioCtx) { audioCtx.close(); audioCtx = null; workletLoaded = false; }
-  if (mediaStream) { mediaStream.getTracks().forEach(t => t.stop()); mediaStream = null; }
-}
-
-let workletLoaded = false;
-
-async function loadWorkletModule() {
-  if (workletLoaded) return true;
-  if (typeof AudioWorkletNode === 'undefined' || !audioCtx.audioWorklet) {
-    console.warn('AudioWorklet API not supported in this browser — using ScriptProcessorNode fallback');
-    return false;
   }
-  try {
-    await audioCtx.audioWorklet.addModule('audio-processor.js');
-    workletLoaded = true;
-    return true;
-  } catch(e) {
-    console.warn('AudioWorklet module failed to load — using ScriptProcessorNode fallback:', e);
-    return false;
-  }
-}
 
-async function startAudioCapture() {
+  function doDisconnect() {
-  const source = audioCtx.createMediaStreamSource(mediaStream);
+    if (capture) { capture.stop(); capture = null; }
-  const hasWorklet = await loadWorkletModule();
+    if (playback) { playback.stop(); playback = null; }
+    if (client) { client.disconnect(); client = null; }
 
-  if (hasWorklet) {
+    var audioCtx = WZPCore.getAudioContext();
-    captureNode = new AudioWorkletNode(audioCtx, 'wzp-capture-processor');
+    if (audioCtx && audioCtx.state !== 'closed') {
-    captureNode.port.onmessage = (e) => {
+      audioCtx.close();
-      if (!active || !ws || ws.readyState !== WebSocket.OPEN || !transmitting) return;
-      ws.send(e.data);
-      framesSent++;
-
-      // Level meter from the PCM data
-      const pcm = new Int16Array(e.data);
-      let max = 0;
-      for (let i = 0; i < pcm.length; i += 16) max = Math.max(max, Math.abs(pcm[i]));
-      document.getElementById('levelBar').style.width = (max / 32768 * 100) + '%';
-    };
-    source.connect(captureNode);
-    captureNode.connect(audioCtx.destination); // needed to keep worklet alive
-  } else {
-    // Fallback to ScriptProcessorNode (deprecated but widely supported)
-    console.warn('Capture: using ScriptProcessorNode fallback');
-    captureNode = audioCtx.createScriptProcessor(4096, 1, 1);
-    let acc = new Float32Array(0);
-    captureNode.onaudioprocess = (ev) => {
-      if (!active || !ws || ws.readyState !== WebSocket.OPEN || !transmitting) return;
-      const input = ev.inputBuffer.getChannelData(0);
-      const n = new Float32Array(acc.length + input.length);
-      n.set(acc); n.set(input, acc.length); acc = n;
-      while (acc.length >= FRAME_SIZE) {
-        const frame = acc.slice(0, FRAME_SIZE); acc = acc.slice(FRAME_SIZE);
-        const pcm = new Int16Array(FRAME_SIZE);
-        for (let i = 0; i < FRAME_SIZE; i++) pcm[i] = Math.max(-32768, Math.min(32767, Math.round(frame[i] * 32767)));
-        let max = 0;
-        for (let i = 0; i < pcm.length; i += 16) max = Math.max(max, Math.abs(pcm[i]));
-        document.getElementById('levelBar').style.width = (max / 32768 * 100) + '%';
-        ws.send(pcm.buffer);
-        framesSent++;
-      }
-    };
-    source.connect(captureNode);
-    captureNode.connect(audioCtx.destination);
-  }
-}
-
-async function startAudioPlayback() {
-  const hasWorklet = await loadWorkletModule();
-
-  if (hasWorklet) {
-    playbackNode = new AudioWorkletNode(audioCtx, 'wzp-playback-processor');
-    playbackNode.connect(audioCtx.destination);
-  } else {
-    console.warn('Playback: using scheduled BufferSource fallback');
-    playbackNode = null; // will use createBufferSource fallback in playAudio()
-  }
-}
-
-let nextPlayTime = 0;
-
-function playAudio(pcmInt16) {
-  if (!audioCtx) return;
-
-  if (playbackNode && playbackNode.port) {
-    // AudioWorklet path — send Int16 PCM directly to the worklet for conversion
-    playbackNode.port.postMessage(pcmInt16.buffer, [pcmInt16.buffer]);
-  } else {
-    // Fallback: scheduled BufferSource (convert Int16 -> Float32 on main thread)
-    const floatData = new Float32Array(pcmInt16.length);
-    for (let i = 0; i < pcmInt16.length; i++) {
-      floatData[i] = pcmInt16[i] / 32768.0;
     }
-    const buffer = audioCtx.createBuffer(1, floatData.length, SAMPLE_RATE);
+
-    buffer.getChannelData(0).set(floatData);
+    WZPCore.updateStatus('');
-    const source = audioCtx.createBufferSource();
+    WZPCore.updateStats('');
-    source.buffer = buffer;
+    document.getElementById('levelBar').style.width = '0%';
-    source.connect(audioCtx.destination);
+
-    const now = audioCtx.currentTime;
+    ui.setConnected(false);
-    if (nextPlayTime < now || nextPlayTime > now + 1.0) {
-      nextPlayTime = now + 0.02;
-    }
-    source.start(nextPlayTime);
-    nextPlayTime += buffer.duration;
   }
 }
-
-function startStatsUpdate() {
-  statsInterval = setInterval(() => {
-    if (!active) { clearInterval(statsInterval); return; }
-    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
-    setStats(elapsed + 's | sent: ' + framesSent + ' | recv: ' + framesRecv);
-  }, 1000);
-}
-
-// --- Push-to-talk ---
-
-function togglePTT() {
-  pttMode = document.getElementById('pttMode').checked;
-  const btn = document.getElementById('pttBtn');
-  if (pttMode) {
-    transmitting = false;
-    btn.style.display = 'block';
-  } else {
-    transmitting = true;
-    btn.style.display = 'none';
-  }
-}
-
-// PTT button — hold to talk (mouse + touch)
-document.getElementById('pttBtn').addEventListener('mousedown', () => { startTransmit(); });
-document.getElementById('pttBtn').addEventListener('mouseup', () => { stopTransmit(); });
-document.getElementById('pttBtn').addEventListener('mouseleave', () => { stopTransmit(); });
-document.getElementById('pttBtn').addEventListener('touchstart', (e) => { e.preventDefault(); startTransmit(); });
-document.getElementById('pttBtn').addEventListener('touchend', (e) => { e.preventDefault(); stopTransmit(); });
-
-// Spacebar PTT
-document.addEventListener('keydown', (e) => { if (pttMode && active && e.code === 'Space' && !e.repeat) { e.preventDefault(); startTransmit(); } });
-document.addEventListener('keyup', (e) => { if (pttMode && active && e.code === 'Space') { e.preventDefault(); stopTransmit(); } });
-
-function startTransmit() {
-  if (!pttMode || !active) return;
-  transmitting = true;
-  document.getElementById('pttBtn').classList.add('transmitting');
-  document.getElementById('pttBtn').textContent = 'Transmitting...';
-}
-
-function stopTransmit() {
-  if (!pttMode) return;
-  transmitting = false;
-  document.getElementById('pttBtn').classList.remove('transmitting');
-  document.getElementById('pttBtn').textContent = 'Hold to Talk';
-}
-
-// Show controls when connected
-function showControls(show) {
-  document.getElementById('controls').style.display = show ? 'flex' : 'none';
-  if (!show) {
-    document.getElementById('pttBtn').style.display = 'none';
-    pttMode = false;
-    transmitting = true;
-  }
-}
-
-// Set room from URL on load
-window.addEventListener('load', () => {
-  const room = getRoom();
-  if (room && room !== 'default') {
-    document.getElementById('room').value = room;
-  }
-});
 </script>
 </body>
 </html>

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

@@ -0,0 +1,378 @@
+// WarzonePhone — Shared UI logic for all client variants.
+// Provides: audio context management, mic capture, playback, UI wiring.
+
+'use strict';
+
+const WZP_SAMPLE_RATE = 48000;
+const WZP_FRAME_SIZE = 960; // 20ms @ 48kHz
+
+// ---------------------------------------------------------------------------
+// Variant detection
+// ---------------------------------------------------------------------------
+
+function wzpDetectVariant() {
+  const params = new URLSearchParams(location.search);
+  const v = (params.get('variant') || 'pure').toLowerCase();
+  if (v === 'hybrid' || v === 'full') return v;
+  return 'pure';
+}
+
+// ---------------------------------------------------------------------------
+// Room helpers
+// ---------------------------------------------------------------------------
+
+function wzpGetRoom() {
+  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
+  if (path && path !== 'index.html') return path;
+  const hash = location.hash.replace('#', '');
+  if (hash) return hash;
+  const el = document.getElementById('room');
+  return (el && el.value.trim()) || 'default';
+}
+
+function wzpPrefillRoom() {
+  const path = location.pathname.replace(/^\//, '').replace(/\/$/, '');
+  if (path && path !== 'index.html') {
+    const el = document.getElementById('room');
+    if (el) el.value = path;
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Status / stats helpers
+// ---------------------------------------------------------------------------
+
+function wzpUpdateStatus(msg) {
+  const el = document.getElementById('status');
+  if (el) el.textContent = msg;
+}
+
+function wzpUpdateStats(stats) {
+  const el = document.getElementById('stats');
+  if (!el) return;
+  if (typeof stats === 'string') {
+    el.textContent = stats;
+  } else {
+    const parts = [];
+    if (stats.elapsed != null) parts.push(stats.elapsed.toFixed(1) + 's');
+    if (stats.sent != null) parts.push('sent: ' + stats.sent);
+    if (stats.recv != null) parts.push('recv: ' + stats.recv);
+    if (stats.loss != null) parts.push('loss: ' + (stats.loss * 100).toFixed(1) + '%');
+    if (stats.fecRecovered != null && stats.fecRecovered > 0) parts.push('fec: ' + stats.fecRecovered);
+    if (stats.fecReady != null) parts.push(stats.fecReady ? 'FEC:on' : 'FEC:off');
+    el.textContent = parts.join(' | ');
+  }
+}
+
+function wzpUpdateLevel(pcmInt16) {
+  const bar = document.getElementById('levelBar');
+  if (!bar) return;
+  let max = 0;
+  for (let i = 0; i < pcmInt16.length; i += 16) {
+    const v = Math.abs(pcmInt16[i]);
+    if (v > max) max = v;
+  }
+  bar.style.width = (max / 32768 * 100) + '%';
+}
+
+// ---------------------------------------------------------------------------
+// Audio context + worklet
+// ---------------------------------------------------------------------------
+
+let _wzpAudioCtx = null;
+let _wzpWorkletLoaded = false;
+
+async function wzpStartAudioContext() {
+  if (_wzpAudioCtx && _wzpAudioCtx.state !== 'closed') return _wzpAudioCtx;
+  _wzpAudioCtx = new AudioContext({ sampleRate: WZP_SAMPLE_RATE });
+  _wzpWorkletLoaded = false;
+  return _wzpAudioCtx;
+}
+
+function wzpGetAudioContext() {
+  return _wzpAudioCtx;
+}
+
+async function _wzpLoadWorklet(audioCtx) {
+  if (_wzpWorkletLoaded) return true;
+  if (typeof AudioWorkletNode === 'undefined' || !audioCtx.audioWorklet) {
+    console.warn('[wzp-core] AudioWorklet not supported, will use fallback');
+    return false;
+  }
+  try {
+    await audioCtx.audioWorklet.addModule('audio-processor.js');
+    _wzpWorkletLoaded = true;
+    return true;
+  } catch (e) {
+    console.warn('[wzp-core] AudioWorklet load failed:', e);
+    return false;
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Mic capture — returns { node, stop() }
+// onFrame(ArrayBuffer) called for each 960-sample Int16 PCM frame
+// ---------------------------------------------------------------------------
+
+async function wzpConnectCapture(audioCtx, onFrame) {
+  let mediaStream;
+  try {
+    mediaStream = await navigator.mediaDevices.getUserMedia({
+      audio: {
+        sampleRate: WZP_SAMPLE_RATE,
+        channelCount: 1,
+        echoCancellation: true,
+        noiseSuppression: true,
+      },
+    });
+  } catch (e) {
+    throw new Error('Mic access denied: ' + e.message);
+  }
+
+  const source = audioCtx.createMediaStreamSource(mediaStream);
+  const hasWorklet = await _wzpLoadWorklet(audioCtx);
+  let captureNode;
+
+  if (hasWorklet) {
+    captureNode = new AudioWorkletNode(audioCtx, 'wzp-capture-processor');
+    captureNode.port.onmessage = (e) => {
+      onFrame(e.data); // ArrayBuffer of Int16 PCM
+    };
+    source.connect(captureNode);
+    captureNode.connect(audioCtx.destination); // keep worklet alive
+  } else {
+    // ScriptProcessorNode fallback
+    captureNode = audioCtx.createScriptProcessor(4096, 1, 1);
+    let acc = new Float32Array(0);
+    captureNode.onaudioprocess = (ev) => {
+      const input = ev.inputBuffer.getChannelData(0);
+      const n = new Float32Array(acc.length + input.length);
+      n.set(acc);
+      n.set(input, acc.length);
+      acc = n;
+      while (acc.length >= WZP_FRAME_SIZE) {
+        const frame = acc.slice(0, WZP_FRAME_SIZE);
+        acc = acc.slice(WZP_FRAME_SIZE);
+        const pcm = new Int16Array(WZP_FRAME_SIZE);
+        for (let i = 0; i < WZP_FRAME_SIZE; i++) {
+          pcm[i] = Math.max(-32768, Math.min(32767, Math.round(frame[i] * 32767)));
+        }
+        onFrame(pcm.buffer);
+      }
+    };
+    source.connect(captureNode);
+    captureNode.connect(audioCtx.destination);
+  }
+
+  return {
+    node: captureNode,
+    stop() {
+      captureNode.disconnect();
+      mediaStream.getTracks().forEach((t) => t.stop());
+    },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Playback — returns { node, play(Int16Array), stop() }
+// ---------------------------------------------------------------------------
+
+async function wzpConnectPlayback(audioCtx) {
+  const hasWorklet = await _wzpLoadWorklet(audioCtx);
+  let playbackNode;
+  let nextPlayTime = 0;
+
+  if (hasWorklet) {
+    playbackNode = new AudioWorkletNode(audioCtx, 'wzp-playback-processor');
+    playbackNode.connect(audioCtx.destination);
+    return {
+      node: playbackNode,
+      play(pcmInt16) {
+        // Transfer Int16 buffer to worklet
+        const buf = pcmInt16.buffer.slice(
+          pcmInt16.byteOffset,
+          pcmInt16.byteOffset + pcmInt16.byteLength
+        );
+        playbackNode.port.postMessage(buf, [buf]);
+      },
+      stop() {
+        playbackNode.disconnect();
+      },
+    };
+  }
+
+  // Fallback: scheduled BufferSource
+  return {
+    node: null,
+    play(pcmInt16) {
+      if (!audioCtx || audioCtx.state === 'closed') return;
+      const floatData = new Float32Array(pcmInt16.length);
+      for (let i = 0; i < pcmInt16.length; i++) {
+        floatData[i] = pcmInt16[i] / 32768.0;
+      }
+      const buffer = audioCtx.createBuffer(1, floatData.length, WZP_SAMPLE_RATE);
+      buffer.getChannelData(0).set(floatData);
+      const source = audioCtx.createBufferSource();
+      source.buffer = buffer;
+      source.connect(audioCtx.destination);
+      const now = audioCtx.currentTime;
+      if (nextPlayTime < now || nextPlayTime > now + 1.0) {
+        nextPlayTime = now + 0.02;
+      }
+      source.start(nextPlayTime);
+      nextPlayTime += buffer.duration;
+    },
+    stop() {
+      // nothing to disconnect for fallback
+    },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// UI wiring — call after DOM ready
+// ---------------------------------------------------------------------------
+
+function wzpInitUI(callbacks) {
+  // callbacks: { onConnect(room), onDisconnect() }
+  const btn = document.getElementById('callBtn');
+  const pttBtn = document.getElementById('pttBtn');
+  const pttCheckbox = document.getElementById('pttMode');
+  let connected = false;
+  let pttMode = false;
+
+  wzpPrefillRoom();
+
+  // Variant badge
+  const variant = wzpDetectVariant();
+  const badge = document.getElementById('variantBadge');
+  if (badge) badge.textContent = variant.toUpperCase();
+
+  // Variant selector radio buttons
+  document.querySelectorAll('input[name="variant"]').forEach((radio) => {
+    if (radio.value === variant) radio.checked = true;
+    radio.addEventListener('change', () => {
+      if (radio.checked) {
+        const params = new URLSearchParams(location.search);
+        params.set('variant', radio.value);
+        location.search = params.toString();
+      }
+    });
+  });
+
+  btn.onclick = () => {
+    if (connected) {
+      connected = false;
+      btn.textContent = 'Connect';
+      btn.classList.remove('active');
+      _showControls(false);
+      if (callbacks.onDisconnect) callbacks.onDisconnect();
+    } else {
+      const room = wzpGetRoom();
+      if (!room) {
+        wzpUpdateStatus('Enter a room name');
+        return;
+      }
+      connected = true;
+      btn.disabled = true;
+      if (callbacks.onConnect) callbacks.onConnect(room);
+    }
+  };
+
+  // PTT toggle
+  if (pttCheckbox) {
+    pttCheckbox.onchange = () => {
+      pttMode = pttCheckbox.checked;
+      if (pttMode) {
+        pttBtn.style.display = 'block';
+        if (callbacks.onTransmit) callbacks.onTransmit(false);
+      } else {
+        pttBtn.style.display = 'none';
+        if (callbacks.onTransmit) callbacks.onTransmit(true);
+      }
+    };
+  }
+
+  // PTT button events
+  function startTx() {
+    if (!pttMode || !connected) return;
+    pttBtn.classList.add('transmitting');
+    pttBtn.textContent = 'Transmitting...';
+    if (callbacks.onTransmit) callbacks.onTransmit(true);
+  }
+  function stopTx() {
+    if (!pttMode) return;
+    pttBtn.classList.remove('transmitting');
+    pttBtn.textContent = 'Hold to Talk';
+    if (callbacks.onTransmit) callbacks.onTransmit(false);
+  }
+
+  if (pttBtn) {
+    pttBtn.addEventListener('mousedown', startTx);
+    pttBtn.addEventListener('mouseup', stopTx);
+    pttBtn.addEventListener('mouseleave', stopTx);
+    pttBtn.addEventListener('touchstart', (e) => { e.preventDefault(); startTx(); });
+    pttBtn.addEventListener('touchend', (e) => { e.preventDefault(); stopTx(); });
+  }
+
+  // Spacebar PTT
+  document.addEventListener('keydown', (e) => {
+    if (pttMode && connected && e.code === 'Space' && !e.repeat) {
+      e.preventDefault();
+      startTx();
+    }
+  });
+  document.addEventListener('keyup', (e) => {
+    if (pttMode && connected && e.code === 'Space') {
+      e.preventDefault();
+      stopTx();
+    }
+  });
+
+  function _showControls(show) {
+    const controls = document.getElementById('controls');
+    if (controls) controls.style.display = show ? 'flex' : 'none';
+    if (!show && pttBtn) {
+      pttBtn.style.display = 'none';
+      pttMode = false;
+      if (pttCheckbox) pttCheckbox.checked = false;
+    }
+  }
+
+  return {
+    setConnected(isConnected) {
+      connected = isConnected;
+      btn.disabled = false;
+      if (isConnected) {
+        btn.textContent = 'Disconnect';
+        btn.classList.add('active');
+        _showControls(true);
+      } else {
+        btn.textContent = 'Connect';
+        btn.classList.remove('active');
+        _showControls(false);
+      }
+    },
+    isPTT() {
+      return pttMode;
+    },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Exports (global)
+// ---------------------------------------------------------------------------
+
+window.WZPCore = {
+  SAMPLE_RATE: WZP_SAMPLE_RATE,
+  FRAME_SIZE: WZP_FRAME_SIZE,
+  detectVariant: wzpDetectVariant,
+  getRoom: wzpGetRoom,
+  updateStatus: wzpUpdateStatus,
+  updateStats: wzpUpdateStats,
+  updateLevel: wzpUpdateLevel,
+  startAudioContext: wzpStartAudioContext,
+  getAudioContext: wzpGetAudioContext,
+  connectCapture: wzpConnectCapture,
+  connectPlayback: wzpConnectPlayback,
+  initUI: wzpInitUI,
+};

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

@@ -0,0 +1,524 @@
+// WarzonePhone — Full WASM + WebTransport client (Variant 3).
+//
+// Architecture:
+//   - WebTransport for unreliable datagrams (UDP-like, no head-of-line blocking)
+//   - ChaCha20-Poly1305 encryption via WASM (wzp-wasm WzpCryptoSession)
+//   - RaptorQ FEC via WASM (wzp-wasm WzpFecEncoder/WzpFecDecoder)
+//   - X25519 key exchange via WASM (wzp-wasm WzpKeyExchange)
+//
+// NOTE: WebTransport requires the relay to support HTTP/3 (h3-quinn).
+// The current wzp-relay uses raw QUIC. This variant demonstrates the full
+// architecture but will need relay-side HTTP/3 support to work end-to-end.
+// For development / testing, use the hybrid variant (WebSocket + WASM FEC).
+//
+// Relies on wzp-core.js for UI and audio helpers.
+
+'use strict';
+
+const WZP_WASM_PATH = '/wasm/wzp_wasm.js';
+
+// 12-byte MediaHeader size (matches wzp-proto MediaHeader::WIRE_SIZE).
+const MEDIA_HEADER_SIZE = 12;
+
+// FEC wire header: block_id(1) + symbol_idx(1) + is_repair(1) = 3 bytes.
+const FEC_HEADER_SIZE = 3;
+
+class WZPFullClient {
+  /**
+   * @param {Object} options
+   * @param {string} options.url          WebTransport URL (https://host:port)
+   * @param {string} options.room         Room name
+   * @param {Function} options.onAudio    callback(Int16Array) for playback
+   * @param {Function} options.onStatus   callback(string) for UI status
+   * @param {Function} options.onStats    callback(Object) for UI stats
+   */
+  constructor(options) {
+    this.url = options.url;
+    this.room = options.room;
+    this.onAudio = options.onAudio || null;
+    this.onStatus = options.onStatus || null;
+    this.onStats = options.onStats || null;
+
+    this.wt = null;                  // WebTransport instance
+    this.datagramWriter = null;      // WritableStreamDefaultWriter
+    this.datagramReader = null;      // ReadableStreamDefaultReader
+    this.cryptoSession = null;       // WzpCryptoSession (WASM)
+    this.fecEncoder = null;          // WzpFecEncoder (WASM)
+    this.fecDecoder = null;          // WzpFecDecoder (WASM)
+    this.sequence = 0;
+    this._wasmModule = null;
+    this._connected = false;
+    this._startTime = 0;
+    this._statsInterval = null;
+    this._recvLoopRunning = false;
+    this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
+  }
+
+  /**
+   * Connect: load WASM, open WebTransport, perform key exchange,
+   * initialise FEC, and start the receive loop.
+   */
+  async connect() {
+    if (this._connected) return;
+
+    // --- Guard: WebTransport support ---
+    if (typeof WebTransport === 'undefined') {
+      throw new Error(
+        'WebTransport is not supported in this browser. ' +
+        'Use the hybrid (?variant=hybrid) or pure (?variant=pure) variant instead.'
+      );
+    }
+
+    this._status('Loading WASM module...');
+
+    // 1. Load WASM
+    this._wasmModule = await import(WZP_WASM_PATH);
+    await this._wasmModule.default();
+
+    this._status('Connecting via WebTransport to ' + this.url + '...');
+
+    // 2. WebTransport connection
+    //    The URL should include the room, e.g. https://host:port/room
+    const wtUrl = this.url + '/' + encodeURIComponent(this.room);
+    this.wt = new WebTransport(wtUrl);
+
+    this.wt.closed.then(() => {
+      const wasConnected = this._connected;
+      this._cleanup();
+      if (wasConnected) {
+        this._status('WebTransport closed');
+      }
+    }).catch((err) => {
+      this._cleanup();
+      this._status('WebTransport error: ' + err.message);
+    });
+
+    await this.wt.ready;
+
+    // 3. Get datagram streams (unreliable, QUIC DATAGRAM frames)
+    this.datagramWriter = this.wt.datagrams.writable.getWriter();
+    this.datagramReader = this.wt.datagrams.readable.getReader();
+
+    // 4. Key exchange over a bidirectional stream
+    this._status('Performing key exchange...');
+    await this._performKeyExchange();
+
+    // 5. Initialise FEC (5 source symbols per block, 256-byte symbols)
+    this.fecEncoder = new this._wasmModule.WzpFecEncoder(5, 256);
+    this.fecDecoder = new this._wasmModule.WzpFecDecoder(5, 256);
+
+    this._connected = true;
+    this.sequence = 0;
+    this.stats = { sent: 0, recv: 0, fecRecovered: 0, encrypted: 0, decrypted: 0 };
+    this._startTime = Date.now();
+    this._startStatsTimer();
+
+    // 6. Start receive loop (runs until disconnect)
+    this._recvLoop();
+
+    this._status('Connected to room: ' + this.room + ' (encrypted, FEC active)');
+  }
+
+  /**
+   * Disconnect and clean up all resources.
+   */
+  disconnect() {
+    this._connected = false;
+    if (this.wt) {
+      try { this.wt.close(); } catch (_) { /* ignore */ }
+      this.wt = null;
+    }
+    this._cleanup();
+  }
+
+  /**
+   * Send a PCM audio frame.
+   *
+   * Pipeline: PCM -> FEC encode -> encrypt -> datagram send.
+   *
+   * @param {ArrayBuffer} pcmBuffer  960-sample Int16 PCM (1920 bytes)
+   */
+  async sendAudio(pcmBuffer) {
+    if (!this._connected || !this.datagramWriter || !this.cryptoSession) return;
+
+    const pcmBytes = new Uint8Array(pcmBuffer);
+
+    // Build a minimal 12-byte MediaHeader for AAD.
+    const header = this._buildMediaHeader(this.sequence);
+
+    // FEC encode: feed the frame; when a block completes we get wire packets.
+    const fecOutput = this.fecEncoder.add_symbol(pcmBytes);
+
+    if (fecOutput) {
+      // FEC block completed — send all packets (source + repair).
+      const packetSize = FEC_HEADER_SIZE + 256; // header + symbol_size
+      for (let offset = 0; offset + packetSize <= fecOutput.length; offset += packetSize) {
+        const fecPacket = fecOutput.slice(offset, offset + packetSize);
+
+        // Encrypt: header bytes as AAD, FEC packet as plaintext.
+        const ciphertext = this.cryptoSession.encrypt(header, fecPacket);
+        this.stats.encrypted++;
+
+        // Build wire datagram: header (12) + ciphertext
+        const datagram = new Uint8Array(MEDIA_HEADER_SIZE + ciphertext.length);
+        datagram.set(header, 0);
+        datagram.set(ciphertext, MEDIA_HEADER_SIZE);
+
+        try {
+          await this.datagramWriter.write(datagram);
+        } catch (e) {
+          // Datagram send can fail if the transport is closing.
+          if (this._connected) {
+            console.warn('[wzp-full] datagram write failed:', e);
+          }
+          return;
+        }
+        this.stats.sent++;
+      }
+    }
+    // If FEC block not yet complete, accumulate (no packets sent yet).
+
+    this.sequence = (this.sequence + 1) & 0xFFFF;
+  }
+
+  /**
+   * Test crypto + FEC roundtrip entirely in WASM (no network).
+   * Useful for verifying the WASM module works correctly in the browser.
+   *
+   * @returns {Object} test results
+   */
+  testCryptoFec() {
+    if (!this._wasmModule) {
+      return { success: false, error: 'WASM module not loaded' };
+    }
+
+    const t0 = performance.now();
+    const wasm = this._wasmModule;
+
+    // Key exchange
+    const alice = new wasm.WzpKeyExchange();
+    const bob = new wasm.WzpKeyExchange();
+    const aliceSecret = alice.derive_shared_secret(bob.public_key());
+    const bobSecret = bob.derive_shared_secret(alice.public_key());
+
+    // Verify secrets match
+    let secretsMatch = aliceSecret.length === bobSecret.length;
+    if (secretsMatch) {
+      for (let i = 0; i < aliceSecret.length; i++) {
+        if (aliceSecret[i] !== bobSecret[i]) { secretsMatch = false; break; }
+      }
+    }
+
+    // Encrypt/decrypt
+    const aliceSession = new wasm.WzpCryptoSession(aliceSecret);
+    const bobSession = new wasm.WzpCryptoSession(bobSecret);
+
+    const header = new Uint8Array([0xDE, 0xAD, 0xBE, 0xEF]);
+    const plaintext = new TextEncoder().encode('hello warzone from full variant');
+
+    const ciphertext = aliceSession.encrypt(header, plaintext);
+    const decrypted = bobSession.decrypt(header, ciphertext);
+
+    let cryptoOk = decrypted.length === plaintext.length;
+    if (cryptoOk) {
+      for (let i = 0; i < plaintext.length; i++) {
+        if (decrypted[i] !== plaintext[i]) { cryptoOk = false; break; }
+      }
+    }
+
+    // FEC test (same as hybrid testFec)
+    const encoder = new wasm.WzpFecEncoder(5, 256);
+    const decoder = new wasm.WzpFecDecoder(5, 256);
+
+    const frames = [];
+    for (let i = 0; i < 5; i++) {
+      const frame = new Uint8Array(100);
+      for (let j = 0; j < 100; j++) frame[j] = ((i * 37 + 7) + j) & 0xFF;
+      frames.push(frame);
+    }
+
+    let wireData = null;
+    for (const frame of frames) {
+      const result = encoder.add_symbol(frame);
+      if (result) wireData = result;
+    }
+
+    const PACKET_SIZE = FEC_HEADER_SIZE + 256;
+    const packets = [];
+    if (wireData) {
+      for (let off = 0; off + PACKET_SIZE <= wireData.length; off += PACKET_SIZE) {
+        packets.push({
+          blockId: wireData[off],
+          symbolIdx: wireData[off + 1],
+          isRepair: wireData[off + 2] !== 0,
+          data: wireData.slice(off + FEC_HEADER_SIZE, off + PACKET_SIZE),
+        });
+      }
+    }
+
+    // Drop 2 packets, try to recover
+    let fecDecoded = null;
+    for (let i = 0; i < packets.length; i++) {
+      if (i === 1 || i === 3) continue; // simulate loss
+      const pkt = packets[i];
+      const result = decoder.add_symbol(pkt.blockId, pkt.symbolIdx, pkt.isRepair, pkt.data);
+      if (result) { fecDecoded = result; break; }
+    }
+
+    let fecOk = false;
+    if (fecDecoded) {
+      const expected = new Uint8Array(5 * 100);
+      let off = 0;
+      for (const f of frames) { expected.set(f, off); off += f.length; }
+      fecOk = fecDecoded.length === expected.length;
+      if (fecOk) {
+        for (let i = 0; i < expected.length; i++) {
+          if (fecDecoded[i] !== expected[i]) { fecOk = false; break; }
+        }
+      }
+    }
+
+    // Cleanup WASM objects
+    alice.free();
+    bob.free();
+    aliceSession.free();
+    bobSession.free();
+    encoder.free();
+    decoder.free();
+
+    const elapsed = performance.now() - t0;
+
+    return {
+      success: secretsMatch && cryptoOk && fecOk,
+      secretsMatch,
+      cryptoOk,
+      fecOk,
+      fecPacketsTotal: packets.length,
+      fecDropped: 2,
+      elapsed: elapsed.toFixed(2) + 'ms',
+    };
+  }
+
+  // =========================================================================
+  // Internal
+  // =========================================================================
+
+  /**
+   * Perform X25519 key exchange over a WebTransport bidirectional stream.
+   *
+   * Protocol (simplified DH, not the full SignalMessage handshake):
+   *   1. Open a bidirectional stream.
+   *   2. Send our 32-byte X25519 public key.
+   *   3. Read the peer's 32-byte public key.
+   *   4. Derive shared secret via HKDF.
+   *   5. Create WzpCryptoSession from the shared secret.
+   *
+   * In production this would use the full SignalMessage protocol over the
+   * bidirectional stream (offer/answer/encrypted-session). For now we do
+   * a simple DH swap to prove the architecture.
+   */
+  async _performKeyExchange() {
+    const wasm = this._wasmModule;
+    const kx = new wasm.WzpKeyExchange();
+    const ourPub = kx.public_key(); // Uint8Array(32)
+
+    // Open a bidirectional stream for signaling.
+    const stream = await this.wt.createBidirectionalStream();
+    const writer = stream.writable.getWriter();
+    const reader = stream.readable.getReader();
+
+    // Send our public key.
+    await writer.write(new Uint8Array(ourPub));
+
+    // Read peer's public key (exactly 32 bytes).
+    // WebTransport streams are byte-oriented; we may get it in chunks.
+    let peerPub = new Uint8Array(0);
+    while (peerPub.length < 32) {
+      const { value, done } = await reader.read();
+      if (done) {
+        throw new Error('Key exchange stream closed before receiving peer public key');
+      }
+      const combined = new Uint8Array(peerPub.length + value.length);
+      combined.set(peerPub, 0);
+      combined.set(value, peerPub.length);
+      peerPub = combined;
+    }
+    peerPub = peerPub.slice(0, 32);
+
+    // Derive shared secret and create crypto session.
+    const secret = kx.derive_shared_secret(peerPub);
+    this.cryptoSession = new wasm.WzpCryptoSession(secret);
+
+    // Close the signaling stream (key exchange complete).
+    try {
+      writer.releaseLock();
+      reader.releaseLock();
+      await stream.writable.close();
+    } catch (_) {
+      // Best-effort close.
+    }
+
+    kx.free();
+  }
+
+  /**
+   * Receive loop: read datagrams, decrypt, FEC decode, play audio.
+   *
+   * Runs until the transport closes or disconnect() is called.
+   */
+  async _recvLoop() {
+    if (this._recvLoopRunning) return;
+    this._recvLoopRunning = true;
+
+    try {
+      while (this._connected && this.datagramReader) {
+        const { value, done } = await this.datagramReader.read();
+        if (done) break;
+
+        this.stats.recv++;
+
+        // value is a Uint8Array datagram: header(12) + ciphertext
+        if (value.length <= MEDIA_HEADER_SIZE) continue; // too short
+
+        const headerAad = value.slice(0, MEDIA_HEADER_SIZE);
+        const ciphertext = value.slice(MEDIA_HEADER_SIZE);
+
+        // Decrypt
+        let fecPacket;
+        try {
+          fecPacket = this.cryptoSession.decrypt(headerAad, ciphertext);
+          this.stats.decrypted++;
+        } catch (e) {
+          // Decryption failure — corrupted or out-of-order packet.
+          // In a real implementation we'd handle sequence number gaps.
+          console.warn('[wzp-full] decrypt failed:', e);
+          continue;
+        }
+
+        // FEC decode: parse the FEC wire header and feed to decoder.
+        if (fecPacket.length < FEC_HEADER_SIZE) continue;
+        const blockId = fecPacket[0];
+        const symbolIdx = fecPacket[1];
+        const isRepair = fecPacket[2] !== 0;
+        const symbolData = fecPacket.slice(FEC_HEADER_SIZE);
+
+        const decoded = this.fecDecoder.add_symbol(blockId, symbolIdx, isRepair, symbolData);
+        if (decoded) {
+          this.stats.fecRecovered++;
+          // decoded is concatenated original PCM frames.
+          // Each frame is 1920 bytes (960 Int16 samples @ 48kHz mono).
+          const FRAME_BYTES = 1920;
+          for (let off = 0; off + FRAME_BYTES <= decoded.length; off += FRAME_BYTES) {
+            const pcmSlice = decoded.slice(off, off + FRAME_BYTES);
+            const pcm = new Int16Array(pcmSlice.buffer, pcmSlice.byteOffset, pcmSlice.byteLength / 2);
+            if (this.onAudio) {
+              this.onAudio(pcm);
+            }
+          }
+        }
+      }
+    } catch (e) {
+      if (this._connected) {
+        console.warn('[wzp-full] recv loop error:', e);
+      }
+    } finally {
+      this._recvLoopRunning = false;
+    }
+  }
+
+  /**
+   * Build a minimal 12-byte MediaHeader for use as AAD.
+   *
+   * Wire layout (from wzp-proto::packet::MediaHeader):
+   *   Byte 0:  V(1)|T(1)|CodecID(4)|Q(1)|FecRatioHi(1)
+   *   Byte 1:  FecRatioLo(6)|unused(2)
+   *   Bytes 2-3: Sequence number (BE u16)
+   *   Bytes 4-7: Timestamp ms (BE u32)
+   *   Byte 8:  FEC block ID
+   *   Byte 9:  FEC symbol index
+   *   Byte 10: Reserved
+   *   Byte 11: CSRC count
+   *
+   * @param {number} seq  Sequence number (u16)
+   * @returns {Uint8Array} 12-byte header
+   */
+  _buildMediaHeader(seq) {
+    const buf = new Uint8Array(MEDIA_HEADER_SIZE);
+    // Byte 0: version=0, is_repair=0, codec=0 (Opus), quality_report=0, fec_ratio_hi=0
+    buf[0] = 0x00;
+    // Byte 1: fec_ratio_lo=0
+    buf[1] = 0x00;
+    // Bytes 2-3: sequence (BE u16)
+    buf[2] = (seq >> 8) & 0xFF;
+    buf[3] = seq & 0xFF;
+    // Bytes 4-7: timestamp (BE u32) — ms since session start
+    const ts = Date.now() - this._startTime;
+    buf[4] = (ts >> 24) & 0xFF;
+    buf[5] = (ts >> 16) & 0xFF;
+    buf[6] = (ts >> 8) & 0xFF;
+    buf[7] = ts & 0xFF;
+    // Bytes 8-11: FEC block/symbol/reserved/csrc — filled by FEC layer in production
+    return buf;
+  }
+
+  _startStatsTimer() {
+    this._stopStatsTimer();
+    this._statsInterval = setInterval(() => {
+      if (!this._connected) {
+        this._stopStatsTimer();
+        return;
+      }
+      const elapsed = (Date.now() - this._startTime) / 1000;
+      const loss = this.stats.sent > 0
+        ? Math.max(0, 1 - this.stats.recv / this.stats.sent)
+        : 0;
+      if (this.onStats) {
+        this.onStats({
+          sent: this.stats.sent,
+          recv: this.stats.recv,
+          loss,
+          elapsed,
+          encrypted: this.stats.encrypted,
+          decrypted: this.stats.decrypted,
+          fecRecovered: this.stats.fecRecovered,
+        });
+      }
+    }, 1000);
+  }
+
+  _stopStatsTimer() {
+    if (this._statsInterval) {
+      clearInterval(this._statsInterval);
+      this._statsInterval = null;
+    }
+  }
+
+  _status(msg) {
+    if (this.onStatus) this.onStatus(msg);
+  }
+
+  _cleanup() {
+    this._connected = false;
+    this._stopStatsTimer();
+    this.datagramWriter = null;
+    this.datagramReader = null;
+    if (this.cryptoSession) {
+      try { this.cryptoSession.free(); } catch (_) { /* ignore */ }
+      this.cryptoSession = null;
+    }
+    if (this.fecEncoder) {
+      try { this.fecEncoder.free(); } catch (_) { /* ignore */ }
+      this.fecEncoder = null;
+    }
+    if (this.fecDecoder) {
+      try { this.fecDecoder.free(); } catch (_) { /* ignore */ }
+      this.fecDecoder = null;
+    }
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Export
+// ---------------------------------------------------------------------------
+
+window.WZPFullClient = WZPFullClient;

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

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

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

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

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

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

crates/wzp-web/static/wasm/wzp_wasm.js

@@ -0,0 +1,556 @@
+/* @ts-self-types="./wzp_wasm.d.ts" */
+
+/**
+ * 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 {
+    __destroy_into_raw() {
+        const ptr = this.__wbg_ptr;
+        this.__wbg_ptr = 0;
+        WzpCryptoSessionFinalization.unregister(this);
+        return ptr;
+    }
+    free() {
+        const ptr = this.__destroy_into_raw();
+        wasm.__wbg_wzpcryptosession_free(ptr, 0);
+    }
+    /**
+     * Decrypt a media payload with AAD.
+     *
+     * Returns plaintext on success, or throws on auth failure.
+     * @param {Uint8Array} header_aad
+     * @param {Uint8Array} ciphertext
+     * @returns {Uint8Array}
+     */
+    decrypt(header_aad, ciphertext) {
+        const ptr0 = passArray8ToWasm0(header_aad, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ptr1 = passArray8ToWasm0(ciphertext, wasm.__wbindgen_malloc);
+        const len1 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpcryptosession_decrypt(this.__wbg_ptr, ptr0, len0, ptr1, len1);
+        if (ret[3]) {
+            throw takeFromExternrefTable0(ret[2]);
+        }
+        var v3 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        return v3;
+    }
+    /**
+     * Encrypt a media payload with AAD (typically the 12-byte MediaHeader).
+     *
+     * Returns `ciphertext || poly1305_tag` (plaintext.len() + 16 bytes).
+     * @param {Uint8Array} header_aad
+     * @param {Uint8Array} plaintext
+     * @returns {Uint8Array}
+     */
+    encrypt(header_aad, plaintext) {
+        const ptr0 = passArray8ToWasm0(header_aad, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ptr1 = passArray8ToWasm0(plaintext, wasm.__wbindgen_malloc);
+        const len1 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpcryptosession_encrypt(this.__wbg_ptr, ptr0, len0, ptr1, len1);
+        if (ret[3]) {
+            throw takeFromExternrefTable0(ret[2]);
+        }
+        var v3 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        return v3;
+    }
+    /**
+     * Create from a 32-byte shared secret (output of `WzpKeyExchange.derive_shared_secret`).
+     * @param {Uint8Array} shared_secret
+     */
+    constructor(shared_secret) {
+        const ptr0 = passArray8ToWasm0(shared_secret, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpcryptosession_new(ptr0, len0);
+        if (ret[2]) {
+            throw takeFromExternrefTable0(ret[1]);
+        }
+        this.__wbg_ptr = ret[0] >>> 0;
+        WzpCryptoSessionFinalization.register(this, this.__wbg_ptr, this);
+        return this;
+    }
+    /**
+     * Current receive sequence number (for diagnostics / UI stats).
+     * @returns {number}
+     */
+    recv_seq() {
+        const ret = wasm.wzpcryptosession_recv_seq(this.__wbg_ptr);
+        return ret >>> 0;
+    }
+    /**
+     * Current send sequence number (for diagnostics / UI stats).
+     * @returns {number}
+     */
+    send_seq() {
+        const ret = wasm.wzpcryptosession_send_seq(this.__wbg_ptr);
+        return ret >>> 0;
+    }
+}
+if (Symbol.dispose) WzpCryptoSession.prototype[Symbol.dispose] = WzpCryptoSession.prototype.free;
+
+export class WzpFecDecoder {
+    __destroy_into_raw() {
+        const ptr = this.__wbg_ptr;
+        this.__wbg_ptr = 0;
+        WzpFecDecoderFinalization.unregister(this);
+        return ptr;
+    }
+    free() {
+        const ptr = this.__destroy_into_raw();
+        wasm.__wbg_wzpfecdecoder_free(ptr, 0);
+    }
+    /**
+     * Feed a received symbol.
+     *
+     * Returns the decoded block (concatenated original frames, unpadded) if
+     * enough symbols have been received to recover the block, or `undefined`.
+     * @param {number} block_id
+     * @param {number} symbol_idx
+     * @param {boolean} _is_repair
+     * @param {Uint8Array} data
+     * @returns {Uint8Array | undefined}
+     */
+    add_symbol(block_id, symbol_idx, _is_repair, data) {
+        const ptr0 = passArray8ToWasm0(data, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpfecdecoder_add_symbol(this.__wbg_ptr, block_id, symbol_idx, _is_repair, ptr0, len0);
+        let v2;
+        if (ret[0] !== 0) {
+            v2 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+            wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        }
+        return v2;
+    }
+    /**
+     * 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).
+     * @param {number} block_size
+     * @param {number} symbol_size
+     */
+    constructor(block_size, symbol_size) {
+        const ret = wasm.wzpfecdecoder_new(block_size, symbol_size);
+        this.__wbg_ptr = ret >>> 0;
+        WzpFecDecoderFinalization.register(this, this.__wbg_ptr, this);
+        return this;
+    }
+}
+if (Symbol.dispose) WzpFecDecoder.prototype[Symbol.dispose] = WzpFecDecoder.prototype.free;
+
+export class WzpFecEncoder {
+    __destroy_into_raw() {
+        const ptr = this.__wbg_ptr;
+        this.__wbg_ptr = 0;
+        WzpFecEncoderFinalization.unregister(this);
+        return ptr;
+    }
+    free() {
+        const ptr = this.__destroy_into_raw();
+        wasm.__wbg_wzpfecencoder_free(ptr, 0);
+    }
+    /**
+     * 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.
+     * @param {Uint8Array} data
+     * @returns {Uint8Array | undefined}
+     */
+    add_symbol(data) {
+        const ptr0 = passArray8ToWasm0(data, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpfecencoder_add_symbol(this.__wbg_ptr, ptr0, len0);
+        let v2;
+        if (ret[0] !== 0) {
+            v2 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+            wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        }
+        return v2;
+    }
+    /**
+     * Force-flush the current (possibly partial) block.
+     *
+     * Returns all source + repair symbols with headers, or empty vec if no
+     * symbols have been accumulated.
+     * @returns {Uint8Array}
+     */
+    flush() {
+        const ret = wasm.wzpfecencoder_flush(this.__wbg_ptr);
+        var v1 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        return v1;
+    }
+    /**
+     * 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).
+     * @param {number} block_size
+     * @param {number} symbol_size
+     */
+    constructor(block_size, symbol_size) {
+        const ret = wasm.wzpfecencoder_new(block_size, symbol_size);
+        this.__wbg_ptr = ret >>> 0;
+        WzpFecEncoderFinalization.register(this, this.__wbg_ptr, this);
+        return this;
+    }
+}
+if (Symbol.dispose) WzpFecEncoder.prototype[Symbol.dispose] = WzpFecEncoder.prototype.free;
+
+/**
+ * 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 {
+    __destroy_into_raw() {
+        const ptr = this.__wbg_ptr;
+        this.__wbg_ptr = 0;
+        WzpKeyExchangeFinalization.unregister(this);
+        return ptr;
+    }
+    free() {
+        const ptr = this.__destroy_into_raw();
+        wasm.__wbg_wzpkeyexchange_free(ptr, 0);
+    }
+    /**
+     * 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`.
+     * @param {Uint8Array} peer_public
+     * @returns {Uint8Array}
+     */
+    derive_shared_secret(peer_public) {
+        const ptr0 = passArray8ToWasm0(peer_public, wasm.__wbindgen_malloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ret = wasm.wzpkeyexchange_derive_shared_secret(this.__wbg_ptr, ptr0, len0);
+        if (ret[3]) {
+            throw takeFromExternrefTable0(ret[2]);
+        }
+        var v2 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        return v2;
+    }
+    /**
+     * Generate a new random X25519 keypair.
+     */
+    constructor() {
+        const ret = wasm.wzpkeyexchange_new();
+        this.__wbg_ptr = ret >>> 0;
+        WzpKeyExchangeFinalization.register(this, this.__wbg_ptr, this);
+        return this;
+    }
+    /**
+     * Our public key (32 bytes).
+     * @returns {Uint8Array}
+     */
+    public_key() {
+        const ret = wasm.wzpkeyexchange_public_key(this.__wbg_ptr);
+        var v1 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+        return v1;
+    }
+}
+if (Symbol.dispose) WzpKeyExchange.prototype[Symbol.dispose] = WzpKeyExchange.prototype.free;
+
+function __wbg_get_imports() {
+    const import0 = {
+        __proto__: null,
+        __wbg___wbindgen_is_function_3c846841762788c1: function(arg0) {
+            const ret = typeof(arg0) === 'function';
+            return ret;
+        },
+        __wbg___wbindgen_is_object_781bc9f159099513: function(arg0) {
+            const val = arg0;
+            const ret = typeof(val) === 'object' && val !== null;
+            return ret;
+        },
+        __wbg___wbindgen_is_string_7ef6b97b02428fae: function(arg0) {
+            const ret = typeof(arg0) === 'string';
+            return ret;
+        },
+        __wbg___wbindgen_is_undefined_52709e72fb9f179c: function(arg0) {
+            const ret = arg0 === undefined;
+            return ret;
+        },
+        __wbg___wbindgen_throw_6ddd609b62940d55: function(arg0, arg1) {
+            throw new Error(getStringFromWasm0(arg0, arg1));
+        },
+        __wbg_call_2d781c1f4d5c0ef8: function() { return handleError(function (arg0, arg1, arg2) {
+            const ret = arg0.call(arg1, arg2);
+            return ret;
+        }, arguments); },
+        __wbg_crypto_38df2bab126b63dc: function(arg0) {
+            const ret = arg0.crypto;
+            return ret;
+        },
+        __wbg_getRandomValues_c44a50d8cfdaebeb: function() { return handleError(function (arg0, arg1) {
+            arg0.getRandomValues(arg1);
+        }, arguments); },
+        __wbg_length_ea16607d7b61445b: function(arg0) {
+            const ret = arg0.length;
+            return ret;
+        },
+        __wbg_msCrypto_bd5a034af96bcba6: function(arg0) {
+            const ret = arg0.msCrypto;
+            return ret;
+        },
+        __wbg_new_with_length_825018a1616e9e55: function(arg0) {
+            const ret = new Uint8Array(arg0 >>> 0);
+            return ret;
+        },
+        __wbg_node_84ea875411254db1: function(arg0) {
+            const ret = arg0.node;
+            return ret;
+        },
+        __wbg_process_44c7a14e11e9f69e: function(arg0) {
+            const ret = arg0.process;
+            return ret;
+        },
+        __wbg_prototypesetcall_d62e5099504357e6: function(arg0, arg1, arg2) {
+            Uint8Array.prototype.set.call(getArrayU8FromWasm0(arg0, arg1), arg2);
+        },
+        __wbg_randomFillSync_6c25eac9869eb53c: function() { return handleError(function (arg0, arg1) {
+            arg0.randomFillSync(arg1);
+        }, arguments); },
+        __wbg_require_b4edbdcf3e2a1ef0: function() { return handleError(function () {
+            const ret = module.require;
+            return ret;
+        }, arguments); },
+        __wbg_static_accessor_GLOBAL_8adb955bd33fac2f: function() {
+            const ret = typeof global === 'undefined' ? null : global;
+            return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+        },
+        __wbg_static_accessor_GLOBAL_THIS_ad356e0db91c7913: function() {
+            const ret = typeof globalThis === 'undefined' ? null : globalThis;
+            return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+        },
+        __wbg_static_accessor_SELF_f207c857566db248: function() {
+            const ret = typeof self === 'undefined' ? null : self;
+            return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+        },
+        __wbg_static_accessor_WINDOW_bb9f1ba69d61b386: function() {
+            const ret = typeof window === 'undefined' ? null : window;
+            return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+        },
+        __wbg_subarray_a068d24e39478a8a: function(arg0, arg1, arg2) {
+            const ret = arg0.subarray(arg1 >>> 0, arg2 >>> 0);
+            return ret;
+        },
+        __wbg_versions_276b2795b1c6a219: function(arg0) {
+            const ret = arg0.versions;
+            return ret;
+        },
+        __wbindgen_cast_0000000000000001: function(arg0, arg1) {
+            // Cast intrinsic for `Ref(Slice(U8)) -> NamedExternref("Uint8Array")`.
+            const ret = getArrayU8FromWasm0(arg0, arg1);
+            return ret;
+        },
+        __wbindgen_cast_0000000000000002: function(arg0, arg1) {
+            // Cast intrinsic for `Ref(String) -> Externref`.
+            const ret = getStringFromWasm0(arg0, arg1);
+            return ret;
+        },
+        __wbindgen_init_externref_table: function() {
+            const table = wasm.__wbindgen_externrefs;
+            const offset = table.grow(4);
+            table.set(0, undefined);
+            table.set(offset + 0, undefined);
+            table.set(offset + 1, null);
+            table.set(offset + 2, true);
+            table.set(offset + 3, false);
+        },
+    };
+    return {
+        __proto__: null,
+        "./wzp_wasm_bg.js": import0,
+    };
+}
+
+const WzpCryptoSessionFinalization = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(ptr => wasm.__wbg_wzpcryptosession_free(ptr >>> 0, 1));
+const WzpFecDecoderFinalization = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(ptr => wasm.__wbg_wzpfecdecoder_free(ptr >>> 0, 1));
+const WzpFecEncoderFinalization = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(ptr => wasm.__wbg_wzpfecencoder_free(ptr >>> 0, 1));
+const WzpKeyExchangeFinalization = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(ptr => wasm.__wbg_wzpkeyexchange_free(ptr >>> 0, 1));
+
+function addToExternrefTable0(obj) {
+    const idx = wasm.__externref_table_alloc();
+    wasm.__wbindgen_externrefs.set(idx, obj);
+    return idx;
+}
+
+function getArrayU8FromWasm0(ptr, len) {
+    ptr = ptr >>> 0;
+    return getUint8ArrayMemory0().subarray(ptr / 1, ptr / 1 + len);
+}
+
+function getStringFromWasm0(ptr, len) {
+    ptr = ptr >>> 0;
+    return decodeText(ptr, len);
+}
+
+let cachedUint8ArrayMemory0 = null;
+function getUint8ArrayMemory0() {
+    if (cachedUint8ArrayMemory0 === null || cachedUint8ArrayMemory0.byteLength === 0) {
+        cachedUint8ArrayMemory0 = new Uint8Array(wasm.memory.buffer);
+    }
+    return cachedUint8ArrayMemory0;
+}
+
+function handleError(f, args) {
+    try {
+        return f.apply(this, args);
+    } catch (e) {
+        const idx = addToExternrefTable0(e);
+        wasm.__wbindgen_exn_store(idx);
+    }
+}
+
+function isLikeNone(x) {
+    return x === undefined || x === null;
+}
+
+function passArray8ToWasm0(arg, malloc) {
+    const ptr = malloc(arg.length * 1, 1) >>> 0;
+    getUint8ArrayMemory0().set(arg, ptr / 1);
+    WASM_VECTOR_LEN = arg.length;
+    return ptr;
+}
+
+function takeFromExternrefTable0(idx) {
+    const value = wasm.__wbindgen_externrefs.get(idx);
+    wasm.__externref_table_dealloc(idx);
+    return value;
+}
+
+let cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+cachedTextDecoder.decode();
+const MAX_SAFARI_DECODE_BYTES = 2146435072;
+let numBytesDecoded = 0;
+function decodeText(ptr, len) {
+    numBytesDecoded += len;
+    if (numBytesDecoded >= MAX_SAFARI_DECODE_BYTES) {
+        cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+        cachedTextDecoder.decode();
+        numBytesDecoded = len;
+    }
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
+let WASM_VECTOR_LEN = 0;
+
+let wasmModule, wasm;
+function __wbg_finalize_init(instance, module) {
+    wasm = instance.exports;
+    wasmModule = module;
+    cachedUint8ArrayMemory0 = null;
+    wasm.__wbindgen_start();
+    return wasm;
+}
+
+async function __wbg_load(module, imports) {
+    if (typeof Response === 'function' && module instanceof Response) {
+        if (typeof WebAssembly.instantiateStreaming === 'function') {
+            try {
+                return await WebAssembly.instantiateStreaming(module, imports);
+            } catch (e) {
+                const validResponse = module.ok && expectedResponseType(module.type);
+
+                if (validResponse && module.headers.get('Content-Type') !== 'application/wasm') {
+                    console.warn("`WebAssembly.instantiateStreaming` failed because your server does not serve Wasm with `application/wasm` MIME type. Falling back to `WebAssembly.instantiate` which is slower. Original error:\n", e);
+
+                } else { throw e; }
+            }
+        }
+
+        const bytes = await module.arrayBuffer();
+        return await WebAssembly.instantiate(bytes, imports);
+    } else {
+        const instance = await WebAssembly.instantiate(module, imports);
+
+        if (instance instanceof WebAssembly.Instance) {
+            return { instance, module };
+        } else {
+            return instance;
+        }
+    }
+
+    function expectedResponseType(type) {
+        switch (type) {
+            case 'basic': case 'cors': case 'default': return true;
+        }
+        return false;
+    }
+}
+
+function initSync(module) {
+    if (wasm !== undefined) return wasm;
+
+
+    if (module !== undefined) {
+        if (Object.getPrototypeOf(module) === Object.prototype) {
+            ({module} = module)
+        } else {
+            console.warn('using deprecated parameters for `initSync()`; pass a single object instead')
+        }
+    }
+
+    const imports = __wbg_get_imports();
+    if (!(module instanceof WebAssembly.Module)) {
+        module = new WebAssembly.Module(module);
+    }
+    const instance = new WebAssembly.Instance(module, imports);
+    return __wbg_finalize_init(instance, module);
+}
+
+async function __wbg_init(module_or_path) {
+    if (wasm !== undefined) return wasm;
+
+
+    if (module_or_path !== undefined) {
+        if (Object.getPrototypeOf(module_or_path) === Object.prototype) {
+            ({module_or_path} = module_or_path)
+        } else {
+            console.warn('using deprecated parameters for the initialization function; pass a single object instead')
+        }
+    }
+
+    if (module_or_path === undefined) {
+        module_or_path = new URL('wzp_wasm_bg.wasm', import.meta.url);
+    }
+    const imports = __wbg_get_imports();
+
+    if (typeof module_or_path === 'string' || (typeof Request === 'function' && module_or_path instanceof Request) || (typeof URL === 'function' && module_or_path instanceof URL)) {
+        module_or_path = fetch(module_or_path);
+    }
+
+    const { instance, module } = await __wbg_load(await module_or_path, imports);
+
+    return __wbg_finalize_init(instance, module);
+}
+
+export { initSync, __wbg_init as default };

docs/ARCHITECTURE.md

@@ -1,329 +1,607 @@
-# WarzonePhone Protocol Design & Architecture
+# WarzonePhone Architecture
 
-## Network Topology
+> Custom lossy VoIP protocol built in Rust. E2E encrypted, FEC-protected, adaptive quality, designed for hostile network conditions.
 
-```
+## System Overview
-                 Lossy / censored link
+
-                 ◄──────────────────────►
+```mermaid
-  ┌────────┐      ┌─────────┐      ┌─────────┐      ┌─────────────┐
+graph TB
-  │ Client │─QUIC─│ Relay A │─QUIC─│ Relay B │─QUIC─│ Destination │
+    subgraph "Client A (Browser/CLI)"
-  └────────┘      └─────────┘      └─────────┘      └─────────────┘
+        MIC[Microphone] --> DN[NoiseSupressor<br/>RNNoise ML]
-      │                │                │                   │
+        DN --> SD[SilenceDetector<br/>VAD + Hangover]
-   Encode           Forward          Forward             Decode
+        SD --> ENC[CallEncoder<br/>Opus/Codec2]
-   FEC              FEC              FEC                 FEC
+        ENC --> FEC_E[FEC Encoder<br/>RaptorQ]
-   Encrypt          (opaque)         (opaque)            Decrypt
+        FEC_E --> CRYPT_E[ChaCha20-Poly1305<br/>Encrypt]
+        CRYPT_E --> QUIC_S[QUIC Datagram<br/>Send]
+
+        QUIC_R[QUIC Datagram<br/>Recv] --> CRYPT_D[ChaCha20-Poly1305<br/>Decrypt]
+        CRYPT_D --> FEC_D[FEC Decoder<br/>RaptorQ]
+        FEC_D --> JIT[JitterBuffer<br/>Adaptive Playout]
+        JIT --> DEC[CallDecoder<br/>Opus/Codec2]
+        DEC --> SPK[Speaker]
+    end
+
+    subgraph "Relay (SFU)"
+        ACCEPT[Accept QUIC] --> AUTH{Auth?}
+        AUTH -->|token| VALIDATE[POST /v1/auth/validate]
+        AUTH -->|no auth| HS
+        VALIDATE --> HS[Crypto Handshake<br/>X25519 + Ed25519]
+        HS --> ROOM[Room Manager<br/>Named Rooms via SNI]
+        ROOM --> FWD[Forward to<br/>Other Participants]
+    end
+
+    subgraph "Client B"
+        B_SPK[Speaker]
+        B_MIC[Microphone]
+    end
+
+    QUIC_S -->|UDP/QUIC| ACCEPT
+    FWD -->|UDP/QUIC| QUIC_R
+    B_MIC -.->|same pipeline| ACCEPT
+    FWD -.->|same pipeline| B_SPK
+
+    style MIC fill:#4a9eff
+    style SPK fill:#4a9eff
+    style B_MIC fill:#4a9eff
+    style B_SPK fill:#4a9eff
+    style ROOM fill:#ff9f43
+    style CRYPT_E fill:#ee5a24
+    style CRYPT_D fill:#ee5a24
 ```
 
-In the simplest deployment a single relay serves as the meeting point (room mode, SFU). Clients connect directly to one relay, which forwards media to all other participants in the same room. For censorship-resistant links, two relays can be chained: a client-facing relay forwards all traffic to a remote relay via QUIC.
+## Crate Dependency Graph
 
-Room names are carried in the QUIC SNI field during the TLS handshake, so a single relay can host many independent rooms without additional signaling.
+```mermaid
+graph TD
+    PROTO[wzp-proto<br/>Types, Traits, Wire Format]
 
-## Protocol Stack
+    CODEC[wzp-codec<br/>Opus + Codec2 + RNNoise]
+    FEC[wzp-fec<br/>RaptorQ FEC]
+    CRYPTO[wzp-crypto<br/>ChaCha20 + Identity]
+    TRANSPORT[wzp-transport<br/>QUIC/Quinn]
 
-```
+    RELAY[wzp-relay<br/>Relay Daemon]
-┌──────────────────────────────────────────────┐
+    CLIENT[wzp-client<br/>CLI + Call Engine]
-│  Application (Opus / Codec2 audio)           │  wzp-codec
+    WEB[wzp-web<br/>Browser Bridge]
-├──────────────────────────────────────────────┤
+
-│  Redundancy (RaptorQ FEC + interleaving)     │  wzp-fec
+    PROTO --> CODEC
-├──────────────────────────────────────────────┤
+    PROTO --> FEC
-│  Crypto (ChaCha20-Poly1305 + AEAD)          │  wzp-crypto
+    PROTO --> CRYPTO
-├──────────────────────────────────────────────┤
+    PROTO --> TRANSPORT
-│  Transport (QUIC DATAGRAM + reliable stream) │  wzp-transport
+
-├──────────────────────────────────────────────┤
+    CODEC --> CLIENT
-│  Obfuscation (Phase 2 — trait defined)       │  wzp-proto::ObfuscationLayer
+    FEC --> CLIENT
-└──────────────────────────────────────────────┘
+    CRYPTO --> CLIENT
+    TRANSPORT --> CLIENT
+    CODEC --> RELAY
+    FEC --> RELAY
+    CRYPTO --> RELAY
+    TRANSPORT --> RELAY
+
+    CLIENT --> WEB
+    TRANSPORT --> WEB
+    CRYPTO --> WEB
+
+    FC[warzone-protocol<br/>featherChat Identity] -.->|path dep| CRYPTO
+
+    style PROTO fill:#6c5ce7
+    style RELAY fill:#ff9f43
+    style CLIENT fill:#00b894
+    style WEB fill:#0984e3
+    style FC fill:#fd79a8
 ```
 
-Audio and FEC are end-to-end between caller and callee. The relay operates on opaque, encrypted, FEC-protected packets. Crypto keys are never shared with relays.
+## Wire Formats
-
-## Wire Format
 
 ### MediaHeader (12 bytes)
 
 ```
-Byte 0:  [V:1][T:1][CodecID:4][Q:1][FecRatioHi:1]
+Byte 0:  [V:1][T:1][CodecID:4][Q:1][FecHi:1]
-Byte 1:  [FecRatioLo:6][unused:2]
+Byte 1:  [FecLo:6][unused:2]
-Byte 2-3: Sequence number (big-endian u16)
+Bytes 2-3:  sequence (u16 BE)
-Byte 4-7: Timestamp in ms since session start (big-endian u32)
+Bytes 4-7:  timestamp_ms (u32 BE)
-Byte 8:   FEC block ID (wrapping u8)
+Byte 8:     fec_block_id (u8)
-Byte 9:   FEC symbol index within block
+Byte 9:     fec_symbol_idx (u8)
-Byte 10:  Reserved / flags
+Byte 10:    reserved
-Byte 11:  CSRC count (for future mixing)
+Byte 11:    csrc_count
+
+V = version (0), T = is_repair, CodecID = codec, Q = quality_report appended
 ```
 
-Field details:
+### MiniHeader (4 bytes, compressed)
-
-| Field | Bits | Description |
-|-------|------|-------------|
-| V | 1 | Protocol version (0 = v1) |
-| T | 1 | 1 = FEC repair packet, 0 = source media |
-| CodecID | 4 | Codec identifier (0=Opus24k, 1=Opus16k, 2=Opus6k, 3=Codec2_3200, 4=Codec2_1200) |
-| Q | 1 | QualityReport trailer appended |
-| FecRatio | 7 | FEC ratio encoded as 7-bit value (0-127 maps to 0.0-2.0) |
-| Seq | 16 | Wrapping packet sequence number |
-| Timestamp | 32 | Milliseconds since session start |
-| FEC block | 8 | Source block ID (wrapping) |
-| FEC symbol | 8 | Symbol index within the FEC block |
-| Reserved | 8 | Reserved flags |
-| CSRC count | 8 | Contributing source count (future) |
-
-Defined in `crates/wzp-proto/src/packet.rs` as `MediaHeader`.
-
-### QualityReport (4 bytes)
-
-Appended to a media packet when the Q flag is set.
 
 ```
-Byte 0: loss_pct     — 0-255 maps to 0-100% loss
+Bytes 0-1: timestamp_delta_ms (u16 BE)
-Byte 1: rtt_4ms      — RTT in 4ms units (0-255 = 0-1020ms)
+Bytes 2-3: payload_len (u16 BE)
-Byte 2: jitter_ms    — Jitter in milliseconds
+
-Byte 3: bitrate_cap  — Max receive bitrate in kbps
+Preceded by FRAME_TYPE_MINI (0x01). Full header every 50 frames (~1s).
+Saves 8 bytes/packet (67% header reduction).
 ```
 
-Defined in `crates/wzp-proto/src/packet.rs` as `QualityReport`.
+### TrunkFrame (batched datagrams)
-
-### MediaPacket
-
-A complete media packet on the wire:
 
 ```
-[MediaHeader: 12 bytes][Payload: variable][QualityReport: 4 bytes if Q=1]
+[count:u16]
+  [session_id:2][len:u16][payload:len]  x count
+
+Packs multiple session packets into one QUIC datagram.
+Max 10 entries or 1200 bytes, flushed every 5ms.
 ```
 
-Defined in `crates/wzp-proto/src/packet.rs` as `MediaPacket`.
+### QualityReport (4 bytes, optional)
-
-### SignalMessage (reliable stream)
-
-Signaling uses length-prefixed JSON over reliable QUIC bidirectional streams. Each message opens a new bidi stream, writes a 4-byte big-endian length prefix followed by the JSON payload, then finishes the send side.
-
-Variants defined in `crates/wzp-proto/src/packet.rs`:
-
-- `CallOffer` — identity_pub, ephemeral_pub, signature, supported_profiles
-- `CallAnswer` — identity_pub, ephemeral_pub, signature, chosen_profile
-- `IceCandidate` — NAT traversal candidate string
-- `Rekey` — new_ephemeral_pub, signature
-- `QualityUpdate` — report, recommended_profile
-- `Ping` / `Pong` — timestamp_ms for RTT measurement
-- `Hangup` — reason (Normal, Busy, Declined, Timeout, Error)
-
-## FEC Strategy
-
-WarzonePhone uses **RaptorQ fountain codes** (via the `raptorq` crate) for forward error correction. This is implemented in `crates/wzp-fec/`.
-
-### Block Structure
-
-Audio frames are grouped into FEC blocks. Each block contains a fixed number of source symbols (configured per quality profile). Each source symbol is a single encoded audio frame, zero-padded to a uniform 256-byte symbol size with a 2-byte little-endian length prefix.
-
-### Encoding Process
-
-1. Audio frames are added to the encoder as source symbols
-2. When a block is full (`frames_per_block` symbols), repair symbols are generated
-3. The repair ratio determines how many repair symbols: `ceil(num_source * ratio)`
-4. Both source and repair packets are transmitted with the block ID and symbol index in the header
-
-### Decoding Process
-
-1. Received symbols (source or repair) are fed to the decoder keyed by block ID
-2. The decoder attempts reconstruction when sufficient symbols arrive
-3. RaptorQ can recover the full block from any `K` symbols out of `K + R` total (where K = source count, R = repair count)
-4. Old blocks are expired via wrapping u8 distance
-
-### Interleaving
-
-The `Interleaver` spreads symbols from multiple FEC blocks across transmission slots in round-robin fashion. With depth=3, a burst loss of 6 consecutive packets damages at most 2 symbols per block instead of 6 symbols in one block.
-
-### FEC Configuration by Quality Tier
-
-| Tier | Frames/Block | Repair Ratio | Total Bandwidth Overhead |
-|------|-------------|-------------|-------------------------|
-| GOOD | 5 | 0.2 (20%) | 1.2x |
-| DEGRADED | 10 | 0.5 (50%) | 1.5x |
-| CATASTROPHIC | 8 | 1.0 (100%) | 2.0x |
-
-## Adaptive Quality
-
-Three quality tiers drive codec and FEC selection. The controller is implemented in `crates/wzp-proto/src/quality.rs` as `AdaptiveQualityController`.
-
-### Tier Thresholds
-
-| Tier | Loss | RTT | Codec | FEC Ratio |
-|------|------|-----|-------|-----------|
-| GOOD | < 10% | < 400ms | Opus 24kbps, 20ms frames | 0.2 |
-| DEGRADED | 10-40% or 400-600ms | | Opus 6kbps, 40ms frames | 0.5 |
-| CATASTROPHIC | > 40% or > 600ms | | Codec2 1200bps, 40ms frames | 1.0 |
-
-### Hysteresis
-
-- **Downgrade**: Triggers after 3 consecutive reports in a worse tier (fast reaction)
-- **Upgrade**: Triggers after 10 consecutive reports in a better tier (slow, cautious)
-- **Step limit**: Upgrades move only one tier at a time (Catastrophic -> Degraded -> Good)
-- **History**: A sliding window of 20 recent reports is maintained for smoothing
-- **Force mode**: Manual `force_profile()` disables adaptive logic entirely
-
-### QualityProfile Constants
-
-```rust
-GOOD:         Opus24k,     fec=0.2, 20ms, 5 frames/block  → 28.8 kbps total
-DEGRADED:     Opus6k,      fec=0.5, 40ms, 10 frames/block → 9.0 kbps total
-CATASTROPHIC: Codec2_1200, fec=1.0, 40ms, 8 frames/block  → 2.4 kbps total
-```
-
-## Encryption
-
-Implemented in `crates/wzp-crypto/`.
-
-### Identity Model (Warzone-Compatible)
-
-- **Seed**: 32-byte random value (BIP39 mnemonic for backup)
-- **Ed25519**: Derived via `HKDF(seed, "warzone-ed25519-identity")` -- signing/identity
-- **X25519**: Derived via `HKDF(seed, "warzone-x25519-identity")` -- encryption
-- **Fingerprint**: `SHA-256(Ed25519_pub)[:16]` -- 128-bit identifier
-
-### Per-Call Key Exchange
-
-1. Each side generates an ephemeral X25519 keypair
-2. Ephemeral public keys are exchanged via `CallOffer`/`CallAnswer` signaling
-3. Signatures are computed: `Ed25519_sign(ephemeral_pub || context_string)`
-4. Shared secret: `X25519_DH(our_ephemeral_secret, peer_ephemeral_pub)`
-5. Session key: `HKDF(shared_secret, "warzone-session-key")` -> 32 bytes
-
-### Nonce Construction (12 bytes, not transmitted)
 
 ```
-session_id[0..4] || sequence_number (u32 BE) || direction (1 byte) || padding (3 bytes zero)
+Byte 0: loss_pct (0-255 maps to 0-100%)
+Byte 1: rtt_4ms (0-255 maps to 0-1020ms)
+Byte 2: jitter_ms
+Byte 3: bitrate_cap_kbps
 ```
 
-- `session_id`: First 4 bytes of `SHA-256(session_key)`
+### SignalMessage (JSON over reliable QUIC stream)
-- `direction`: 0 = Send, 1 = Recv
-- Nonces are derived deterministically, saving 12 bytes per packet
-
-### AEAD Encryption
-
-- Algorithm: ChaCha20-Poly1305
-- AAD: The 12-byte MediaHeader (authenticated but not encrypted)
-- Tag: 16 bytes appended to ciphertext
-- Overhead per packet: 16 bytes
-
-### Rekeying
-
-- Trigger: Every 2^16 packets (65536)
-- Process: New ephemeral X25519 exchange, mixed with old key via HKDF
-- Key evolution: `HKDF(old_key as salt, new_DH_result, "warzone-rekey")`
-- Old key is zeroized after derivation (forward secrecy)
-- Sequence counters reset to 0 after rekey
-
-### Anti-Replay
-
-- Sliding window of 1024 packets using a bitmap
-- Sequence numbers too old (> 1024 behind highest seen) are rejected
-- Handles u16 wrapping correctly (RFC 1982 serial number arithmetic)
-- Implemented in `crates/wzp-crypto/src/anti_replay.rs` as `AntiReplayWindow`
-
-## Jitter Buffer
-
-Implemented in `crates/wzp-proto/src/jitter.rs` as `JitterBuffer`.
-
-- **Structure**: BTreeMap keyed by sequence number for ordered playout
-- **Target depth**: 50 packets (1 second) default
-- **Max depth**: 250 packets (5 seconds at 20ms/frame)
-- **Min depth**: 25 packets (0.5 seconds) before playout begins
-- **Sequence wrapping**: RFC 1982 serial number arithmetic for u16
-- **Duplicate handling**: Silently dropped
-- **Late packets**: Packets arriving after their sequence has been played out are dropped
-- **Overflow**: When buffer exceeds max depth, oldest packets are evicted
-
-### Playout Results
-
-- `Packet(MediaPacket)` -- normal delivery
-- `Missing { seq }` -- gap detected, decoder should generate PLC
-- `NotReady` -- buffer not yet filled to minimum depth
-
-### Known Limitations
-
-- No adaptive depth adjustment based on observed jitter (target_depth is configurable but not self-tuning in the current implementation)
-- No timestamp-based playout scheduling (uses sequence-number ordering only)
-- Jitter buffer drift has been observed during long echo tests
-
-## Session State Machine
-
-Defined in `crates/wzp-proto/src/session.rs`:
 
 ```
-Idle -> Connecting -> Handshaking -> Active <-> Rekeying -> Active
+[4-byte length prefix][serde_json payload]
-                                       |
+
-                                     Closed
+Variants:
+  CallOffer    { identity_pub, ephemeral_pub, signature, supported_profiles }
+  CallAnswer   { identity_pub, ephemeral_pub, signature, chosen_profile }
+  IceCandidate { candidate }
+  Hangup       { reason: Normal|Busy|Declined|Timeout|Error }
+  AuthToken    { token }
+  Hold, Unhold, Mute, Unmute
+  Transfer     { target_fingerprint, relay_addr }
+  TransferAck
+  Rekey        { new_ephemeral_pub, signature }
+  QualityUpdate { report, recommended_profile }
+  Ping/Pong    { timestamp_ms }
 ```
 
-- Media flows during both `Active` and `Rekeying` states
+## Quality Profiles
-- Any state can transition to `Closed` via `Terminate` or `ConnectionLost`
+
-- Invalid transitions produce a `TransitionError`
+```mermaid
+graph LR
+    subgraph GOOD ["GOOD (28.8 kbps)"]
+        G_C[Opus 24kbps]
+        G_F[FEC 20%]
+        G_FR[20ms frames]
+    end
+
+    subgraph DEGRADED ["DEGRADED (9.0 kbps)"]
+        D_C[Opus 6kbps]
+        D_F[FEC 50%]
+        D_FR[40ms frames]
+    end
+
+    subgraph CATASTROPHIC ["CATASTROPHIC (2.4 kbps)"]
+        C_C[Codec2 1200bps]
+        C_F[FEC 100%]
+        C_FR[40ms frames]
+    end
+
+    GOOD -->|"loss>5% or RTT>100ms<br/>3 consecutive reports"| DEGRADED
+    DEGRADED -->|"loss>15% or RTT>200ms<br/>3 consecutive"| CATASTROPHIC
+    CATASTROPHIC -->|"loss<5% and RTT<100ms<br/>3 consecutive"| DEGRADED
+    DEGRADED -->|"loss<5% and RTT<100ms<br/>3 consecutive"| GOOD
+
+    style GOOD fill:#00b894
+    style DEGRADED fill:#fdcb6e
+    style CATASTROPHIC fill:#e17055
+```
+
+## Cryptographic Handshake
+
+```mermaid
+sequenceDiagram
+    participant C as Caller
+    participant R as Relay/Callee
+
+    Note over C: Derive identity from seed<br/>Ed25519 + X25519 via HKDF
+
+    C->>C: Generate ephemeral X25519
+    C->>C: Sign(ephemeral_pub || "call-offer")
+    C->>R: CallOffer { identity_pub, ephemeral_pub, signature, profiles }
+
+    R->>R: Verify Ed25519 signature
+    R->>R: Generate ephemeral X25519
+    R->>R: shared_secret = DH(eph_b, eph_a)
+    R->>R: session_key = HKDF(shared_secret, "warzone-session-key")
+    R->>R: Sign(ephemeral_pub || "call-answer")
+    R->>C: CallAnswer { identity_pub, ephemeral_pub, signature, chosen_profile }
+
+    C->>C: Verify signature
+    C->>C: shared_secret = DH(eph_a, eph_b)
+    C->>C: session_key = HKDF(shared_secret)
+
+    Note over C,R: Both have identical ChaCha20-Poly1305 session key
+    C->>R: Encrypted media (QUIC datagrams)
+    R->>C: Encrypted media (QUIC datagrams)
+
+    Note over C,R: Rekey every 65,536 packets<br/>New ephemeral DH + HKDF mix
+```
+
+## Identity Model (featherChat Compatible)
+
+```mermaid
+graph TD
+    SEED[32-byte Seed<br/>BIP39 Mnemonic 24 words] --> HKDF1[HKDF<br/>salt=None<br/>info=warzone-ed25519]
+    SEED --> HKDF2[HKDF<br/>salt=None<br/>info=warzone-x25519]
+
+    HKDF1 --> ED[Ed25519 SigningKey<br/>Digital Signatures]
+    HKDF2 --> X25519[X25519 StaticSecret<br/>Key Agreement]
+
+    ED --> VKEY[Ed25519 VerifyingKey<br/>Public]
+    X25519 --> XPUB[X25519 PublicKey<br/>Public]
+
+    VKEY --> FP[Fingerprint<br/>SHA-256 pubkey truncated 16 bytes<br/>xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx]
+
+    style SEED fill:#6c5ce7
+    style FP fill:#fd79a8
+    style ED fill:#ee5a24
+    style X25519 fill:#00b894
+```
 
 ## Relay Modes
 
-### Room Mode (Default, SFU)
+```mermaid
+graph TB
+    subgraph "Room Mode (Default SFU)"
+        C1[Client 1] -->|QUIC SNI=room-hash| RM[Room Manager]
+        C2[Client 2] -->|QUIC SNI=room-hash| RM
+        C3[Client 3] -->|QUIC SNI=room-hash| RM
+        RM --> R1[Room abc123]
+        R1 -->|fan-out| C1
+        R1 -->|fan-out| C2
+        R1 -->|fan-out| C3
+    end
 
-- Clients join named rooms via QUIC SNI
+    subgraph "Forward Mode with --remote"
-- When a participant sends a packet, the relay forwards it to all other participants
+        C4[Client] -->|QUIC| RA[Relay A]
-- No transcoding -- packets are forwarded opaquely
+        RA -->|FEC decode then jitter then FEC encode| RB[Relay B]
-- Rooms are auto-created when the first participant joins and auto-deleted when empty
+        RB -->|QUIC| C5[Client]
-- Managed by `RoomManager` in `crates/wzp-relay/src/room.rs`
+    end
 
-### Forward Mode (`--remote`)
+    subgraph "Probe Mode with --probe"
+        PA[Relay A] -->|Ping 1/s ~50 bytes| PB[Relay B]
+        PB -->|Pong| PA
+        PA --> PM[Prometheus<br/>RTT Loss Jitter Up/Down]
+    end
 
-- All incoming traffic is forwarded to a remote relay via QUIC
+    style RM fill:#ff9f43
-- Two-pipeline architecture: upstream (client->remote) and downstream (remote->client)
+    style R1 fill:#fdcb6e
-- Each direction has its own `RelayPipeline` with FEC decode/encode and jitter buffering
+    style PM fill:#0984e3
-- Intended for chaining relays across censored/lossy boundaries
-
-### Relay Pipeline (Forward Mode)
-
-Implemented in `crates/wzp-relay/src/pipeline.rs` as `RelayPipeline`:
-
-```
-Inbound:  recv -> FEC decode -> jitter buffer -> pop
-Outbound: packet -> assign seq -> FEC encode -> repair packets -> send
 ```
 
-The pipeline does NOT decode/re-encode audio. It operates on FEC-protected packets, managing loss recovery and re-FEC-encoding for the next hop.
+## Web Bridge Architecture
 
-## Transport
+```mermaid
+sequenceDiagram
+    participant B as Browser
+    participant W as wzp-web
+    participant R as wzp-relay
 
-Implemented in `crates/wzp-transport/` using QUIC via the `quinn` crate.
+    B->>W: HTTPS GET /room-name
+    W->>B: index.html (SPA)
 
-### QUIC Configuration
+    B->>W: WebSocket /ws/room-name
+    Note over B,W: Optional auth JSON message
 
-- ALPN protocol: `wzp`
+    W->>R: QUIC connect (SNI = hashed room name)
-- Idle timeout: 30 seconds
+    Note over W,R: AuthToken then Handshake then Join Room
-- Keep-alive interval: 5 seconds
-- DATAGRAM extension enabled (for unreliable media)
-- Datagram receive buffer: 64 KB
-- Receive window: 256 KB
-- Send window: 128 KB
-- Stream receive window: 64 KB per stream
-- Initial RTT estimate: 300ms (tuned for high-latency links)
 
-### Media Transport
+    loop Every 20ms
+        B->>W: WS Binary Int16 x 960 PCM
+        W->>W: CallEncoder Opus + FEC
+        W->>R: QUIC Datagram encrypted
+    end
 
-- **Unreliable media**: QUIC DATAGRAM frames (no retransmission, no head-of-line blocking)
+    loop Incoming audio
-- **Reliable signaling**: QUIC bidirectional streams with length-prefixed JSON framing
+        R->>W: QUIC Datagram
+        W->>W: CallDecoder FEC + Opus
+        W->>B: WS Binary Int16 x 960 PCM
+    end
 
-### Path Quality Monitoring
+    Note over B: AudioWorklet<br/>WZPCaptureProcessor mic to 960 frames<br/>WZPPlaybackProcessor ring buffer to speaker
+```
 
-`PathMonitor` in `crates/wzp-transport/src/path_monitor.rs` tracks:
+## FEC Protection (RaptorQ)
 
-- **Loss**: EWMA-smoothed percentage from sent/received packet counts
+```mermaid
-- **RTT**: EWMA-smoothed round-trip time (alpha=0.1)
+graph LR
-- **Jitter**: EWMA of RTT variance (|current_rtt - previous_rtt|)
+    subgraph "Encoder"
-- **Bandwidth**: Estimated from bytes received over elapsed time
+        F1[Frame 1] --> BLK[Source Block<br/>5-10 frames]
+        F2[Frame 2] --> BLK
+        F3[Frame 3] --> BLK
+        F4[Frame 4] --> BLK
+        F5[Frame 5] --> BLK
+        BLK --> SRC[5 Source Symbols]
+        BLK --> REP[1-10 Repair Symbols<br/>ratio dependent]
+        SRC --> INT[Interleaver<br/>depth=3]
+        REP --> INT
+    end
 
-### Codec Selection by Tier
+    subgraph "Network"
+        INT --> LOSS{Packet Loss}
+        LOSS -->|some lost| RCV[Received Symbols]
+    end
 
-| Codec | Sample Rate | Frame Duration | Bitrate | Use Case |
+    subgraph "Decoder"
-|-------|------------|----------------|---------|----------|
+        RCV --> DEINT[De-interleaver]
-| Opus24k | 48 kHz | 20ms (960 samples) | 24 kbps | Good conditions |
+        DEINT --> RAPTORQ[RaptorQ Decoder<br/>Reconstruct from<br/>any K of K+R symbols]
-| Opus16k | 48 kHz | 20ms | 16 kbps | Moderate conditions |
+        RAPTORQ --> OUT[Original Frames]
-| Opus6k | 48 kHz | 40ms (1920 samples) | 6 kbps | Degraded conditions |
+    end
-| Codec2_3200 | 8 kHz | 20ms (160 samples) | 3.2 kbps | Poor conditions |
-| Codec2_1200 | 8 kHz | 40ms (320 samples) | 1.2 kbps | Catastrophic conditions |
 
-Opus operates at 48 kHz natively. When Codec2 is selected, the adaptive codec layer handles 48 kHz <-> 8 kHz resampling transparently using a simple linear resampler (6:1 decimation/interpolation).
+    style LOSS fill:#e17055
+    style RAPTORQ fill:#00b894
+```
+
+## Telemetry Stack
+
+```mermaid
+graph TB
+    subgraph "Relay"
+        RM[RelayMetrics<br/>sessions rooms packets]
+        SM[SessionMetrics<br/>per-session jitter loss RTT]
+        PM[ProbeMetrics<br/>inter-relay RTT loss]
+        RM --> PROM1[GET /metrics :9090]
+        SM --> PROM1
+        PM --> PROM1
+    end
+
+    subgraph "Web Bridge"
+        WM[WebMetrics<br/>connections frames latency]
+        WM --> PROM2[GET /metrics :8080]
+    end
+
+    subgraph "Client"
+        CM[JitterStats + QualityAdapter]
+        CM --> JSONL[--metrics-file<br/>JSONL 1 line/sec]
+    end
+
+    PROM1 --> GRAF[Grafana Dashboard<br/>4 rows 18 panels]
+    PROM2 --> GRAF
+    JSONL --> ANALYSIS[Offline Analysis]
+
+    style GRAF fill:#ff6b6b
+    style PROM1 fill:#0984e3
+    style PROM2 fill:#0984e3
+```
+
+## Session State Machine
+
+```mermaid
+stateDiagram-v2
+    [*] --> Idle
+    Idle --> Connecting: connect
+    Connecting --> Handshaking: QUIC established
+    Handshaking --> Active: CallOffer/Answer complete
+    Active --> Rekeying: 65536 packets
+    Rekeying --> Active: new key derived
+    Active --> Closed: Hangup/Error/Timeout
+    Rekeying --> Closed: Error
+    Connecting --> Closed: Timeout
+    Handshaking --> Closed: Signature fail
+
+    note right of Active: Media flows
+    note right of Rekeying: Media continues while rekeying
+```
+
+## Audio Processing Pipeline Detail
+
+```mermaid
+graph TD
+    subgraph "Capture 20ms at 48kHz = 960 samples"
+        MIC[Microphone / AudioWorklet] --> PCM[PCM i16 x 960]
+        PCM --> RNN[RNNoise Denoise<br/>2 x 480 samples]
+        RNN --> VAD{Silent?}
+        VAD -->|Yes over 100ms| CN[ComfortNoise packet<br/>every 200ms]
+        VAD -->|No or Hangover| OPUS[Opus/Codec2 Encode]
+    end
+
+    subgraph "FEC + Crypto"
+        OPUS --> SYMBOL[Pad to 256-byte symbol]
+        CN --> SYMBOL
+        SYMBOL --> BLOCK[Accumulate block<br/>5-10 symbols]
+        BLOCK --> RAPTOR[RaptorQ encode<br/>+ repair symbols]
+        RAPTOR --> INTERLEAVE[Interleave depth=3]
+        INTERLEAVE --> HDR[Add MediaHeader<br/>or MiniHeader]
+        HDR --> ENCRYPT[ChaCha20-Poly1305<br/>header=AAD payload=encrypted]
+        ENCRYPT --> QUIC[QUIC Datagram]
+    end
+
+    style RNN fill:#a29bfe
+    style ENCRYPT fill:#ee5a24
+    style RAPTOR fill:#00b894
+```
+
+## Adaptive Jitter Buffer
+
+```mermaid
+graph TD
+    PKT[Incoming Packet] --> SEQ{Sequence Check}
+    SEQ -->|Duplicate| DROP[Drop + AntiReplay]
+    SEQ -->|Valid| BUF[BTreeMap Buffer<br/>ordered by seq]
+
+    BUF --> ADAPT[AdaptivePlayoutDelay<br/>EMA jitter tracking]
+    ADAPT --> TARGET[target_delay =<br/>ceil jitter_ema/20ms + 2]
+
+    BUF --> READY{depth >= target?}
+    READY -->|No| WAIT[Wait / Underrun++]
+    READY -->|Yes| POP[Pop lowest seq]
+    POP --> DECODE[Decode to PCM]
+    DECODE --> PLAY[Playout]
+
+    BUF --> OVERFLOW{depth > max?}
+    OVERFLOW -->|Yes| EVICT[Drop oldest<br/>Overrun++]
+
+    style ADAPT fill:#fdcb6e
+    style DROP fill:#e17055
+    style EVICT fill:#e17055
+```
+
+## Deployment Topology
+
+```mermaid
+graph TB
+    subgraph "Region A"
+        RA[wzp-relay A<br/>:4433 UDP]
+        WA[wzp-web A<br/>:8080 HTTPS]
+        WA --> RA
+    end
+
+    subgraph "Region B"
+        RB[wzp-relay B<br/>:4433 UDP]
+        WB[wzp-web B<br/>:8080 HTTPS]
+        WB --> RB
+    end
+
+    RA <-->|Probe 1/s| RB
+
+    BA[Browser A] -->|WSS| WA
+    BB[Browser B] -->|WSS| WB
+    CA[CLI Client] -->|QUIC| RA
+
+    PROM[Prometheus] -->|scrape| RA
+    PROM -->|scrape| RB
+    PROM -->|scrape| WA
+    PROM --> GRAF[Grafana]
+
+    FC[featherChat Server] -->|auth validate| RA
+    FC -->|auth validate| RB
+
+    style RA fill:#ff9f43
+    style RB fill:#ff9f43
+    style GRAF fill:#ff6b6b
+    style FC fill:#fd79a8
+```
+
+## featherChat Integration Flow
+
+```mermaid
+sequenceDiagram
+    participant A as User A WZP Client
+    participant FC as featherChat Server
+    participant R as WZP Relay
+    participant B as User B WZP Client
+
+    Note over A,B: Both users share BIP39 seed = same identity
+
+    A->>FC: WS CallSignal Offer payload=JSON SignalMessage
+    FC->>B: WS CallSignal Offer payload + relay_addr + room
+
+    B->>R: QUIC connect SNI = hashed room
+    B->>R: AuthToken fc_bearer_token
+    R->>FC: POST /v1/auth/validate token
+    FC->>R: valid true fingerprint ...
+    B->>R: CallOffer then CallAnswer handshake
+
+    A->>R: QUIC connect same room
+    A->>R: AuthToken + Handshake
+
+    Note over A,B: Both in same room media flows E2E encrypted
+    A->>R: Encrypted media
+    R->>B: Forward SFU no decryption
+    B->>R: Encrypted media
+    R->>A: Forward
+```
+
+## Bandwidth Usage
+
+| Profile | Audio | FEC Overhead | Total | Use Case |
+|---------|-------|-------------|-------|----------|
+| **GOOD** | 24 kbps (Opus) | 20% = 4.8 kbps | **28.8 kbps** | WiFi, LTE, good links |
+| **DEGRADED** | 6 kbps (Opus) | 50% = 3 kbps | **9.0 kbps** | 3G, congested WiFi |
+| **CATASTROPHIC** | 1.2 kbps (Codec2) | 100% = 1.2 kbps | **2.4 kbps** | Satellite, extreme loss |
+
+With silence suppression: ~50% savings in typical conversations.
+With mini-frames: 8 bytes/packet saved (67% header reduction).
+With trunking: shared QUIC overhead across multiplexed sessions.
+
+## Project Structure
+
+```
+warzonePhone/
+├── Cargo.toml                    # Workspace root
+├── crates/
+│   ├── wzp-proto/                # Protocol types, traits, wire format
+│   │   └── src/
+│   │       ├── codec_id.rs       # CodecId, QualityProfile
+│   │       ├── error.rs          # Error types
+│   │       ├── jitter.rs         # JitterBuffer, AdaptivePlayoutDelay
+│   │       ├── packet.rs         # MediaHeader, MiniHeader, TrunkFrame, SignalMessage
+│   │       ├── quality.rs        # Tier, AdaptiveQualityController
+│   │       ├── session.rs        # SessionState machine
+│   │       └── traits.rs         # AudioEncoder, FecEncoder, CryptoSession, etc.
+│   ├── wzp-codec/                # Audio codecs
+│   │   └── src/
+│   │       ├── adaptive.rs       # AdaptiveEncoder/Decoder (Opus + Codec2)
+│   │       ├── denoise.rs        # NoiseSupressor (RNNoise/nnnoiseless)
+│   │       └── silence.rs        # SilenceDetector, ComfortNoise
+│   ├── wzp-fec/                  # Forward error correction
+│   │   └── src/
+│   │       ├── encoder.rs        # RaptorQFecEncoder
+│   │       ├── decoder.rs        # RaptorQFecDecoder
+│   │       └── interleave.rs     # Interleaver (burst protection)
+│   ├── wzp-crypto/               # Cryptography + identity
+│   │   └── src/
+│   │       ├── identity.rs       # Seed, Fingerprint, hash_room_name
+│   │       ├── handshake.rs      # WarzoneKeyExchange (X25519 + Ed25519)
+│   │       ├── session.rs        # ChaChaSession (ChaCha20-Poly1305)
+│   │       ├── nonce.rs          # Deterministic nonce construction
+│   │       ├── anti_replay.rs    # Sliding window replay protection
+│   │       └── rekey.rs          # Forward secrecy rekeying
+│   ├── wzp-transport/            # QUIC transport layer
+│   │   └── src/lib.rs            # QuinnTransport, send/recv media/signal/trunk
+│   ├── wzp-relay/                # Relay daemon
+│   │   └── src/
+│   │       ├── main.rs           # CLI, connection loop, auth + handshake
+│   │       ├── room.rs           # RoomManager, TrunkedForwarder
+│   │       ├── pipeline.rs       # RelayPipeline (forward mode)
+│   │       ├── session_mgr.rs    # SessionManager (limits, lifecycle)
+│   │       ├── auth.rs           # featherChat token validation
+│   │       ├── handshake.rs      # Relay-side accept_handshake
+│   │       ├── metrics.rs        # Prometheus RelayMetrics + per-session
+│   │       ├── probe.rs          # Inter-relay probes + ProbeMesh
+│   │       └── trunk.rs          # TrunkBatcher
+│   ├── wzp-client/               # Call engine + CLI
+│   │   └── src/
+│   │       ├── cli.rs            # CLI arg parsing + main
+│   │       ├── call.rs           # CallEncoder, CallDecoder, QualityAdapter
+│   │       ├── handshake.rs      # Client-side perform_handshake
+│   │       ├── featherchat.rs    # CallSignal bridge
+│   │       ├── echo_test.rs      # Automated echo quality test
+│   │       ├── drift_test.rs     # Clock drift measurement
+│   │       ├── sweep.rs          # Jitter buffer parameter sweep
+│   │       ├── metrics.rs        # JSONL telemetry writer
+│   │       └── bench.rs          # Component benchmarks
+│   └── wzp-web/                  # Browser bridge
+│       ├── src/
+│       │   ├── main.rs           # Axum server, WS handler, TLS
+│       │   └── metrics.rs        # Prometheus WebMetrics
+│       └── static/
+│           ├── index.html        # SPA UI (room, PTT, level meter)
+│           └── audio-processor.js # AudioWorklet (capture + playback)
+├── deps/featherchat/             # Git submodule
+├── docs/
+│   ├── ARCHITECTURE.md           # This file
+│   ├── TELEMETRY.md              # Metrics specification
+│   ├── INTEGRATION_TASKS.md      # featherChat task tracker
+│   ├── WZP-FC-SHARED-CRATES.md   # Shared crate strategy
+│   └── grafana-dashboard.json    # Pre-built Grafana dashboard
+└── scripts/
+    └── build-linux.sh            # Hetzner VM build
+```
+
+## Test Coverage
+
+272 tests across all crates, 0 failures.
+
+| Crate | Tests | Key Coverage |
+|-------|-------|-------------|
+| wzp-proto | 41 | Wire format, jitter buffer, quality tiers, mini-frames, trunking |
+| wzp-codec | 31 | Opus/Codec2 roundtrip, silence detection, noise suppression |
+| wzp-fec | 22 | RaptorQ encode/decode, loss recovery, interleaving |
+| wzp-crypto | 34 + 28 compat | Encrypt/decrypt, handshake, anti-replay, featherChat identity compat |
+| wzp-transport | 2 | QUIC connection setup |
+| wzp-relay | 40 + 4 integration | Room ACL, session mgmt, metrics, probes, mesh, trunking |
+| wzp-client | 30 + 2 integration | Encoder/decoder, quality adapter, silence, drift, sweep |
+| wzp-web | 2 | Metrics |

docs/INTEGRATION_TASKS.md

@@ -77,7 +77,9 @@ Based on featherChat commit 65f6390 — FUTURE_TASKS.md with WZP integration ite
 ### WZP-FC-7. Missed call notifications — TODO (0.5d)
 ### WZP-FC-8. Cross-project identity verification — DONE (15 tests, 26dc848)
 ### WZP-FC-9. HKDF salt investigation — DONE (no mismatch)
-### WZP-FC-10. Web bridge shared auth — TODO (1-2d)
+### WZP-FC-10. Web bridge shared auth — DONE
+- FC: GET /v1/wzp/relay-config, CORS layer, service token
+- WZP: web bridge --auth-url validates browser tokens via FC
 ### FC-CRATE-1. Standalone warzone-protocol — DONE (v0.0.21, 4a4fa9f)
 
 ---