fix: send alias via CallOffer handshake (match Android approach)

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

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

@@ -0,0 +1,135 @@
+package com.wzp.data
+
+import android.content.Context
+import android.content.SharedPreferences
+import com.wzp.ui.call.ServerEntry
+import org.json.JSONArray
+import org.json.JSONObject
+import java.security.SecureRandom
+
+/**
+ * Persists user settings via SharedPreferences.
+ *
+ * Stores: servers, default server index, room name, alias, gain values,
+ * IPv6 preference, and the identity seed (hex-encoded 32 bytes).
+ */
+class SettingsRepository(context: Context) {
+
+    private val prefs: SharedPreferences =
+        context.applicationContext.getSharedPreferences("wzp_settings", Context.MODE_PRIVATE)
+
+    companion object {
+        private const val KEY_SERVERS = "servers_json"
+        private const val KEY_SELECTED_SERVER = "selected_server"
+        private const val KEY_ROOM = "room_name"
+        private const val KEY_ALIAS = "alias"
+        private const val KEY_PLAYOUT_GAIN = "playout_gain_db"
+        private const val KEY_CAPTURE_GAIN = "capture_gain_db"
+        private const val KEY_PREFER_IPV6 = "prefer_ipv6"
+        private const val KEY_IDENTITY_SEED = "identity_seed_hex"
+    }
+
+    // --- Servers ---
+
+    fun saveServers(servers: List<ServerEntry>) {
+        val arr = JSONArray()
+        servers.forEach { entry ->
+            arr.put(JSONObject().apply {
+                put("address", entry.address)
+                put("label", entry.label)
+            })
+        }
+        prefs.edit().putString(KEY_SERVERS, arr.toString()).apply()
+    }
+
+    fun loadServers(): List<ServerEntry>? {
+        val json = prefs.getString(KEY_SERVERS, null) ?: return null
+        return try {
+            val arr = JSONArray(json)
+            (0 until arr.length()).map { i ->
+                val obj = arr.getJSONObject(i)
+                ServerEntry(obj.getString("address"), obj.getString("label"))
+            }
+        } catch (_: Exception) { null }
+    }
+
+    fun saveSelectedServer(index: Int) {
+        prefs.edit().putInt(KEY_SELECTED_SERVER, index).apply()
+    }
+
+    fun loadSelectedServer(): Int = prefs.getInt(KEY_SELECTED_SERVER, 0)
+
+    // --- Room ---
+
+    fun saveRoom(name: String) { prefs.edit().putString(KEY_ROOM, name).apply() }
+    fun loadRoom(): String = prefs.getString(KEY_ROOM, "android") ?: "android"
+
+    // --- Alias ---
+
+    fun saveAlias(alias: String) { prefs.edit().putString(KEY_ALIAS, alias).apply() }
+
+    /**
+     * Load alias, generating a random name on first launch.
+     */
+    fun getOrCreateAlias(): String {
+        val existing = prefs.getString(KEY_ALIAS, null)
+        if (!existing.isNullOrEmpty()) return existing
+        val name = generateRandomName()
+        prefs.edit().putString(KEY_ALIAS, name).apply()
+        return name
+    }
+
+    private fun generateRandomName(): String {
+        val adjectives = listOf(
+            "Swift", "Silent", "Brave", "Calm", "Dark", "Fierce", "Ghost",
+            "Iron", "Lucky", "Noble", "Quick", "Sharp", "Storm", "Wild",
+            "Cold", "Bright", "Lone", "Red", "Grey", "Frosty", "Dusty",
+            "Rusty", "Neon", "Void", "Solar", "Lunar", "Cyber", "Pixel",
+            "Sonic", "Hyper", "Turbo", "Nano", "Mega", "Ultra", "Zinc"
+        )
+        val nouns = listOf(
+            "Wolf", "Hawk", "Fox", "Bear", "Lynx", "Crow", "Viper",
+            "Cobra", "Tiger", "Eagle", "Shark", "Raven", "Falcon", "Otter",
+            "Mantis", "Panda", "Jackal", "Badger", "Heron", "Bison",
+            "Condor", "Coyote", "Gecko", "Hornet", "Marten", "Osprey",
+            "Parrot", "Puma", "Raptor", "Stork", "Toucan", "Walrus"
+        )
+        val adj = adjectives.random()
+        val noun = nouns.random()
+        return "$adj $noun"
+    }
+
+    // --- Gain ---
+
+    fun savePlayoutGain(db: Float) { prefs.edit().putFloat(KEY_PLAYOUT_GAIN, db).apply() }
+    fun loadPlayoutGain(): Float = prefs.getFloat(KEY_PLAYOUT_GAIN, 0f)
+
+    fun saveCaptureGain(db: Float) { prefs.edit().putFloat(KEY_CAPTURE_GAIN, db).apply() }
+    fun loadCaptureGain(): Float = prefs.getFloat(KEY_CAPTURE_GAIN, 0f)
+
+    // --- IPv6 ---
+
+    fun savePreferIPv6(prefer: Boolean) { prefs.edit().putBoolean(KEY_PREFER_IPV6, prefer).apply() }
+    fun loadPreferIPv6(): Boolean = prefs.getBoolean(KEY_PREFER_IPV6, false)
+
+    // --- Identity seed ---
+
+    /**
+     * Get or generate the identity seed. On first call, generates a random
+     * 32-byte seed and persists it. Subsequent calls return the same seed.
+     */
+    fun getOrCreateSeedHex(): String {
+        val existing = prefs.getString(KEY_IDENTITY_SEED, null)
+        if (!existing.isNullOrEmpty()) return existing
+        val seed = ByteArray(32).also { SecureRandom().nextBytes(it) }
+        val hex = seed.joinToString("") { "%02x".format(it) }
+        prefs.edit().putString(KEY_IDENTITY_SEED, hex).apply()
+        return hex
+    }
+
+    fun loadSeedHex(): String = prefs.getString(KEY_IDENTITY_SEED, "") ?: ""
+
+    fun saveSeedHex(hex: String) {
+        prefs.edit().putString(KEY_IDENTITY_SEED, hex).apply()
+    }
+}

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

@@ -35,11 +35,12 @@ class WzpEngine(private val callback: WzpCallback) {
      * @param room      room identifier (used as QUIC SNI)
      * @param seedHex   64-char hex-encoded 32-byte identity seed (empty = random)
      * @param token     authentication token (empty = no auth)
+     * @param alias     display name sent to relay for room participant list
      * @return 0 on success, negative error code on failure
      */
-    fun startCall(relayAddr: String, room: String, seedHex: String = "", token: String = ""): Int {
+    fun startCall(relayAddr: String, room: String, seedHex: String = "", token: String = "", alias: String = ""): Int {
         check(nativeHandle != 0L) { "Engine not initialized" }
-        val result = nativeStartCall(nativeHandle, relayAddr, room, seedHex, token)
+        val result = nativeStartCall(nativeHandle, relayAddr, room, seedHex, token, alias)
         if (result == 0) {
             callback.onCallStateChanged(CallStateConstants.CONNECTING)
         } else {
@@ -120,7 +121,7 @@ class WzpEngine(private val callback: WzpCallback) {
 
     private external fun nativeInit(): Long
     private external fun nativeStartCall(
-        handle: Long, relay: String, room: String, seed: String, token: String
+        handle: Long, relay: String, room: String, seed: String, token: String, alias: String
     ): Int
     private external fun nativeStopCall(handle: Long)
     private external fun nativeSetMute(handle: Long, muted: Boolean)

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

@@ -15,8 +15,13 @@ import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalContext
 import androidx.core.content.ContextCompat
+import com.wzp.ui.settings.SettingsScreen
 
 /**
  * Main activity hosting the in-call Compose UI.
@@ -43,12 +48,19 @@ class CallActivity : ComponentActivity() {
 
         setContent {
             WzpTheme {
-                InCallScreen(
-                    viewModel = viewModel,
-                    onHangUp = {
-                        viewModel.stopCall()
-                    }
-                )
+                var showSettings by remember { mutableStateOf(false) }
+                if (showSettings) {
+                    SettingsScreen(
+                        viewModel = viewModel,
+                        onBack = { showSettings = false }
+                    )
+                } else {
+                    InCallScreen(
+                        viewModel = viewModel,
+                        onHangUp = { viewModel.stopCall() },
+                        onOpenSettings = { showSettings = true }
+                    )
+                }
             }
         }
 

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

@@ -6,6 +6,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.wzp.audio.AudioPipeline
 import com.wzp.audio.AudioRouteManager
+import com.wzp.data.SettingsRepository
 import com.wzp.engine.CallStats
 import com.wzp.service.CallService
 import com.wzp.engine.WzpCallback
@@ -31,6 +32,7 @@ class CallViewModel : ViewModel(), WzpCallback {
     private var audioRouteManager: AudioRouteManager? = null
     private var audioStarted = false
     private var appContext: Context? = null
+    private var settings: SettingsRepository? = null
 
     private val _callState = MutableStateFlow(0)
     val callState: StateFlow<Int> get() = _callState.asStateFlow()
@@ -68,6 +70,12 @@ class CallViewModel : ViewModel(), WzpCallback {
     private val _captureGainDb = MutableStateFlow(0f)
     val captureGainDb: StateFlow<Float> = _captureGainDb.asStateFlow()
 
+    private val _alias = MutableStateFlow("")
+    val alias: StateFlow<String> = _alias.asStateFlow()
+
+    private val _seedHex = MutableStateFlow("")
+    val seedHex: StateFlow<String> = _seedHex.asStateFlow()
+
     private var statsJob: Job? = null
 
     companion object {
@@ -88,20 +96,43 @@ class CallViewModel : ViewModel(), WzpCallback {
         if (audioRouteManager == null) {
             audioRouteManager = AudioRouteManager(appCtx)
         }
+        if (settings == null) {
+            settings = SettingsRepository(appCtx)
+            loadSettings()
+        }
+    }
+
+    private fun loadSettings() {
+        val s = settings ?: return
+        s.loadServers()?.let { saved ->
+            if (saved.isNotEmpty()) _servers.value = saved
+        }
+        _selectedServer.value = s.loadSelectedServer().coerceIn(0, _servers.value.lastIndex)
+        _roomName.value = s.loadRoom()
+        _alias.value = s.getOrCreateAlias()
+        _preferIPv6.value = s.loadPreferIPv6()
+        _playoutGainDb.value = s.loadPlayoutGain()
+        _captureGainDb.value = s.loadCaptureGain()
+        _seedHex.value = s.getOrCreateSeedHex()
     }
 
     fun selectServer(index: Int) {
         if (index in _servers.value.indices) {
             _selectedServer.value = index
+            settings?.saveSelectedServer(index)
         }
     }
 
-    fun setPreferIPv6(prefer: Boolean) { _preferIPv6.value = prefer }
+    fun setPreferIPv6(prefer: Boolean) {
+        _preferIPv6.value = prefer
+        settings?.savePreferIPv6(prefer)
+    }
 
     fun addServer(hostPort: String, label: String) {
         val current = _servers.value.toMutableList()
         current.add(ServerEntry(hostPort, label))
         _servers.value = current
+        settings?.saveServers(current)
     }
 
     fun removeServer(index: Int) {
@@ -113,19 +144,36 @@ class CallViewModel : ViewModel(), WzpCallback {
             if (_selectedServer.value >= current.size) {
                 _selectedServer.value = 0
             }
+            settings?.saveServers(current)
+            settings?.saveSelectedServer(_selectedServer.value)
         }
     }
 
-    fun setRoomName(name: String) { _roomName.value = name }
+    fun setRoomName(name: String) {
+        _roomName.value = name
+        settings?.saveRoom(name)
+    }
 
     fun setPlayoutGainDb(db: Float) {
         _playoutGainDb.value = db
         audioPipeline?.playoutGainDb = db
+        settings?.savePlayoutGain(db)
     }
 
     fun setCaptureGainDb(db: Float) {
         _captureGainDb.value = db
         audioPipeline?.captureGainDb = db
+        settings?.saveCaptureGain(db)
+    }
+
+    fun setAlias(alias: String) {
+        _alias.value = alias
+        settings?.saveAlias(alias)
+    }
+
+    fun restoreSeed(hex: String) {
+        _seedHex.value = hex
+        settings?.saveSeedHex(hex)
     }
 
     /**
@@ -203,8 +251,10 @@ class CallViewModel : ViewModel(), WzpCallback {
             viewModelScope.launch(kotlinx.coroutines.Dispatchers.IO) {
                 try {
                     val relay = resolveToIp(serverEntry.address)
-                    Log.i(TAG, "startCall: resolved=$relay, calling engine.startCall")
-                    val result = engine?.startCall(relay, room) ?: -1
+                    val seed = _seedHex.value
+                    val name = _alias.value
+                    Log.i(TAG, "startCall: resolved=$relay, alias=$name, calling engine.startCall")
+                    val result = engine?.startCall(relay, room, seedHex = seed, alias = name) ?: -1
                     Log.i(TAG, "startCall: engine returned $result")
                     // Only wire up notification callback after engine is running
                     CallService.onStopFromNotification = { stopCall() }

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

@@ -54,7 +54,8 @@ import kotlin.math.roundToInt
 @Composable
 fun InCallScreen(
     viewModel: CallViewModel,
-    onHangUp: () -> Unit
+    onHangUp: () -> Unit,
+    onOpenSettings: () -> Unit = {}
 ) {
     val callState by viewModel.callState.collectAsState()
     val isMuted by viewModel.isMuted.collectAsState()
@@ -82,7 +83,16 @@ fun InCallScreen(
                 .verticalScroll(rememberScrollState()),
             horizontalAlignment = Alignment.CenterHorizontally
         ) {
-            Spacer(modifier = Modifier.height(48.dp))
+            // Settings button (top-right)
+            if (callState == 0) {
+                Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.End) {
+                    TextButton(onClick = onOpenSettings) {
+                        Text("Settings")
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.height(if (callState == 0) 16.dp else 48.dp))
 
             Text(
                 text = "WZ Phone",

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

@@ -0,0 +1,437 @@
+package com.wzp.ui.settings
+
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.widget.Toast
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.FilledTonalIconButton
+import androidx.compose.material3.Divider
+import androidx.compose.material3.IconButtonDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Slider
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import com.wzp.ui.call.CallViewModel
+
+@OptIn(ExperimentalLayoutApi::class)
+@Composable
+fun SettingsScreen(
+    viewModel: CallViewModel,
+    onBack: () -> Unit
+) {
+    val context = LocalContext.current
+    val servers by viewModel.servers.collectAsState()
+    val selectedServer by viewModel.selectedServer.collectAsState()
+    val roomName by viewModel.roomName.collectAsState()
+    val preferIPv6 by viewModel.preferIPv6.collectAsState()
+    val playoutGainDb by viewModel.playoutGainDb.collectAsState()
+    val captureGainDb by viewModel.captureGainDb.collectAsState()
+    val alias by viewModel.alias.collectAsState()
+    val seedHex by viewModel.seedHex.collectAsState()
+
+    var showAddServerDialog by remember { mutableStateOf(false) }
+    var showRestoreKeyDialog by remember { mutableStateOf(false) }
+
+    Surface(
+        modifier = Modifier.fillMaxSize(),
+        color = MaterialTheme.colorScheme.background
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(24.dp)
+                .verticalScroll(rememberScrollState())
+        ) {
+            // Header
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                TextButton(onClick = onBack) {
+                    Text("< Back")
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                Text(
+                    text = "Settings",
+                    style = MaterialTheme.typography.headlineSmall.copy(
+                        fontWeight = FontWeight.Bold
+                    ),
+                    color = MaterialTheme.colorScheme.primary
+                )
+                Spacer(modifier = Modifier.weight(1f))
+                // Balance the back button
+                Spacer(modifier = Modifier.width(64.dp))
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+
+            // --- Identity ---
+            SectionHeader("Identity")
+
+            OutlinedTextField(
+                value = alias,
+                onValueChange = { viewModel.setAlias(it) },
+                label = { Text("Display Name") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // Fingerprint display
+            val fingerprint = if (seedHex.length >= 16) seedHex.take(16).uppercase() else "Not generated"
+            Text(
+                text = "Fingerprint",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+            Text(
+                text = fingerprint.chunked(4).joinToString(" "),
+                style = MaterialTheme.typography.bodyMedium.copy(
+                    fontFamily = FontFamily.Monospace
+                ),
+                color = MaterialTheme.colorScheme.onSurface
+            )
+
+            Spacer(modifier = Modifier.height(12.dp))
+
+            // Key backup/restore
+            Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                FilledTonalButton(onClick = {
+                    val clipboard = context.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
+                    clipboard.setPrimaryClip(ClipData.newPlainText("WZP Key", seedHex))
+                    Toast.makeText(context, "Key copied to clipboard", Toast.LENGTH_SHORT).show()
+                }) {
+                    Text("Copy Key")
+                }
+                OutlinedButton(onClick = { showRestoreKeyDialog = true }) {
+                    Text("Restore Key")
+                }
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Audio ---
+            SectionHeader("Audio Defaults")
+
+            GainSlider(
+                label = "Voice Volume",
+                gainDb = playoutGainDb,
+                onGainChange = { viewModel.setPlayoutGainDb(it) }
+            )
+            Spacer(modifier = Modifier.height(4.dp))
+            GainSlider(
+                label = "Mic Gain",
+                gainDb = captureGainDb,
+                onGainChange = { viewModel.setCaptureGainDb(it) }
+            )
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Servers ---
+            SectionHeader("Servers")
+
+            FlowRow(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.Start,
+                verticalArrangement = Arrangement.spacedBy(4.dp)
+            ) {
+                servers.forEachIndexed { idx, entry ->
+                    val isSelected = selectedServer == idx
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        FilledTonalIconButton(
+                            onClick = { viewModel.selectServer(idx) },
+                            modifier = Modifier
+                                .padding(end = 2.dp)
+                                .height(36.dp)
+                                .width(140.dp),
+                            shape = RoundedCornerShape(8.dp),
+                            colors = if (isSelected) {
+                                IconButtonDefaults.filledTonalIconButtonColors(
+                                    containerColor = MaterialTheme.colorScheme.primaryContainer,
+                                    contentColor = MaterialTheme.colorScheme.onPrimaryContainer
+                                )
+                            } else {
+                                IconButtonDefaults.filledTonalIconButtonColors()
+                            }
+                        ) {
+                            Text(
+                                text = entry.label,
+                                style = MaterialTheme.typography.labelSmall,
+                                maxLines = 1
+                            )
+                        }
+                        // Show remove button for non-default servers
+                        if (idx >= 2) {
+                            TextButton(
+                                onClick = { viewModel.removeServer(idx) },
+                                modifier = Modifier.height(36.dp)
+                            ) {
+                                Text("X", color = MaterialTheme.colorScheme.error)
+                            }
+                        }
+                    }
+                }
+            }
+
+            Spacer(modifier = Modifier.height(8.dp))
+            OutlinedButton(
+                onClick = { showAddServerDialog = true },
+                shape = RoundedCornerShape(8.dp)
+            ) {
+                Text("+ Add Server")
+            }
+
+            // Show selected server address
+            Spacer(modifier = Modifier.height(8.dp))
+            Text(
+                text = "Default: ${servers.getOrNull(selectedServer)?.address ?: "none"}",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Network ---
+            SectionHeader("Network")
+
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                Text(
+                    text = "Prefer IPv6",
+                    style = MaterialTheme.typography.bodyMedium,
+                    modifier = Modifier.weight(1f)
+                )
+                Switch(
+                    checked = preferIPv6,
+                    onCheckedChange = { viewModel.setPreferIPv6(it) }
+                )
+            }
+
+            Spacer(modifier = Modifier.height(24.dp))
+            Divider()
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // --- Room ---
+            SectionHeader("Room")
+
+            OutlinedTextField(
+                value = roomName,
+                onValueChange = { viewModel.setRoomName(it) },
+                label = { Text("Default Room") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+
+            Spacer(modifier = Modifier.height(32.dp))
+        }
+    }
+
+    if (showAddServerDialog) {
+        AddServerDialog(
+            onDismiss = { showAddServerDialog = false },
+            onAdd = { host, port, label ->
+                viewModel.addServer("$host:$port", label)
+                showAddServerDialog = false
+            }
+        )
+    }
+
+    if (showRestoreKeyDialog) {
+        RestoreKeyDialog(
+            onDismiss = { showRestoreKeyDialog = false },
+            onRestore = { hex ->
+                viewModel.restoreSeed(hex)
+                showRestoreKeyDialog = false
+                Toast.makeText(context, "Key restored", Toast.LENGTH_SHORT).show()
+            }
+        )
+    }
+}
+
+@Composable
+private fun SectionHeader(title: String) {
+    Text(
+        text = title,
+        style = MaterialTheme.typography.titleMedium.copy(fontWeight = FontWeight.Bold),
+        color = MaterialTheme.colorScheme.primary
+    )
+    Spacer(modifier = Modifier.height(8.dp))
+}
+
+@Composable
+private fun GainSlider(label: String, gainDb: Float, onGainChange: (Float) -> Unit) {
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        val sign = if (gainDb >= 0) "+" else ""
+        Text(
+            text = "$label: ${sign}${"%.0f".format(gainDb)} dB",
+            style = MaterialTheme.typography.labelSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+        Slider(
+            value = gainDb,
+            onValueChange = { onGainChange(Math.round(it).toFloat()) },
+            valueRange = -20f..20f,
+            steps = 0,
+            modifier = Modifier.fillMaxWidth()
+        )
+    }
+}
+
+@Composable
+private fun AddServerDialog(
+    onDismiss: () -> Unit,
+    onAdd: (host: String, port: String, label: String) -> Unit
+) {
+    var host by remember { mutableStateOf("") }
+    var port by remember { mutableStateOf("4433") }
+    var label by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Add Server") },
+        text = {
+            Column {
+                OutlinedTextField(
+                    value = host,
+                    onValueChange = { host = it },
+                    label = { Text("Host (IP or domain)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = port,
+                    onValueChange = { port = it },
+                    label = { Text("Port") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = label,
+                    onValueChange = { label = it },
+                    label = { Text("Label (optional)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    if (host.isNotBlank()) {
+                        val displayLabel = label.ifBlank { host }
+                        onAdd(host.trim(), port.trim(), displayLabel)
+                    }
+                }
+            ) { Text("Add") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        }
+    )
+}
+
+@Composable
+private fun RestoreKeyDialog(
+    onDismiss: () -> Unit,
+    onRestore: (hex: String) -> Unit
+) {
+    var keyInput by remember { mutableStateOf("") }
+    var error by remember { mutableStateOf<String?>(null) }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Restore Identity Key") },
+        text = {
+            Column {
+                Text(
+                    text = "Paste your 64-character hex key below. This will replace your current identity.",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                OutlinedTextField(
+                    value = keyInput,
+                    onValueChange = {
+                        keyInput = it.trim().lowercase()
+                        error = null
+                    },
+                    label = { Text("Identity Key (hex)") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth(),
+                    isError = error != null
+                )
+                error?.let {
+                    Text(
+                        text = it,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.error
+                    )
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = {
+                    val cleaned = keyInput.replace("\\s".toRegex(), "")
+                    if (cleaned.length != 64 || !cleaned.all { it in '0'..'9' || it in 'a'..'f' }) {
+                        error = "Key must be exactly 64 hex characters"
+                    } else {
+                        onRestore(cleaned)
+                    }
+                }
+            ) { Text("Restore") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        }
+    )
+}

crates/wzp-android/src/engine.rs

@@ -39,6 +39,7 @@ pub struct CallStartConfig {
     pub room: String,
     pub auth_token: Vec<u8>,
     pub identity_seed: [u8; 32],
+    pub alias: Option<String>,
 }
 
 impl Default for CallStartConfig {
@@ -49,6 +50,7 @@ impl Default for CallStartConfig {
             room: String::new(),
             auth_token: Vec::new(),
             identity_seed: [0u8; 32],
+            alias: None,
         }
     }
 }
@@ -117,6 +119,7 @@ impl WzpEngine {
         let room = config.room.clone();
         let identity_seed = config.identity_seed;
         let profile = config.profile;
+        let alias = config.alias.clone();
         let state = self.state.clone();
 
         self.state.running.store(true, Ordering::Release);
@@ -124,7 +127,7 @@ impl WzpEngine {
 
         let state_clone = state.clone();
         runtime.block_on(async move {
-            if let Err(e) = run_call(relay_addr, &room, &identity_seed, profile, state_clone).await
+            if let Err(e) = run_call(relay_addr, &room, &identity_seed, profile, alias.as_deref(), state_clone).await
             {
                 error!("call failed: {e}");
             }
@@ -204,6 +207,7 @@ async fn run_call(
     room: &str,
     identity_seed: &[u8; 32],
     profile: QualityProfile,
+    alias: Option<&str>,
     state: Arc<EngineState>,
 ) -> Result<(), anyhow::Error> {
     let _ = rustls::crypto::ring::default_provider().install_default();
@@ -238,6 +242,7 @@ async fn run_call(
             QualityProfile::DEGRADED,
             QualityProfile::CATASTROPHIC,
         ],
+        alias: alias.map(|s| s.to_string()),
     };
     transport.send_signal(&offer).await?;
     info!("CallOffer sent, waiting for CallAnswer...");

crates/wzp-android/src/jni_bridge.rs

@@ -54,12 +54,14 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartCall(
     room_j: JString,
     seed_hex_j: JString,
     token_j: JString,
+    alias_j: JString,
 ) -> jint {
     let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
         let relay_addr: String = env.get_string(&relay_addr_j).map(|s| s.into()).unwrap_or_default();
         let room: String = env.get_string(&room_j).map(|s| s.into()).unwrap_or_default();
         let seed_hex: String = env.get_string(&seed_hex_j).map(|s| s.into()).unwrap_or_default();
         let token: String = env.get_string(&token_j).map(|s| s.into()).unwrap_or_default();
+        let alias: String = env.get_string(&alias_j).map(|s| s.into()).unwrap_or_default();
 
         let h = unsafe { handle_ref(handle) };
 
@@ -83,6 +85,7 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartCall(
             room,
             auth_token: if token.is_empty() { Vec::new() } else { token.into_bytes() },
             identity_seed,
+            alias: if alias.is_empty() { None } else { Some(alias) },
         };
 
         match h.engine.start_call(config) {

crates/wzp-client/src/audio_io.rs

@@ -3,12 +3,10 @@
 //! Both structs use 48 kHz, mono, i16 format to match the WarzonePhone codec
 //! pipeline. Frames are 960 samples (20 ms at 48 kHz).
 //!
-//! The cpal `Stream` type is not `Send`, so each struct spawns a dedicated OS
-//! thread that owns the stream. The public API exposes only `Send + Sync`
-//! channel handles.
+//! Audio callbacks are **lock-free**: they read/write directly to an `AudioRing`
+//! (atomic SPSC ring buffer). No Mutex, no channel, no allocation on the hot path.
 
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::mpsc;
 use std::sync::Arc;
 
 use anyhow::{anyhow, Context};
@@ -16,6 +14,8 @@ use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::{SampleFormat, SampleRate, StreamConfig};
 use tracing::{info, warn};
 
+use crate::audio_ring::AudioRing;
+
 /// Number of samples per 20 ms frame at 48 kHz mono.
 pub const FRAME_SAMPLES: usize = 960;
 
@@ -23,22 +23,24 @@ pub const FRAME_SAMPLES: usize = 960;
 // AudioCapture
 // ---------------------------------------------------------------------------
 
-/// Captures microphone input and yields 960-sample PCM frames.
+/// Captures microphone input via CPAL and writes PCM into a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioCapture {
-    rx: mpsc::Receiver<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioCapture {
     /// Create and start capturing from the default input device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-capture".into())
@@ -54,21 +56,17 @@ impl AudioCapture {
                     let config = StreamConfig {
                         channels: 1,
                         sample_rate: SampleRate(48_000),
-                        buffer_size: cpal::BufferSize::Default,
+                        buffer_size: cpal::BufferSize::Fixed(FRAME_SAMPLES as u32),
                     };
 
                     let use_f32 = !supports_i16_input(&device)?;
 
-                    let buf = Arc::new(std::sync::Mutex::new(
-                        Vec::<i16>::with_capacity(FRAME_SAMPLES),
-                    ));
                     let err_cb = |e: cpal::StreamError| {
                         warn!("input stream error: {e}");
                     };
 
                     let stream = if use_f32 {
-                        let buf = buf.clone();
-                        let tx = tx.clone();
+                        let ring = ring_cb.clone();
                         let running = running_clone.clone();
                         device.build_input_stream(
                             &config,
@@ -76,21 +74,22 @@ impl AudioCapture {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
-                                for &s in data {
-                                    lock.push(f32_to_i16(s));
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
+                                // Batch convert f32 → i16, then write entire slice to ring.
+                                // Stack alloc for typical callback sizes (≤ 960 samples).
+                                let mut tmp = [0i16; FRAME_SAMPLES];
+                                for chunk in data.chunks(FRAME_SAMPLES) {
+                                    let n = chunk.len();
+                                    for i in 0..n {
+                                        tmp[i] = f32_to_i16(chunk[i]);
                                     }
+                                    ring.write(&tmp[..n]);
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let buf = buf.clone();
-                        let tx = tx.clone();
+                        let ring = ring_cb.clone();
                         let running = running_clone.clone();
                         device.build_input_stream(
                             &config,
@@ -98,14 +97,7 @@ impl AudioCapture {
                                 if !running.load(Ordering::Relaxed) {
                                     return;
                                 }
-                                let mut lock = buf.lock().unwrap();
-                                for &s in data {
-                                    lock.push(s);
-                                    if lock.len() == FRAME_SAMPLES {
-                                        let frame = lock.drain(..).collect();
-                                        let _ = tx.try_send(frame);
-                                    }
-                                }
+                                ring.write(data);
                             },
                             err_cb,
                             None,
@@ -114,7 +106,6 @@ impl AudioCapture {
 
                     stream.play().context("failed to start input stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -135,15 +126,12 @@ impl AudioCapture {
             .map_err(|_| anyhow!("capture thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { rx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Read the next frame of 960 PCM samples (blocking until available).
-    ///
-    /// Returns `None` when the stream has been stopped or the channel is
-    /// disconnected.
-    pub fn read_frame(&self) -> Option<Vec<i16>> {
-        self.rx.recv().ok()
+    /// Get a reference to the capture ring buffer for direct polling.
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
     }
 
     /// Stop capturing.
@@ -152,26 +140,34 @@ impl AudioCapture {
     }
 }
 
+impl Drop for AudioCapture {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // AudioPlayback
 // ---------------------------------------------------------------------------
 
-/// Plays PCM frames through the default output device at 48 kHz mono.
+/// Plays PCM through the default output device, reading from a lock-free ring buffer.
 ///
 /// The cpal stream lives on a dedicated OS thread; this handle is `Send + Sync`.
 pub struct AudioPlayback {
-    tx: mpsc::SyncSender<Vec<i16>>,
+    ring: Arc<AudioRing>,
     running: Arc<AtomicBool>,
 }
 
 impl AudioPlayback {
     /// Create and start playback on the default output device at 48 kHz mono.
     pub fn start() -> Result<Self, anyhow::Error> {
-        let (tx, rx) = mpsc::sync_channel::<Vec<i16>>(64);
+        let ring = Arc::new(AudioRing::new());
         let running = Arc::new(AtomicBool::new(true));
-        let running_clone = running.clone();
 
-        let (init_tx, init_rx) = mpsc::sync_channel::<Result<(), String>>(1);
+        let (init_tx, init_rx) = std::sync::mpsc::sync_channel::<Result<(), String>>(1);
+
+        let ring_cb = ring.clone();
+        let running_clone = running.clone();
 
         std::thread::Builder::new()
             .name("wzp-audio-playback".into())
@@ -187,67 +183,45 @@ impl AudioPlayback {
                     let config = StreamConfig {
                         channels: 1,
                         sample_rate: SampleRate(48_000),
-                        buffer_size: cpal::BufferSize::Default,
+                        buffer_size: cpal::BufferSize::Fixed(FRAME_SAMPLES as u32),
                     };
 
                     let use_f32 = !supports_i16_output(&device)?;
 
-                    // Shared ring of samples the cpal callback drains from.
-                    let ring = Arc::new(std::sync::Mutex::new(
-                        std::collections::VecDeque::<i16>::with_capacity(FRAME_SAMPLES * 8),
-                    ));
-
-                    // Background drainer: moves frames from the mpsc channel into the ring.
-                    {
-                        let ring = ring.clone();
-                        let running = running_clone.clone();
-                        std::thread::Builder::new()
-                            .name("wzp-playback-drain".into())
-                            .spawn(move || {
-                                while running.load(Ordering::Relaxed) {
-                                    match rx.recv_timeout(std::time::Duration::from_millis(100)) {
-                                        Ok(frame) => {
-                                            let mut lock = ring.lock().unwrap();
-                                            lock.extend(frame);
-                                            while lock.len() > FRAME_SAMPLES * 16 {
-                                                lock.pop_front();
-                                            }
-                                        }
-                                        Err(mpsc::RecvTimeoutError::Timeout) => {}
-                                        Err(mpsc::RecvTimeoutError::Disconnected) => break,
-                                    }
-                                }
-                            })?;
-                    }
-
                     let err_cb = |e: cpal::StreamError| {
                         warn!("output stream error: {e}");
                     };
 
                     let stream = if use_f32 {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
-                                for sample in data.iter_mut() {
-                                    *sample = match lock.pop_front() {
-                                        Some(s) => i16_to_f32(s),
-                                        None => 0.0,
-                                    };
+                                let mut tmp = [0i16; FRAME_SAMPLES];
+                                for chunk in data.chunks_mut(FRAME_SAMPLES) {
+                                    let n = chunk.len();
+                                    let read = ring.read(&mut tmp[..n]);
+                                    for i in 0..read {
+                                        chunk[i] = i16_to_f32(tmp[i]);
+                                    }
+                                    // Fill remainder with silence if ring underran
+                                    for i in read..n {
+                                        chunk[i] = 0.0;
+                                    }
                                 }
                             },
                             err_cb,
                             None,
                         )?
                     } else {
-                        let ring = ring.clone();
+                        let ring = ring_cb.clone();
                         device.build_output_stream(
                             &config,
                             move |data: &mut [i16], _: &cpal::OutputCallbackInfo| {
-                                let mut lock = ring.lock().unwrap();
-                                for sample in data.iter_mut() {
-                                    *sample = lock.pop_front().unwrap_or(0);
+                                let read = ring.read(data);
+                                // Fill remainder with silence if ring underran
+                                for sample in &mut data[read..] {
+                                    *sample = 0;
                                 }
                             },
                             err_cb,
@@ -257,7 +231,6 @@ impl AudioPlayback {
 
                     stream.play().context("failed to start output stream")?;
 
-                    // Signal success to the caller before parking.
                     let _ = init_tx.send(Ok(()));
 
                     // Keep stream alive until stopped.
@@ -278,12 +251,12 @@ impl AudioPlayback {
             .map_err(|_| anyhow!("playback thread exited before signaling"))?
             .map_err(|e| anyhow!("{e}"))?;
 
-        Ok(Self { tx, running })
+        Ok(Self { ring, running })
     }
 
-    /// Write a frame of PCM samples for playback.
-    pub fn write_frame(&self, pcm: &[i16]) {
-        let _ = self.tx.try_send(pcm.to_vec());
+    /// Get a reference to the playout ring buffer for direct writing.
+    pub fn ring(&self) -> &Arc<AudioRing> {
+        &self.ring
     }
 
     /// Stop playback.
@@ -292,11 +265,16 @@ impl AudioPlayback {
     }
 }
 
+impl Drop for AudioPlayback {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Helpers
 // ---------------------------------------------------------------------------
 
-/// Check if the input device supports i16 at 48 kHz mono.
 fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_input_configs()
@@ -313,7 +291,6 @@ fn supports_i16_input(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     Ok(false)
 }
 
-/// Check if the output device supports i16 at 48 kHz mono.
 fn supports_i16_output(device: &cpal::Device) -> Result<bool, anyhow::Error> {
     let supported = device
         .supported_output_configs()

crates/wzp-client/src/audio_ring.rs

@@ -0,0 +1,89 @@
+//! Lock-free SPSC ring buffer for audio PCM transfer between
+//! CPAL audio callbacks and the Rust engine.
+//!
+//! Identical design to wzp-android's audio_ring: the producer writes and
+//! advances a write cursor, the consumer reads and advances a read cursor.
+//! Both cursors are atomic — no mutex, no blocking on the audio thread.
+
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+/// Ring buffer capacity in i16 samples.
+/// 960 samples * 10 frames = ~200ms of audio at 48kHz mono.
+const RING_CAPACITY: usize = 960 * 10;
+
+/// Lock-free single-producer single-consumer ring buffer for i16 PCM samples.
+pub struct AudioRing {
+    buf: Box<[i16; RING_CAPACITY]>,
+    write_pos: AtomicUsize,
+    read_pos: AtomicUsize,
+}
+
+// SAFETY: AudioRing is designed for SPSC — one thread writes, one reads.
+// The atomics ensure visibility. The buffer itself is never accessed
+// from the same index by both threads simultaneously because the
+// producer only writes to positions between write_pos and read_pos,
+// and the consumer only reads from positions between read_pos and write_pos.
+unsafe impl Send for AudioRing {}
+unsafe impl Sync for AudioRing {}
+
+impl AudioRing {
+    pub fn new() -> Self {
+        Self {
+            buf: Box::new([0i16; RING_CAPACITY]),
+            write_pos: AtomicUsize::new(0),
+            read_pos: AtomicUsize::new(0),
+        }
+    }
+
+    /// Number of samples available to read.
+    pub fn available(&self) -> usize {
+        let w = self.write_pos.load(Ordering::Acquire);
+        let r = self.read_pos.load(Ordering::Acquire);
+        w.wrapping_sub(r)
+    }
+
+    /// Write samples into the ring. Returns number of samples written.
+    /// Drops oldest samples if the ring is full.
+    pub fn write(&self, samples: &[i16]) -> usize {
+        let w = self.write_pos.load(Ordering::Relaxed);
+        let count = samples.len().min(RING_CAPACITY);
+
+        for i in 0..count {
+            let idx = (w + i) % RING_CAPACITY;
+            unsafe {
+                let ptr = self.buf.as_ptr() as *mut i16;
+                *ptr.add(idx) = samples[i];
+            }
+        }
+
+        self.write_pos
+            .store(w.wrapping_add(count), Ordering::Release);
+
+        // If we overwrote unread data, advance read_pos
+        if self.available() > RING_CAPACITY {
+            let new_read = self
+                .write_pos
+                .load(Ordering::Relaxed)
+                .wrapping_sub(RING_CAPACITY);
+            self.read_pos.store(new_read, Ordering::Release);
+        }
+
+        count
+    }
+
+    /// Read samples from the ring into `out`. Returns number of samples read.
+    pub fn read(&self, out: &mut [i16]) -> usize {
+        let avail = self.available();
+        let count = out.len().min(avail);
+
+        let r = self.read_pos.load(Ordering::Relaxed);
+        for i in 0..count {
+            let idx = (r + i) % RING_CAPACITY;
+            out[i] = unsafe { *self.buf.as_ptr().add(idx) };
+        }
+
+        self.read_pos
+            .store(r.wrapping_add(count), Ordering::Release);
+        count
+    }
+}

crates/wzp-client/src/cli.rs

@@ -45,12 +45,22 @@ struct CliArgs {
     seed_hex: Option<String>,
     mnemonic: Option<String>,
     room: Option<String>,
+    raw_room: bool,
+    alias: Option<String>,
     token: Option<String>,
     _metrics_file: Option<String>,
 }
 
+/// Default identity file path: ~/.wzp/identity
+fn default_identity_path() -> std::path::PathBuf {
+    let home = std::env::var("HOME").unwrap_or_else(|_| ".".to_string());
+    std::path::PathBuf::from(home).join(".wzp").join("identity")
+}
+
 impl CliArgs {
-    /// Resolve the identity seed from --seed, --mnemonic, or generate a new one.
+    /// Resolve the identity seed from --seed, --mnemonic, or persistent file.
+    ///
+    /// Priority: --seed > --mnemonic > ~/.wzp/identity > generate + save.
     pub fn resolve_seed(&self) -> wzp_crypto::Seed {
         if let Some(ref hex_str) = self.seed_hex {
             let seed = wzp_crypto::Seed::from_hex(hex_str).expect("invalid --seed hex");
@@ -65,10 +75,30 @@ impl CliArgs {
             info!(fingerprint = %fp, "identity from --mnemonic");
             seed
         } else {
+            let path = default_identity_path();
+            // Try loading existing identity
+            if path.exists() {
+                if let Ok(hex_str) = std::fs::read_to_string(&path) {
+                    let hex_str = hex_str.trim();
+                    if let Ok(seed) = wzp_crypto::Seed::from_hex(hex_str) {
+                        let id = seed.derive_identity();
+                        let fp = id.public_identity().fingerprint;
+                        info!(fingerprint = %fp, path = %path.display(), "loaded persistent identity");
+                        return seed;
+                    }
+                }
+            }
+            // Generate new and save
             let seed = wzp_crypto::Seed::generate();
             let id = seed.derive_identity();
             let fp = id.public_identity().fingerprint;
-            info!(fingerprint = %fp, "generated ephemeral identity");
+            if let Some(parent) = path.parent() {
+                std::fs::create_dir_all(parent).ok();
+            }
+            // Encode seed as hex manually (avoid dep on `hex` crate in binary)
+            let hex_str: String = seed.0.iter().map(|b| format!("{b:02x}")).collect();
+            std::fs::write(&path, hex_str).ok();
+            info!(fingerprint = %fp, path = %path.display(), "generated and saved new identity");
             seed
         }
     }
@@ -86,6 +116,8 @@ fn parse_args() -> CliArgs {
     let mut seed_hex = None;
     let mut mnemonic = None;
     let mut room = None;
+    let mut raw_room = false;
+    let mut alias = None;
     let mut token = None;
     let mut metrics_file = None;
     let mut relay_str = None;
@@ -130,6 +162,11 @@ fn parse_args() -> CliArgs {
                 i += 1;
                 room = Some(args.get(i).expect("--room requires a name").to_string());
             }
+            "--raw-room" => raw_room = true,
+            "--alias" => {
+                i += 1;
+                alias = Some(args.get(i).expect("--alias requires a name").to_string());
+            }
             "--token" => {
                 i += 1;
                 token = Some(args.get(i).expect("--token requires a value").to_string());
@@ -183,10 +220,13 @@ fn parse_args() -> CliArgs {
                 eprintln!("  --seed <hex>           Identity seed (64 hex chars, featherChat compatible)");
                 eprintln!("  --mnemonic <words...>  Identity seed as BIP39 mnemonic (24 words)");
                 eprintln!("  --room <name>          Room name (hashed for privacy before sending)");
+                eprintln!("  --raw-room             Send room name as-is (no hash, for Android compat)");
+                eprintln!("  --alias <name>         Display name shown to other participants");
                 eprintln!("  --token <token>        featherChat bearer token for relay auth");
                 eprintln!("  --metrics-file <path>  Write JSONL telemetry to file (1 line/sec)");
                 eprintln!("                         (48kHz mono s16le, play with ffplay -f s16le -ar 48000 -ch_layout mono file.raw)");
                 eprintln!();
+                eprintln!("Identity is auto-saved to ~/.wzp/identity on first run.");
                 eprintln!("Default relay: 127.0.0.1:4433");
                 std::process::exit(0);
             }
@@ -219,6 +259,8 @@ fn parse_args() -> CliArgs {
         seed_hex,
         mnemonic,
         room,
+        raw_room,
+        alias,
         token,
         _metrics_file: metrics_file,
     }
@@ -250,8 +292,14 @@ async fn main() -> anyhow::Result<()> {
         "WarzonePhone client"
     );
 
-    // Hash room name for SNI privacy (or "default" if none specified)
+    // Compute SNI from room name.
+    // --raw-room sends the name as-is (for Android compat — Android doesn't hash).
+    // Default behaviour hashes for privacy.
     let sni = match &cli.room {
+        Some(name) if cli.raw_room => {
+            info!(room = %name, "using raw room name as SNI (no hash)");
+            name.clone()
+        }
         Some(name) => {
             let hashed = wzp_crypto::hash_room_name(name);
             info!(room = %name, hashed = %hashed, "room name hashed for SNI");
@@ -287,6 +335,7 @@ async fn main() -> anyhow::Result<()> {
     let _crypto_session = wzp_client::handshake::perform_handshake(
         &*transport,
         &seed.0,
+        cli.alias.as_deref(),
     ).await?;
     info!("crypto handshake complete");
 
@@ -548,78 +597,225 @@ async fn run_file_mode(
 }
 
 /// Live mode: capture from mic, encode, send; receive, decode, play.
+///
+/// Architecture (mirrors wzp-android/engine.rs):
+///   CPAL capture callback → AudioRing → send task (5ms poll) → QUIC
+///   QUIC → recv task → jitter buffer → decode tick (20ms) → AudioRing → CPAL playback callback
+///
+/// All lock-free: CPAL callbacks use atomic ring buffers, no Mutex on the audio path.
 #[cfg(feature = "audio")]
-async fn run_live(transport: Arc<wzp_transport::QuinnTransport>) -> anyhow::Result<()> {
+async fn run_live(
+    transport: Arc<wzp_transport::QuinnTransport>,
+) -> anyhow::Result<()> {
+    use std::sync::Arc as StdArc;
+    use std::sync::atomic::{AtomicBool, Ordering};
     use wzp_client::audio_io::{AudioCapture, AudioPlayback};
+    use wzp_client::call::JitterTelemetry;
 
     let capture = AudioCapture::start()?;
     let playback = AudioPlayback::start()?;
-    info!("Audio I/O started — press Ctrl+C to stop");
+    info!("audio I/O started (lock-free ring buffers) — press Ctrl+C to stop");
 
+    let capture_ring = capture.ring().clone();
+    let playout_ring = playback.ring().clone();
+
+    let running = StdArc::new(AtomicBool::new(true));
+
+    // --- Signal handler: set running=false on first Ctrl+C, force-quit on second ---
+    let signal_running = running.clone();
+    tokio::spawn(async move {
+        tokio::signal::ctrl_c().await.ok();
+        eprintln!(); // newline after ^C
+        info!("Ctrl+C received, shutting down...");
+        signal_running.store(false, Ordering::SeqCst);
+
+        tokio::signal::ctrl_c().await.ok();
+        eprintln!("\nForce quit");
+        std::process::exit(1);
+    });
+
+    let config = CallConfig::default();
+
+    // --- Send task: poll capture ring → encode → send via async ---
     let send_transport = transport.clone();
-    let rt_handle = tokio::runtime::Handle::current();
-    let send_handle = std::thread::Builder::new()
-        .name("wzp-send-loop".into())
-        .spawn(move || {
-            let config = CallConfig::default();
-            let mut encoder = CallEncoder::new(&config);
-            loop {
-                let frame = match capture.read_frame() {
-                    Some(f) => f,
-                    None => break,
-                };
-                let packets = match encoder.encode_frame(&frame) {
-                    Ok(p) => p,
-                    Err(e) => {
-                        error!("encode error: {e}");
-                        continue;
-                    }
-                };
-                for pkt in &packets {
-                    if let Err(e) = rt_handle.block_on(send_transport.send_media(pkt)) {
-                        error!("send error: {e}");
-                        return;
-                    }
+    let send_running = running.clone();
+    let send_task = async move {
+        let mut encoder = CallEncoder::new(&config);
+        let mut capture_buf = vec![0i16; FRAME_SAMPLES];
+        let mut frames_sent: u64 = 0;
+
+        loop {
+            if !send_running.load(Ordering::Relaxed) {
+                break;
+            }
+
+            let avail = capture_ring.available();
+            if avail < FRAME_SAMPLES {
+                tokio::time::sleep(std::time::Duration::from_millis(5)).await;
+                continue;
+            }
+
+            let read = capture_ring.read(&mut capture_buf);
+            if read < FRAME_SAMPLES {
+                continue;
+            }
+
+            let packets = match encoder.encode_frame(&capture_buf) {
+                Ok(p) => p,
+                Err(e) => {
+                    error!("encode error: {e}");
+                    continue;
+                }
+            };
+
+            for pkt in &packets {
+                if let Err(e) = send_transport.send_media(pkt).await {
+                    error!("send error: {e}");
+                    return;
                 }
             }
-        })?;
 
+            frames_sent += 1;
+            if frames_sent == 1 || frames_sent % 500 == 0 {
+                info!(frames_sent, "send progress");
+            }
+        }
+    };
+
+    // --- Recv task: receive packets → ingest into jitter buffer ---
+    // Uses timeout so it can check the running flag and exit on Ctrl+C.
     let recv_transport = transport.clone();
-    let recv_handle = tokio::spawn(async move {
-        let config = CallConfig::default();
-        let mut decoder = CallDecoder::new(&config);
-        let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+    let recv_running = running.clone();
+    let config = CallConfig::default();
+    let decoder = StdArc::new(tokio::sync::Mutex::new(CallDecoder::new(&config)));
+    let decoder_recv = decoder.clone();
+
+    let recv_task = async move {
+        let mut packets_received: u64 = 0;
         loop {
-            match recv_transport.recv_media().await {
-                Ok(Some(pkt)) => {
-                    let is_repair = pkt.header.is_repair;
-                    decoder.ingest(pkt);
-                    // Only decode for source packets (1 source = 1 audio frame).
-                    // Repair packets feed the FEC decoder but don't produce audio.
-                    if !is_repair {
-                        if let Some(_n) = decoder.decode_next(&mut pcm_buf) {
-                            playback.write_frame(&pcm_buf);
-                        }
+            if !recv_running.load(Ordering::Relaxed) {
+                break;
+            }
+            // Timeout so we can check running flag periodically
+            let result = tokio::time::timeout(
+                std::time::Duration::from_millis(100),
+                recv_transport.recv_media(),
+            )
+            .await;
+            match result {
+                Ok(Ok(Some(pkt))) => {
+                    let mut dec = decoder_recv.lock().await;
+                    dec.ingest(pkt);
+                    packets_received += 1;
+                    if packets_received == 1 || packets_received % 500 == 0 {
+                        info!(packets_received, depth = dec.stats().current_depth, "recv progress");
                     }
                 }
-                Ok(None) => {
+                Ok(Ok(None)) => {
                     info!("connection closed");
                     break;
                 }
-                Err(e) => {
+                Ok(Err(e)) => {
                     error!("recv error: {e}");
                     break;
                 }
+                Err(_) => {} // timeout — loop and check running flag
             }
         }
-    });
+    };
 
-    tokio::signal::ctrl_c().await?;
-    info!("Shutting down...");
+    // --- Playout tick: decode from jitter buffer at steady 20ms intervals ---
+    let playout_running = running.clone();
+    let decoder_playout = decoder.clone();
+    let playout_task = async move {
+        let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+        let mut interval = tokio::time::interval(std::time::Duration::from_millis(20));
+        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
+        let mut telemetry = JitterTelemetry::new(5);
+        loop {
+            interval.tick().await;
+            if !playout_running.load(Ordering::Relaxed) {
+                break;
+            }
 
-    recv_handle.abort();
-    drop(send_handle);
-    transport.close().await?;
-    info!("done");
+            let mut dec = decoder_playout.lock().await;
+
+            // Drain ready frames from jitter buffer into playout ring.
+            let mut decoded_this_tick = 0;
+            while let Some(n) = dec.decode_next(&mut pcm_buf) {
+                playout_ring.write(&pcm_buf[..n]);
+                decoded_this_tick += 1;
+                if decoded_this_tick >= 2 {
+                    break; // Don't drain too aggressively in one tick
+                }
+            }
+
+            telemetry.maybe_log(dec.stats());
+        }
+    };
+
+    // --- Signal task: listen for RoomUpdate and display presence ---
+    let signal_transport = transport.clone();
+    let signal_running = running.clone();
+    let signal_task = async move {
+        loop {
+            if !signal_running.load(Ordering::Relaxed) {
+                break;
+            }
+            let result = tokio::time::timeout(
+                std::time::Duration::from_millis(200),
+                signal_transport.recv_signal(),
+            )
+            .await;
+            match result {
+                Ok(Ok(Some(wzp_proto::SignalMessage::RoomUpdate { count, participants }))) => {
+                    info!(count, "room update");
+                    for p in &participants {
+                        let name = p
+                            .alias
+                            .as_deref()
+                            .unwrap_or("(no alias)");
+                        let fp = if p.fingerprint.is_empty() {
+                            "(no fingerprint)"
+                        } else {
+                            &p.fingerprint
+                        };
+                        info!("  participant: {name} [{fp}]");
+                    }
+                }
+                Ok(Ok(Some(msg))) => {
+                    info!("signal: {:?}", std::mem::discriminant(&msg));
+                }
+                Ok(Ok(None)) => {
+                    info!("signal stream closed");
+                    break;
+                }
+                Ok(Err(e)) => {
+                    error!("signal recv error: {e}");
+                    break;
+                }
+                Err(_) => {} // timeout — loop and check running flag
+            }
+        }
+    };
+
+    // --- Run all tasks, exit when any finishes (or running flag cleared by Ctrl+C) ---
+    tokio::select! {
+        _ = send_task => info!("send task ended"),
+        _ = recv_task => info!("recv task ended"),
+        _ = playout_task => info!("playout task ended"),
+        _ = signal_task => info!("signal task ended"),
+    }
+
+    running.store(false, Ordering::SeqCst);
+    capture.stop();
+    playback.stop();
+
+    // Give transport 2s to close gracefully, then bail
+    match tokio::time::timeout(std::time::Duration::from_secs(2), transport.close()).await {
+        Ok(Ok(())) => info!("done"),
+        Ok(Err(e)) => info!("close error (non-fatal): {e}"),
+        Err(_) => info!("close timed out, exiting anyway"),
+    }
     Ok(())
 }

crates/wzp-client/src/featherchat.rs

@@ -110,6 +110,7 @@ pub fn signal_to_call_type(signal: &SignalMessage) -> CallSignalType {
         SignalMessage::SessionForward { .. } => CallSignalType::Offer, // reuse
         SignalMessage::SessionForwardAck { .. } => CallSignalType::Offer, // reuse
         SignalMessage::RoomUpdate { .. } => CallSignalType::Offer, // reuse
+        SignalMessage::SetAlias { .. } => CallSignalType::Offer, // reuse
     }
 }
 

crates/wzp-client/src/handshake.rs

@@ -17,6 +17,7 @@ use wzp_proto::{MediaTransport, QualityProfile, SignalMessage};
 pub async fn perform_handshake(
     transport: &dyn MediaTransport,
     seed: &[u8; 32],
+    alias: Option<&str>,
 ) -> Result<Box<dyn CryptoSession>, anyhow::Error> {
     // 1. Create key exchange from identity seed
     let mut kx = WarzoneKeyExchange::from_identity_seed(seed);
@@ -41,6 +42,7 @@ pub async fn perform_handshake(
             QualityProfile::DEGRADED,
             QualityProfile::CATASTROPHIC,
         ],
+        alias: alias.map(|s| s.to_string()),
     };
     transport.send_signal(&offer).await?;
 

crates/wzp-client/src/lib.rs

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

crates/wzp-proto/src/packet.rs

@@ -548,6 +548,9 @@ pub enum SignalMessage {
         signature: Vec<u8>,
         /// Supported quality profiles.
         supported_profiles: Vec<crate::QualityProfile>,
+        /// Optional display name set by the caller.
+        #[serde(default)]
+        alias: Option<String>,
     },
 
     /// Call acceptance (analogous to Warzone's WireMessage::CallAnswer).
@@ -653,6 +656,11 @@ pub enum SignalMessage {
         /// List of participants currently in the room.
         participants: Vec<RoomParticipant>,
     },
+
+    /// Set or update the client's display name.
+    /// Sent by client after joining; relay updates the participant entry and
+    /// re-broadcasts a RoomUpdate to all participants.
+    SetAlias { alias: String },
 }
 
 /// A participant entry in a RoomUpdate message.

crates/wzp-relay/src/handshake.rs

@@ -15,25 +15,27 @@ use wzp_proto::{MediaTransport, QualityProfile, SignalMessage};
 /// 5. Derive shared ChaCha20-Poly1305 session
 /// 6. Send `CallAnswer` back
 ///
-/// Returns the derived `CryptoSession` and the chosen `QualityProfile`.
+/// Returns the derived `CryptoSession`, the chosen `QualityProfile`, the caller's fingerprint,
+/// and the caller's alias (if provided in CallOffer).
 pub async fn accept_handshake(
     transport: &dyn MediaTransport,
     seed: &[u8; 32],
-) -> Result<(Box<dyn CryptoSession>, QualityProfile), anyhow::Error> {
+) -> Result<(Box<dyn CryptoSession>, QualityProfile, String, Option<String>), anyhow::Error> {
     // 1. Receive CallOffer
     let offer = transport
         .recv_signal()
         .await?
         .ok_or_else(|| anyhow::anyhow!("connection closed before receiving CallOffer"))?;
 
-    let (caller_identity_pub, caller_ephemeral_pub, caller_signature, supported_profiles) =
+    let (caller_identity_pub, caller_ephemeral_pub, caller_signature, supported_profiles, caller_alias) =
         match offer {
             SignalMessage::CallOffer {
                 identity_pub,
                 ephemeral_pub,
                 signature,
                 supported_profiles,
-            } => (identity_pub, ephemeral_pub, signature, supported_profiles),
+                alias,
+            } => (identity_pub, ephemeral_pub, signature, supported_profiles, alias),
             other => {
                 return Err(anyhow::anyhow!(
                     "expected CallOffer, got {:?}",
@@ -76,7 +78,13 @@ pub async fn accept_handshake(
     };
     transport.send_signal(&answer).await?;
 
-    Ok((session, chosen_profile))
+    // Derive caller fingerprint from their identity public key (first 8 bytes as hex)
+    let caller_fp = caller_identity_pub[..8]
+        .iter()
+        .map(|b| format!("{b:02x}"))
+        .collect::<String>();
+
+    Ok((session, chosen_profile, caller_fp, caller_alias))
 }
 
 /// Select the best quality profile from those the caller supports.

crates/wzp-relay/src/main.rs

@@ -431,7 +431,7 @@ async fn main() -> anyhow::Result<()> {
 
             // Crypto handshake: verify client identity + negotiate quality profile
             let handshake_start = std::time::Instant::now();
-            let (_crypto_session, _chosen_profile) = match wzp_relay::handshake::accept_handshake(
+            let (_crypto_session, _chosen_profile, caller_fp, caller_alias) = match wzp_relay::handshake::accept_handshake(
                 &*transport,
                 &relay_seed_bytes,
             ).await {
@@ -448,10 +448,13 @@ async fn main() -> anyhow::Result<()> {
                 }
             };
 
+            // Use the caller's identity fingerprint from the handshake
+            let participant_fp = authenticated_fp.clone().unwrap_or(caller_fp);
+
             // Register in presence registry
-            if let Some(ref fp) = authenticated_fp {
+            {
                 let mut reg = presence.lock().await;
-                reg.register_local(fp, None, Some(room_name.clone()));
+                reg.register_local(&participant_fp, None, Some(room_name.clone()));
             }
 
             info!(%addr, room = %room_name, "client joining");
@@ -506,8 +509,8 @@ async fn main() -> anyhow::Result<()> {
                         &room_name,
                         addr,
                         room::ParticipantSender::Quic(transport.clone()),
-                        authenticated_fp.as_deref(),
-                        None, // alias — TODO: accept from client
+                        Some(&participant_fp),
+                        caller_alias.as_deref(),
                     ) {
                         Ok((id, update, senders)) => {
                             metrics.active_rooms.set(mgr.list().len() as i64);

crates/wzp-relay/src/room.rs

@@ -141,6 +141,17 @@ impl Room {
         self.participants.iter().map(|p| p.sender.clone()).collect()
     }
 
+    /// Update a participant's alias. Returns true if the participant was found.
+    fn set_alias(&mut self, id: ParticipantId, alias: String) -> bool {
+        if let Some(p) = self.participants.iter_mut().find(|p| p.id == id) {
+            info!(participant = id, %alias, "alias updated");
+            p.alias = Some(alias);
+            true
+        } else {
+            false
+        }
+    }
+
     fn is_empty(&self) -> bool {
         self.participants.is_empty()
     }
@@ -255,6 +266,26 @@ impl RoomManager {
         }
     }
 
+    /// Update a participant's alias and return a RoomUpdate + senders for broadcasting.
+    pub fn set_alias(
+        &mut self,
+        room_name: &str,
+        participant_id: ParticipantId,
+        alias: String,
+    ) -> Option<(wzp_proto::SignalMessage, Vec<ParticipantSender>)> {
+        if let Some(room) = self.rooms.get_mut(room_name) {
+            if room.set_alias(participant_id, alias) {
+                let update = wzp_proto::SignalMessage::RoomUpdate {
+                    count: room.len() as u32,
+                    participants: room.participant_list(),
+                };
+                let senders = room.all_senders();
+                return Some((update, senders));
+            }
+        }
+        None
+    }
+
     /// Get senders for all OTHER participants in a room.
     pub fn others(
         &self,
@@ -374,68 +405,111 @@ async fn run_participant_plain(
     session_id: &str,
 ) {
     let addr = transport.connection().remote_address();
-    let mut packets_forwarded = 0u64;
 
-    loop {
-        let pkt = match transport.recv_media().await {
-            Ok(Some(pkt)) => pkt,
-            Ok(None) => {
-                info!(%addr, participant = participant_id, "disconnected");
-                break;
-            }
-            Err(e) => {
-                let msg = e.to_string();
-                if msg.contains("timed out") || msg.contains("reset") || msg.contains("closed") {
-                    info!(%addr, participant = participant_id, "connection closed: {e}");
-                } else {
-                    error!(%addr, participant = participant_id, "recv error: {e}");
+    // Media forwarding task
+    let media_room_mgr = room_mgr.clone();
+    let media_room_name = room_name.clone();
+    let media_transport = transport.clone();
+    let media_metrics = metrics.clone();
+    let media_session_id = session_id.to_string();
+    let media_task = async move {
+        let mut packets_forwarded = 0u64;
+        loop {
+            let pkt = match media_transport.recv_media().await {
+                Ok(Some(pkt)) => pkt,
+                Ok(None) => {
+                    info!(%addr, participant = participant_id, "disconnected");
+                    break;
                 }
-                break;
-            }
-        };
-
-        // Update per-session quality metrics if a quality report is present
-        if let Some(ref report) = pkt.quality_report {
-            metrics.update_session_quality(session_id, report);
-        }
-
-        // Get current list of other participants
-        let others = {
-            let mgr = room_mgr.lock().await;
-            mgr.others(&room_name, participant_id)
-        };
-
-        // Forward to all others
-        let pkt_bytes = pkt.payload.len() as u64;
-        for other in &others {
-            match other {
-                ParticipantSender::Quic(t) => {
-                    let _ = t.send_media(&pkt).await;
+                Err(e) => {
+                    let msg = e.to_string();
+                    if msg.contains("timed out") || msg.contains("reset") || msg.contains("closed") {
+                        info!(%addr, participant = participant_id, "connection closed: {e}");
+                    } else {
+                        error!(%addr, participant = participant_id, "recv error: {e}");
+                    }
+                    break;
                 }
-                ParticipantSender::WebSocket(_) => {
-                    // WS clients receive raw payload bytes
-                    let _ = other.send_raw(&pkt.payload).await;
-                }
-            }
-        }
-
-        let fan_out = others.len() as u64;
-        metrics.packets_forwarded.inc_by(fan_out);
-        metrics.bytes_forwarded.inc_by(pkt_bytes * fan_out);
-        packets_forwarded += 1;
-        if packets_forwarded % 500 == 0 {
-            let room_size = {
-                let mgr = room_mgr.lock().await;
-                mgr.room_size(&room_name)
             };
-            info!(
-                room = %room_name,
-                participant = participant_id,
-                forwarded = packets_forwarded,
-                room_size,
-                "participant stats"
-            );
+
+            if let Some(ref report) = pkt.quality_report {
+                media_metrics.update_session_quality(&media_session_id, report);
+            }
+
+            let others = {
+                let mgr = media_room_mgr.lock().await;
+                mgr.others(&media_room_name, participant_id)
+            };
+
+            let pkt_bytes = pkt.payload.len() as u64;
+            for other in &others {
+                match other {
+                    ParticipantSender::Quic(t) => {
+                        let _ = t.send_media(&pkt).await;
+                    }
+                    ParticipantSender::WebSocket(_) => {
+                        let _ = other.send_raw(&pkt.payload).await;
+                    }
+                }
+            }
+
+            let fan_out = others.len() as u64;
+            media_metrics.packets_forwarded.inc_by(fan_out);
+            media_metrics.bytes_forwarded.inc_by(pkt_bytes * fan_out);
+            packets_forwarded += 1;
+            if packets_forwarded % 500 == 0 {
+                let room_size = {
+                    let mgr = media_room_mgr.lock().await;
+                    mgr.room_size(&media_room_name)
+                };
+                info!(
+                    room = %media_room_name,
+                    participant = participant_id,
+                    forwarded = packets_forwarded,
+                    room_size,
+                    "participant stats"
+                );
+            }
         }
+    };
+
+    // Signal handling task — processes SetAlias and other in-call signals
+    let signal_room_mgr = room_mgr.clone();
+    let signal_room_name = room_name.clone();
+    let signal_transport = transport.clone();
+    let signal_task = async move {
+        loop {
+            match signal_transport.recv_signal().await {
+                Ok(Some(wzp_proto::SignalMessage::SetAlias { alias })) => {
+                    info!(%addr, participant = participant_id, %alias, "SetAlias received");
+                    let mut mgr = signal_room_mgr.lock().await;
+                    if let Some((update, senders)) =
+                        mgr.set_alias(&signal_room_name, participant_id, alias)
+                    {
+                        drop(mgr);
+                        broadcast_signal(&senders, &update).await;
+                    }
+                }
+                Ok(Some(wzp_proto::SignalMessage::Hangup { .. })) => {
+                    info!(%addr, participant = participant_id, "hangup received");
+                    break;
+                }
+                Ok(Some(msg)) => {
+                    info!(%addr, participant = participant_id, "signal: {:?}", std::mem::discriminant(&msg));
+                }
+                Ok(None) => break,
+                Err(e) => {
+                    warn!(%addr, participant = participant_id, "signal recv error: {e}");
+                    break;
+                }
+            }
+        }
+    };
+
+    // Run both in parallel — exit when either finishes (disconnection)
+    tokio::select! {
+        _ = media_task => {}
+        _ = signal_task => {}
     }
 
     // Clean up — leave room and broadcast update to remaining participants