diff --git a/android/app/build.gradle.kts b/android/app/build.gradle.kts
index 9994ece..694f359 100644
--- a/android/app/build.gradle.kts
+++ b/android/app/build.gradle.kts
@@ -1,5 +1,6 @@
 plugins {
     id("com.android.application")
+    id("org.jetbrains.kotlin.android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
     id("dev.flutter.flutter-gradle-plugin")
 }
@@ -40,3 +41,7 @@ kotlin {
 flutter {
     source = "../.."
 }
+
+dependencies {
+    implementation("com.google.android.gms:play-services-wearable:19.0.0")
+}
diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index bc7d6d5..43248fa 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -1,8 +1,15 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+
     <application
         android:label="GameTime"
         android:name="${applicationName}"
-        android:icon="@mipmap/ic_launcher">
+        android:icon="@mipmap/ic_launcher"
+        android:usesCleartextTraffic="true">
         <activity
             android:name=".MainActivity"
             android:exported="true"
@@ -30,6 +37,22 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+        <service
+            android:name=".watch.WatchCompanionForegroundService"
+            android:exported="false"
+            android:foregroundServiceType="connectedDevice|dataSync" />
+        <service
+            android:name=".watch.PhoneWatchBridgeListenerService"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="com.google.android.gms.wearable.MESSAGE_RECEIVED" />
+                <action android:name="com.google.android.gms.wearable.CAPABILITY_CHANGED" />
+                <data
+                    android:host="*"
+                    android:pathPrefix="/gametime"
+                    android:scheme="wear" />
+            </intent-filter>
+        </service>
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility and
diff --git a/android/app/src/main/kotlin/com/gametime/app/MainActivity.kt b/android/app/src/main/kotlin/com/gametime/app/MainActivity.kt
index e9ef322..4a55248 100644
--- a/android/app/src/main/kotlin/com/gametime/app/MainActivity.kt
+++ b/android/app/src/main/kotlin/com/gametime/app/MainActivity.kt
@@ -1,5 +1,12 @@
 package com.gametime.app
 
+import com.gametime.app.watch.WatchBridgePlugin
 import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
 
-class MainActivity : FlutterActivity()
+class MainActivity : FlutterActivity() {
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+        WatchBridgePlugin.register(flutterEngine, applicationContext)
+    }
+}
diff --git a/android/app/src/main/kotlin/com/gametime/app/watch/PhoneWatchBridgeListenerService.kt b/android/app/src/main/kotlin/com/gametime/app/watch/PhoneWatchBridgeListenerService.kt
new file mode 100644
index 0000000..d995c1d
--- /dev/null
+++ b/android/app/src/main/kotlin/com/gametime/app/watch/PhoneWatchBridgeListenerService.kt
@@ -0,0 +1,63 @@
+package com.gametime.app.watch
+
+import com.google.android.gms.wearable.CapabilityInfo
+import com.google.android.gms.wearable.MessageEvent
+import com.google.android.gms.wearable.Wearable
+import com.google.android.gms.wearable.WearableListenerService
+import org.json.JSONObject
+import java.nio.charset.StandardCharsets
+
+class PhoneWatchBridgeListenerService : WearableListenerService() {
+    override fun onMessageReceived(messageEvent: MessageEvent) {
+        if (messageEvent.path != WatchBridgePlugin.COMMAND_PATH) {
+            return
+        }
+        val payload = JSONObject(String(messageEvent.data, StandardCharsets.UTF_8))
+        val command = payload.toMap()
+        val delivered = WatchBridgePlugin.emitCommand(command, messageEvent.sourceNodeId)
+        if (!delivered) {
+            sendPhoneBusyAck(command, messageEvent.sourceNodeId)
+        }
+    }
+
+    override fun onCapabilityChanged(capabilityInfo: CapabilityInfo) {
+        if (capabilityInfo.name != WatchBridgePlugin.WATCH_CAPABILITY) {
+            return
+        }
+        WatchBridgePlugin.emitConnection(
+            isReachable = capabilityInfo.nodes.isNotEmpty(),
+            requestsResync = capabilityInfo.nodes.isNotEmpty(),
+        )
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+        WatchBridgePlugin.requestCapabilityRefresh(applicationContext)
+    }
+
+    private fun sendPhoneBusyAck(command: Map<String, Any?>, sourceNodeId: String) {
+        val ack = JSONObject(
+            mapOf(
+                "schemaVersion" to (command["schemaVersion"] ?: 1),
+                "commandId" to command["commandId"],
+                "sessionId" to command["sessionId"],
+                "expectedRevision" to command["expectedRevision"],
+                "status" to "rejectedPhoneBusy",
+                "ackedAtEpochMs" to System.currentTimeMillis(),
+            ),
+        ).toString().toByteArray(StandardCharsets.UTF_8)
+        Wearable.getMessageClient(this)
+            .sendMessage(sourceNodeId, WatchBridgePlugin.ACK_PATH, ack)
+    }
+}
+
+private fun JSONObject.toMap(): Map<String, Any?> {
+    val output = linkedMapOf<String, Any?>()
+    val keys = keys()
+    while (keys.hasNext()) {
+        val key = keys.next()
+        val value = get(key)
+        output[key] = if (value == JSONObject.NULL) null else value
+    }
+    return output
+}
diff --git a/android/app/src/main/kotlin/com/gametime/app/watch/WatchBridgePlugin.kt b/android/app/src/main/kotlin/com/gametime/app/watch/WatchBridgePlugin.kt
new file mode 100644
index 0000000..02aa3f4
--- /dev/null
+++ b/android/app/src/main/kotlin/com/gametime/app/watch/WatchBridgePlugin.kt
@@ -0,0 +1,214 @@
+package com.gametime.app.watch
+
+import android.content.Context
+import android.content.Intent
+import com.google.android.gms.wearable.CapabilityClient
+import com.google.android.gms.wearable.PutDataMapRequest
+import com.google.android.gms.wearable.Wearable
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.EventChannel
+import io.flutter.plugin.common.MethodCall
+import io.flutter.plugin.common.MethodChannel
+import org.json.JSONObject
+import java.nio.charset.StandardCharsets
+import java.util.concurrent.ConcurrentHashMap
+
+object WatchBridgePlugin {
+    private const val METHOD_CHANNEL = "gametime.watch_bridge/methods"
+    private const val COMMAND_CHANNEL = "gametime.watch_bridge/commands"
+    private const val CONNECTION_CHANNEL = "gametime.watch_bridge/connection"
+
+    const val COMMAND_PATH = "/gametime/watch/command"
+    const val ACK_PATH = "/gametime/phone/ack"
+    const val STATE_PATH = "/gametime/phone/projection"
+    const val WATCH_CAPABILITY = "gametime_watch_companion"
+
+    private val pendingCommandNodes = ConcurrentHashMap<String, String>()
+    private var appContext: Context? = null
+    private var commandSink: EventChannel.EventSink? = null
+    private var connectionSink: EventChannel.EventSink? = null
+
+    fun register(flutterEngine: FlutterEngine, context: Context) {
+        appContext = context.applicationContext
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, METHOD_CHANNEL)
+            .setMethodCallHandler(::handleMethodCall)
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, COMMAND_CHANNEL)
+            .setStreamHandler(
+                object : EventChannel.StreamHandler {
+                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                        commandSink = events
+                    }
+
+                    override fun onCancel(arguments: Any?) {
+                        commandSink = null
+                    }
+                },
+            )
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, CONNECTION_CHANNEL)
+            .setStreamHandler(
+                object : EventChannel.StreamHandler {
+                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                        connectionSink = events
+                        requestCapabilityRefresh(context.applicationContext)
+                    }
+
+                    override fun onCancel(arguments: Any?) {
+                        connectionSink = null
+                    }
+                },
+            )
+    }
+
+    fun emitCommand(payload: Map<String, Any?>, sourceNodeId: String): Boolean {
+        val sink = commandSink ?: return false
+        val commandId = payload["commandId"] as? String
+        if (commandId != null) {
+            pendingCommandNodes[commandId] = sourceNodeId
+        }
+        sink.success(payload)
+        return true
+    }
+
+    fun emitConnection(isReachable: Boolean, requestsResync: Boolean) {
+        connectionSink?.success(
+            mapOf(
+                "isReachable" to isReachable,
+                "requestsResync" to requestsResync,
+            ),
+        )
+    }
+
+    private fun handleMethodCall(call: MethodCall, result: MethodChannel.Result) {
+        val context = appContext
+        if (context == null) {
+            result.error("watch_bridge_unavailable", "Application context unavailable.", null)
+            return
+        }
+        when (call.method) {
+            "publishProjection" -> publishProjection(context, call.arguments, result)
+            "sendCommandAck" -> sendCommandAck(context, call.arguments, result)
+            "requestCapabilityRefresh" -> {
+                requestCapabilityRefresh(context)
+                result.success(null)
+            }
+            "startForegroundService" -> {
+                startForegroundService(context)
+                result.success(null)
+            }
+            "stopForegroundService" -> {
+                context.stopService(Intent(context, WatchCompanionForegroundService::class.java))
+                result.success(null)
+            }
+            else -> result.notImplemented()
+        }
+    }
+
+    private fun publishProjection(
+        context: Context,
+        arguments: Any?,
+        result: MethodChannel.Result,
+    ) {
+        val map = arguments as? Map<*, *>
+        if (map == null) {
+            result.error("invalid_projection", "Projection payload must be a map.", null)
+            return
+        }
+        val projectionJson = JSONObject(map).toString()
+        val request = PutDataMapRequest.create(STATE_PATH).apply {
+            dataMap.putString("projectionJson", projectionJson)
+            dataMap.putInt("schemaVersion", (map["schemaVersion"] as? Number)?.toInt() ?: 1)
+            dataMap.putInt("revision", (map["revision"] as? Number)?.toInt() ?: 0)
+            dataMap.putLong(
+                "projectedAtEpochMs",
+                (map["projectedAtEpochMs"] as? Number)?.toLong() ?: 0L,
+            )
+        }.asPutDataRequest().setUrgent()
+        Wearable.getDataClient(context).putDataItem(request)
+            .addOnSuccessListener { result.success(null) }
+            .addOnFailureListener { error ->
+                result.error("publish_projection_failed", error.message, null)
+            }
+    }
+
+    private fun sendCommandAck(
+        context: Context,
+        arguments: Any?,
+        result: MethodChannel.Result,
+    ) {
+        val map = arguments as? Map<*, *>
+        if (map == null) {
+            result.error("invalid_ack", "Ack payload must be a map.", null)
+            return
+        }
+        val commandId = map["commandId"] as? String
+        val targetNode = commandId?.let { pendingCommandNodes.remove(it) }
+        val payload = JSONObject(map).toString().toByteArray(StandardCharsets.UTF_8)
+        if (targetNode != null) {
+            sendMessage(context, targetNode, payload, result)
+            return
+        }
+        Wearable.getCapabilityClient(context)
+            .getCapability(WATCH_CAPABILITY, CapabilityClient.FILTER_REACHABLE)
+            .addOnSuccessListener { capability ->
+                val nodes = capability.nodes.toList()
+                if (nodes.isEmpty()) {
+                    result.success(null)
+                    return@addOnSuccessListener
+                }
+                var remaining = nodes.size
+                var failed = false
+                for (node in nodes) {
+                    Wearable.getMessageClient(context)
+                        .sendMessage(node.id, ACK_PATH, payload)
+                        .addOnSuccessListener {
+                            remaining -= 1
+                            if (remaining == 0 && !failed) result.success(null)
+                        }
+                        .addOnFailureListener { error ->
+                            failed = true
+                            result.error("send_ack_failed", error.message, null)
+                        }
+                }
+            }
+            .addOnFailureListener { error ->
+                result.error("capability_lookup_failed", error.message, null)
+            }
+    }
+
+    private fun sendMessage(
+        context: Context,
+        nodeId: String,
+        payload: ByteArray,
+        result: MethodChannel.Result,
+    ) {
+        Wearable.getMessageClient(context)
+            .sendMessage(nodeId, ACK_PATH, payload)
+            .addOnSuccessListener { result.success(null) }
+            .addOnFailureListener { error ->
+                result.error("send_ack_failed", error.message, null)
+            }
+    }
+
+    fun requestCapabilityRefresh(context: Context) {
+        Wearable.getCapabilityClient(context)
+            .getCapability(WATCH_CAPABILITY, CapabilityClient.FILTER_REACHABLE)
+            .addOnSuccessListener { capability ->
+                emitConnection(
+                    isReachable = capability.nodes.isNotEmpty(),
+                    requestsResync = capability.nodes.isNotEmpty(),
+                )
+            }
+            .addOnFailureListener {
+                emitConnection(isReachable = false, requestsResync = false)
+            }
+    }
+
+    private fun startForegroundService(context: Context) {
+        val intent = Intent(context, WatchCompanionForegroundService::class.java)
+        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
+            context.startForegroundService(intent)
+        } else {
+            context.startService(intent)
+        }
+    }
+}
diff --git a/android/app/src/main/kotlin/com/gametime/app/watch/WatchCompanionForegroundService.kt b/android/app/src/main/kotlin/com/gametime/app/watch/WatchCompanionForegroundService.kt
new file mode 100644
index 0000000..ef5db54
--- /dev/null
+++ b/android/app/src/main/kotlin/com/gametime/app/watch/WatchCompanionForegroundService.kt
@@ -0,0 +1,58 @@
+package com.gametime.app.watch
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import com.gametime.app.R
+
+class WatchCompanionForegroundService : Service() {
+    override fun onCreate() {
+        super.onCreate()
+        ensureNotificationChannel()
+        startForeground(NOTIFICATION_ID, notification())
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        return START_STICKY
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    private fun notification(): Notification {
+        val builder = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            Notification.Builder(this, CHANNEL_ID)
+        } else {
+            @Suppress("DEPRECATION")
+            Notification.Builder(this)
+        }
+        return builder
+            .setSmallIcon(R.mipmap.ic_launcher)
+            .setContentTitle("GameTime")
+            .setContentText("Séance en cours")
+            .setOngoing(true)
+            .setCategory(Notification.CATEGORY_SERVICE)
+            .build()
+    }
+
+    private fun ensureNotificationChannel() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+            return
+        }
+        val manager = getSystemService(NotificationManager::class.java)
+        val channel = NotificationChannel(
+            CHANNEL_ID,
+            "Synchronisation montre",
+            NotificationManager.IMPORTANCE_LOW,
+        )
+        manager.createNotificationChannel(channel)
+    }
+
+    private companion object {
+        const val CHANNEL_ID = "gametime_watch_companion"
+        const val NOTIFICATION_ID = 91
+    }
+}
diff --git a/android/app/src/main/res/values/wear.xml b/android/app/src/main/res/values/wear.xml
new file mode 100644
index 0000000..9842987
--- /dev/null
+++ b/android/app/src/main/res/values/wear.xml
@@ -0,0 +1,5 @@
+<resources>
+    <string-array name="android_wear_capabilities">
+        <item>gametime_phone_companion</item>
+    </string-array>
+</resources>
diff --git a/lib/application/app_bootstrap.dart b/lib/application/app_bootstrap.dart
index 2678ffe..3f9227f 100644
--- a/lib/application/app_bootstrap.dart
+++ b/lib/application/app_bootstrap.dart
@@ -1,6 +1,7 @@
 import '../infrastructure/local/local.dart';
 import '../infrastructure/remote/remote.dart';
 import '../infrastructure/security/security.dart';
+import '../infrastructure/watch_bridge/watch_bridge.dart';
 import 'application.dart';
 
 abstract interface class AppDependencies {
@@ -31,6 +32,9 @@ final class AppBootstrap implements AppDependencies {
     required this.workoutTemplateUseCases,
     required this.activeWorkoutSessionUseCases,
     required this.activeExerciseStepUseCases,
+    required this.watchCompanionProjectionUseCases,
+    required this.watchCompanionCommandHandler,
+    required this.watchWearDataLayerAdapter,
     required this.closeWorkoutSessionUseCase,
     required this.workoutHistoryUseCases,
     required this.progressionStatsUseCase,
@@ -57,6 +61,9 @@ final class AppBootstrap implements AppDependencies {
   final ActiveWorkoutSessionUseCases activeWorkoutSessionUseCases;
   @override
   final ActiveExerciseStepUseCases activeExerciseStepUseCases;
+  final WatchCompanionProjectionUseCases watchCompanionProjectionUseCases;
+  final WatchCompanionCommandHandler watchCompanionCommandHandler;
+  final WatchWearDataLayerAdapter watchWearDataLayerAdapter;
   @override
   final CloseWorkoutSessionUseCase closeWorkoutSessionUseCase;
   @override
@@ -103,6 +110,37 @@ final class AppBootstrap implements AppDependencies {
     final ids = LocalIdGenerator();
     const clock = SystemClock();
     const originDeviceId = 'local-device';
+    final activeWorkoutSessionUseCases = ActiveWorkoutSessionUseCases(
+      sessionRepository: activeSessionRepository,
+      templateRepository: templateRepository,
+      clock: clock,
+      ids: ids,
+      originDeviceId: originDeviceId,
+    );
+    final activeExerciseStepUseCases = ActiveExerciseStepUseCases(
+      sessionRepository: activeSessionRepository,
+      clock: clock,
+      ids: ids,
+      originDeviceId: originDeviceId,
+    );
+    final watchCompanionProjectionUseCases = WatchCompanionProjectionUseCases(
+      sessionRepository: activeSessionRepository,
+      clock: clock,
+      ids: ids,
+      originDeviceId: originDeviceId,
+    );
+    final watchCompanionCommandHandler = WatchCompanionCommandHandler(
+      sessionRepository: activeSessionRepository,
+      activeSessionUseCases: activeWorkoutSessionUseCases,
+      stepUseCases: activeExerciseStepUseCases,
+      projectionSource: watchCompanionProjectionUseCases,
+    );
+    final watchWearDataLayerAdapter = WatchWearDataLayerAdapter(
+      nativeChannel: const MethodChannelWatchBridgeNativeChannel(),
+      commandIngress: watchCompanionCommandHandler,
+      projectionSource: watchCompanionProjectionUseCases,
+    );
+    await watchWearDataLayerAdapter.start();
     await SeedStarterContentUseCase(
       seedStateRepository: starterSeedRepository,
       contentRepository: starterSeedRepository,
@@ -158,19 +196,11 @@ final class AppBootstrap implements AppDependencies {
         ids: ids,
         originDeviceId: originDeviceId,
       ),
-      activeWorkoutSessionUseCases: ActiveWorkoutSessionUseCases(
-        sessionRepository: activeSessionRepository,
-        templateRepository: templateRepository,
-        clock: clock,
-        ids: ids,
-        originDeviceId: originDeviceId,
-      ),
-      activeExerciseStepUseCases: ActiveExerciseStepUseCases(
-        sessionRepository: activeSessionRepository,
-        clock: clock,
-        ids: ids,
-        originDeviceId: originDeviceId,
-      ),
+      activeWorkoutSessionUseCases: activeWorkoutSessionUseCases,
+      activeExerciseStepUseCases: activeExerciseStepUseCases,
+      watchCompanionProjectionUseCases: watchCompanionProjectionUseCases,
+      watchCompanionCommandHandler: watchCompanionCommandHandler,
+      watchWearDataLayerAdapter: watchWearDataLayerAdapter,
       closeWorkoutSessionUseCase: CloseWorkoutSessionUseCase(
         sessionRepository: activeSessionRepository,
         historyRepository: historyRepository,
@@ -224,5 +254,9 @@ final class AppBootstrap implements AppDependencies {
     );
   }
 
-  Future<void> dispose() => database.close();
+  Future<void> dispose() async {
+    await watchWearDataLayerAdapter.stop();
+    await watchCompanionProjectionUseCases.dispose();
+    await database.close();
+  }
 }
diff --git a/lib/application/application.dart b/lib/application/application.dart
index c115371..f07094e 100644
--- a/lib/application/application.dart
+++ b/lib/application/application.dart
@@ -8,3 +8,4 @@ export 'ports.dart';
 export 'starter_content/basket_starter_seed_v1.dart';
 export 'starter_content/starter_content.dart';
 export 'use_cases.dart';
+export 'watch_companion_use_cases.dart';
diff --git a/lib/application/use_cases.dart b/lib/application/use_cases.dart
index 17992da..ba3ccb0 100644
--- a/lib/application/use_cases.dart
+++ b/lib/application/use_cases.dart
@@ -1,10 +1,14 @@
+import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
 import '../domain/domain.dart';
 import 'ports.dart';
 import 'starter_content/basket_starter_seed_v1.dart';
 import 'starter_content/starter_content.dart';
+import 'watch_companion_use_cases.dart';
 
 const Object _useCaseUnchanged = Object();
 
@@ -3084,6 +3088,865 @@ final class ActiveExerciseStepProgressView {
       : steps[state.currentStepIndex];
 }
 
+final class WatchCompanionProjectionUseCases implements WatchProjectionSource {
+  WatchCompanionProjectionUseCases({
+    required ActiveSessionRepository sessionRepository,
+    required Clock clock,
+    required IdGenerator ids,
+    required String originDeviceId,
+    WatchProjectionPublisher? publisher,
+  }) : _projector = WatchSessionProjectionProjector(
+         sessionRepository: sessionRepository,
+         clock: clock,
+         ids: ids,
+         originDeviceId: originDeviceId,
+       ),
+       _publisher = publisher;
+
+  final WatchSessionProjectionProjector _projector;
+  final WatchProjectionPublisher? _publisher;
+  final _controller = StreamController<WatchSessionProjection>.broadcast();
+  WatchSessionProjection? _latestProjection;
+  int _revision = 0;
+
+  @override
+  Stream<WatchSessionProjection> get projections => _controller.stream;
+
+  @override
+  Future<WatchSessionProjection> currentProjection() async {
+    return _latestProjection ?? _projectWithCurrentRevision();
+  }
+
+  @override
+  Future<WatchSessionProjection> emitCurrentProjection() async {
+    _revision += 1;
+    final projection = await _projector.project(revision: _revision);
+    _latestProjection = projection;
+    _controller.add(projection);
+    await _publisher?.publish(projection);
+    return projection;
+  }
+
+  Future<void> dispose() => _controller.close();
+
+  Future<WatchSessionProjection> _projectWithCurrentRevision() {
+    return _projector.project(revision: _revision);
+  }
+}
+
+final class WatchCompanionCommandHandler implements WatchCommandIngress {
+  WatchCompanionCommandHandler({
+    required ActiveSessionRepository sessionRepository,
+    required ActiveWorkoutSessionUseCases activeSessionUseCases,
+    required ActiveExerciseStepUseCases stepUseCases,
+    required WatchProjectionSource projectionSource,
+  }) : _sessionRepository = sessionRepository,
+       _activeSessionUseCases = activeSessionUseCases,
+       _stepUseCases = stepUseCases,
+       _projectionSource = projectionSource;
+
+  final ActiveSessionRepository _sessionRepository;
+  final ActiveWorkoutSessionUseCases _activeSessionUseCases;
+  final ActiveExerciseStepUseCases _stepUseCases;
+  final WatchProjectionSource _projectionSource;
+  final _handledCommands = <_WatchCommandKey, WatchCommandAck>{};
+  Future<void> _tail = Future<void>.value();
+
+  @override
+  Future<WatchCommandAck> dispatch(WatchCommandEnvelope command) {
+    final run = _tail.then(
+      (_) => _dispatch(command),
+      onError: (_) => _dispatch(command),
+    );
+    _tail = run.then((_) {}, onError: (_) {});
+    return run;
+  }
+
+  Future<WatchCommandAck> _dispatch(WatchCommandEnvelope command) async {
+    final key = _WatchCommandKey(command);
+    final previousAck = _handledCommands[key];
+    if (previousAck == WatchCommandAck.accepted ||
+        previousAck == WatchCommandAck.acceptedNoOp) {
+      return WatchCommandAck.acceptedNoOp;
+    }
+
+    try {
+      final projection = await _projectionSource.currentProjection();
+      if (projection.phase == WatchSessionPhase.noActiveSession ||
+          projection.deviceSessionId.isEmpty) {
+        return WatchCommandAck.rejectedNoActiveSession;
+      }
+      if (command.sessionId != projection.deviceSessionId) {
+        return WatchCommandAck.rejectedSessionMismatch;
+      }
+      if (command.expectedRevision != projection.revision) {
+        return WatchCommandAck.rejectedStaleRevision;
+      }
+      if (!_isApplicable(command.type, projection)) {
+        return WatchCommandAck.rejectedNotApplicable;
+      }
+
+      final session = await _sessionRepository.findOpen();
+      if (session == null ||
+          session.status == ActiveWorkoutStatus.completed ||
+          session.status == ActiveWorkoutStatus.abandoned ||
+          session.status == ActiveWorkoutStatus.savedExit) {
+        return WatchCommandAck.rejectedNoActiveSession;
+      }
+      if (session.metadata.id != command.sessionId) {
+        return WatchCommandAck.rejectedSessionMismatch;
+      }
+
+      final ack = await _route(command.type, session);
+      if (ack == WatchCommandAck.accepted ||
+          ack == WatchCommandAck.acceptedNoOp) {
+        _handledCommands[key] = ack;
+      }
+      if (ack == WatchCommandAck.accepted) {
+        await _emitProjectionAfterCommand();
+      }
+      return ack;
+    } on DomainException {
+      return WatchCommandAck.rejectedNotApplicable;
+    } on StateError {
+      return WatchCommandAck.rejectedNotApplicable;
+    } on Exception {
+      return WatchCommandAck.rejectedPhoneBusy;
+    }
+  }
+
+  bool _isApplicable(WatchCommandType type, WatchSessionProjection projection) {
+    return switch (type) {
+      WatchCommandType.startCurrentExercise =>
+        projection.primaryAction == WatchPrimaryAction.startCurrentExercise,
+      WatchCommandType.pauseSession =>
+        projection.primaryAction == WatchPrimaryAction.pauseSession,
+      WatchCommandType.resumeSession =>
+        projection.primaryAction == WatchPrimaryAction.resumeSession,
+      WatchCommandType.startPreparedTimedStep =>
+        projection.primaryAction == WatchPrimaryAction.startPreparedTimedStep,
+      WatchCommandType.skipCurrentStep => projection.secondaryActions.contains(
+        WatchSecondaryAction.skipCurrentStep,
+      ),
+      WatchCommandType.skipCurrentPassage =>
+        projection.secondaryActions.contains(
+          WatchSecondaryAction.skipCurrentPassage,
+        ),
+      WatchCommandType.finishCurrentSet => projection.secondaryActions.contains(
+        WatchSecondaryAction.finishCurrentSet,
+      ),
+      WatchCommandType.skipCurrentSet => projection.secondaryActions.contains(
+        WatchSecondaryAction.skipCurrentSet,
+      ),
+      WatchCommandType.skipCurrentRest =>
+        projection.primaryAction == WatchPrimaryAction.skipCurrentRest ||
+            projection.secondaryActions.contains(
+              WatchSecondaryAction.skipCurrentRest,
+            ),
+    };
+  }
+
+  Future<WatchCommandAck> _route(
+    WatchCommandType type,
+    ActiveWorkoutSession session,
+  ) {
+    return switch (type) {
+      WatchCommandType.startCurrentExercise => _startCurrentExercise(session),
+      WatchCommandType.pauseSession => _pause(session),
+      WatchCommandType.resumeSession => _resume(session),
+      WatchCommandType.startPreparedTimedStep => _startPreparedTimedStep(
+        session,
+      ),
+      WatchCommandType.skipCurrentStep => _skipCurrentStep(session),
+      WatchCommandType.skipCurrentPassage => _skipCurrentPassage(session),
+      WatchCommandType.finishCurrentSet => _finishCurrentSet(
+        session,
+        skipped: false,
+      ),
+      WatchCommandType.skipCurrentSet => _finishCurrentSet(
+        session,
+        skipped: true,
+      ),
+      WatchCommandType.skipCurrentRest => _skipCurrentRest(session),
+    };
+  }
+
+  Future<WatchCommandAck> _startCurrentExercise(
+    ActiveWorkoutSession session,
+  ) async {
+    final result = await _activeSessionUseCases.startCurrentExerciseTimers(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    final changed =
+        result.setTimer != null ||
+        result.scoreStopwatch != null ||
+        result.stepProgress != null;
+    return changed ? WatchCommandAck.accepted : WatchCommandAck.acceptedNoOp;
+  }
+
+  Future<WatchCommandAck> _pause(ActiveWorkoutSession session) async {
+    await _activeSessionUseCases.pause(session.metadata.id);
+    return WatchCommandAck.accepted;
+  }
+
+  Future<WatchCommandAck> _resume(ActiveWorkoutSession session) async {
+    await _activeSessionUseCases.resume(session.metadata.id);
+    return WatchCommandAck.accepted;
+  }
+
+  Future<WatchCommandAck> _startPreparedTimedStep(
+    ActiveWorkoutSession session,
+  ) async {
+    await _stepUseCases.startTimer(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    return WatchCommandAck.accepted;
+  }
+
+  Future<WatchCommandAck> _skipCurrentStep(ActiveWorkoutSession session) async {
+    await _stepUseCases.skipCurrentStep(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    return WatchCommandAck.accepted;
+  }
+
+  Future<WatchCommandAck> _skipCurrentPassage(
+    ActiveWorkoutSession session,
+  ) async {
+    await _stepUseCases.skipCurrentPassage(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    return WatchCommandAck.accepted;
+  }
+
+  Future<WatchCommandAck> _finishCurrentSet(
+    ActiveWorkoutSession session, {
+    required bool skipped,
+  }) async {
+    final snapshot = _findExerciseSnapshot(
+      resolvedTemplateSnapshotJson: session.resolvedTemplateSnapshotJson,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+    );
+    if (snapshot == null) {
+      return WatchCommandAck.rejectedNotApplicable;
+    }
+    final setTimer = skipped
+        ? await _activeSessionUseCases.skipSetExecutionTimers(
+            sessionId: session.metadata.id,
+            programIndex: session.currentProgramIndex,
+            exerciseIndex: session.currentExerciseIndex,
+            setIndex: session.currentSetIndex,
+          )
+        : await _activeSessionUseCases.stopSetExecutionTimers(
+            sessionId: session.metadata.id,
+            programIndex: session.currentProgramIndex,
+            exerciseIndex: session.currentExerciseIndex,
+            setIndex: session.currentSetIndex,
+          );
+    final actualScoreTimeMs = skipped
+        ? null
+        : await _scoreStopwatchMsIfNeeded(session, snapshot);
+    await _activeSessionUseCases.recordCurrentSetResult(
+      sessionId: session.metadata.id,
+      programSnapshotId: snapshot.programSnapshotId,
+      exerciseSnapshotId: snapshot.exerciseSnapshotId,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+      actualTimeMs: skipped || !snapshot.timeEnabled
+          ? null
+          : setTimer?.accumulatedMs,
+      actualReps: skipped || !snapshot.repsEnabled ? null : snapshot.targetReps,
+      actualScoreTimeMs: actualScoreTimeMs,
+      scoreInputModeSnapshot: snapshot.scoreInputModeSnapshot,
+      scoreLabelSnapshot: snapshot.scoreLabelSnapshot,
+      scoreUnitSnapshot: snapshot.scoreUnitSnapshot,
+    );
+    await _advanceAfterSet(session, snapshot);
+    return WatchCommandAck.accepted;
+  }
+
+  Future<int?> _scoreStopwatchMsIfNeeded(
+    ActiveWorkoutSession session,
+    _ResolvedExerciseSnapshot snapshot,
+  ) async {
+    if (!snapshot.scoreEnabled ||
+        snapshot.scoreInputModeSnapshot != ScoreInputMode.stopwatch) {
+      return null;
+    }
+    final state = await _sessionRepository.findScoreStopwatchState(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    return state?.accumulatedMs;
+  }
+
+  Future<void> _advanceAfterSet(
+    ActiveWorkoutSession session,
+    _ResolvedExerciseSnapshot snapshot,
+  ) async {
+    final next = _nextPosition(session.resolvedTemplateSnapshotJson, session);
+    if (next == null) {
+      await _activeSessionUseCases.complete(session.metadata.id);
+      return;
+    }
+    if (snapshot.restSeconds > 0) {
+      await _activeSessionUseCases.startRestAfterSet(
+        sessionId: session.metadata.id,
+        afterProgramIndex: session.currentProgramIndex,
+        afterExerciseIndex: session.currentExerciseIndex,
+        afterSetIndex: session.currentSetIndex,
+        plannedRestSeconds: snapshot.restSeconds,
+      );
+      return;
+    }
+    await _activeSessionUseCases.updateProgress(
+      sessionId: session.metadata.id,
+      programIndex: next.programIndex,
+      exerciseIndex: next.exerciseIndex,
+      setIndex: next.setIndex,
+    );
+  }
+
+  Future<WatchCommandAck> _skipCurrentRest(ActiveWorkoutSession session) async {
+    final rest = await _activeSessionUseCases.findActiveRest(
+      sessionId: session.metadata.id,
+    );
+    if (rest == null) {
+      return WatchCommandAck.acceptedNoOp;
+    }
+    await _activeSessionUseCases.skipRest(restStateId: rest.metadata.id);
+    final next = _nextPositionAfter(
+      session.resolvedTemplateSnapshotJson,
+      programIndex: rest.afterProgramIndex,
+      exerciseIndex: rest.afterExerciseIndex,
+      setIndex: rest.afterSetIndex,
+    );
+    if (next == null) {
+      await _activeSessionUseCases.complete(session.metadata.id);
+    } else {
+      await _activeSessionUseCases.updateProgress(
+        sessionId: session.metadata.id,
+        programIndex: next.programIndex,
+        exerciseIndex: next.exerciseIndex,
+        setIndex: next.setIndex,
+      );
+    }
+    return WatchCommandAck.accepted;
+  }
+
+  Future<void> _emitProjectionAfterCommand() async {
+    try {
+      await _projectionSource.emitCurrentProjection();
+    } on Exception {
+      // The command has already been applied; a publish failure must not turn
+      // the watch retry path into a second mutation.
+    }
+  }
+}
+
+final class _WatchCommandKey {
+  _WatchCommandKey(WatchCommandEnvelope command)
+    : sessionId = command.sessionId,
+      expectedRevision = command.expectedRevision,
+      commandId = command.commandId,
+      type = command.type;
+
+  final String sessionId;
+  final int expectedRevision;
+  final String commandId;
+  final WatchCommandType type;
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is _WatchCommandKey &&
+            sessionId == other.sessionId &&
+            expectedRevision == other.expectedRevision &&
+            commandId == other.commandId &&
+            type == other.type;
+  }
+
+  @override
+  int get hashCode => Object.hash(sessionId, expectedRevision, commandId, type);
+}
+
+final class WatchSessionProjectionProjector {
+  const WatchSessionProjectionProjector({
+    required this.sessionRepository,
+    required this.clock,
+    required this.ids,
+    required this.originDeviceId,
+  });
+
+  final ActiveSessionRepository sessionRepository;
+  final Clock clock;
+  final IdGenerator ids;
+  final String originDeviceId;
+
+  Future<WatchSessionProjection> project({required int revision}) async {
+    final now = clock.now();
+    final session = await sessionRepository.findOpen();
+    if (session == null ||
+        session.status == ActiveWorkoutStatus.completed ||
+        session.status == ActiveWorkoutStatus.abandoned ||
+        session.status == ActiveWorkoutStatus.savedExit) {
+      return WatchSessionProjection(
+        deviceSessionId: '',
+        revision: revision,
+        projectedAtEpochMs: _epochMs(now),
+        phase: WatchSessionPhase.noActiveSession,
+        phoneReachable: true,
+        seriesIndex: 0,
+        seriesTotal: 0,
+        exerciseName: '',
+        primaryAction: WatchPrimaryAction.none,
+        statusLabel: 'Aucune séance en cours',
+      );
+    }
+
+    final snapshot = _findExerciseSnapshot(
+      resolvedTemplateSnapshotJson: session.resolvedTemplateSnapshotJson,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+    );
+    if (snapshot == null) {
+      return WatchSessionProjection(
+        deviceSessionId: session.metadata.id,
+        revision: revision,
+        projectedAtEpochMs: _epochMs(now),
+        phase: WatchSessionPhase.noActiveSession,
+        phoneReachable: true,
+        seriesIndex: session.currentSetIndex + 1,
+        seriesTotal: 0,
+        exerciseName: '',
+        primaryAction: WatchPrimaryAction.none,
+        statusLabel: 'Séance indisponible',
+      );
+    }
+
+    final activeRest = await _findActiveRest(session.metadata.id);
+    final setTimer = await sessionRepository.findSetTimerState(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    final scoreStopwatch = await sessionRepository.findScoreStopwatchState(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    final stepView = await _readStepViewIfStarted(session, snapshot);
+    final stepState = stepView?.state;
+    final currentStep = stepView?.currentStep ?? _initialStep(snapshot);
+    final expectedPassages = _expectedPassages(snapshot);
+    final projectedAtEpochMs = _epochMs(now);
+
+    final timers = <WatchTimerProjection>[
+      if (activeRest != null) _restTimerProjection(activeRest, now),
+      if (currentStep != null && currentStep.type == ExerciseStepType.time)
+        _stepTimerProjection(stepState, currentStep, now),
+      if (scoreStopwatch != null)
+        ?_scoreStopwatchTimerProjection(scoreStopwatch, now),
+      if (setTimer != null) ?_setTimerProjection(setTimer, now),
+    ];
+    final dominantTimer = timers.isEmpty ? null : timers.first;
+    final secondaryTimers = dominantTimer == null
+        ? const <WatchTimerProjection>[]
+        : timers.skip(1).toList(growable: false);
+    final phase = _phase(
+      session: session,
+      snapshot: snapshot,
+      activeRest: activeRest,
+      stepState: stepState,
+      currentStep: currentStep,
+      timers: timers,
+    );
+
+    return WatchSessionProjection(
+      deviceSessionId: session.metadata.id,
+      revision: revision,
+      projectedAtEpochMs: projectedAtEpochMs,
+      phase: phase,
+      phoneReachable: true,
+      seriesIndex: session.currentSetIndex + 1,
+      seriesTotal: snapshot.setsCount,
+      exerciseName: snapshot.exerciseNameSnapshot,
+      passageIndex: expectedPassages > 1 && stepState != null
+          ? stepState.currentPassageIndex + 1
+          : null,
+      passageTotal: expectedPassages > 1 ? expectedPassages : null,
+      stepIndex: currentStep == null
+          ? null
+          : (stepState?.currentStepIndex ?? 0) + 1,
+      stepTotal: snapshot.steps.isEmpty ? null : snapshot.steps.length,
+      stepName: currentStep?.name,
+      dominantTimer: dominantTimer,
+      secondaryTimers: secondaryTimers,
+      primaryAction: _primaryAction(phase),
+      secondaryActions: _secondaryActions(
+        phase: phase,
+        snapshot: snapshot,
+        stepState: stepState,
+        expectedPassages: expectedPassages,
+      ),
+      nextExerciseName: activeRest != null
+          ? _restNextExerciseName(
+              session.resolvedTemplateSnapshotJson,
+              session,
+              activeRest,
+              snapshot,
+            )
+          : phase == WatchSessionPhase.betweenSetsReady
+          ? _betweenSetsNextExerciseName(
+              session.resolvedTemplateSnapshotJson,
+              session,
+              snapshot,
+            )
+          : null,
+      statusLabel: _statusLabel(phase, dominantTimer),
+    );
+  }
+
+  Future<ActiveExerciseStepProgressView?> _readStepViewIfStarted(
+    ActiveWorkoutSession session,
+    _ResolvedExerciseSnapshot snapshot,
+  ) async {
+    if (snapshot.steps.isEmpty) {
+      return null;
+    }
+    final state = await sessionRepository.findExerciseStepProgressState(
+      sessionId: session.metadata.id,
+      programIndex: session.currentProgramIndex,
+      exerciseIndex: session.currentExerciseIndex,
+      setIndex: session.currentSetIndex,
+    );
+    if (state == null) {
+      return null;
+    }
+    if (state.status == ActiveExerciseStepProgressStatus.runningTimer) {
+      return ActiveExerciseStepUseCases(
+        sessionRepository: sessionRepository,
+        clock: clock,
+        ids: ids,
+        originDeviceId: originDeviceId,
+      ).readProgress(
+        sessionId: session.metadata.id,
+        programIndex: session.currentProgramIndex,
+        exerciseIndex: session.currentExerciseIndex,
+        setIndex: session.currentSetIndex,
+      );
+    }
+    return ActiveExerciseStepProgressView(
+      state: state,
+      steps: snapshot.steps,
+      expectedPassages: _expectedPassages(snapshot),
+      results: const [],
+    );
+  }
+
+  Future<ActiveRestState?> _findActiveRest(String sessionId) async {
+    final active =
+        (await sessionRepository.listRestStates(sessionId))
+            .where((rest) => rest.endedAt == null && rest.skippedAt == null)
+            .toList()
+          ..sort((left, right) => right.startedAt.compareTo(left.startedAt));
+    return active.isEmpty ? null : active.first;
+  }
+}
+
+WatchSessionPhase _phase({
+  required ActiveWorkoutSession session,
+  required _ResolvedExerciseSnapshot snapshot,
+  required ActiveRestState? activeRest,
+  required ActiveExerciseStepProgressState? stepState,
+  required ExerciseStep? currentStep,
+  required List<WatchTimerProjection> timers,
+}) {
+  if (activeRest != null) {
+    return activeRest.pausedAt == null
+        ? WatchSessionPhase.restRunning
+        : WatchSessionPhase.restPaused;
+  }
+  if (session.status == ActiveWorkoutStatus.paused) {
+    return WatchSessionPhase.paused;
+  }
+  if (_isNextTimerReady(snapshot, stepState, currentStep)) {
+    return WatchSessionPhase.nextTimerReady;
+  }
+  if (timers.any((timer) => timer.runState == WatchTimerRunState.running)) {
+    return WatchSessionPhase.running;
+  }
+  return session.currentProgramIndex == 0 &&
+          session.currentExerciseIndex == 0 &&
+          session.currentSetIndex == 0
+      ? WatchSessionPhase.ready
+      : WatchSessionPhase.betweenSetsReady;
+}
+
+WatchPrimaryAction _primaryAction(WatchSessionPhase phase) {
+  return switch (phase) {
+    WatchSessionPhase.noActiveSession => WatchPrimaryAction.none,
+    WatchSessionPhase.ready => WatchPrimaryAction.startCurrentExercise,
+    WatchSessionPhase.running => WatchPrimaryAction.pauseSession,
+    WatchSessionPhase.paused => WatchPrimaryAction.resumeSession,
+    WatchSessionPhase.nextTimerReady =>
+      WatchPrimaryAction.startPreparedTimedStep,
+    WatchSessionPhase.restRunning => WatchPrimaryAction.pauseSession,
+    WatchSessionPhase.restPaused => WatchPrimaryAction.resumeSession,
+    WatchSessionPhase.betweenSetsReady =>
+      WatchPrimaryAction.startCurrentExercise,
+  };
+}
+
+List<WatchSecondaryAction> _secondaryActions({
+  required WatchSessionPhase phase,
+  required _ResolvedExerciseSnapshot snapshot,
+  required ActiveExerciseStepProgressState? stepState,
+  required int expectedPassages,
+}) {
+  if (phase == WatchSessionPhase.noActiveSession) {
+    return const [];
+  }
+  if (phase == WatchSessionPhase.restRunning ||
+      phase == WatchSessionPhase.restPaused) {
+    return const [WatchSecondaryAction.skipCurrentRest];
+  }
+  final hasCurrentStep =
+      snapshot.steps.isNotEmpty &&
+      stepState?.status != ActiveExerciseStepProgressStatus.sequenceComplete;
+  final hasPassageToSkip =
+      hasCurrentStep &&
+      expectedPassages > 1 &&
+      stepState != null &&
+      stepState.currentPassageIndex < expectedPassages - 1;
+  return [
+    if (hasCurrentStep) WatchSecondaryAction.skipCurrentStep,
+    if (hasPassageToSkip) WatchSecondaryAction.skipCurrentPassage,
+    WatchSecondaryAction.finishCurrentSet,
+    WatchSecondaryAction.skipCurrentSet,
+  ];
+}
+
+String _statusLabel(
+  WatchSessionPhase phase,
+  WatchTimerProjection? dominantTimer,
+) {
+  return switch (phase) {
+    WatchSessionPhase.noActiveSession => 'Aucune séance en cours',
+    WatchSessionPhase.ready => 'Prêt à démarrer',
+    WatchSessionPhase.running => dominantTimer?.label ?? 'En cours',
+    WatchSessionPhase.paused => 'Séance en pause',
+    WatchSessionPhase.nextTimerReady => 'Chrono suivant prêt',
+    WatchSessionPhase.restRunning => 'Repos en cours',
+    WatchSessionPhase.restPaused => 'Repos en pause',
+    WatchSessionPhase.betweenSetsReady => 'Prêt pour la série suivante',
+  };
+}
+
+WatchTimerProjection _restTimerProjection(ActiveRestState rest, DateTime now) {
+  final paused = rest.pausedAt != null;
+  return WatchTimerProjection(
+    kind: WatchTimerKind.rest,
+    label: 'Repos',
+    displayMode: WatchTimerDisplayMode.countdown,
+    runState: paused ? WatchTimerRunState.paused : WatchTimerRunState.running,
+    referenceEpochMs: _epochMs(now),
+    accumulatedMs: rest.elapsedMillisecondsAt(now),
+    startedAtEpochMs: paused ? null : _epochMs(now),
+    targetMs: rest.adjustedRestSeconds * 1000,
+  );
+}
+
+WatchTimerProjection _stepTimerProjection(
+  ActiveExerciseStepProgressState? state,
+  ExerciseStep step,
+  DateTime now,
+) {
+  return WatchTimerProjection(
+    kind: WatchTimerKind.step,
+    label: 'Chrono étape',
+    displayMode: WatchTimerDisplayMode.countdown,
+    runState: switch (state?.status) {
+      ActiveExerciseStepProgressStatus.runningTimer =>
+        WatchTimerRunState.running,
+      ActiveExerciseStepProgressStatus.pausedTimer => WatchTimerRunState.paused,
+      _ => WatchTimerRunState.stopped,
+    },
+    referenceEpochMs: _epochMs(now),
+    accumulatedMs: state?.accumulatedMs ?? 0,
+    startedAtEpochMs:
+        state?.status == ActiveExerciseStepProgressStatus.runningTimer
+        ? _epochMs(state!.startedAt!)
+        : null,
+    targetMs: step.defaultTargetValue * 1000,
+  );
+}
+
+WatchTimerProjection? _scoreStopwatchTimerProjection(
+  ActiveScoreStopwatchState state,
+  DateTime now,
+) {
+  if (state.status == ActiveScoreStopwatchStatus.stopped) {
+    return null;
+  }
+  return WatchTimerProjection(
+    kind: WatchTimerKind.scoreStopwatch,
+    label: 'Score chrono',
+    displayMode: WatchTimerDisplayMode.elapsed,
+    runState: state.status == ActiveScoreStopwatchStatus.running
+        ? WatchTimerRunState.running
+        : WatchTimerRunState.paused,
+    referenceEpochMs: _epochMs(now),
+    accumulatedMs: state.accumulatedMs,
+    startedAtEpochMs: state.status == ActiveScoreStopwatchStatus.running
+        ? _epochMs(state.startedAt)
+        : null,
+  );
+}
+
+WatchTimerProjection? _setTimerProjection(
+  ActiveSetTimerState state,
+  DateTime now,
+) {
+  if (state.status == ActiveSetTimerStatus.stopped ||
+      state.status == ActiveSetTimerStatus.skipped) {
+    return null;
+  }
+  return WatchTimerProjection(
+    kind: WatchTimerKind.setTimer,
+    label: 'Temps de série',
+    displayMode: WatchTimerDisplayMode.elapsed,
+    runState: state.status == ActiveSetTimerStatus.running
+        ? WatchTimerRunState.running
+        : WatchTimerRunState.paused,
+    referenceEpochMs: _epochMs(now),
+    accumulatedMs: state.accumulatedMs,
+    startedAtEpochMs:
+        state.status == ActiveSetTimerStatus.running && state.startedAt != null
+        ? _epochMs(state.startedAt!)
+        : null,
+  );
+}
+
+ExerciseStep? _initialStep(_ResolvedExerciseSnapshot snapshot) {
+  return snapshot.steps.isEmpty ? null : snapshot.steps.first;
+}
+
+bool _isNextTimerReady(
+  _ResolvedExerciseSnapshot snapshot,
+  ActiveExerciseStepProgressState? state,
+  ExerciseStep? currentStep,
+) {
+  if (state == null ||
+      currentStep == null ||
+      state.status != ActiveExerciseStepProgressStatus.stoppedTimer ||
+      currentStep.type != ExerciseStepType.time ||
+      snapshot.autoStartNextTimedStepEffective) {
+    return false;
+  }
+  final previous = _previousStep(snapshot, state);
+  return previous?.type == ExerciseStepType.time;
+}
+
+ExerciseStep? _previousStep(
+  _ResolvedExerciseSnapshot snapshot,
+  ActiveExerciseStepProgressState state,
+) {
+  if (snapshot.steps.isEmpty) {
+    return null;
+  }
+  if (state.currentStepIndex > 0) {
+    return snapshot.steps[state.currentStepIndex - 1];
+  }
+  if (state.currentPassageIndex > 0) {
+    return snapshot.steps.last;
+  }
+  return null;
+}
+
+int _expectedPassages(_ResolvedExerciseSnapshot snapshot) {
+  return snapshot.repsEnabled
+      ? (snapshot.targetReps ?? 1).clamp(1, 1 << 31)
+      : 1;
+}
+
+String? _restNextExerciseName(
+  String resolvedTemplateSnapshotJson,
+  ActiveWorkoutSession session,
+  ActiveRestState rest,
+  _ResolvedExerciseSnapshot currentSnapshot,
+) {
+  final sessionIsAfterRestSource =
+      _comparePositions(
+        session.currentProgramIndex,
+        session.currentExerciseIndex,
+        session.currentSetIndex,
+        rest.afterProgramIndex,
+        rest.afterExerciseIndex,
+        rest.afterSetIndex,
+      ) >
+      0;
+  if (sessionIsAfterRestSource) {
+    return currentSnapshot.exerciseNameSnapshot;
+  }
+  final snapshots = _exerciseSnapshotsById(resolvedTemplateSnapshotJson);
+  final setSnapshots = _listSetSnapshots(resolvedTemplateSnapshotJson);
+  final currentIndex = setSnapshots.indexWhere(
+    (snapshot) =>
+        snapshot.programIndex == rest.afterProgramIndex &&
+        snapshot.exerciseIndex == rest.afterExerciseIndex &&
+        snapshot.setIndex == rest.afterSetIndex,
+  );
+  if (currentIndex == -1 || currentIndex + 1 >= setSnapshots.length) {
+    return null;
+  }
+  final next = setSnapshots[currentIndex + 1];
+  return snapshots[next.exerciseSnapshotId]?.exerciseNameSnapshot;
+}
+
+String? _betweenSetsNextExerciseName(
+  String resolvedTemplateSnapshotJson,
+  ActiveWorkoutSession session,
+  _ResolvedExerciseSnapshot currentSnapshot,
+) {
+  final setSnapshots = _listSetSnapshots(resolvedTemplateSnapshotJson);
+  final currentIndex = setSnapshots.indexWhere(
+    (snapshot) =>
+        snapshot.programIndex == session.currentProgramIndex &&
+        snapshot.exerciseIndex == session.currentExerciseIndex &&
+        snapshot.setIndex == session.currentSetIndex,
+  );
+  if (currentIndex <= 0) {
+    return null;
+  }
+  final previous = setSnapshots[currentIndex - 1];
+  final current = setSnapshots[currentIndex];
+  if (previous.exerciseSnapshotId == current.exerciseSnapshotId) {
+    return null;
+  }
+  return currentSnapshot.exerciseNameSnapshot;
+}
+
+int _epochMs(DateTime value) => value.toUtc().millisecondsSinceEpoch;
+
 final class ActiveExerciseStepUseCases {
   const ActiveExerciseStepUseCases({
     required this.sessionRepository,
@@ -4466,6 +5329,37 @@ _SetPositionSnapshot? _findSetSnapshot({
   return null;
 }
 
+_SetPositionSnapshot? _nextPosition(
+  String resolvedTemplateSnapshotJson,
+  ActiveWorkoutSession session,
+) {
+  return _nextPositionAfter(
+    resolvedTemplateSnapshotJson,
+    programIndex: session.currentProgramIndex,
+    exerciseIndex: session.currentExerciseIndex,
+    setIndex: session.currentSetIndex,
+  );
+}
+
+_SetPositionSnapshot? _nextPositionAfter(
+  String resolvedTemplateSnapshotJson, {
+  required int programIndex,
+  required int exerciseIndex,
+  required int setIndex,
+}) {
+  final snapshots = _listSetSnapshots(resolvedTemplateSnapshotJson);
+  final currentIndex = snapshots.indexWhere(
+    (snapshot) =>
+        snapshot.programIndex == programIndex &&
+        snapshot.exerciseIndex == exerciseIndex &&
+        snapshot.setIndex == setIndex,
+  );
+  if (currentIndex == -1 || currentIndex + 1 >= snapshots.length) {
+    return null;
+  }
+  return snapshots[currentIndex + 1];
+}
+
 _ResolvedExerciseSnapshot? _findExerciseSnapshot({
   required String resolvedTemplateSnapshotJson,
   required int programIndex,
@@ -4519,6 +5413,8 @@ _ResolvedExerciseSnapshot? _findExerciseSnapshot({
     ),
     scoreLabelSnapshot: exercise['scoreLabelSnapshot'] as String?,
     scoreUnitSnapshot: exercise['scoreUnitSnapshot'] as String?,
+    setsCount: exercise['setsCount'] as int? ?? 0,
+    restSeconds: exercise['restSecondsOverride'] as int? ?? 0,
     steps: _exerciseStepsFromSnapshot(exercise['exerciseStepsSnapshot']),
     autoStartNextTimedStepEffective: autoStartNextTimedStepEffective,
   );
@@ -4586,6 +5482,7 @@ List<_SetPositionSnapshot> _listSetSnapshots(
             scoreInputModeSnapshot: _scoreInputModeFromSnapshot(
               exercise['scoreInputModeSnapshot'],
             ),
+            restSeconds: exercise['restSecondsOverride'] as int? ?? 0,
           ),
         );
       }
@@ -4604,6 +5501,7 @@ final class _SetPositionSnapshot {
     this.scoreLabelSnapshot,
     this.scoreUnitSnapshot,
     required this.scoreInputModeSnapshot,
+    required this.restSeconds,
   });
 
   final String programSnapshotId;
@@ -4614,6 +5512,7 @@ final class _SetPositionSnapshot {
   final String? scoreLabelSnapshot;
   final String? scoreUnitSnapshot;
   final ScoreInputMode scoreInputModeSnapshot;
+  final int restSeconds;
 }
 
 final class _StepSequenceContext {
@@ -4730,6 +5629,8 @@ Map<String, _ResolvedExerciseSnapshot> _exerciseSnapshotsById(
         ),
         scoreLabelSnapshot: exercise['scoreLabelSnapshot'] as String?,
         scoreUnitSnapshot: exercise['scoreUnitSnapshot'] as String?,
+        setsCount: exercise['setsCount'] as int? ?? 0,
+        restSeconds: exercise['restSecondsOverride'] as int? ?? 0,
         steps: _exerciseStepsFromSnapshot(exercise['exerciseStepsSnapshot']),
         autoStartNextTimedStepEffective:
             (exercise['autoStartNextTimedStepOverride'] as bool?) ??
@@ -4758,6 +5659,8 @@ final class _ResolvedExerciseSnapshot {
     required this.scoreInputModeSnapshot,
     this.scoreLabelSnapshot,
     this.scoreUnitSnapshot,
+    required this.setsCount,
+    required this.restSeconds,
     this.steps = const [],
     this.autoStartNextTimedStepEffective = true,
   });
@@ -4777,6 +5680,8 @@ final class _ResolvedExerciseSnapshot {
   final ScoreInputMode scoreInputModeSnapshot;
   final String? scoreLabelSnapshot;
   final String? scoreUnitSnapshot;
+  final int setsCount;
+  final int restSeconds;
   final List<ExerciseStep> steps;
   final bool autoStartNextTimedStepEffective;
 }
diff --git a/lib/application/watch_companion_use_cases.dart b/lib/application/watch_companion_use_cases.dart
new file mode 100644
index 0000000..dd8803b
--- /dev/null
+++ b/lib/application/watch_companion_use_cases.dart
@@ -0,0 +1,20 @@
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+abstract interface class WatchCommandIngress {
+  Future<WatchCommandAck> dispatch(WatchCommandEnvelope command);
+}
+
+abstract interface class WatchProjectionPublisher {
+  Future<void> publish(WatchSessionProjection projection);
+}
+
+abstract interface class WatchProjectionSource {
+  Stream<WatchSessionProjection> get projections;
+
+  Future<WatchSessionProjection> currentProjection();
+
+  Future<WatchSessionProjection> emitCurrentProjection();
+}
+
+abstract interface class WatchCompanionUseCases
+    implements WatchCommandIngress, WatchProjectionSource {}
diff --git a/lib/infrastructure/infrastructure.dart b/lib/infrastructure/infrastructure.dart
index b8732f3..7a27f39 100644
--- a/lib/infrastructure/infrastructure.dart
+++ b/lib/infrastructure/infrastructure.dart
@@ -7,3 +7,4 @@ library;
 export 'local/local.dart';
 export 'remote/remote.dart';
 export 'security/security.dart';
+export 'watch_bridge/watch_bridge.dart';
diff --git a/lib/infrastructure/watch_bridge/native_watch_bridge_channel.dart b/lib/infrastructure/watch_bridge/native_watch_bridge_channel.dart
new file mode 100644
index 0000000..22738e1
--- /dev/null
+++ b/lib/infrastructure/watch_bridge/native_watch_bridge_channel.dart
@@ -0,0 +1,137 @@
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+final class WatchBridgeConnectionEvent {
+  const WatchBridgeConnectionEvent({
+    required this.isReachable,
+    this.requestsResync = false,
+  });
+
+  final bool isReachable;
+  final bool requestsResync;
+}
+
+abstract interface class WatchBridgeNativeChannel {
+  Stream<WatchCommandEnvelope> get commands;
+
+  Stream<WatchBridgeConnectionEvent> get connectionEvents;
+
+  Future<void> publishProjection(WatchSessionProjection projection);
+
+  Future<void> sendCommandAck(
+    WatchCommandEnvelope command,
+    WatchCommandAck ack, {
+    int? revisionAtAck,
+  });
+
+  Future<void> requestCapabilityRefresh();
+
+  Future<void> startForegroundService();
+
+  Future<void> stopForegroundService();
+}
+
+final class MethodChannelWatchBridgeNativeChannel
+    implements WatchBridgeNativeChannel {
+  const MethodChannelWatchBridgeNativeChannel({
+    MethodChannel methodChannel = const MethodChannel(_methodChannelName),
+    EventChannel commandChannel = const EventChannel(_commandChannelName),
+    EventChannel connectionChannel = const EventChannel(_connectionChannelName),
+  }) : _methodChannel = methodChannel,
+       _commandChannel = commandChannel,
+       _connectionChannel = connectionChannel;
+
+  static const _methodChannelName = 'gametime.watch_bridge/methods';
+  static const _commandChannelName = 'gametime.watch_bridge/commands';
+  static const _connectionChannelName = 'gametime.watch_bridge/connection';
+
+  final MethodChannel _methodChannel;
+  final EventChannel _commandChannel;
+  final EventChannel _connectionChannel;
+
+  @override
+  Stream<WatchCommandEnvelope> get commands {
+    return _commandChannel
+        .receiveBroadcastStream()
+        .where((event) {
+          return event is Map;
+        })
+        .map((event) {
+          return WatchCommandEnvelope.fromJson(_stringObjectMap(event));
+        });
+  }
+
+  @override
+  Stream<WatchBridgeConnectionEvent> get connectionEvents {
+    return _connectionChannel
+        .receiveBroadcastStream()
+        .where((event) {
+          return event is Map;
+        })
+        .map((event) {
+          final json = _stringObjectMap(event);
+          return WatchBridgeConnectionEvent(
+            isReachable: json['isReachable'] == true,
+            requestsResync: json['requestsResync'] == true,
+          );
+        });
+  }
+
+  @override
+  Future<void> publishProjection(WatchSessionProjection projection) {
+    return _invokeIgnoringMissingPlugin(
+      'publishProjection',
+      projection.toJson(),
+    );
+  }
+
+  @override
+  Future<void> requestCapabilityRefresh() {
+    return _invokeIgnoringMissingPlugin('requestCapabilityRefresh');
+  }
+
+  @override
+  Future<void> sendCommandAck(
+    WatchCommandEnvelope command,
+    WatchCommandAck ack, {
+    int? revisionAtAck,
+  }) {
+    return _invokeIgnoringMissingPlugin('sendCommandAck', {
+      'schemaVersion': watchBridgeSchemaVersion,
+      'commandId': command.commandId,
+      'sessionId': command.sessionId,
+      'expectedRevision': command.expectedRevision,
+      'status': ack.name,
+      'revisionAtAck': revisionAtAck,
+      'ackedAtEpochMs': DateTime.now().toUtc().millisecondsSinceEpoch,
+    });
+  }
+
+  @override
+  Future<void> startForegroundService() {
+    return _invokeIgnoringMissingPlugin('startForegroundService');
+  }
+
+  @override
+  Future<void> stopForegroundService() {
+    return _invokeIgnoringMissingPlugin('stopForegroundService');
+  }
+
+  Future<void> _invokeIgnoringMissingPlugin(
+    String method, [
+    Object? arguments,
+  ]) {
+    return _methodChannel
+        .invokeMethod<void>(method, arguments)
+        .onError<MissingPluginException>((_, _) {});
+  }
+}
+
+Map<String, Object?> _stringObjectMap(Object? value) {
+  if (value is Map) {
+    return value.map((key, value) => MapEntry(key.toString(), value));
+  }
+  return const {};
+}
diff --git a/lib/infrastructure/watch_bridge/watch_bridge.dart b/lib/infrastructure/watch_bridge/watch_bridge.dart
new file mode 100644
index 0000000..96a3711
--- /dev/null
+++ b/lib/infrastructure/watch_bridge/watch_bridge.dart
@@ -0,0 +1,2 @@
+export 'native_watch_bridge_channel.dart';
+export 'wear_data_layer_adapter.dart';
diff --git a/lib/infrastructure/watch_bridge/wear_data_layer_adapter.dart b/lib/infrastructure/watch_bridge/wear_data_layer_adapter.dart
new file mode 100644
index 0000000..9f06fbf
--- /dev/null
+++ b/lib/infrastructure/watch_bridge/wear_data_layer_adapter.dart
@@ -0,0 +1,183 @@
+import 'dart:async';
+
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+import '../../application/watch_companion_use_cases.dart';
+import 'native_watch_bridge_channel.dart';
+
+final class WatchWearDataLayerAdapter implements WatchProjectionPublisher {
+  WatchWearDataLayerAdapter({
+    required WatchBridgeNativeChannel nativeChannel,
+    required WatchCommandIngress commandIngress,
+    required WatchProjectionSource projectionSource,
+    Duration heartbeatInterval = const Duration(seconds: 5),
+  }) : _nativeChannel = nativeChannel,
+       _commandIngress = commandIngress,
+       _projectionSource = projectionSource,
+       _heartbeatInterval = heartbeatInterval;
+
+  final WatchBridgeNativeChannel _nativeChannel;
+  final WatchCommandIngress _commandIngress;
+  final WatchProjectionSource _projectionSource;
+  final Duration _heartbeatInterval;
+  final _commandAcks = <_WatchAdapterCommandKey, WatchCommandAck>{};
+  final _subscriptions = <StreamSubscription<dynamic>>[];
+  Future<void> _commandTail = Future<void>.value();
+  Timer? _heartbeatTimer;
+  WatchSessionProjection? _latestProjection;
+  bool _started = false;
+  bool _foregroundActive = false;
+
+  Future<void> start() async {
+    if (_started) {
+      return;
+    }
+    _started = true;
+    _subscriptions.add(
+      _projectionSource.projections.listen((projection) {
+        unawaited(publish(projection));
+      }),
+    );
+    _subscriptions.add(
+      _nativeChannel.commands.listen((command) {
+        unawaited(_enqueueCommand(command));
+      }),
+    );
+    _subscriptions.add(
+      _nativeChannel.connectionEvents.listen((event) {
+        if (event.isReachable || event.requestsResync) {
+          unawaited(_projectionSource.emitCurrentProjection());
+        }
+      }),
+    );
+    await _projectionSource.emitCurrentProjection();
+    await _nativeChannel.requestCapabilityRefresh();
+  }
+
+  Future<void> stop() async {
+    _heartbeatTimer?.cancel();
+    _heartbeatTimer = null;
+    for (final subscription in _subscriptions) {
+      await subscription.cancel();
+    }
+    _subscriptions.clear();
+    _started = false;
+  }
+
+  @override
+  Future<void> publish(WatchSessionProjection projection) async {
+    _latestProjection = projection;
+    await _nativeChannel.publishProjection(projection);
+    await _syncForegroundService(projection);
+    _syncHeartbeat(projection);
+  }
+
+  Future<void> _enqueueCommand(WatchCommandEnvelope command) {
+    final run = _commandTail.then(
+      (_) => _handleCommand(command),
+      onError: (_) => _handleCommand(command),
+    );
+    _commandTail = run.then((_) {}, onError: (_) {});
+    return run;
+  }
+
+  Future<void> _handleCommand(WatchCommandEnvelope command) async {
+    final key = _WatchAdapterCommandKey(command);
+    final cachedAck = _commandAcks[key];
+    if (cachedAck != null) {
+      await _sendAck(command, WatchCommandAck.acceptedNoOp);
+      return;
+    }
+    final ack = await _commandIngress.dispatch(command);
+    if (ack == WatchCommandAck.accepted ||
+        ack == WatchCommandAck.acceptedNoOp) {
+      _rememberAck(key, ack);
+    }
+    await _sendAck(command, ack);
+  }
+
+  Future<void> _sendAck(
+    WatchCommandEnvelope command,
+    WatchCommandAck ack,
+  ) async {
+    int? revisionAtAck;
+    try {
+      revisionAtAck = (await _projectionSource.currentProjection()).revision;
+    } on Exception {
+      revisionAtAck = _latestProjection?.revision;
+    }
+    await _nativeChannel.sendCommandAck(
+      command,
+      ack,
+      revisionAtAck: revisionAtAck,
+    );
+  }
+
+  void _rememberAck(_WatchAdapterCommandKey key, WatchCommandAck ack) {
+    _commandAcks[key] = ack;
+    if (_commandAcks.length <= 128) {
+      return;
+    }
+    _commandAcks.remove(_commandAcks.keys.first);
+  }
+
+  Future<void> _syncForegroundService(WatchSessionProjection projection) async {
+    final shouldRun =
+        projection.phase != WatchSessionPhase.noActiveSession &&
+        projection.deviceSessionId.isNotEmpty;
+    if (shouldRun == _foregroundActive) {
+      return;
+    }
+    _foregroundActive = shouldRun;
+    if (shouldRun) {
+      await _nativeChannel.startForegroundService();
+    } else {
+      await _nativeChannel.stopForegroundService();
+    }
+  }
+
+  void _syncHeartbeat(WatchSessionProjection projection) {
+    if (!_hasRunningTimer(projection)) {
+      _heartbeatTimer?.cancel();
+      _heartbeatTimer = null;
+      return;
+    }
+    _heartbeatTimer ??= Timer.periodic(_heartbeatInterval, (_) {
+      unawaited(_projectionSource.emitCurrentProjection());
+    });
+  }
+}
+
+bool _hasRunningTimer(WatchSessionProjection projection) {
+  final timers = [
+    if (projection.dominantTimer != null) projection.dominantTimer!,
+    ...projection.secondaryTimers,
+  ];
+  return timers.any((timer) => timer.runState == WatchTimerRunState.running);
+}
+
+final class _WatchAdapterCommandKey {
+  _WatchAdapterCommandKey(WatchCommandEnvelope command)
+    : sessionId = command.sessionId,
+      expectedRevision = command.expectedRevision,
+      commandId = command.commandId,
+      type = command.type;
+
+  final String sessionId;
+  final int expectedRevision;
+  final String commandId;
+  final WatchCommandType type;
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is _WatchAdapterCommandKey &&
+            sessionId == other.sessionId &&
+            expectedRevision == other.expectedRevision &&
+            commandId == other.commandId &&
+            type == other.type;
+  }
+
+  @override
+  int get hashCode => Object.hash(sessionId, expectedRevision, commandId, type);
+}
diff --git a/packages/watch_bridge_contract/analysis_options.yaml b/packages/watch_bridge_contract/analysis_options.yaml
new file mode 100644
index 0000000..1eb34bb
--- /dev/null
+++ b/packages/watch_bridge_contract/analysis_options.yaml
@@ -0,0 +1,5 @@
+include: package:lints/recommended.yaml
+
+linter:
+  rules:
+    prefer_single_quotes: true
diff --git a/packages/watch_bridge_contract/lib/src/watch_bridge_contract.dart b/packages/watch_bridge_contract/lib/src/watch_bridge_contract.dart
new file mode 100644
index 0000000..a378749
--- /dev/null
+++ b/packages/watch_bridge_contract/lib/src/watch_bridge_contract.dart
@@ -0,0 +1,458 @@
+const int watchBridgeSchemaVersion = 1;
+
+enum WatchCommandType {
+  startCurrentExercise,
+  pauseSession,
+  resumeSession,
+  startPreparedTimedStep,
+  skipCurrentStep,
+  skipCurrentPassage,
+  finishCurrentSet,
+  skipCurrentSet,
+  skipCurrentRest,
+}
+
+enum WatchCommandAck {
+  accepted,
+  acceptedNoOp,
+  rejectedStaleRevision,
+  rejectedNotApplicable,
+  rejectedNoActiveSession,
+  rejectedSessionMismatch,
+  rejectedPhoneBusy,
+}
+
+enum WatchSessionPhase {
+  noActiveSession,
+  ready,
+  running,
+  paused,
+  nextTimerReady,
+  restRunning,
+  restPaused,
+  betweenSetsReady,
+}
+
+enum WatchPrimaryAction {
+  none,
+  startCurrentExercise,
+  pauseSession,
+  resumeSession,
+  startPreparedTimedStep,
+  skipCurrentRest,
+}
+
+enum WatchSecondaryAction {
+  skipCurrentStep,
+  skipCurrentPassage,
+  finishCurrentSet,
+  skipCurrentSet,
+  skipCurrentRest,
+}
+
+enum WatchTimerKind { rest, step, scoreStopwatch, setTimer }
+
+enum WatchTimerDisplayMode { countdown, elapsed }
+
+enum WatchTimerRunState { stopped, running, paused }
+
+final class WatchCommandEnvelope {
+  const WatchCommandEnvelope({
+    this.schemaVersion = watchBridgeSchemaVersion,
+    required this.commandId,
+    required this.type,
+    required this.sessionId,
+    required this.expectedRevision,
+    required this.sentAtEpochMs,
+  });
+
+  factory WatchCommandEnvelope.fromJson(Map<String, Object?> json) {
+    return WatchCommandEnvelope(
+      schemaVersion: _intFromJson(
+        json['schemaVersion'],
+        watchBridgeSchemaVersion,
+      ),
+      commandId: _stringFromJson(json['commandId']),
+      type: _enumFromJson(
+        json['type'],
+        WatchCommandType.values,
+        WatchCommandType.startCurrentExercise,
+      ),
+      sessionId: _stringFromJson(json['sessionId']),
+      expectedRevision: _intFromJson(json['expectedRevision'], 0),
+      sentAtEpochMs: _intFromJson(json['sentAtEpochMs'], 0),
+    );
+  }
+
+  final int schemaVersion;
+  final String commandId;
+  final WatchCommandType type;
+  final String sessionId;
+  final int expectedRevision;
+  final int sentAtEpochMs;
+
+  Map<String, Object?> toJson() {
+    return {
+      'schemaVersion': schemaVersion,
+      'commandId': commandId,
+      'type': type.name,
+      'sessionId': sessionId,
+      'expectedRevision': expectedRevision,
+      'sentAtEpochMs': sentAtEpochMs,
+    };
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is WatchCommandEnvelope &&
+            schemaVersion == other.schemaVersion &&
+            commandId == other.commandId &&
+            type == other.type &&
+            sessionId == other.sessionId &&
+            expectedRevision == other.expectedRevision &&
+            sentAtEpochMs == other.sentAtEpochMs;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(
+      schemaVersion,
+      commandId,
+      type,
+      sessionId,
+      expectedRevision,
+      sentAtEpochMs,
+    );
+  }
+}
+
+final class WatchSessionProjection {
+  const WatchSessionProjection({
+    this.schemaVersion = watchBridgeSchemaVersion,
+    required this.deviceSessionId,
+    required this.revision,
+    required this.projectedAtEpochMs,
+    required this.phase,
+    required this.phoneReachable,
+    required this.seriesIndex,
+    required this.seriesTotal,
+    required this.exerciseName,
+    this.passageIndex,
+    this.passageTotal,
+    this.stepIndex,
+    this.stepTotal,
+    this.stepName,
+    this.dominantTimer,
+    this.secondaryTimers = const [],
+    required this.primaryAction,
+    this.secondaryActions = const [],
+    this.nextExerciseName,
+    this.statusLabel,
+  });
+
+  factory WatchSessionProjection.fromJson(Map<String, Object?> json) {
+    return WatchSessionProjection(
+      schemaVersion: _intFromJson(
+        json['schemaVersion'],
+        watchBridgeSchemaVersion,
+      ),
+      deviceSessionId: _stringFromJson(json['deviceSessionId']),
+      revision: _intFromJson(json['revision'], 0),
+      projectedAtEpochMs: _intFromJson(json['projectedAtEpochMs'], 0),
+      phase: _enumFromJson(
+        json['phase'],
+        WatchSessionPhase.values,
+        WatchSessionPhase.noActiveSession,
+      ),
+      phoneReachable: _boolFromJson(json['phoneReachable'], false),
+      seriesIndex: _intFromJson(json['seriesIndex'], 0),
+      seriesTotal: _intFromJson(json['seriesTotal'], 0),
+      exerciseName: _stringFromJson(json['exerciseName']),
+      passageIndex: _nullableIntFromJson(json['passageIndex']),
+      passageTotal: _nullableIntFromJson(json['passageTotal']),
+      stepIndex: _nullableIntFromJson(json['stepIndex']),
+      stepTotal: _nullableIntFromJson(json['stepTotal']),
+      stepName: _nullableStringFromJson(json['stepName']),
+      dominantTimer: _timerFromJson(json['dominantTimer']),
+      secondaryTimers: _timerListFromJson(json['secondaryTimers']),
+      primaryAction: _enumFromJson(
+        json['primaryAction'],
+        WatchPrimaryAction.values,
+        WatchPrimaryAction.none,
+      ),
+      secondaryActions: _enumListFromJson(
+        json['secondaryActions'],
+        WatchSecondaryAction.values,
+      ),
+      nextExerciseName: _nullableStringFromJson(json['nextExerciseName']),
+      statusLabel: _nullableStringFromJson(json['statusLabel']),
+    );
+  }
+
+  final int schemaVersion;
+  final String deviceSessionId;
+  final int revision;
+  final int projectedAtEpochMs;
+  final WatchSessionPhase phase;
+  final bool phoneReachable;
+  final int seriesIndex;
+  final int seriesTotal;
+  final String exerciseName;
+  final int? passageIndex;
+  final int? passageTotal;
+  final int? stepIndex;
+  final int? stepTotal;
+  final String? stepName;
+  final WatchTimerProjection? dominantTimer;
+  final List<WatchTimerProjection> secondaryTimers;
+  final WatchPrimaryAction primaryAction;
+  final List<WatchSecondaryAction> secondaryActions;
+  final String? nextExerciseName;
+  final String? statusLabel;
+
+  Map<String, Object?> toJson() {
+    return {
+      'schemaVersion': schemaVersion,
+      'deviceSessionId': deviceSessionId,
+      'revision': revision,
+      'projectedAtEpochMs': projectedAtEpochMs,
+      'phase': phase.name,
+      'phoneReachable': phoneReachable,
+      'seriesIndex': seriesIndex,
+      'seriesTotal': seriesTotal,
+      'exerciseName': exerciseName,
+      'passageIndex': passageIndex,
+      'passageTotal': passageTotal,
+      'stepIndex': stepIndex,
+      'stepTotal': stepTotal,
+      'stepName': stepName,
+      'dominantTimer': dominantTimer?.toJson(),
+      'secondaryTimers': secondaryTimers
+          .map((timer) => timer.toJson())
+          .toList(),
+      'primaryAction': primaryAction.name,
+      'secondaryActions': secondaryActions
+          .map((action) => action.name)
+          .toList(),
+      'nextExerciseName': nextExerciseName,
+      'statusLabel': statusLabel,
+    };
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is WatchSessionProjection &&
+            schemaVersion == other.schemaVersion &&
+            deviceSessionId == other.deviceSessionId &&
+            revision == other.revision &&
+            projectedAtEpochMs == other.projectedAtEpochMs &&
+            phase == other.phase &&
+            phoneReachable == other.phoneReachable &&
+            seriesIndex == other.seriesIndex &&
+            seriesTotal == other.seriesTotal &&
+            exerciseName == other.exerciseName &&
+            passageIndex == other.passageIndex &&
+            passageTotal == other.passageTotal &&
+            stepIndex == other.stepIndex &&
+            stepTotal == other.stepTotal &&
+            stepName == other.stepName &&
+            dominantTimer == other.dominantTimer &&
+            _listEquals(secondaryTimers, other.secondaryTimers) &&
+            primaryAction == other.primaryAction &&
+            _listEquals(secondaryActions, other.secondaryActions) &&
+            nextExerciseName == other.nextExerciseName &&
+            statusLabel == other.statusLabel;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(
+      schemaVersion,
+      deviceSessionId,
+      revision,
+      projectedAtEpochMs,
+      phase,
+      phoneReachable,
+      seriesIndex,
+      seriesTotal,
+      exerciseName,
+      passageIndex,
+      passageTotal,
+      stepIndex,
+      stepTotal,
+      stepName,
+      dominantTimer,
+      Object.hashAll(secondaryTimers),
+      primaryAction,
+      Object.hashAll(secondaryActions),
+      nextExerciseName,
+      statusLabel,
+    );
+  }
+}
+
+final class WatchTimerProjection {
+  const WatchTimerProjection({
+    required this.kind,
+    required this.label,
+    required this.displayMode,
+    required this.runState,
+    required this.referenceEpochMs,
+    required this.accumulatedMs,
+    this.startedAtEpochMs,
+    this.targetMs,
+  });
+
+  factory WatchTimerProjection.fromJson(Map<String, Object?> json) {
+    return WatchTimerProjection(
+      kind: _enumFromJson(
+        json['kind'],
+        WatchTimerKind.values,
+        WatchTimerKind.setTimer,
+      ),
+      label: _stringFromJson(json['label']),
+      displayMode: _enumFromJson(
+        json['displayMode'],
+        WatchTimerDisplayMode.values,
+        WatchTimerDisplayMode.elapsed,
+      ),
+      runState: _enumFromJson(
+        json['runState'],
+        WatchTimerRunState.values,
+        WatchTimerRunState.stopped,
+      ),
+      referenceEpochMs: _intFromJson(json['referenceEpochMs'], 0),
+      accumulatedMs: _intFromJson(json['accumulatedMs'], 0),
+      startedAtEpochMs: _nullableIntFromJson(json['startedAtEpochMs']),
+      targetMs: _nullableIntFromJson(json['targetMs']),
+    );
+  }
+
+  final WatchTimerKind kind;
+  final String label;
+  final WatchTimerDisplayMode displayMode;
+  final WatchTimerRunState runState;
+  final int referenceEpochMs;
+  final int accumulatedMs;
+  final int? startedAtEpochMs;
+  final int? targetMs;
+
+  Map<String, Object?> toJson() {
+    return {
+      'kind': kind.name,
+      'label': label,
+      'displayMode': displayMode.name,
+      'runState': runState.name,
+      'referenceEpochMs': referenceEpochMs,
+      'accumulatedMs': accumulatedMs,
+      'startedAtEpochMs': startedAtEpochMs,
+      'targetMs': targetMs,
+    };
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        other is WatchTimerProjection &&
+            kind == other.kind &&
+            label == other.label &&
+            displayMode == other.displayMode &&
+            runState == other.runState &&
+            referenceEpochMs == other.referenceEpochMs &&
+            accumulatedMs == other.accumulatedMs &&
+            startedAtEpochMs == other.startedAtEpochMs &&
+            targetMs == other.targetMs;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(
+      kind,
+      label,
+      displayMode,
+      runState,
+      referenceEpochMs,
+      accumulatedMs,
+      startedAtEpochMs,
+      targetMs,
+    );
+  }
+}
+
+T _enumFromJson<T extends Enum>(Object? value, List<T> values, T fallback) {
+  if (value is String) {
+    for (final enumValue in values) {
+      if (enumValue.name == value) {
+        return enumValue;
+      }
+    }
+  }
+  return fallback;
+}
+
+List<T> _enumListFromJson<T extends Enum>(Object? value, List<T> values) {
+  if (value is! List) {
+    return const [];
+  }
+  return [
+    for (final item in value)
+      if (item is String)
+        for (final enumValue in values)
+          if (enumValue.name == item) enumValue,
+  ];
+}
+
+WatchTimerProjection? _timerFromJson(Object? value) {
+  if (value is! Map) {
+    return null;
+  }
+  return WatchTimerProjection.fromJson(Map<String, Object?>.from(value));
+}
+
+List<WatchTimerProjection> _timerListFromJson(Object? value) {
+  if (value is! List) {
+    return const [];
+  }
+  return [
+    for (final item in value)
+      if (item is Map)
+        WatchTimerProjection.fromJson(Map<String, Object?>.from(item)),
+  ];
+}
+
+String _stringFromJson(Object? value) {
+  return value is String ? value : '';
+}
+
+String? _nullableStringFromJson(Object? value) {
+  return value is String ? value : null;
+}
+
+int _intFromJson(Object? value, int fallback) {
+  return value is int ? value : fallback;
+}
+
+int? _nullableIntFromJson(Object? value) {
+  return value is int ? value : null;
+}
+
+bool _boolFromJson(Object? value, bool fallback) {
+  return value is bool ? value : fallback;
+}
+
+bool _listEquals<T>(List<T> left, List<T> right) {
+  if (identical(left, right)) {
+    return true;
+  }
+  if (left.length != right.length) {
+    return false;
+  }
+  for (var index = 0; index < left.length; index += 1) {
+    if (left[index] != right[index]) {
+      return false;
+    }
+  }
+  return true;
+}
diff --git a/packages/watch_bridge_contract/lib/watch_bridge_contract.dart b/packages/watch_bridge_contract/lib/watch_bridge_contract.dart
new file mode 100644
index 0000000..19fef40
--- /dev/null
+++ b/packages/watch_bridge_contract/lib/watch_bridge_contract.dart
@@ -0,0 +1,7 @@
+/// Shared transport contracts between the GameTime phone app and Wear OS app.
+///
+/// This package is pure Dart by design: no Flutter, Android, persistence, or
+/// business logic belongs here.
+library;
+
+export 'src/watch_bridge_contract.dart';
diff --git a/packages/watch_bridge_contract/pubspec.lock b/packages/watch_bridge_contract/pubspec.lock
new file mode 100644
index 0000000..6643f26
--- /dev/null
+++ b/packages/watch_bridge_contract/pubspec.lock
@@ -0,0 +1,389 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages:
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      sha256: "9a3386eea899815698dd55995277cf7cb8572ee52b399a6edfb7ae2b50e5fc19"
+      url: "https://pub.dev"
+    source: hosted
+    version: "105.0.0"
+  analyzer:
+    dependency: transitive
+    description:
+      name: analyzer
+      sha256: "62993bed6eadbe9596c5c20d5c167e7bc563c5fe266657a04ddeb93bdb84f4c9"
+      url: "https://pub.dev"
+    source: hosted
+    version: "14.1.0"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      sha256: d0481093c50b1da8910eb0bb301626d4d8eb7284aa739614d2b394ee09e3ea04
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.7.0"
+  async:
+    dependency: transitive
+    description:
+      name: async
+      sha256: e2eb0491ba5ddb6177742d2da23904574082139b07c1e33b8503b9f46f3e1a37
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.13.1"
+  boolean_selector:
+    dependency: transitive
+    description:
+      name: boolean_selector
+      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.2"
+  cli_config:
+    dependency: transitive
+    description:
+      name: cli_config
+      sha256: ac20a183a07002b700f0c25e61b7ee46b23c309d76ab7b7640a028f18e4d99ec
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.2.0"
+  collection:
+    dependency: transitive
+    description:
+      name: collection
+      sha256: "2f5709ae4d3d59dd8f7cd309b4e023046b57d8a6c82130785d2b0e5868084e76"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.19.1"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      sha256: b30acd5944035672bc15c6b7a8b47d773e41e2f17de064350988c5d02adb1c68
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.2"
+  coverage:
+    dependency: transitive
+    description:
+      name: coverage
+      sha256: "956a3de0725ca232ad353565a8290d3357592bf4250f6f298a185e2d949c5d3d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.15.1"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      sha256: c8ea0233063ba03258fbcf2ca4d6dadfefe14f02fab57702265467a19f27fadf
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.7"
+  file:
+    dependency: transitive
+    description:
+      name: file
+      sha256: a3b4f84adafef897088c160faf7dfffb7696046cb13ae90b508c2cbc95d3b8d4
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.1"
+  frontend_server_client:
+    dependency: transitive
+    description:
+      name: frontend_server_client
+      sha256: f64a0333a82f30b0cca061bc3d143813a486dc086b574bfb233b7c1372427694
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.0"
+  glob:
+    dependency: transitive
+    description:
+      name: glob
+      sha256: c3f1ee72c96f8f78935e18aa8cecced9ab132419e8625dc187e1c2408efc20de
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.3"
+  http_multi_server:
+    dependency: transitive
+    description:
+      name: http_multi_server
+      sha256: aa6199f908078bb1c5efb8d8638d4ae191aac11b311132c3ef48ce352fb52ef8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      sha256: "178d74305e7866013777bab2c3d8726205dc5a4dd935297175b19a23a2e66571"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.2"
+  io:
+    dependency: transitive
+    description:
+      name: io
+      sha256: dfd5a80599cf0165756e3181807ed3e77daf6dd4137caaad72d0b7931597650b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.5"
+  lints:
+    dependency: "direct dev"
+    description:
+      name: lints
+      sha256: "12f842a479589fea194fe5c5a3095abc7be0c1f2ddfa9a0e76aed1dbd26a87df"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.0"
+  logging:
+    dependency: transitive
+    description:
+      name: logging
+      sha256: c8245ada5f1717ed44271ed1c26b8ce85ca3228fd2ffdb75468ab01979309d61
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.0"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      sha256: "31bd099b47c10cd1aeb55146a2d46ce0277630ecef3f7dae54ad7873f36696cd"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.12.20"
+  meta:
+    dependency: transitive
+    description:
+      name: meta
+      sha256: "307249ce4ff29d58a18e97f6345f539382eb9c9c29ecda628900f31de0443dd9"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.19.0"
+  mime:
+    dependency: transitive
+    description:
+      name: mime
+      sha256: "41a20518f0cb1256669420fdba0cd90d21561e560ac240f26ef8322e45bb7ed6"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.0"
+  node_preamble:
+    dependency: transitive
+    description:
+      name: node_preamble
+      sha256: "6e7eac89047ab8a8d26cf16127b5ed26de65209847630400f9aefd7cd5c730db"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.2"
+  package_config:
+    dependency: transitive
+    description:
+      name: package_config
+      sha256: ffcf4cf3d6c0b74ac43708d9f56625506e8a68aa935abe9d267a7330f320eb5d
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.0"
+  path:
+    dependency: transitive
+    description:
+      name: path
+      sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.9.1"
+  pool:
+    dependency: transitive
+    description:
+      name: pool
+      sha256: "978783255c543aa3586a1b3c21f6e9d720eb315376a915872c61ef8b5c20177d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.2"
+  pub_semver:
+    dependency: transitive
+    description:
+      name: pub_semver
+      sha256: "5bfcf68ca79ef689f8990d1160781b4bad40a3bd5e5218ad4076ddb7f4081585"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  shelf:
+    dependency: transitive
+    description:
+      name: shelf
+      sha256: e7dd780a7ffb623c57850b33f43309312fc863fb6aa3d276a754bb299839ef12
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.2"
+  shelf_packages_handler:
+    dependency: transitive
+    description:
+      name: shelf_packages_handler
+      sha256: "89f967eca29607c933ba9571d838be31d67f53f6e4ee15147d5dc2934fee1b1e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.2"
+  shelf_static:
+    dependency: transitive
+    description:
+      name: shelf_static
+      sha256: c87c3875f91262785dade62d135760c2c69cb217ac759485334c5857ad89f6e3
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.3"
+  shelf_web_socket:
+    dependency: transitive
+    description:
+      name: shelf_web_socket
+      sha256: "3632775c8e90d6c9712f883e633716432a27758216dfb61bd86a8321c0580925"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.0"
+  source_map_stack_trace:
+    dependency: transitive
+    description:
+      name: source_map_stack_trace
+      sha256: c0713a43e323c3302c2abe2a1cc89aa057a387101ebd280371d6a6c9fa68516b
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.2"
+  source_maps:
+    dependency: transitive
+    description:
+      name: source_maps
+      sha256: "190222579a448b03896e0ca6eca5998fa810fda630c1d65e2f78b3f638f54812"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.10.13"
+  source_span:
+    dependency: transitive
+    description:
+      name: source_span
+      sha256: "56a02f1f4cd1a2d96303c0144c93bd6d909eea6bee6bf5a0e0b685edbd4c47ab"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.10.2"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      sha256: "8b27215b45d22309b5cddda1aa2b19bdfec9df0e765f2de506401c071d38d1b1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.12.1"
+  stream_channel:
+    dependency: transitive
+    description:
+      name: stream_channel
+      sha256: "969e04c80b8bcdf826f8f16579c7b14d780458bd97f56d107d3950fdbeef059d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.4"
+  string_scanner:
+    dependency: transitive
+    description:
+      name: string_scanner
+      sha256: "921cd31725b72fe181906c6a94d987c78e3b98c2e205b397ea399d4054872b43"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.1"
+  term_glyph:
+    dependency: transitive
+    description:
+      name: term_glyph
+      sha256: "7f554798625ea768a7518313e58f83891c7f5024f88e46e7182a4558850a4b8e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.2"
+  test:
+    dependency: "direct dev"
+    description:
+      name: test
+      sha256: "0d5ba5602ec3baa28c8ce365e1efc5575969c765f45c554a3e167dc7945b9c30"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.31.2"
+  test_api:
+    dependency: transitive
+    description:
+      name: test_api
+      sha256: "475610b2aa23c19687cce2961e44b0cc57cafe220f67c2b80201231b2a07fbe7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.13"
+  test_core:
+    dependency: transitive
+    description:
+      name: test_core
+      sha256: a39c204a4fc7a7ccb04a2b985e359fda3cc37e45e0b8ac61c3fb1a05aa832132
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.6.19"
+  typed_data:
+    dependency: transitive
+    description:
+      name: typed_data
+      sha256: f9049c039ebfeb4cf7a7104a675823cd72dba8297f264b6637062516699fa006
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.0"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      sha256: "0016aef94fc66495ac78af5859181e3f3bf2026bd8eecc72b9565601e19ab360"
+      url: "https://pub.dev"
+    source: hosted
+    version: "15.2.0"
+  watcher:
+    dependency: transitive
+    description:
+      name: watcher
+      sha256: "1398c9f081a753f9226febe8900fce8f7d0a67163334e1c94a2438339d79d635"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.1"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: "868d88a33d8a87b18ffc05f9f030ba328ffefba92d6c127917a2ba740f9cfe4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.1"
+  web_socket:
+    dependency: transitive
+    description:
+      name: web_socket
+      sha256: "34d64019aa8e36bf9842ac014bb5d2f5586ca73df5e4d9bf5c936975cae6982c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.1"
+  web_socket_channel:
+    dependency: transitive
+    description:
+      name: web_socket_channel
+      sha256: d645757fb0f4773d602444000a8131ff5d48c9e47adfe9772652dd1a4f2d45c8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.3"
+  webkit_inspection_protocol:
+    dependency: transitive
+    description:
+      name: webkit_inspection_protocol
+      sha256: "87d3f2333bb240704cd3f1c6b5b7acd8a10e7f0bc28c28dcf14e782014f4a572"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.1"
+  yaml:
+    dependency: transitive
+    description:
+      name: yaml
+      sha256: b9da305ac7c39faa3f030eccd175340f968459dae4af175130b3fc47e40d76ce
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.3"
+sdks:
+  dart: ">=3.11.0 <4.0.0"
diff --git a/packages/watch_bridge_contract/pubspec.yaml b/packages/watch_bridge_contract/pubspec.yaml
new file mode 100644
index 0000000..7314039
--- /dev/null
+++ b/packages/watch_bridge_contract/pubspec.yaml
@@ -0,0 +1,11 @@
+name: watch_bridge_contract
+description: Shared Dart contracts for the GameTime phone/watch bridge.
+publish_to: 'none'
+version: 0.1.0
+
+environment:
+  sdk: ^3.10.0
+
+dev_dependencies:
+  lints: ^6.0.0
+  test: ^1.25.0
diff --git a/packages/watch_bridge_contract/test/watch_bridge_contract_test.dart b/packages/watch_bridge_contract/test/watch_bridge_contract_test.dart
new file mode 100644
index 0000000..e58483f
--- /dev/null
+++ b/packages/watch_bridge_contract/test/watch_bridge_contract_test.dart
@@ -0,0 +1,217 @@
+import 'dart:convert';
+
+import 'package:test/test.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+void main() {
+  group('WatchCommandEnvelope', () {
+    test('round-trips every command type through JSON', () {
+      for (final type in WatchCommandType.values) {
+        final command = WatchCommandEnvelope(
+          commandId: 'command-${type.name}',
+          type: type,
+          sessionId: 'session-1',
+          expectedRevision: 12,
+          sentAtEpochMs: 1710000000000,
+        );
+
+        final decoded = WatchCommandEnvelope.fromJson(
+          jsonDecode(jsonEncode(command.toJson())) as Map<String, Object?>,
+        );
+
+        expect(decoded, command);
+      }
+    });
+
+    test('ignores unknown fields and falls back for missing fields', () {
+      final command = WatchCommandEnvelope.fromJson({
+        'type': 'pauseSession',
+        'unknown': 'ignored',
+      });
+
+      expect(command.schemaVersion, watchBridgeSchemaVersion);
+      expect(command.commandId, '');
+      expect(command.type, WatchCommandType.pauseSession);
+      expect(command.sessionId, '');
+      expect(command.expectedRevision, 0);
+      expect(command.sentAtEpochMs, 0);
+    });
+  });
+
+  group('WatchCommandAck', () {
+    test('round-trips every ack enum value by stable JSON name', () {
+      for (final ack in WatchCommandAck.values) {
+        final encoded = jsonEncode(ack.name);
+        final decodedName = jsonDecode(encoded) as String;
+        final decoded = WatchCommandAck.values.singleWhere(
+          (value) => value.name == decodedName,
+        );
+
+        expect(decoded, ack);
+      }
+    });
+  });
+
+  group('WatchSessionProjection', () {
+    test('round-trips every phase, primary action, and secondary action', () {
+      for (final phase in WatchSessionPhase.values) {
+        for (final primaryAction in WatchPrimaryAction.values) {
+          final projection = WatchSessionProjection(
+            deviceSessionId: 'session-${phase.name}-${primaryAction.name}',
+            revision: 4,
+            projectedAtEpochMs: 1710000000100,
+            phase: phase,
+            phoneReachable: true,
+            seriesIndex: 2,
+            seriesTotal: 5,
+            exerciseName: 'Pompes tempo',
+            passageIndex: 1,
+            passageTotal: 3,
+            stepIndex: 2,
+            stepTotal: 4,
+            stepName: 'Descente',
+            dominantTimer: _stepTimer(),
+            secondaryTimers: [_scoreStopwatchTimer(), _setTimer()],
+            primaryAction: primaryAction,
+            secondaryActions: WatchSecondaryAction.values,
+            nextExerciseName: 'Fentes sautees',
+            statusLabel: 'Chrono etape',
+          );
+
+          final decoded = WatchSessionProjection.fromJson(
+            jsonDecode(jsonEncode(projection.toJson())) as Map<String, Object?>,
+          );
+
+          expect(decoded, projection);
+        }
+      }
+    });
+
+    test('ignores unknown fields and accepts absent optional fields', () {
+      final projection = WatchSessionProjection.fromJson({
+        'schemaVersion': 1,
+        'deviceSessionId': 'session-1',
+        'revision': 9,
+        'projectedAtEpochMs': 1710000000200,
+        'phase': 'restPaused',
+        'phoneReachable': true,
+        'seriesIndex': 3,
+        'seriesTotal': 5,
+        'exerciseName': 'Burpees',
+        'primaryAction': 'resumeSession',
+        'secondaryActions': ['skipCurrentRest', 'futureAction'],
+        'extra': {'ignored': true},
+      });
+
+      expect(projection.phase, WatchSessionPhase.restPaused);
+      expect(projection.passageIndex, isNull);
+      expect(projection.stepIndex, isNull);
+      expect(projection.dominantTimer, isNull);
+      expect(projection.secondaryTimers, isEmpty);
+      expect(projection.primaryAction, WatchPrimaryAction.resumeSession);
+      expect(projection.secondaryActions, [
+        WatchSecondaryAction.skipCurrentRest,
+      ]);
+      expect(projection.nextExerciseName, isNull);
+      expect(projection.statusLabel, isNull);
+    });
+
+    test('falls back to neutral values for absent required fields', () {
+      final projection = WatchSessionProjection.fromJson({});
+
+      expect(projection.schemaVersion, watchBridgeSchemaVersion);
+      expect(projection.deviceSessionId, '');
+      expect(projection.revision, 0);
+      expect(projection.projectedAtEpochMs, 0);
+      expect(projection.phase, WatchSessionPhase.noActiveSession);
+      expect(projection.phoneReachable, false);
+      expect(projection.seriesIndex, 0);
+      expect(projection.seriesTotal, 0);
+      expect(projection.exerciseName, '');
+      expect(projection.primaryAction, WatchPrimaryAction.none);
+      expect(projection.secondaryActions, isEmpty);
+    });
+  });
+
+  group('WatchTimerProjection', () {
+    test('round-trips every timer enum combination through JSON', () {
+      for (final kind in WatchTimerKind.values) {
+        for (final displayMode in WatchTimerDisplayMode.values) {
+          for (final runState in WatchTimerRunState.values) {
+            final timer = WatchTimerProjection(
+              kind: kind,
+              label: 'timer-${kind.name}',
+              displayMode: displayMode,
+              runState: runState,
+              referenceEpochMs: 1710000000300,
+              accumulatedMs: 42000,
+              startedAtEpochMs: 1710000000000,
+              targetMs: 90000,
+            );
+
+            final decoded = WatchTimerProjection.fromJson(
+              jsonDecode(jsonEncode(timer.toJson())) as Map<String, Object?>,
+            );
+
+            expect(decoded, timer);
+          }
+        }
+      }
+    });
+
+    test('ignores unknown fields and falls back for missing fields', () {
+      final timer = WatchTimerProjection.fromJson({
+        'kind': 'rest',
+        'displayMode': 'countdown',
+        'runState': 'paused',
+        'unknown': 'ignored',
+      });
+
+      expect(timer.kind, WatchTimerKind.rest);
+      expect(timer.label, '');
+      expect(timer.displayMode, WatchTimerDisplayMode.countdown);
+      expect(timer.runState, WatchTimerRunState.paused);
+      expect(timer.referenceEpochMs, 0);
+      expect(timer.accumulatedMs, 0);
+      expect(timer.startedAtEpochMs, isNull);
+      expect(timer.targetMs, isNull);
+    });
+  });
+}
+
+WatchTimerProjection _stepTimer() {
+  return const WatchTimerProjection(
+    kind: WatchTimerKind.step,
+    label: 'Chrono etape',
+    displayMode: WatchTimerDisplayMode.countdown,
+    runState: WatchTimerRunState.running,
+    referenceEpochMs: 1710000000000,
+    accumulatedMs: 18000,
+    startedAtEpochMs: 1710000000000,
+    targetMs: 20000,
+  );
+}
+
+WatchTimerProjection _scoreStopwatchTimer() {
+  return const WatchTimerProjection(
+    kind: WatchTimerKind.scoreStopwatch,
+    label: 'Score chrono',
+    displayMode: WatchTimerDisplayMode.elapsed,
+    runState: WatchTimerRunState.running,
+    referenceEpochMs: 1710000000000,
+    accumulatedMs: 51000,
+    startedAtEpochMs: 1710000000000,
+  );
+}
+
+WatchTimerProjection _setTimer() {
+  return const WatchTimerProjection(
+    kind: WatchTimerKind.setTimer,
+    label: 'Temps de serie',
+    displayMode: WatchTimerDisplayMode.elapsed,
+    runState: WatchTimerRunState.running,
+    referenceEpochMs: 1710000000000,
+    accumulatedMs: 102000,
+    startedAtEpochMs: 1710000000000,
+  );
+}
diff --git a/pubspec.lock b/pubspec.lock
index 0176e37..8b5f3d6 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1085,6 +1085,13 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "15.2.0"
+  watch_bridge_contract:
+    dependency: "direct main"
+    description:
+      path: "packages/watch_bridge_contract"
+      relative: true
+    source: path
+    version: "0.1.0"
   watcher:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index efedffc..08d852f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -24,6 +24,8 @@ dependencies:
   video_player: ^2.11.1
   file_picker: ^11.0.2
   share_plus: ^12.0.2
+  watch_bridge_contract:
+    path: packages/watch_bridge_contract
 
 dev_dependencies:
   flutter_test:
diff --git a/test/application/watch_companion_command_handler_test.dart b/test/application/watch_companion_command_handler_test.dart
new file mode 100644
index 0000000..07b99a9
--- /dev/null
+++ b/test/application/watch_companion_command_handler_test.dart
@@ -0,0 +1,686 @@
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gametime/application/application.dart';
+import 'package:gametime/domain/domain.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+void main() {
+  test('routes startCurrentExercise to active execution timers', () async {
+    final env = _env(
+      session: _session(timeEnabled: true),
+      projection: _projection(
+        primaryAction: WatchPrimaryAction.startCurrentExercise,
+      ),
+    );
+
+    final ack = await env.dispatch(WatchCommandType.startCurrentExercise);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(env.repository.setTimerStates, hasLength(1));
+    expect(env.projections.emitCount, 1);
+  });
+
+  test('routes pauseSession and resumeSession to session use cases', () async {
+    final pauseEnv = _env(
+      session: _session(timeEnabled: true),
+      projection: _projection(
+        phase: WatchSessionPhase.running,
+        primaryAction: WatchPrimaryAction.pauseSession,
+      ),
+    );
+
+    expect(
+      await pauseEnv.dispatch(WatchCommandType.pauseSession),
+      WatchCommandAck.accepted,
+    );
+    expect(pauseEnv.repository.session?.status, ActiveWorkoutStatus.paused);
+
+    final resumeEnv = _env(
+      session: _session(status: ActiveWorkoutStatus.paused, pausedAt: _now),
+      projection: _projection(
+        phase: WatchSessionPhase.paused,
+        primaryAction: WatchPrimaryAction.resumeSession,
+      ),
+    );
+
+    expect(
+      await resumeEnv.dispatch(WatchCommandType.resumeSession),
+      WatchCommandAck.accepted,
+    );
+    expect(resumeEnv.repository.session?.status, ActiveWorkoutStatus.running);
+  });
+
+  test('routes startPreparedTimedStep to step timer start', () async {
+    final session = _session(
+      steps: [
+        _step(),
+        _step(id: 'step-2', position: 1),
+      ],
+    );
+    final env = _env(
+      session: session,
+      projection: _projection(
+        phase: WatchSessionPhase.nextTimerReady,
+        primaryAction: WatchPrimaryAction.startPreparedTimedStep,
+      ),
+    );
+    env.repository.stepProgressStates['step-state'] = _stepState(
+      sessionId: session.metadata.id,
+      stepId: 'step-2',
+      stepIndex: 1,
+    );
+
+    final ack = await env.dispatch(WatchCommandType.startPreparedTimedStep);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(
+      env.repository.stepProgressStates['step-state']?.status,
+      ActiveExerciseStepProgressStatus.runningTimer,
+    );
+  });
+
+  test('routes skipCurrentStep to step use case', () async {
+    final session = _session(steps: [_step()]);
+    final env = _env(
+      session: session,
+      projection: _projection(
+        secondaryActions: [WatchSecondaryAction.skipCurrentStep],
+      ),
+    );
+    env.repository.stepProgressStates['step-state'] = _stepState(
+      sessionId: session.metadata.id,
+    );
+
+    final ack = await env.dispatch(WatchCommandType.skipCurrentStep);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(env.repository.stepResults, hasLength(1));
+  });
+
+  test('routes skipCurrentPassage to step use case', () async {
+    final session = _session(
+      targetReps: 2,
+      steps: [
+        _step(),
+        _step(id: 'step-2', position: 1),
+      ],
+    );
+    final env = _env(
+      session: session,
+      projection: _projection(
+        secondaryActions: [WatchSecondaryAction.skipCurrentPassage],
+      ),
+    );
+    env.repository.stepProgressStates['step-state'] = _stepState(
+      sessionId: session.metadata.id,
+    );
+
+    final ack = await env.dispatch(WatchCommandType.skipCurrentPassage);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(env.repository.stepResults, hasLength(2));
+  });
+
+  test(
+    'routes finishCurrentSet and advances to next set without rest',
+    () async {
+      final session = _session(timeEnabled: true, setsCount: 2);
+      final env = _env(
+        session: session,
+        projection: _projection(
+          secondaryActions: [WatchSecondaryAction.finishCurrentSet],
+        ),
+      );
+      env.repository.setTimerStates['set'] = _setTimer(
+        sessionId: session.metadata.id,
+      );
+
+      final ack = await env.dispatch(WatchCommandType.finishCurrentSet);
+
+      expect(ack, WatchCommandAck.accepted);
+      expect(env.repository.results, hasLength(1));
+      expect(env.repository.session?.currentSetIndex, 1);
+    },
+  );
+
+  test('routes finishCurrentSet and starts rest before next set', () async {
+    final session = _session(timeEnabled: true, setsCount: 2, restSeconds: 60);
+    final env = _env(
+      session: session,
+      projection: _projection(
+        secondaryActions: [WatchSecondaryAction.finishCurrentSet],
+      ),
+    );
+    env.repository.setTimerStates['set'] = _setTimer(
+      sessionId: session.metadata.id,
+    );
+
+    final ack = await env.dispatch(WatchCommandType.finishCurrentSet);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(env.repository.restStates.values.single.plannedRestSeconds, 60);
+    expect(env.repository.session?.currentSetIndex, 0);
+  });
+
+  test('routes skipCurrentSet and advances once on retry duplicate', () async {
+    final session = _session(timeEnabled: true, setsCount: 3);
+    final env = _env(
+      session: session,
+      projection: _projection(
+        secondaryActions: [WatchSecondaryAction.skipCurrentSet],
+      ),
+    );
+    env.repository.setTimerStates['set'] = _setTimer(
+      sessionId: session.metadata.id,
+    );
+    final command = _command(WatchCommandType.skipCurrentSet);
+
+    final firstAck = await env.handler.dispatch(command);
+    final retryAck = await env.handler.dispatch(command);
+
+    expect(firstAck, WatchCommandAck.accepted);
+    expect(retryAck, WatchCommandAck.acceptedNoOp);
+    expect(env.repository.results, hasLength(1));
+    expect(env.repository.session?.currentSetIndex, 1);
+  });
+
+  test('routes skipCurrentRest to rest skip and next position', () async {
+    final session = _session(setsCount: 2);
+    final env = _env(
+      session: session,
+      projection: _projection(
+        phase: WatchSessionPhase.restRunning,
+        primaryAction: WatchPrimaryAction.pauseSession,
+        secondaryActions: [WatchSecondaryAction.skipCurrentRest],
+      ),
+    );
+    env.repository.restStates['rest'] = ActiveRestState(
+      metadata: _metadata('rest'),
+      activeWorkoutSessionId: session.metadata.id,
+      afterProgramIndex: 0,
+      afterExerciseIndex: 0,
+      afterSetIndex: 0,
+      plannedRestSeconds: 60,
+      adjustedRestSeconds: 60,
+      startedAt: _now,
+    );
+
+    final ack = await env.dispatch(WatchCommandType.skipCurrentRest);
+
+    expect(ack, WatchCommandAck.accepted);
+    expect(env.repository.restStates['rest']?.skippedAt, isNotNull);
+    expect(env.repository.session?.currentSetIndex, 1);
+  });
+
+  test(
+    'rejects stale revision, non applicable, missing and mismatch',
+    () async {
+      final stale = _env(
+        session: _session(),
+        projection: _projection(revision: 2),
+      );
+      expect(
+        await stale.dispatch(WatchCommandType.startCurrentExercise),
+        WatchCommandAck.rejectedStaleRevision,
+      );
+
+      final nonApplicable = _env(
+        session: _session(),
+        projection: _projection(),
+      );
+      expect(
+        await nonApplicable.dispatch(WatchCommandType.pauseSession),
+        WatchCommandAck.rejectedNotApplicable,
+      );
+
+      final missing = _env(
+        projection: _projection(
+          phase: WatchSessionPhase.noActiveSession,
+          deviceSessionId: '',
+          primaryAction: WatchPrimaryAction.none,
+        ),
+      );
+      expect(
+        await missing.dispatch(WatchCommandType.startCurrentExercise),
+        WatchCommandAck.rejectedNoActiveSession,
+      );
+
+      final mismatch = _env(
+        session: _session(),
+        projection: _projection(deviceSessionId: 'other-session'),
+      );
+      expect(
+        await mismatch.dispatch(WatchCommandType.startCurrentExercise),
+        WatchCommandAck.rejectedSessionMismatch,
+      );
+    },
+  );
+}
+
+final _now = DateTime.utc(2026, 7, 25, 12);
+
+_Harness _env({
+  ActiveWorkoutSession? session,
+  required WatchSessionProjection projection,
+}) {
+  final repository = _FakeActiveSessionRepository()..session = session;
+  final clock = _FakeClock(_now);
+  final ids = _FakeIds();
+  final activeUseCases = ActiveWorkoutSessionUseCases(
+    sessionRepository: repository,
+    templateRepository: _FakeWorkoutTemplateRepository(),
+    clock: clock,
+    ids: ids,
+    originDeviceId: 'device-1',
+  );
+  final stepUseCases = ActiveExerciseStepUseCases(
+    sessionRepository: repository,
+    clock: clock,
+    ids: ids,
+    originDeviceId: 'device-1',
+  );
+  final projections = _FakeProjectionSource(projection);
+  return _Harness(
+    repository: repository,
+    projections: projections,
+    handler: WatchCompanionCommandHandler(
+      sessionRepository: repository,
+      activeSessionUseCases: activeUseCases,
+      stepUseCases: stepUseCases,
+      projectionSource: projections,
+    ),
+  );
+}
+
+final class _Harness {
+  const _Harness({
+    required this.repository,
+    required this.projections,
+    required this.handler,
+  });
+
+  final _FakeActiveSessionRepository repository;
+  final _FakeProjectionSource projections;
+  final WatchCompanionCommandHandler handler;
+
+  Future<WatchCommandAck> dispatch(WatchCommandType type) {
+    return handler.dispatch(_command(type));
+  }
+}
+
+WatchCommandEnvelope _command(
+  WatchCommandType type, {
+  String commandId = 'command-1',
+}) {
+  return WatchCommandEnvelope(
+    commandId: commandId,
+    type: type,
+    sessionId: 'session-1',
+    expectedRevision: 1,
+    sentAtEpochMs: _now.millisecondsSinceEpoch,
+  );
+}
+
+WatchSessionProjection _projection({
+  WatchSessionPhase phase = WatchSessionPhase.ready,
+  String deviceSessionId = 'session-1',
+  int revision = 1,
+  WatchPrimaryAction primaryAction = WatchPrimaryAction.startCurrentExercise,
+  List<WatchSecondaryAction> secondaryActions = const [
+    WatchSecondaryAction.finishCurrentSet,
+    WatchSecondaryAction.skipCurrentSet,
+  ],
+}) {
+  return WatchSessionProjection(
+    deviceSessionId: deviceSessionId,
+    revision: revision,
+    projectedAtEpochMs: _now.millisecondsSinceEpoch,
+    phase: phase,
+    phoneReachable: true,
+    seriesIndex: 1,
+    seriesTotal: 2,
+    exerciseName: 'Squat',
+    primaryAction: primaryAction,
+    secondaryActions: secondaryActions,
+  );
+}
+
+ActiveWorkoutSession _session({
+  ActiveWorkoutStatus status = ActiveWorkoutStatus.running,
+  DateTime? pausedAt,
+  int currentSetIndex = 0,
+  int setsCount = 2,
+  bool timeEnabled = false,
+  int? targetReps = 10,
+  int restSeconds = 0,
+  List<ExerciseStep> steps = const [],
+}) {
+  final exerciseSnapshot = {
+    'id': 'exercise-snapshot-1',
+    'exerciseNameSnapshot': 'Squat',
+    'setsCount': setsCount,
+    'timeEnabled': timeEnabled,
+    'repsEnabled': true,
+    'scoreEnabled': false,
+    'targetReps': targetReps,
+    'scoreInputModeSnapshot': ScoreInputMode.manual.name,
+    'restSecondsOverride': restSeconds,
+    'exerciseStepsSnapshot': steps
+        .map((step) => step.toSnapshotJson())
+        .toList(),
+    'autoStartNextTimedStepSnapshot': false,
+  };
+  return ActiveWorkoutSession(
+    metadata: _metadata('session-1'),
+    status: status,
+    startedAt: _now,
+    pausedAt: pausedAt,
+    lastPersistedAt: _now,
+    elapsedActiveMs: 0,
+    currentProgramIndex: 0,
+    currentExerciseIndex: 0,
+    currentSetIndex: currentSetIndex,
+    resolvedTemplateSnapshotJson: jsonEncode({
+      'programs': [
+        {
+          'id': 'program-snapshot-1',
+          'programNameSnapshot': 'Programme',
+          'programSnapshotJson': jsonEncode({
+            'exercises': [exerciseSnapshot],
+          }),
+        },
+      ],
+    }),
+  );
+}
+
+ExerciseStep _step({String id = 'step-1', int position = 0}) {
+  return ExerciseStep(
+    id: id,
+    position: position,
+    name: 'Step ${position + 1}',
+    type: ExerciseStepType.time,
+    defaultTargetValue: 1,
+  );
+}
+
+ActiveExerciseStepProgressState _stepState({
+  required String sessionId,
+  String stepId = 'step-1',
+  int stepIndex = 0,
+}) {
+  return ActiveExerciseStepProgressState(
+    metadata: _metadata('step-state'),
+    activeWorkoutSessionId: sessionId,
+    programIndex: 0,
+    exerciseIndex: 0,
+    setIndex: 0,
+    currentPassageIndex: 0,
+    currentStepIndex: stepIndex,
+    currentStepSnapshotId: stepId,
+    status: ActiveExerciseStepProgressStatus.stoppedTimer,
+    accumulatedMs: 0,
+    lastTransitionAt: _now,
+  );
+}
+
+ActiveSetTimerState _setTimer({required String sessionId}) {
+  return ActiveSetTimerState(
+    metadata: _metadata('set'),
+    activeWorkoutSessionId: sessionId,
+    programIndex: 0,
+    exerciseIndex: 0,
+    setIndex: 0,
+    status: ActiveSetTimerStatus.running,
+    startedAt: _now,
+    accumulatedMs: 0,
+  );
+}
+
+EntityMetadata _metadata(String id) {
+  return EntityMetadata(
+    id: id,
+    createdAt: _now,
+    updatedAt: _now,
+    originDeviceId: 'device-1',
+  );
+}
+
+final class _FakeProjectionSource implements WatchProjectionSource {
+  _FakeProjectionSource(this.projection);
+
+  WatchSessionProjection projection;
+  var emitCount = 0;
+
+  @override
+  Stream<WatchSessionProjection> get projections => const Stream.empty();
+
+  @override
+  Future<WatchSessionProjection> currentProjection() async => projection;
+
+  @override
+  Future<WatchSessionProjection> emitCurrentProjection() async {
+    emitCount += 1;
+    projection = WatchSessionProjection(
+      deviceSessionId: projection.deviceSessionId,
+      revision: projection.revision + 1,
+      projectedAtEpochMs: projection.projectedAtEpochMs,
+      phase: projection.phase,
+      phoneReachable: projection.phoneReachable,
+      seriesIndex: projection.seriesIndex,
+      seriesTotal: projection.seriesTotal,
+      exerciseName: projection.exerciseName,
+      primaryAction: projection.primaryAction,
+      secondaryActions: projection.secondaryActions,
+    );
+    return projection;
+  }
+}
+
+final class _FakeClock implements Clock {
+  const _FakeClock(this.value);
+
+  final DateTime value;
+
+  @override
+  DateTime now() => value;
+}
+
+final class _FakeIds implements IdGenerator {
+  var next = 0;
+
+  @override
+  String newId() {
+    next += 1;
+    return 'id-$next';
+  }
+}
+
+final class _FakeWorkoutTemplateRepository
+    implements WorkoutTemplateRepository {
+  @override
+  Future<WorkoutTemplate?> findById(String id) async => null;
+
+  @override
+  Future<List<WorkoutTemplate>> listActive() async => const [];
+
+  @override
+  Future<void> replaceComposition(
+    WorkoutTemplate template,
+    DateTime deletedAt,
+  ) async {}
+
+  @override
+  Future<void> save(WorkoutTemplate template) async {}
+
+  @override
+  Future<void> saveOverride(WorkoutTemplateExerciseOverride override) async {}
+
+  @override
+  Future<void> saveProgram(WorkoutTemplateProgram program) async {}
+}
+
+final class _FakeActiveSessionRepository implements ActiveSessionRepository {
+  ActiveWorkoutSession? session;
+  final results = <ActiveSetResult>[];
+  final restStates = <String, ActiveRestState>{};
+  final setTimerStates = <String, ActiveSetTimerState>{};
+  final scoreStopwatchStates = <String, ActiveScoreStopwatchState>{};
+  final stepProgressStates = <String, ActiveExerciseStepProgressState>{};
+  final stepResults = <ActiveExerciseStepResult>[];
+
+  @override
+  Future<void> deleteScoreStopwatchState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+    required DateTime deletedAt,
+  }) async {
+    scoreStopwatchStates.clear();
+  }
+
+  @override
+  Future<ActiveWorkoutSession?> findById(String id) async {
+    return session?.metadata.id == id ? session : null;
+  }
+
+  @override
+  Future<ActiveWorkoutSession?> findOpen() async => session;
+
+  @override
+  Future<ActiveExerciseStepProgressState?> findExerciseStepProgressState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return stepProgressStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<ActiveRestState?> findRestStateById(String id) async {
+    return restStates[id];
+  }
+
+  @override
+  Future<ActiveScoreStopwatchState?> findScoreStopwatchState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return scoreStopwatchStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<ActiveSetTimerState?> findSetTimerState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return setTimerStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<List<ActiveExerciseStepProgressState>> listExerciseStepProgressStates(
+    String sessionId,
+  ) async {
+    return stepProgressStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveExerciseStepResult>> listExerciseStepResults(
+    String sessionId,
+  ) async {
+    return stepResults
+        .where((result) => result.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveRestState>> listRestStates(String sessionId) async {
+    return restStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveScoreStopwatchState>> listScoreStopwatchStates(
+    String sessionId,
+  ) async {
+    return scoreStopwatchStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveSetResult>> listSetResults(String sessionId) async {
+    return results
+        .where((result) => result.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveSetTimerState>> listSetTimerStates(String sessionId) async {
+    return setTimerStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<void> save(ActiveWorkoutSession session) async {
+    this.session = session;
+  }
+
+  @override
+  Future<void> saveExerciseStepProgressState(
+    ActiveExerciseStepProgressState state,
+  ) async {
+    stepProgressStates[state.metadata.id] = state;
+  }
+
+  @override
+  Future<void> saveExerciseStepResult(ActiveExerciseStepResult result) async {
+    stepResults.add(result);
+  }
+
+  @override
+  Future<void> saveRestState(ActiveRestState restState) async {
+    restStates[restState.metadata.id] = restState;
+  }
+
+  @override
+  Future<void> saveScoreStopwatchState(ActiveScoreStopwatchState state) async {
+    scoreStopwatchStates[state.metadata.id] = state;
+  }
+
+  @override
+  Future<void> saveSetResult(ActiveSetResult result) async {
+    results.add(result);
+  }
+
+  @override
+  Future<void> saveSetTimerState(ActiveSetTimerState state) async {
+    setTimerStates[state.metadata.id] = state;
+  }
+}
diff --git a/test/application/watch_companion_projection_test.dart b/test/application/watch_companion_projection_test.dart
new file mode 100644
index 0000000..629fc6a
--- /dev/null
+++ b/test/application/watch_companion_projection_test.dart
@@ -0,0 +1,673 @@
+import 'dart:convert';
+
+import 'package:gametime/application/application.dart';
+import 'package:gametime/domain/domain.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+void main() {
+  test('projects noActiveSession without an open session', () async {
+    final projector = _projector(_FakeActiveSessionRepository(), _clock());
+
+    final projection = await projector.project(revision: 1);
+
+    expect(projection.phase, WatchSessionPhase.noActiveSession);
+    expect(projection.primaryAction, WatchPrimaryAction.none);
+    expect(projection.phoneReachable, isTrue);
+  });
+
+  test('projects ready at the first set before timers start', () async {
+    final repository = _FakeActiveSessionRepository()
+      ..session = _session(
+        currentSetIndex: 0,
+        timeEnabled: true,
+        targetTimeSeconds: 20,
+        steps: [_step(defaultTargetValue: 20)],
+      );
+    final projector = _projector(repository, _clock());
+
+    final projection = await projector.project(revision: 1);
+
+    expect(projection.phase, WatchSessionPhase.ready);
+    expect(projection.seriesIndex, 1);
+    expect(projection.seriesTotal, 2);
+    expect(projection.exerciseName, 'Squat');
+    expect(projection.stepIndex, 1);
+    expect(projection.stepTotal, 1);
+    expect(projection.dominantTimer?.kind, WatchTimerKind.step);
+    expect(projection.dominantTimer?.runState, WatchTimerRunState.stopped);
+    expect(projection.dominantTimer?.targetMs, 20000);
+    expect(projection.primaryAction, WatchPrimaryAction.startCurrentExercise);
+  });
+
+  test(
+    'projects running with dominant step timer and secondary timers',
+    () async {
+      final now = DateTime.utc(2026, 7, 25, 12);
+      final session = _session(
+        timeEnabled: true,
+        scoreEnabled: true,
+        scoreInputMode: ScoreInputMode.stopwatch,
+        steps: [_step(defaultTargetValue: 30)],
+      );
+      final repository = _FakeActiveSessionRepository()
+        ..session = session
+        ..stepProgressStates['step-state'] = _stepState(
+          sessionId: session.metadata.id,
+          status: ActiveExerciseStepProgressStatus.runningTimer,
+          startedAt: now.subtract(const Duration(seconds: 5)),
+        )
+        ..scoreStopwatchStates['score'] = _scoreStopwatch(
+          sessionId: session.metadata.id,
+          startedAt: now.subtract(const Duration(seconds: 4)),
+        )
+        ..setTimerStates['set'] = _setTimer(
+          sessionId: session.metadata.id,
+          startedAt: now.subtract(const Duration(seconds: 6)),
+        );
+      final projector = _projector(repository, _clock(now));
+
+      final projection = await projector.project(revision: 1);
+
+      expect(projection.phase, WatchSessionPhase.running);
+      expect(projection.dominantTimer?.kind, WatchTimerKind.step);
+      expect(projection.dominantTimer?.accumulatedMs, 0);
+      expect(
+        projection.dominantTimer?.startedAtEpochMs,
+        now.subtract(const Duration(seconds: 5)).millisecondsSinceEpoch,
+      );
+      expect(projection.secondaryTimers.map((timer) => timer.kind), [
+        WatchTimerKind.scoreStopwatch,
+        WatchTimerKind.setTimer,
+      ]);
+      expect(projection.primaryAction, WatchPrimaryAction.pauseSession);
+      expect(
+        projection.secondaryActions,
+        contains(WatchSecondaryAction.finishCurrentSet),
+      );
+    },
+  );
+
+  test('projects paused after a running session is paused', () async {
+    final now = DateTime.utc(2026, 7, 25, 12);
+    final session = _session(
+      status: ActiveWorkoutStatus.paused,
+      pausedAt: now,
+      timeEnabled: true,
+      steps: [_step()],
+    );
+    final repository = _FakeActiveSessionRepository()
+      ..session = session
+      ..stepProgressStates['step-state'] = _stepState(
+        sessionId: session.metadata.id,
+        status: ActiveExerciseStepProgressStatus.pausedTimer,
+        accumulatedMs: 5000,
+        lastTransitionAt: now,
+      );
+    final projector = _projector(repository, _clock(now));
+
+    final projection = await projector.project(revision: 2);
+
+    expect(projection.phase, WatchSessionPhase.paused);
+    expect(projection.primaryAction, WatchPrimaryAction.resumeSession);
+    expect(projection.statusLabel, 'Séance en pause');
+    expect(projection.dominantTimer?.runState, WatchTimerRunState.paused);
+  });
+
+  test(
+    'projects nextTimerReady after an elapsed timer with chaining disabled',
+    () async {
+      final now = DateTime.utc(2026, 7, 25, 12);
+      final session = _session(
+        autoStartNextTimedStepSnapshot: false,
+        steps: [
+          _step(id: 'step-1'),
+          _step(id: 'step-2', position: 1),
+        ],
+      );
+      final repository = _FakeActiveSessionRepository()
+        ..session = session
+        ..stepProgressStates['step-state'] = _stepState(
+          sessionId: session.metadata.id,
+          stepId: 'step-1',
+          status: ActiveExerciseStepProgressStatus.runningTimer,
+          startedAt: now.subtract(const Duration(milliseconds: 1500)),
+        );
+      final projector = _projector(repository, _clock(now));
+
+      final projection = await projector.project(revision: 3);
+
+      expect(projection.phase, WatchSessionPhase.nextTimerReady);
+      expect(projection.stepIndex, 2);
+      expect(projection.stepName, 'Step 2');
+      expect(projection.statusLabel, 'Chrono suivant prêt');
+      expect(
+        projection.primaryAction,
+        WatchPrimaryAction.startPreparedTimedStep,
+      );
+      expect(projection.dominantTimer?.runState, WatchTimerRunState.stopped);
+      expect(repository.stepResults, hasLength(1));
+    },
+  );
+
+  test('projects restRunning after finishing a set with rest', () async {
+    final now = DateTime.utc(2026, 7, 25, 12);
+    final session = _session(currentSetIndex: 1);
+    final repository = _FakeActiveSessionRepository()
+      ..session = session
+      ..restStates['rest'] = ActiveRestState(
+        metadata: _metadata('rest'),
+        activeWorkoutSessionId: session.metadata.id,
+        afterProgramIndex: 0,
+        afterExerciseIndex: 0,
+        afterSetIndex: 0,
+        plannedRestSeconds: 60,
+        adjustedRestSeconds: 60,
+        startedAt: now.subtract(const Duration(seconds: 10)),
+      );
+    final projector = _projector(repository, _clock(now));
+
+    final projection = await projector.project(revision: 4);
+
+    expect(projection.phase, WatchSessionPhase.restRunning);
+    expect(projection.primaryAction, WatchPrimaryAction.pauseSession);
+    expect(projection.secondaryActions, [WatchSecondaryAction.skipCurrentRest]);
+    expect(projection.dominantTimer?.kind, WatchTimerKind.rest);
+    expect(projection.dominantTimer?.targetMs, 60000);
+    expect(projection.dominantTimer?.accumulatedMs, 10000);
+    expect(projection.nextExerciseName, 'Squat');
+  });
+
+  test(
+    'projects restRunning next exercise when rest precedes another exercise',
+    () async {
+      final now = DateTime.utc(2026, 7, 25, 12);
+      final session = _session(
+        currentExerciseIndex: 1,
+        currentSetIndex: 0,
+        secondExerciseName: 'Fentes',
+      );
+      final repository = _FakeActiveSessionRepository()
+        ..session = session
+        ..restStates['rest'] = ActiveRestState(
+          metadata: _metadata('rest'),
+          activeWorkoutSessionId: session.metadata.id,
+          afterProgramIndex: 0,
+          afterExerciseIndex: 0,
+          afterSetIndex: 1,
+          plannedRestSeconds: 60,
+          adjustedRestSeconds: 60,
+          startedAt: now.subtract(const Duration(seconds: 10)),
+        );
+      final projector = _projector(repository, _clock(now));
+
+      final projection = await projector.project(revision: 4);
+
+      expect(projection.phase, WatchSessionPhase.restRunning);
+      expect(projection.exerciseName, 'Fentes');
+      expect(projection.nextExerciseName, 'Fentes');
+    },
+  );
+
+  test('projects restPaused', () async {
+    final now = DateTime.utc(2026, 7, 25, 12);
+    final session = _session(status: ActiveWorkoutStatus.paused, pausedAt: now);
+    final repository = _FakeActiveSessionRepository()
+      ..session = session
+      ..restStates['rest'] = ActiveRestState(
+        metadata: _metadata('rest'),
+        activeWorkoutSessionId: session.metadata.id,
+        afterProgramIndex: 0,
+        afterExerciseIndex: 0,
+        afterSetIndex: 0,
+        plannedRestSeconds: 60,
+        adjustedRestSeconds: 60,
+        startedAt: now.subtract(const Duration(seconds: 15)),
+        pausedAt: now,
+      );
+    final projector = _projector(repository, _clock(now));
+
+    final projection = await projector.project(revision: 5);
+
+    expect(projection.phase, WatchSessionPhase.restPaused);
+    expect(projection.primaryAction, WatchPrimaryAction.resumeSession);
+    expect(projection.dominantTimer?.runState, WatchTimerRunState.paused);
+  });
+
+  test(
+    'projects betweenSetsReady after rest ends before the next set',
+    () async {
+      final now = DateTime.utc(2026, 7, 25, 12);
+      final session = _session(currentSetIndex: 1);
+      final repository = _FakeActiveSessionRepository()
+        ..session = session
+        ..restStates['rest'] = ActiveRestState(
+          metadata: _metadata('rest'),
+          activeWorkoutSessionId: session.metadata.id,
+          afterProgramIndex: 0,
+          afterExerciseIndex: 0,
+          afterSetIndex: 0,
+          plannedRestSeconds: 60,
+          adjustedRestSeconds: 60,
+          startedAt: now.subtract(const Duration(seconds: 60)),
+          endedAt: now,
+        );
+      final projector = _projector(repository, _clock(now));
+
+      final projection = await projector.project(revision: 6);
+
+      expect(projection.phase, WatchSessionPhase.betweenSetsReady);
+      expect(projection.statusLabel, 'Prêt pour la série suivante');
+      expect(projection.primaryAction, WatchPrimaryAction.startCurrentExercise);
+    },
+  );
+
+  test(
+    'projects nextExerciseName between sets when exercise changes',
+    () async {
+      final session = _session(
+        currentExerciseIndex: 1,
+        currentSetIndex: 0,
+        secondExerciseName: 'Fentes',
+      );
+      final repository = _FakeActiveSessionRepository()..session = session;
+      final projector = _projector(repository, _clock());
+
+      final projection = await projector.project(revision: 7);
+
+      expect(projection.phase, WatchSessionPhase.betweenSetsReady);
+      expect(projection.exerciseName, 'Fentes');
+      expect(projection.nextExerciseName, 'Fentes');
+    },
+  );
+
+  test(
+    'emits projections through stream and publisher with incremented revision',
+    () async {
+      final repository = _FakeActiveSessionRepository()
+        ..session = _session(steps: [_step()]);
+      final publisher = _FakeWatchProjectionPublisher();
+      final useCases = WatchCompanionProjectionUseCases(
+        sessionRepository: repository,
+        clock: _clock(),
+        ids: _FakeIds(),
+        originDeviceId: 'device-1',
+        publisher: publisher,
+      );
+      final emitted = <WatchSessionProjection>[];
+      final subscription = useCases.projections.listen(emitted.add);
+
+      final first = await useCases.emitCurrentProjection();
+      final second = await useCases.emitCurrentProjection();
+      await Future<void>.delayed(Duration.zero);
+
+      expect(first.revision, 1);
+      expect(second.revision, 2);
+      expect(emitted.map((projection) => projection.revision), [1, 2]);
+      expect(publisher.published.map((projection) => projection.revision), [
+        1,
+        2,
+      ]);
+
+      await subscription.cancel();
+      await useCases.dispose();
+    },
+  );
+}
+
+WatchSessionProjectionProjector _projector(
+  _FakeActiveSessionRepository repository,
+  _FakeClock clock,
+) {
+  return WatchSessionProjectionProjector(
+    sessionRepository: repository,
+    clock: clock,
+    ids: _FakeIds(),
+    originDeviceId: 'device-1',
+  );
+}
+
+_FakeClock _clock([DateTime? now]) {
+  return _FakeClock(now ?? DateTime.utc(2026, 7, 25, 12));
+}
+
+ActiveWorkoutSession _session({
+  ActiveWorkoutStatus status = ActiveWorkoutStatus.running,
+  DateTime? pausedAt,
+  int currentExerciseIndex = 0,
+  int currentSetIndex = 0,
+  int setsCount = 2,
+  bool timeEnabled = false,
+  bool repsEnabled = true,
+  bool scoreEnabled = false,
+  int? targetTimeSeconds,
+  ScoreInputMode scoreInputMode = ScoreInputMode.manual,
+  bool? autoStartNextTimedStepSnapshot = true,
+  List<ExerciseStep> steps = const [],
+  String? secondExerciseName,
+}) {
+  final exerciseSnapshot = {
+    'id': 'exercise-snapshot-1',
+    'exerciseNameSnapshot': 'Squat',
+    'setsCount': setsCount,
+    'timeEnabled': timeEnabled,
+    'repsEnabled': repsEnabled,
+    'scoreEnabled': scoreEnabled,
+    'targetTimeSeconds': targetTimeSeconds,
+    'targetReps': repsEnabled ? setsCount : null,
+    'scoreInputModeSnapshot': scoreInputMode.name,
+    'exerciseStepsSnapshot': steps
+        .map((step) => step.toSnapshotJson())
+        .toList(),
+    'autoStartNextTimedStepSnapshot': ?autoStartNextTimedStepSnapshot,
+  };
+  final secondExerciseSnapshot = secondExerciseName == null
+      ? null
+      : {
+          'id': 'exercise-snapshot-2',
+          'exerciseNameSnapshot': secondExerciseName,
+          'setsCount': 1,
+          'timeEnabled': false,
+          'repsEnabled': true,
+          'scoreEnabled': false,
+          'targetReps': 1,
+          'scoreInputModeSnapshot': ScoreInputMode.manual.name,
+          'exerciseStepsSnapshot': const [],
+          'autoStartNextTimedStepSnapshot': true,
+        };
+  return ActiveWorkoutSession(
+    metadata: _metadata('session-1'),
+    status: status,
+    startedAt: DateTime.utc(2026, 7, 25, 12),
+    pausedAt: pausedAt,
+    lastPersistedAt: DateTime.utc(2026, 7, 25, 12),
+    elapsedActiveMs: 0,
+    currentProgramIndex: 0,
+    currentExerciseIndex: currentExerciseIndex,
+    currentSetIndex: currentSetIndex,
+    resolvedTemplateSnapshotJson: jsonEncode({
+      'programs': [
+        {
+          'id': 'program-snapshot-1',
+          'programNameSnapshot': 'Programme',
+          'programSnapshotJson': jsonEncode({
+            'exercises': [exerciseSnapshot, ?secondExerciseSnapshot],
+          }),
+        },
+      ],
+    }),
+  );
+}
+
+ExerciseStep _step({
+  String id = 'step-1',
+  int position = 0,
+  int defaultTargetValue = 1,
+}) {
+  return ExerciseStep(
+    id: id,
+    position: position,
+    name: 'Step ${position + 1}',
+    type: ExerciseStepType.time,
+    defaultTargetValue: defaultTargetValue,
+  );
+}
+
+ActiveExerciseStepProgressState _stepState({
+  required String sessionId,
+  String stepId = 'step-1',
+  int stepIndex = 0,
+  ActiveExerciseStepProgressStatus status =
+      ActiveExerciseStepProgressStatus.stoppedTimer,
+  DateTime? startedAt,
+  int accumulatedMs = 0,
+  DateTime? lastTransitionAt,
+}) {
+  return ActiveExerciseStepProgressState(
+    metadata: _metadata('step-state'),
+    activeWorkoutSessionId: sessionId,
+    programIndex: 0,
+    exerciseIndex: 0,
+    setIndex: 0,
+    currentPassageIndex: 0,
+    currentStepIndex: stepIndex,
+    currentStepSnapshotId: stepId,
+    status: status,
+    startedAt: startedAt,
+    accumulatedMs: accumulatedMs,
+    lastTransitionAt: lastTransitionAt ?? DateTime.utc(2026, 7, 25, 12),
+  );
+}
+
+ActiveScoreStopwatchState _scoreStopwatch({
+  required String sessionId,
+  required DateTime startedAt,
+}) {
+  return ActiveScoreStopwatchState(
+    metadata: _metadata('score'),
+    activeWorkoutSessionId: sessionId,
+    programIndex: 0,
+    exerciseIndex: 0,
+    setIndex: 0,
+    status: ActiveScoreStopwatchStatus.running,
+    startedAt: startedAt,
+    accumulatedMs: 0,
+  );
+}
+
+ActiveSetTimerState _setTimer({
+  required String sessionId,
+  required DateTime startedAt,
+}) {
+  return ActiveSetTimerState(
+    metadata: _metadata('set'),
+    activeWorkoutSessionId: sessionId,
+    programIndex: 0,
+    exerciseIndex: 0,
+    setIndex: 0,
+    status: ActiveSetTimerStatus.running,
+    startedAt: startedAt,
+    accumulatedMs: 0,
+  );
+}
+
+EntityMetadata _metadata(String id) {
+  return EntityMetadata(
+    id: id,
+    createdAt: DateTime.utc(2026, 7, 25, 12),
+    updatedAt: DateTime.utc(2026, 7, 25, 12),
+    originDeviceId: 'device-1',
+  );
+}
+
+final class _FakeWatchProjectionPublisher implements WatchProjectionPublisher {
+  final published = <WatchSessionProjection>[];
+
+  @override
+  Future<void> publish(WatchSessionProjection projection) async {
+    published.add(projection);
+  }
+}
+
+final class _FakeClock implements Clock {
+  _FakeClock(this.value);
+
+  DateTime value;
+
+  @override
+  DateTime now() => value;
+}
+
+final class _FakeIds implements IdGenerator {
+  var _next = 0;
+
+  @override
+  String newId() {
+    _next += 1;
+    return 'id-$_next';
+  }
+}
+
+final class _FakeActiveSessionRepository implements ActiveSessionRepository {
+  ActiveWorkoutSession? session;
+  final results = <ActiveSetResult>[];
+  final restStates = <String, ActiveRestState>{};
+  final setTimerStates = <String, ActiveSetTimerState>{};
+  final scoreStopwatchStates = <String, ActiveScoreStopwatchState>{};
+  final stepProgressStates = <String, ActiveExerciseStepProgressState>{};
+  final stepResults = <ActiveExerciseStepResult>[];
+
+  @override
+  Future<void> deleteScoreStopwatchState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+    required DateTime deletedAt,
+  }) async {
+    scoreStopwatchStates.clear();
+  }
+
+  @override
+  Future<ActiveWorkoutSession?> findById(String id) async {
+    return session?.metadata.id == id ? session : null;
+  }
+
+  @override
+  Future<ActiveWorkoutSession?> findOpen() async => session;
+
+  @override
+  Future<ActiveExerciseStepProgressState?> findExerciseStepProgressState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return stepProgressStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<ActiveRestState?> findRestStateById(String id) async {
+    return restStates[id];
+  }
+
+  @override
+  Future<ActiveScoreStopwatchState?> findScoreStopwatchState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return scoreStopwatchStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<ActiveSetTimerState?> findSetTimerState({
+    required String sessionId,
+    required int programIndex,
+    required int exerciseIndex,
+    required int setIndex,
+  }) async {
+    return setTimerStates.values.where((state) {
+      return state.activeWorkoutSessionId == sessionId &&
+          state.programIndex == programIndex &&
+          state.exerciseIndex == exerciseIndex &&
+          state.setIndex == setIndex;
+    }).firstOrNull;
+  }
+
+  @override
+  Future<List<ActiveExerciseStepProgressState>> listExerciseStepProgressStates(
+    String sessionId,
+  ) async {
+    return stepProgressStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveExerciseStepResult>> listExerciseStepResults(
+    String sessionId,
+  ) async {
+    return stepResults
+        .where((result) => result.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveRestState>> listRestStates(String sessionId) async {
+    return restStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveScoreStopwatchState>> listScoreStopwatchStates(
+    String sessionId,
+  ) async {
+    return scoreStopwatchStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveSetResult>> listSetResults(String sessionId) async {
+    return results
+        .where((result) => result.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<List<ActiveSetTimerState>> listSetTimerStates(String sessionId) async {
+    return setTimerStates.values
+        .where((state) => state.activeWorkoutSessionId == sessionId)
+        .toList();
+  }
+
+  @override
+  Future<void> save(ActiveWorkoutSession session) async {
+    this.session = session;
+  }
+
+  @override
+  Future<void> saveExerciseStepProgressState(
+    ActiveExerciseStepProgressState state,
+  ) async {
+    stepProgressStates[state.metadata.id] = state;
+  }
+
+  @override
+  Future<void> saveExerciseStepResult(ActiveExerciseStepResult result) async {
+    stepResults.add(result);
+  }
+
+  @override
+  Future<void> saveRestState(ActiveRestState restState) async {
+    restStates[restState.metadata.id] = restState;
+  }
+
+  @override
+  Future<void> saveScoreStopwatchState(ActiveScoreStopwatchState state) async {
+    scoreStopwatchStates[state.metadata.id] = state;
+  }
+
+  @override
+  Future<void> saveSetResult(ActiveSetResult result) async {
+    results.add(result);
+  }
+
+  @override
+  Future<void> saveSetTimerState(ActiveSetTimerState state) async {
+    setTimerStates[state.metadata.id] = state;
+  }
+}
diff --git a/test/infrastructure/watch_bridge/wear_data_layer_adapter_test.dart b/test/infrastructure/watch_bridge/wear_data_layer_adapter_test.dart
new file mode 100644
index 0000000..f3d4794
--- /dev/null
+++ b/test/infrastructure/watch_bridge/wear_data_layer_adapter_test.dart
@@ -0,0 +1,319 @@
+import 'dart:async';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gametime/application/application.dart';
+import 'package:gametime/infrastructure/infrastructure.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+void main() {
+  test('publishes every projection revision from the source stream', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final source = _FakeProjectionSource(_projection(revision: 0));
+    final adapter = _adapter(native: native, source: source);
+    await adapter.start();
+    native.published.clear();
+
+    source.emit(_projection(revision: 1));
+    source.emit(_projection(revision: 2));
+    await Future<void>.delayed(Duration.zero);
+
+    expect(native.published.map((projection) => projection.revision), [1, 2]);
+    await adapter.stop();
+  });
+
+  test('heartbeats while a timer is running', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final source = _FakeProjectionSource(_runningProjection(revision: 1));
+    final adapter = _adapter(
+      native: native,
+      source: source,
+      heartbeatInterval: const Duration(milliseconds: 10),
+    );
+    await adapter.start();
+    native.published.clear();
+    source.emitCount = 0;
+
+    await adapter.publish(_runningProjection(revision: 1));
+    await Future<void>.delayed(const Duration(milliseconds: 35));
+
+    expect(source.emitCount, greaterThanOrEqualTo(1));
+    expect(native.published.length, greaterThanOrEqualTo(2));
+    await adapter.stop();
+  });
+
+  test('dispatches watch command and sends ack back to native layer', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final ingress = _FakeCommandIngress();
+    final source = _FakeProjectionSource(_projection(revision: 0));
+    final adapter = _adapter(native: native, ingress: ingress, source: source);
+    await adapter.start();
+
+    native.emitCommand(_command(WatchCommandType.pauseSession));
+    await Future<void>.delayed(Duration.zero);
+
+    expect(ingress.commands.single.type, WatchCommandType.pauseSession);
+    expect(native.acks.single.ack, WatchCommandAck.accepted);
+    expect(native.acks.single.revisionAtAck, 1);
+    await adapter.stop();
+  });
+
+  test('deduplicates retry before dispatching to ingress again', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final ingress = _FakeCommandIngress();
+    final source = _FakeProjectionSource(_projection(revision: 0));
+    final adapter = _adapter(native: native, ingress: ingress, source: source);
+    await adapter.start();
+    final command = _command(WatchCommandType.skipCurrentSet);
+
+    native.emitCommand(command);
+    native.emitCommand(command);
+    await Future<void>.delayed(Duration.zero);
+
+    expect(ingress.commands, hasLength(1));
+    expect(native.acks.map((ack) => ack.ack), [
+      WatchCommandAck.accepted,
+      WatchCommandAck.acceptedNoOp,
+    ]);
+    await adapter.stop();
+  });
+
+  test('emits a full resync when a watch node reconnects', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final source = _FakeProjectionSource(_projection(revision: 3));
+    final adapter = _adapter(native: native, source: source);
+    await adapter.start();
+    native.published.clear();
+    source.emitCount = 0;
+
+    native.emitConnection(
+      const WatchBridgeConnectionEvent(isReachable: true, requestsResync: true),
+    );
+    await Future<void>.delayed(Duration.zero);
+
+    expect(source.emitCount, 1);
+    expect(native.published.single.revision, 5);
+    await adapter.stop();
+  });
+
+  test('processes commands sequentially in receive order', () async {
+    final native = _FakeWatchBridgeNativeChannel();
+    final ingress = _BlockingCommandIngress();
+    final source = _FakeProjectionSource(_projection(revision: 0));
+    final adapter = _adapter(native: native, ingress: ingress, source: source);
+    await adapter.start();
+
+    native.emitCommand(_command(WatchCommandType.skipCurrentStep, id: 'first'));
+    native.emitCommand(_command(WatchCommandType.skipCurrentSet, id: 'second'));
+    await Future<void>.delayed(Duration.zero);
+
+    expect(ingress.started, ['first']);
+    ingress.completeNext();
+    await Future<void>.delayed(Duration.zero);
+
+    expect(ingress.started, ['first', 'second']);
+    ingress.completeNext();
+    await Future<void>.delayed(Duration.zero);
+
+    expect(native.acks.map((ack) => ack.command.commandId), [
+      'first',
+      'second',
+    ]);
+    await adapter.stop();
+  });
+}
+
+WatchWearDataLayerAdapter _adapter({
+  required _FakeWatchBridgeNativeChannel native,
+  WatchCommandIngress? ingress,
+  required _FakeProjectionSource source,
+  Duration heartbeatInterval = const Duration(seconds: 5),
+}) {
+  return WatchWearDataLayerAdapter(
+    nativeChannel: native,
+    commandIngress: ingress ?? _FakeCommandIngress(),
+    projectionSource: source,
+    heartbeatInterval: heartbeatInterval,
+  );
+}
+
+WatchCommandEnvelope _command(
+  WatchCommandType type, {
+  String id = 'command-1',
+}) {
+  return WatchCommandEnvelope(
+    commandId: id,
+    type: type,
+    sessionId: 'session-1',
+    expectedRevision: 1,
+    sentAtEpochMs: _now.millisecondsSinceEpoch,
+  );
+}
+
+WatchSessionProjection _projection({required int revision}) {
+  return WatchSessionProjection(
+    deviceSessionId: 'session-1',
+    revision: revision,
+    projectedAtEpochMs: _now.millisecondsSinceEpoch,
+    phase: WatchSessionPhase.ready,
+    phoneReachable: true,
+    seriesIndex: 1,
+    seriesTotal: 2,
+    exerciseName: 'Squat',
+    primaryAction: WatchPrimaryAction.startCurrentExercise,
+  );
+}
+
+WatchSessionProjection _runningProjection({required int revision}) {
+  return WatchSessionProjection(
+    deviceSessionId: 'session-1',
+    revision: revision,
+    projectedAtEpochMs: _now.millisecondsSinceEpoch,
+    phase: WatchSessionPhase.running,
+    phoneReachable: true,
+    seriesIndex: 1,
+    seriesTotal: 2,
+    exerciseName: 'Squat',
+    primaryAction: WatchPrimaryAction.pauseSession,
+    dominantTimer: WatchTimerProjection(
+      kind: WatchTimerKind.step,
+      label: 'Chrono étape',
+      displayMode: WatchTimerDisplayMode.countdown,
+      runState: WatchTimerRunState.running,
+      referenceEpochMs: _now.millisecondsSinceEpoch,
+      accumulatedMs: 0,
+      startedAtEpochMs: _now.millisecondsSinceEpoch,
+      targetMs: 30000,
+    ),
+  );
+}
+
+final _now = DateTime.utc(2026, 7, 25, 12);
+
+final class _FakeProjectionSource implements WatchProjectionSource {
+  _FakeProjectionSource(this.current);
+
+  WatchSessionProjection current;
+  var emitCount = 0;
+  final _controller = StreamController<WatchSessionProjection>.broadcast();
+
+  @override
+  Stream<WatchSessionProjection> get projections => _controller.stream;
+
+  void emit(WatchSessionProjection projection) {
+    current = projection;
+    _controller.add(projection);
+  }
+
+  @override
+  Future<WatchSessionProjection> currentProjection() async => current;
+
+  @override
+  Future<WatchSessionProjection> emitCurrentProjection() async {
+    emitCount += 1;
+    current = WatchSessionProjection(
+      deviceSessionId: current.deviceSessionId,
+      revision: current.revision + 1,
+      projectedAtEpochMs: current.projectedAtEpochMs,
+      phase: current.phase,
+      phoneReachable: current.phoneReachable,
+      seriesIndex: current.seriesIndex,
+      seriesTotal: current.seriesTotal,
+      exerciseName: current.exerciseName,
+      dominantTimer: current.dominantTimer,
+      secondaryTimers: current.secondaryTimers,
+      primaryAction: current.primaryAction,
+      secondaryActions: current.secondaryActions,
+    );
+    _controller.add(current);
+    return current;
+  }
+}
+
+final class _FakeCommandIngress implements WatchCommandIngress {
+  final commands = <WatchCommandEnvelope>[];
+
+  @override
+  Future<WatchCommandAck> dispatch(WatchCommandEnvelope command) async {
+    commands.add(command);
+    return WatchCommandAck.accepted;
+  }
+}
+
+final class _BlockingCommandIngress implements WatchCommandIngress {
+  final started = <String>[];
+  final _pending = <Completer<WatchCommandAck>>[];
+
+  @override
+  Future<WatchCommandAck> dispatch(WatchCommandEnvelope command) {
+    started.add(command.commandId);
+    final completer = Completer<WatchCommandAck>();
+    _pending.add(completer);
+    return completer.future;
+  }
+
+  void completeNext() {
+    _pending.removeAt(0).complete(WatchCommandAck.accepted);
+  }
+}
+
+final class _FakeWatchBridgeNativeChannel implements WatchBridgeNativeChannel {
+  final published = <WatchSessionProjection>[];
+  final acks = <_SentAck>[];
+  final _commands = StreamController<WatchCommandEnvelope>.broadcast();
+  final _connections = StreamController<WatchBridgeConnectionEvent>.broadcast();
+  var capabilityRefreshCount = 0;
+  var foregroundStartCount = 0;
+  var foregroundStopCount = 0;
+
+  @override
+  Stream<WatchCommandEnvelope> get commands => _commands.stream;
+
+  @override
+  Stream<WatchBridgeConnectionEvent> get connectionEvents =>
+      _connections.stream;
+
+  void emitCommand(WatchCommandEnvelope command) {
+    _commands.add(command);
+  }
+
+  void emitConnection(WatchBridgeConnectionEvent event) {
+    _connections.add(event);
+  }
+
+  @override
+  Future<void> publishProjection(WatchSessionProjection projection) async {
+    published.add(projection);
+  }
+
+  @override
+  Future<void> requestCapabilityRefresh() async {
+    capabilityRefreshCount += 1;
+  }
+
+  @override
+  Future<void> sendCommandAck(
+    WatchCommandEnvelope command,
+    WatchCommandAck ack, {
+    int? revisionAtAck,
+  }) async {
+    acks.add(_SentAck(command, ack, revisionAtAck));
+  }
+
+  @override
+  Future<void> startForegroundService() async {
+    foregroundStartCount += 1;
+  }
+
+  @override
+  Future<void> stopForegroundService() async {
+    foregroundStopCount += 1;
+  }
+}
+
+final class _SentAck {
+  const _SentAck(this.command, this.ack, this.revisionAtAck);
+
+  final WatchCommandEnvelope command;
+  final WatchCommandAck ack;
+  final int? revisionAtAck;
+}
diff --git a/watch_app/.gitignore b/watch_app/.gitignore
new file mode 100644
index 0000000..ff464d3
--- /dev/null
+++ b/watch_app/.gitignore
@@ -0,0 +1,15 @@
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+build/
+**/GeneratedPluginRegistrant.java
+**/generated_plugin_registrant.*
+android/local.properties
+android/.gradle/
+android/captures/
+android/app/debug/
+android/app/profile/
+android/app/release/
+*.iml
+.idea/
+.DS_Store
diff --git a/watch_app/analysis_options.yaml b/watch_app/analysis_options.yaml
new file mode 100644
index 0000000..5e2133e
--- /dev/null
+++ b/watch_app/analysis_options.yaml
@@ -0,0 +1 @@
+include: ../analysis_options.yaml
diff --git a/watch_app/android/app/build.gradle.kts b/watch_app/android/app/build.gradle.kts
new file mode 100644
index 0000000..4fcfa4f
--- /dev/null
+++ b/watch_app/android/app/build.gradle.kts
@@ -0,0 +1,38 @@
+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+android {
+    namespace = "com.gametime.watch"
+    compileSdk = flutter.compileSdkVersion
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    defaultConfig {
+        applicationId = "com.gametime.watch"
+        minSdk = 26
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.getByName("debug")
+        }
+    }
+}
+
+flutter {
+    source = "../.."
+}
+
+dependencies {
+    implementation("com.google.android.gms:play-services-wearable:19.0.0")
+}
diff --git a/watch_app/android/app/src/main/AndroidManifest.xml b/watch_app/android/app/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..4cc8229
--- /dev/null
+++ b/watch_app/android/app/src/main/AndroidManifest.xml
@@ -0,0 +1,54 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-feature
+        android:name="android.hardware.type.watch"
+        android:required="true" />
+
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
+
+    <application
+        android:label="GameTime"
+        android:name="${applicationName}"
+        android:icon="@drawable/ic_launcher"
+        android:theme="@style/LaunchTheme"
+        android:usesCleartextTraffic="false">
+        <uses-library
+            android:name="com.google.android.wearable"
+            android:required="true" />
+        <meta-data
+            android:name="com.google.android.wearable.standalone"
+            android:value="false" />
+        <activity
+            android:name=".MainActivity"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:exported="true"
+            android:hardwareAccelerated="true"
+            android:launchMode="singleTop"
+            android:taskAffinity=""
+            android:theme="@style/LaunchTheme"
+            android:windowSoftInputMode="adjustResize">
+            <meta-data
+                android:name="io.flutter.embedding.android.NormalTheme"
+                android:resource="@style/NormalTheme" />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
+        <service
+            android:name=".bridge.WatchBridgeListenerService"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="com.google.android.gms.wearable.DATA_CHANGED" />
+                <action android:name="com.google.android.gms.wearable.MESSAGE_RECEIVED" />
+                <action android:name="com.google.android.gms.wearable.CAPABILITY_CHANGED" />
+                <data
+                    android:host="*"
+                    android:pathPrefix="/gametime"
+                    android:scheme="wear" />
+            </intent-filter>
+        </service>
+    </application>
+</manifest>
diff --git a/watch_app/android/app/src/main/kotlin/com/gametime/watch/MainActivity.kt b/watch_app/android/app/src/main/kotlin/com/gametime/watch/MainActivity.kt
new file mode 100644
index 0000000..4ad6f1c
--- /dev/null
+++ b/watch_app/android/app/src/main/kotlin/com/gametime/watch/MainActivity.kt
@@ -0,0 +1,12 @@
+package com.gametime.watch
+
+import com.gametime.watch.bridge.WatchBridgePlugin
+import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
+
+class MainActivity : FlutterActivity() {
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+        WatchBridgePlugin.register(flutterEngine, applicationContext)
+    }
+}
diff --git a/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgeListenerService.kt b/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgeListenerService.kt
new file mode 100644
index 0000000..3577e63
--- /dev/null
+++ b/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgeListenerService.kt
@@ -0,0 +1,58 @@
+package com.gametime.watch.bridge
+
+import com.google.android.gms.wearable.CapabilityInfo
+import com.google.android.gms.wearable.DataEventBuffer
+import com.google.android.gms.wearable.MessageEvent
+import com.google.android.gms.wearable.WearableListenerService
+import org.json.JSONObject
+import java.nio.charset.StandardCharsets
+
+class WatchBridgeListenerService : WearableListenerService() {
+    override fun onDataChanged(dataEvents: DataEventBuffer) {
+        try {
+            for (event in dataEvents) {
+                WatchBridgePlugin.handleDataEvent(event)
+            }
+        } finally {
+            dataEvents.release()
+        }
+    }
+
+    override fun onMessageReceived(messageEvent: MessageEvent) {
+        if (messageEvent.path != WatchBridgePlugin.ACK_PATH) {
+            return
+        }
+        val payload = JSONObject(String(messageEvent.data, StandardCharsets.UTF_8))
+        WatchBridgePlugin.emitAck(payload.toMap())
+    }
+
+    override fun onCapabilityChanged(capabilityInfo: CapabilityInfo) {
+        if (capabilityInfo.name != WatchBridgePlugin.PHONE_CAPABILITY) {
+            return
+        }
+        WatchBridgePlugin.emitConnection(
+            isReachable = capabilityInfo.nodes.isNotEmpty(),
+            requestsResync = capabilityInfo.nodes.isNotEmpty(),
+        )
+        if (capabilityInfo.nodes.isNotEmpty()) {
+            WatchBridgePlugin.requestLatestProjection(applicationContext)
+        }
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+        WatchBridgePlugin.requestCapabilityRefresh(applicationContext)
+        WatchBridgePlugin.requestLatestProjection(applicationContext)
+    }
+}
+
+private fun JSONObject.toMap(): Map<String, Any?> {
+    val output = linkedMapOf<String, Any?>()
+    val keys = keys()
+    while (keys.hasNext()) {
+        val key = keys.next()
+        val value = get(key)
+        output[key] = if (value == JSONObject.NULL) null else value
+    }
+    return output
+}
diff --git a/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgePlugin.kt b/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgePlugin.kt
new file mode 100644
index 0000000..9529700
--- /dev/null
+++ b/watch_app/android/app/src/main/kotlin/com/gametime/watch/bridge/WatchBridgePlugin.kt
@@ -0,0 +1,242 @@
+package com.gametime.watch.bridge
+
+import android.content.Context
+import android.net.Uri
+import com.google.android.gms.wearable.CapabilityClient
+import com.google.android.gms.wearable.DataEvent
+import com.google.android.gms.wearable.DataMapItem
+import com.google.android.gms.wearable.Wearable
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.EventChannel
+import io.flutter.plugin.common.MethodCall
+import io.flutter.plugin.common.MethodChannel
+import org.json.JSONArray
+import org.json.JSONObject
+import java.nio.charset.StandardCharsets
+
+object WatchBridgePlugin {
+    private const val METHOD_CHANNEL = "gametime.watch_bridge/methods"
+    private const val PROJECTION_CHANNEL = "gametime.watch_bridge/projections"
+    private const val ACK_CHANNEL = "gametime.watch_bridge/acks"
+    private const val CONNECTION_CHANNEL = "gametime.watch_bridge/connection"
+
+    const val COMMAND_PATH = "/gametime/watch/command"
+    const val ACK_PATH = "/gametime/phone/ack"
+    const val STATE_PATH = "/gametime/phone/projection"
+    const val PHONE_CAPABILITY = "gametime_phone_companion"
+
+    private var appContext: Context? = null
+    private var projectionSink: EventChannel.EventSink? = null
+    private var ackSink: EventChannel.EventSink? = null
+    private var connectionSink: EventChannel.EventSink? = null
+
+    fun register(flutterEngine: FlutterEngine, context: Context) {
+        appContext = context.applicationContext
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, METHOD_CHANNEL)
+            .setMethodCallHandler(::handleMethodCall)
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, PROJECTION_CHANNEL)
+            .setStreamHandler(
+                object : EventChannel.StreamHandler {
+                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                        projectionSink = events
+                        requestLatestProjection(context.applicationContext)
+                    }
+
+                    override fun onCancel(arguments: Any?) {
+                        projectionSink = null
+                    }
+                },
+            )
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, ACK_CHANNEL)
+            .setStreamHandler(
+                object : EventChannel.StreamHandler {
+                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                        ackSink = events
+                    }
+
+                    override fun onCancel(arguments: Any?) {
+                        ackSink = null
+                    }
+                },
+            )
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, CONNECTION_CHANNEL)
+            .setStreamHandler(
+                object : EventChannel.StreamHandler {
+                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                        connectionSink = events
+                        requestCapabilityRefresh(context.applicationContext)
+                    }
+
+                    override fun onCancel(arguments: Any?) {
+                        connectionSink = null
+                    }
+                },
+            )
+    }
+
+    fun emitProjection(payload: Map<String, Any?>): Boolean {
+        val sink = projectionSink ?: return false
+        sink.success(payload)
+        return true
+    }
+
+    fun emitAck(payload: Map<String, Any?>): Boolean {
+        val sink = ackSink ?: return false
+        sink.success(payload)
+        return true
+    }
+
+    fun emitConnection(isReachable: Boolean, requestsResync: Boolean) {
+        connectionSink?.success(
+            mapOf(
+                "isReachable" to isReachable,
+                "requestsResync" to requestsResync,
+            ),
+        )
+    }
+
+    fun handleDataEvent(event: DataEvent) {
+        if (event.type != DataEvent.TYPE_CHANGED ||
+            event.dataItem.uri.path != STATE_PATH
+        ) {
+            return
+        }
+        val projectionJson = DataMapItem.fromDataItem(event.dataItem)
+            .dataMap
+            .getString("projectionJson")
+            ?: return
+        emitProjection(JSONObject(projectionJson).toMap())
+    }
+
+    private fun handleMethodCall(call: MethodCall, result: MethodChannel.Result) {
+        val context = appContext
+        if (context == null) {
+            result.error("watch_bridge_unavailable", "Application context unavailable.", null)
+            return
+        }
+        when (call.method) {
+            "sendCommand" -> sendCommand(context, call.arguments, result)
+            "requestCapabilityRefresh" -> {
+                requestCapabilityRefresh(context)
+                result.success(null)
+            }
+            "requestResync" -> {
+                requestLatestProjection(context)
+                requestCapabilityRefresh(context)
+                result.success(null)
+            }
+            else -> result.notImplemented()
+        }
+    }
+
+    private fun sendCommand(
+        context: Context,
+        arguments: Any?,
+        result: MethodChannel.Result,
+    ) {
+        val map = arguments as? Map<*, *>
+        if (map == null) {
+            result.error("invalid_command", "Command payload must be a map.", null)
+            return
+        }
+        val payload = JSONObject(map).toString().toByteArray(StandardCharsets.UTF_8)
+        Wearable.getCapabilityClient(context)
+            .getCapability(PHONE_CAPABILITY, CapabilityClient.FILTER_REACHABLE)
+            .addOnSuccessListener { capability ->
+                val nodes = capability.nodes.toList()
+                if (nodes.isEmpty()) {
+                    emitConnection(isReachable = false, requestsResync = false)
+                    result.error("phone_unreachable", "No reachable phone companion.", null)
+                    return@addOnSuccessListener
+                }
+                var remaining = nodes.size
+                var failed = false
+                for (node in nodes) {
+                    Wearable.getMessageClient(context)
+                        .sendMessage(node.id, COMMAND_PATH, payload)
+                        .addOnSuccessListener {
+                            remaining -= 1
+                            if (remaining == 0 && !failed) {
+                                emitConnection(isReachable = true, requestsResync = false)
+                                result.success(null)
+                            }
+                        }
+                        .addOnFailureListener { error ->
+                            if (failed) {
+                                return@addOnFailureListener
+                            }
+                            failed = true
+                            emitConnection(isReachable = false, requestsResync = false)
+                            result.error("send_command_failed", error.message, null)
+                        }
+                }
+            }
+            .addOnFailureListener { error ->
+                emitConnection(isReachable = false, requestsResync = false)
+                result.error("capability_lookup_failed", error.message, null)
+            }
+    }
+
+    fun requestCapabilityRefresh(context: Context) {
+        Wearable.getCapabilityClient(context)
+            .getCapability(PHONE_CAPABILITY, CapabilityClient.FILTER_REACHABLE)
+            .addOnSuccessListener { capability ->
+                emitConnection(
+                    isReachable = capability.nodes.isNotEmpty(),
+                    requestsResync = capability.nodes.isNotEmpty(),
+                )
+            }
+            .addOnFailureListener {
+                emitConnection(isReachable = false, requestsResync = false)
+            }
+    }
+
+    fun requestLatestProjection(context: Context) {
+        val uri = Uri.Builder()
+            .scheme("wear")
+            .path(STATE_PATH)
+            .build()
+        Wearable.getDataClient(context)
+            .getDataItems(uri)
+            .addOnSuccessListener { buffer ->
+                try {
+                    for (item in buffer) {
+                        val projectionJson = DataMapItem.fromDataItem(item)
+                            .dataMap
+                            .getString("projectionJson")
+                            ?: continue
+                        emitProjection(JSONObject(projectionJson).toMap())
+                    }
+                } finally {
+                    buffer.release()
+                }
+            }
+    }
+}
+
+private fun JSONObject.toMap(): Map<String, Any?> {
+    val output = linkedMapOf<String, Any?>()
+    val keys = keys()
+    while (keys.hasNext()) {
+        val key = keys.next()
+        output[key] = unwrapJsonValue(get(key))
+    }
+    return output
+}
+
+private fun JSONArray.toList(): List<Any?> {
+    val output = mutableListOf<Any?>()
+    for (index in 0 until length()) {
+        output.add(unwrapJsonValue(get(index)))
+    }
+    return output
+}
+
+private fun unwrapJsonValue(value: Any?): Any? {
+    return when (value) {
+        JSONObject.NULL -> null
+        is JSONObject -> value.toMap()
+        is JSONArray -> value.toList()
+        else -> value
+    }
+}
diff --git a/watch_app/android/app/src/main/res/drawable/ic_launcher.xml b/watch_app/android/app/src/main/res/drawable/ic_launcher.xml
new file mode 100644
index 0000000..c4043cc
--- /dev/null
+++ b/watch_app/android/app/src/main/res/drawable/ic_launcher.xml
@@ -0,0 +1,12 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="48dp"
+    android:height="48dp"
+    android:viewportWidth="48"
+    android:viewportHeight="48">
+    <path
+        android:fillColor="#080A12"
+        android:pathData="M24,2a22,22 0,1 0,0.1 0z" />
+    <path
+        android:fillColor="#D72638"
+        android:pathData="M13,12h22v6H22v5h11v6H22v7h-9z" />
+</vector>
diff --git a/watch_app/android/app/src/main/res/drawable/launch_background.xml b/watch_app/android/app/src/main/res/drawable/launch_background.xml
new file mode 100644
index 0000000..95584a9
--- /dev/null
+++ b/watch_app/android/app/src/main/res/drawable/launch_background.xml
@@ -0,0 +1,3 @@
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@android:color/black" />
+</layer-list>
diff --git a/watch_app/android/app/src/main/res/values-round/styles.xml b/watch_app/android/app/src/main/res/values-round/styles.xml
new file mode 100644
index 0000000..2ed69d5
--- /dev/null
+++ b/watch_app/android/app/src/main/res/values-round/styles.xml
@@ -0,0 +1,11 @@
+<resources>
+    <style name="LaunchTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
+        <item name="android:windowBackground">@drawable/launch_background</item>
+        <item name="android:windowIsTranslucent">false</item>
+    </style>
+
+    <style name="NormalTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
+        <item name="android:windowBackground">#080A12</item>
+        <item name="android:windowIsTranslucent">false</item>
+    </style>
+</resources>
diff --git a/watch_app/android/app/src/main/res/values/styles.xml b/watch_app/android/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000..15c53e4
--- /dev/null
+++ b/watch_app/android/app/src/main/res/values/styles.xml
@@ -0,0 +1,9 @@
+<resources>
+    <style name="LaunchTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+
+    <style name="NormalTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
+        <item name="android:windowBackground">#080A12</item>
+    </style>
+</resources>
diff --git a/watch_app/android/app/src/main/res/values/wear.xml b/watch_app/android/app/src/main/res/values/wear.xml
new file mode 100644
index 0000000..d4cf88d
--- /dev/null
+++ b/watch_app/android/app/src/main/res/values/wear.xml
@@ -0,0 +1,5 @@
+<resources>
+    <string-array name="android_wear_capabilities">
+        <item>gametime_watch_companion</item>
+    </string-array>
+</resources>
diff --git a/watch_app/android/build.gradle.kts b/watch_app/android/build.gradle.kts
new file mode 100644
index 0000000..c410017
--- /dev/null
+++ b/watch_app/android/build.gradle.kts
@@ -0,0 +1,25 @@
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+val newBuildDir: Directory =
+    rootProject.layout.buildDirectory
+        .dir("../../build/watch_app")
+        .get()
+rootProject.layout.buildDirectory.value(newBuildDir)
+
+subprojects {
+    val newSubprojectBuildDir: Directory = newBuildDir.dir(project.name)
+    project.layout.buildDirectory.value(newSubprojectBuildDir)
+}
+
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
+tasks.register<Delete>("clean") {
+    delete(rootProject.layout.buildDirectory)
+}
diff --git a/watch_app/android/gradle/wrapper/gradle-wrapper.jar b/watch_app/android/gradle/wrapper/gradle-wrapper.jar
new file mode 100755
index 0000000..13372ae
Binary files /dev/null and b/watch_app/android/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/watch_app/android/gradle/wrapper/gradle-wrapper.properties b/watch_app/android/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..2d428bf
--- /dev/null
+++ b/watch_app/android/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-all.zip
diff --git a/watch_app/android/gradlew b/watch_app/android/gradlew
new file mode 100755
index 0000000..9d82f78
--- /dev/null
+++ b/watch_app/android/gradlew
@@ -0,0 +1,160 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+esac
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+    JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"
diff --git a/watch_app/android/gradlew.bat b/watch_app/android/gradlew.bat
new file mode 100755
index 0000000..aec9973
--- /dev/null
+++ b/watch_app/android/gradlew.bat
@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/watch_app/android/settings.gradle.kts b/watch_app/android/settings.gradle.kts
new file mode 100644
index 0000000..c21f0c5
--- /dev/null
+++ b/watch_app/android/settings.gradle.kts
@@ -0,0 +1,26 @@
+pluginManagement {
+    val flutterSdkPath =
+        run {
+            val properties = java.util.Properties()
+            file("local.properties").inputStream().use { properties.load(it) }
+            val flutterSdkPath = properties.getProperty("flutter.sdk")
+            require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+            flutterSdkPath
+        }
+
+    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("dev.flutter.flutter-plugin-loader") version "1.0.0"
+    id("com.android.application") version "9.0.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.3.20" apply false
+}
+
+include(":app")
diff --git a/watch_app/lib/application/watch_session_view_model.dart b/watch_app/lib/application/watch_session_view_model.dart
new file mode 100644
index 0000000..011b4ea
--- /dev/null
+++ b/watch_app/lib/application/watch_session_view_model.dart
@@ -0,0 +1,285 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+import '../infrastructure/watch_bridge/native_watch_bridge_client.dart';
+
+final class WatchSessionUiState {
+  const WatchSessionUiState({
+    required this.projection,
+    this.commandPending = false,
+    this.waitingForPhone = false,
+    this.connectionLost = false,
+    this.staleProjection = false,
+    this.lastAck,
+  });
+
+  final WatchSessionProjection projection;
+  final bool commandPending;
+  final bool waitingForPhone;
+  final bool connectionLost;
+  final bool staleProjection;
+  final WatchCommandAckEvent? lastAck;
+
+  bool get actionsEnabled => !commandPending && !connectionLost;
+
+  WatchSessionUiState copyWith({
+    WatchSessionProjection? projection,
+    bool? commandPending,
+    bool? waitingForPhone,
+    bool? connectionLost,
+    bool? staleProjection,
+    WatchCommandAckEvent? lastAck,
+  }) {
+    return WatchSessionUiState(
+      projection: projection ?? this.projection,
+      commandPending: commandPending ?? this.commandPending,
+      waitingForPhone: waitingForPhone ?? this.waitingForPhone,
+      connectionLost: connectionLost ?? this.connectionLost,
+      staleProjection: staleProjection ?? this.staleProjection,
+      lastAck: lastAck ?? this.lastAck,
+    );
+  }
+}
+
+final class WatchSessionViewModel extends ValueNotifier<WatchSessionUiState> {
+  WatchSessionViewModel({
+    NativeWatchBridgeClient nativeClient =
+        const MethodChannelNativeWatchBridgeClient(),
+    Duration waitingThreshold = const Duration(milliseconds: 500),
+    Duration commandTimeout = const Duration(seconds: 2),
+    Duration staleProjectionThreshold = const Duration(seconds: 6),
+    Duration connectionLostThreshold = const Duration(seconds: 10),
+  }) : _nativeClient = nativeClient,
+       _waitingThreshold = waitingThreshold,
+       _commandTimeout = commandTimeout,
+       _staleProjectionThreshold = staleProjectionThreshold,
+       _connectionLostThreshold = connectionLostThreshold,
+       super(WatchSessionUiState(projection: _initialProjection())) {
+    _subscriptions.add(_nativeClient.projections.listen(_handleProjection));
+    _subscriptions.add(_nativeClient.acks.listen(_handleAck));
+    _subscriptions.add(
+      _nativeClient.connectionEvents.listen(_handleConnectionEvent),
+    );
+    unawaited(_nativeClient.requestCapabilityRefresh());
+    unawaited(_nativeClient.requestResync());
+    _freshnessTimer = Timer.periodic(const Duration(seconds: 1), (_) {
+      _syncFreshnessState();
+    });
+  }
+
+  final NativeWatchBridgeClient _nativeClient;
+  final Duration _waitingThreshold;
+  final Duration _commandTimeout;
+  final Duration _staleProjectionThreshold;
+  final Duration _connectionLostThreshold;
+  final _subscriptions = <StreamSubscription<dynamic>>[];
+
+  Timer? _waitingTimer;
+  Timer? _commandTimeoutTimer;
+  Timer? _freshnessTimer;
+  WatchCommandEnvelope? _pendingCommand;
+  DateTime? _lastProjectionReceivedAt;
+  var _commandCounter = 0;
+
+  Future<void> refresh() async {
+    value = value.copyWith(connectionLost: false);
+    try {
+      await _nativeClient.requestCapabilityRefresh();
+      await _nativeClient.requestResync();
+    } on PlatformException {
+      value = value.copyWith(connectionLost: true);
+      unawaited(HapticFeedback.heavyImpact());
+    }
+  }
+
+  Future<void> sendPrimaryAction() async {
+    final action = value.projection.primaryAction;
+    final command = switch (action) {
+      WatchPrimaryAction.none => null,
+      WatchPrimaryAction.startCurrentExercise =>
+        WatchCommandType.startCurrentExercise,
+      WatchPrimaryAction.pauseSession => WatchCommandType.pauseSession,
+      WatchPrimaryAction.resumeSession => WatchCommandType.resumeSession,
+      WatchPrimaryAction.startPreparedTimedStep =>
+        WatchCommandType.startPreparedTimedStep,
+      WatchPrimaryAction.skipCurrentRest => WatchCommandType.skipCurrentRest,
+    };
+    if (command == null) {
+      await refresh();
+      return;
+    }
+    await _sendCommand(command);
+  }
+
+  Future<void> sendSecondaryAction(WatchSecondaryAction action) {
+    final command = switch (action) {
+      WatchSecondaryAction.skipCurrentStep => WatchCommandType.skipCurrentStep,
+      WatchSecondaryAction.skipCurrentPassage =>
+        WatchCommandType.skipCurrentPassage,
+      WatchSecondaryAction.finishCurrentSet => WatchCommandType.finishCurrentSet,
+      WatchSecondaryAction.skipCurrentSet => WatchCommandType.skipCurrentSet,
+      WatchSecondaryAction.skipCurrentRest => WatchCommandType.skipCurrentRest,
+    };
+    return _sendCommand(command);
+  }
+
+  @override
+  void dispose() {
+    _waitingTimer?.cancel();
+    _commandTimeoutTimer?.cancel();
+    _freshnessTimer?.cancel();
+    for (final subscription in _subscriptions) {
+      unawaited(subscription.cancel());
+    }
+    super.dispose();
+  }
+
+  Future<void> _sendCommand(WatchCommandType type) async {
+    if (!value.actionsEnabled || value.projection.deviceSessionId.isEmpty) {
+      return;
+    }
+    final nowMs = DateTime.now().toUtc().millisecondsSinceEpoch;
+    final command = WatchCommandEnvelope(
+      commandId: 'watch-$nowMs-${_commandCounter++}',
+      type: type,
+      sessionId: value.projection.deviceSessionId,
+      expectedRevision: value.projection.revision,
+      sentAtEpochMs: nowMs,
+    );
+    _pendingCommand = command;
+    value = value.copyWith(
+      commandPending: true,
+      waitingForPhone: false,
+      connectionLost: false,
+    );
+    _waitingTimer?.cancel();
+    _commandTimeoutTimer?.cancel();
+    _waitingTimer = Timer(_waitingThreshold, () {
+      value = value.copyWith(waitingForPhone: true);
+    });
+    _commandTimeoutTimer = Timer(_commandTimeout, () {
+      _pendingCommand = null;
+      value = value.copyWith(
+        commandPending: false,
+        waitingForPhone: false,
+        connectionLost: true,
+      );
+      unawaited(HapticFeedback.heavyImpact());
+    });
+    try {
+      await _nativeClient.sendCommand(command);
+    } on PlatformException {
+      _pendingCommand = null;
+      _clearCommandTimers();
+      value = value.copyWith(
+        commandPending: false,
+        waitingForPhone: false,
+        connectionLost: true,
+      );
+      unawaited(HapticFeedback.heavyImpact());
+    }
+  }
+
+  void _handleProjection(WatchSessionProjection projection) {
+    final previousProjection = value.projection;
+    _lastProjectionReceivedAt = DateTime.now();
+    _pendingCommand = null;
+    _clearCommandTimers();
+    value = WatchSessionUiState(
+      projection: projection,
+      lastAck: value.lastAck,
+    );
+    _triggerProjectionHaptic(previousProjection, projection);
+  }
+
+  void _handleAck(WatchCommandAckEvent ack) {
+    if (_pendingCommand?.commandId != ack.commandId) {
+      value = value.copyWith(lastAck: ack);
+      return;
+    }
+    _waitingTimer?.cancel();
+    value = value.copyWith(
+      waitingForPhone: false,
+      connectionLost: false,
+      lastAck: ack,
+    );
+    unawaited(HapticFeedback.lightImpact());
+    if (_isRejected(ack.status)) {
+      _pendingCommand = null;
+      _clearCommandTimers();
+      value = value.copyWith(commandPending: false);
+      unawaited(_nativeClient.requestResync());
+    }
+  }
+
+  void _handleConnectionEvent(WatchBridgeConnectionEvent event) {
+    value = value.copyWith(connectionLost: !event.isReachable);
+    if (event.isReachable || event.requestsResync) {
+      unawaited(_nativeClient.requestResync());
+    }
+  }
+
+  void _syncFreshnessState() {
+    final receivedAt = _lastProjectionReceivedAt;
+    if (receivedAt == null) {
+      return;
+    }
+    final age = DateTime.now().difference(receivedAt);
+    final stale = age >= _staleProjectionThreshold;
+    final lost = age >= _connectionLostThreshold;
+    if (stale != value.staleProjection || lost != value.connectionLost) {
+      value = value.copyWith(staleProjection: stale, connectionLost: lost);
+    }
+  }
+
+  void _clearCommandTimers() {
+    _waitingTimer?.cancel();
+    _waitingTimer = null;
+    _commandTimeoutTimer?.cancel();
+    _commandTimeoutTimer = null;
+  }
+
+  void _triggerProjectionHaptic(
+    WatchSessionProjection previous,
+    WatchSessionProjection current,
+  ) {
+    final phaseChanged = previous.phase != current.phase;
+    final enteredReadyTimer = current.phase == WatchSessionPhase.nextTimerReady &&
+        previous.phase != WatchSessionPhase.nextTimerReady;
+    final enteredRestEnd =
+        previous.phase == WatchSessionPhase.restRunning &&
+        current.phase != WatchSessionPhase.restRunning &&
+        current.phase != WatchSessionPhase.restPaused;
+    if (phaseChanged && (enteredReadyTimer || enteredRestEnd)) {
+      unawaited(HapticFeedback.mediumImpact());
+      unawaited(Future<void>.delayed(const Duration(milliseconds: 120), () {
+        return HapticFeedback.mediumImpact();
+      }));
+    }
+  }
+}
+
+bool _isRejected(WatchCommandAck ack) {
+  return switch (ack) {
+    WatchCommandAck.accepted || WatchCommandAck.acceptedNoOp => false,
+    _ => true,
+  };
+}
+
+WatchSessionProjection _initialProjection() {
+  return WatchSessionProjection(
+    deviceSessionId: '',
+    revision: 0,
+    projectedAtEpochMs: DateTime.now().toUtc().millisecondsSinceEpoch,
+    phase: WatchSessionPhase.noActiveSession,
+    phoneReachable: false,
+    seriesIndex: 0,
+    seriesTotal: 0,
+    exerciseName: '',
+    primaryAction: WatchPrimaryAction.none,
+    statusLabel: 'Téléphone indisponible',
+  );
+}
diff --git a/watch_app/lib/infrastructure/watch_bridge/native_watch_bridge_client.dart b/watch_app/lib/infrastructure/watch_bridge/native_watch_bridge_client.dart
new file mode 100644
index 0000000..a2b924b
--- /dev/null
+++ b/watch_app/lib/infrastructure/watch_bridge/native_watch_bridge_client.dart
@@ -0,0 +1,159 @@
+import 'package:flutter/services.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+final class WatchBridgeConnectionEvent {
+  const WatchBridgeConnectionEvent({
+    required this.isReachable,
+    this.requestsResync = false,
+  });
+
+  final bool isReachable;
+  final bool requestsResync;
+}
+
+final class WatchCommandAckEvent {
+  const WatchCommandAckEvent({
+    required this.commandId,
+    required this.status,
+    required this.sessionId,
+    this.revisionAtAck,
+    this.reasonCode,
+  });
+
+  final String commandId;
+  final WatchCommandAck status;
+  final String sessionId;
+  final int? revisionAtAck;
+  final String? reasonCode;
+}
+
+abstract interface class NativeWatchBridgeClient {
+  Stream<WatchSessionProjection> get projections;
+
+  Stream<WatchCommandAckEvent> get acks;
+
+  Stream<WatchBridgeConnectionEvent> get connectionEvents;
+
+  Future<void> sendCommand(WatchCommandEnvelope command);
+
+  Future<void> requestResync();
+
+  Future<void> requestCapabilityRefresh();
+}
+
+final class MethodChannelNativeWatchBridgeClient
+    implements NativeWatchBridgeClient {
+  const MethodChannelNativeWatchBridgeClient({
+    MethodChannel methodChannel = const MethodChannel(_methodChannelName),
+    EventChannel projectionChannel = const EventChannel(
+      _projectionChannelName,
+    ),
+    EventChannel ackChannel = const EventChannel(_ackChannelName),
+    EventChannel connectionChannel = const EventChannel(
+      _connectionChannelName,
+    ),
+  }) : _methodChannel = methodChannel,
+       _projectionChannel = projectionChannel,
+       _ackChannel = ackChannel,
+       _connectionChannel = connectionChannel;
+
+  static const _methodChannelName = 'gametime.watch_bridge/methods';
+  static const _projectionChannelName = 'gametime.watch_bridge/projections';
+  static const _ackChannelName = 'gametime.watch_bridge/acks';
+  static const _connectionChannelName = 'gametime.watch_bridge/connection';
+
+  final MethodChannel _methodChannel;
+  final EventChannel _projectionChannel;
+  final EventChannel _ackChannel;
+  final EventChannel _connectionChannel;
+
+  @override
+  Stream<WatchSessionProjection> get projections {
+    return _projectionChannel
+        .receiveBroadcastStream()
+        .where((event) => event is Map)
+        .map((event) {
+          return WatchSessionProjection.fromJson(_stringObjectMap(event));
+        });
+  }
+
+  @override
+  Stream<WatchCommandAckEvent> get acks {
+    return _ackChannel
+        .receiveBroadcastStream()
+        .where((event) => event is Map)
+        .map((event) {
+          final json = _stringObjectMap(event);
+          return WatchCommandAckEvent(
+            commandId: _stringFromJson(json['commandId']),
+            status: _enumFromJson(
+              json['status'],
+              WatchCommandAck.values,
+              WatchCommandAck.rejectedPhoneBusy,
+            ),
+            sessionId: _stringFromJson(json['sessionId']),
+            revisionAtAck: _nullableIntFromJson(json['revisionAtAck']),
+            reasonCode: _nullableStringFromJson(json['reasonCode']),
+          );
+        });
+  }
+
+  @override
+  Stream<WatchBridgeConnectionEvent> get connectionEvents {
+    return _connectionChannel
+        .receiveBroadcastStream()
+        .where((event) => event is Map)
+        .map((event) {
+          final json = _stringObjectMap(event);
+          return WatchBridgeConnectionEvent(
+            isReachable: json['isReachable'] == true,
+            requestsResync: json['requestsResync'] == true,
+          );
+        });
+  }
+
+  @override
+  Future<void> sendCommand(WatchCommandEnvelope command) {
+    return _methodChannel.invokeMethod<void>('sendCommand', command.toJson());
+  }
+
+  @override
+  Future<void> requestCapabilityRefresh() {
+    return _methodChannel.invokeMethod<void>('requestCapabilityRefresh');
+  }
+
+  @override
+  Future<void> requestResync() {
+    return _methodChannel.invokeMethod<void>('requestResync');
+  }
+}
+
+Map<String, Object?> _stringObjectMap(Object? value) {
+  if (value is Map) {
+    return value.map((key, value) => MapEntry(key.toString(), value));
+  }
+  return const {};
+}
+
+String _stringFromJson(Object? value) {
+  return value is String ? value : '';
+}
+
+String? _nullableStringFromJson(Object? value) {
+  return value is String ? value : null;
+}
+
+int? _nullableIntFromJson(Object? value) {
+  return value is int ? value : value is num ? value.toInt() : null;
+}
+
+T _enumFromJson<T extends Enum>(Object? value, List<T> values, T fallback) {
+  if (value is String) {
+    for (final enumValue in values) {
+      if (enumValue.name == value) {
+        return enumValue;
+      }
+    }
+  }
+  return fallback;
+}
diff --git a/watch_app/lib/main.dart b/watch_app/lib/main.dart
new file mode 100644
index 0000000..5e8d23b
--- /dev/null
+++ b/watch_app/lib/main.dart
@@ -0,0 +1,7 @@
+import 'package:flutter/material.dart';
+
+import 'presentation/watch_session_app.dart';
+
+void main() {
+  runApp(const WatchSessionApp());
+}
diff --git a/watch_app/lib/presentation/watch_session_app.dart b/watch_app/lib/presentation/watch_session_app.dart
new file mode 100644
index 0000000..6f1da18
--- /dev/null
+++ b/watch_app/lib/presentation/watch_session_app.dart
@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+
+import '../application/watch_session_view_model.dart';
+import 'watch_session_screen.dart';
+import 'watch_theme.dart';
+
+final class WatchSessionApp extends StatefulWidget {
+  const WatchSessionApp({super.key});
+
+  @override
+  State<WatchSessionApp> createState() => _WatchSessionAppState();
+}
+
+final class _WatchSessionAppState extends State<WatchSessionApp> {
+  late final WatchSessionViewModel _viewModel;
+
+  @override
+  void initState() {
+    super.initState();
+    _viewModel = WatchSessionViewModel();
+  }
+
+  @override
+  void dispose() {
+    _viewModel.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      debugShowCheckedModeBanner: false,
+      title: 'GameTime',
+      theme: watchTheme(),
+      home: WatchSessionScreen(viewModel: _viewModel),
+    );
+  }
+}
diff --git a/watch_app/lib/presentation/watch_session_screen.dart b/watch_app/lib/presentation/watch_session_screen.dart
new file mode 100644
index 0000000..8f865f2
--- /dev/null
+++ b/watch_app/lib/presentation/watch_session_screen.dart
@@ -0,0 +1,549 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:watch_bridge_contract/watch_bridge_contract.dart';
+
+import '../application/watch_session_view_model.dart';
+
+final class WatchSessionScreen extends StatefulWidget {
+  const WatchSessionScreen({required this.viewModel, super.key});
+
+  final WatchSessionViewModel viewModel;
+
+  @override
+  State<WatchSessionScreen> createState() => _WatchSessionScreenState();
+}
+
+final class _WatchSessionScreenState extends State<WatchSessionScreen> {
+  late final PageController _pageController;
+  Timer? _ticker;
+
+  @override
+  void initState() {
+    super.initState();
+    _pageController = PageController();
+    _ticker = Timer.periodic(const Duration(seconds: 1), (_) {
+      if (mounted) {
+        setState(() {});
+      }
+    });
+  }
+
+  @override
+  void dispose() {
+    _ticker?.cancel();
+    _pageController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ValueListenableBuilder<WatchSessionUiState>(
+      valueListenable: widget.viewModel,
+      builder: (context, state, _) {
+        final projection = state.projection;
+        if (projection.phase == WatchSessionPhase.noActiveSession) {
+          return _RoundScaffold(
+            child: _NoSessionView(
+              projection: projection,
+              pending: state.commandPending,
+              onRefresh: widget.viewModel.refresh,
+            ),
+          );
+        }
+        return PageView(
+          controller: _pageController,
+          children: [
+            _RoundScaffold(
+              child: _SessionMainView(
+                state: state,
+                onPrimary: widget.viewModel.sendPrimaryAction,
+                onRetry: widget.viewModel.refresh,
+                onActions: _showActions,
+              ),
+            ),
+            _RoundScaffold(
+              child: _ActionsView(
+                state: state,
+                onAction: _handleSecondaryAction,
+                onSession: _showSession,
+              ),
+            ),
+          ],
+        );
+      },
+    );
+  }
+
+  void _showActions() {
+    _pageController.animateToPage(
+      1,
+      duration: const Duration(milliseconds: 180),
+      curve: Curves.easeOut,
+    );
+  }
+
+  void _showSession() {
+    _pageController.animateToPage(
+      0,
+      duration: const Duration(milliseconds: 180),
+      curve: Curves.easeOut,
+    );
+  }
+
+  Future<void> _handleSecondaryAction(WatchSecondaryAction action) async {
+    final confirmed = switch (action) {
+      WatchSecondaryAction.skipCurrentPassage => await _confirm(
+        title: 'Passer le passage ?',
+        message: "L'étape en cours sera ignorée.",
+        confirmLabel: 'Passer',
+      ),
+      WatchSecondaryAction.skipCurrentSet => await _confirm(
+        title: 'Passer la série ?',
+        message: 'Le chrono en cours sera ignoré.',
+        confirmLabel: 'Passer',
+      ),
+      _ => true,
+    };
+    if (confirmed && mounted) {
+      unawaited(widget.viewModel.sendSecondaryAction(action));
+      _showSession();
+    }
+  }
+
+  Future<bool> _confirm({
+    required String title,
+    required String message,
+    required String confirmLabel,
+  }) async {
+    final result = await showDialog<bool>(
+      context: context,
+      builder: (context) {
+        return AlertDialog(
+          title: Text(title),
+          content: Text(message),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.of(context).pop(false),
+              child: const Text('Annuler'),
+            ),
+            FilledButton(
+              onPressed: () => Navigator.of(context).pop(true),
+              child: Text(confirmLabel),
+            ),
+          ],
+        );
+      },
+    );
+    return result ?? false;
+  }
+}
+
+final class _RoundScaffold extends StatelessWidget {
+  const _RoundScaffold({required this.child});
+
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: SafeArea(
+        minimum: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
+        child: Center(
+          child: ConstrainedBox(
+            constraints: const BoxConstraints(maxWidth: 210, maxHeight: 210),
+            child: child,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+final class _NoSessionView extends StatelessWidget {
+  const _NoSessionView({
+    required this.projection,
+    required this.pending,
+    required this.onRefresh,
+  });
+
+  final WatchSessionProjection projection;
+  final bool pending;
+  final VoidCallback onRefresh;
+
+  @override
+  Widget build(BuildContext context) {
+    final phoneReachable = projection.phoneReachable;
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: [
+        Text(
+          phoneReachable ? 'Aucune séance en cours' : 'Téléphone indisponible',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.titleSmall,
+        ),
+        const SizedBox(height: 10),
+        Text(
+          phoneReachable
+              ? 'Lance une séance sur le téléphone.'
+              : 'Rouvre GameTime sur le téléphone.',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.bodySmall,
+        ),
+        const SizedBox(height: 16),
+        FilledButton(
+          onPressed: pending ? null : onRefresh,
+          child: Text(pending ? 'Envoi...' : 'Actualiser'),
+        ),
+      ],
+    );
+  }
+}
+
+final class _SessionMainView extends StatelessWidget {
+  const _SessionMainView({
+    required this.state,
+    required this.onPrimary,
+    required this.onRetry,
+    required this.onActions,
+  });
+
+  final WatchSessionUiState state;
+  final VoidCallback onPrimary;
+  final VoidCallback onRetry;
+  final VoidCallback onActions;
+
+  @override
+  Widget build(BuildContext context) {
+    final projection = state.projection;
+    final isRest = projection.phase == WatchSessionPhase.restRunning ||
+        projection.phase == WatchSessionPhase.restPaused;
+    if (state.connectionLost || !projection.phoneReachable) {
+      return _ConnectionLostView(onRetry: onRetry);
+    }
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Align(
+          alignment: Alignment.centerRight,
+          child: TextButton(
+            onPressed: onActions,
+            style: TextButton.styleFrom(
+              visualDensity: VisualDensity.compact,
+              minimumSize: const Size(56, 26),
+              padding: const EdgeInsets.symmetric(horizontal: 8),
+            ),
+            child: const Text('Actions'),
+          ),
+        ),
+        Expanded(
+          child: isRest
+              ? _RestContent(projection: projection)
+              : _ActiveContent(projection: projection),
+        ),
+        if (state.staleProjection)
+          Padding(
+            padding: const EdgeInsets.only(bottom: 4),
+            child: Text(
+              'Dernier état reçu',
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+        FilledButton(
+          onPressed: state.actionsEnabled ? onPrimary : null,
+          child: Text(_primaryLabel(state)),
+        ),
+      ],
+    );
+  }
+}
+
+final class _ActiveContent extends StatelessWidget {
+  const _ActiveContent({required this.projection});
+
+  final WatchSessionProjection projection;
+
+  @override
+  Widget build(BuildContext context) {
+    final timer = projection.dominantTimer;
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: [
+        Text(
+          'SÉRIE ${projection.seriesIndex} / ${projection.seriesTotal}',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.labelSmall,
+        ),
+        const SizedBox(height: 3),
+        Text(
+          projection.exerciseName,
+          maxLines: 2,
+          overflow: TextOverflow.ellipsis,
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.titleSmall,
+        ),
+        if (_contextLine(projection) case final contextLine?)
+          Padding(
+            padding: const EdgeInsets.only(top: 4),
+            child: Text(
+              contextLine,
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+        const SizedBox(height: 8),
+        if (timer == null)
+          Text(
+            projection.statusLabel ?? '',
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.bodyMedium,
+          )
+        else ...[
+          Text(
+            _timerText(timer),
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.displayLarge,
+          ),
+          Text(
+            projection.statusLabel ?? timer.label,
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+        ],
+        if (projection.secondaryTimers.isNotEmpty)
+          Padding(
+            padding: const EdgeInsets.only(top: 7),
+            child: Text(
+              projection.secondaryTimers.map(_compactTimerText).join(' · '),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+      ],
+    );
+  }
+}
+
+final class _RestContent extends StatelessWidget {
+  const _RestContent({required this.projection});
+
+  final WatchSessionProjection projection;
+
+  @override
+  Widget build(BuildContext context) {
+    final timer = projection.dominantTimer;
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: [
+        Text(
+          'REPOS',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.labelSmall,
+        ),
+        const SizedBox(height: 3),
+        Text(
+          'Après série ${projection.seriesIndex} / ${projection.seriesTotal}',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.bodySmall,
+        ),
+        const SizedBox(height: 10),
+        Text(
+          timer == null ? '--:--' : _timerText(timer),
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.displayLarge,
+        ),
+        Text(
+          projection.statusLabel ?? timer?.label ?? '',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.bodySmall,
+        ),
+        if (projection.nextExerciseName case final next?)
+          Padding(
+            padding: const EdgeInsets.only(top: 9),
+            child: Column(
+              children: [
+                Text(
+                  'Exercice suivant',
+                  textAlign: TextAlign.center,
+                  style: Theme.of(context).textTheme.bodySmall,
+                ),
+                Text(
+                  next,
+                  maxLines: 1,
+                  overflow: TextOverflow.ellipsis,
+                  textAlign: TextAlign.center,
+                  style: Theme.of(context).textTheme.bodyMedium,
+                ),
+              ],
+            ),
+          ),
+      ],
+    );
+  }
+}
+
+final class _ActionsView extends StatelessWidget {
+  const _ActionsView({
+    required this.state,
+    required this.onAction,
+    required this.onSession,
+  });
+
+  final WatchSessionUiState state;
+  final ValueChanged<WatchSecondaryAction> onAction;
+  final VoidCallback onSession;
+
+  @override
+  Widget build(BuildContext context) {
+    final actions = state.projection.secondaryActions;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Row(
+          children: [
+            Expanded(
+              child: Text(
+                'Actions',
+                style: Theme.of(context).textTheme.titleSmall,
+              ),
+            ),
+            IconButton(
+              onPressed: onSession,
+              tooltip: 'Séance',
+              visualDensity: VisualDensity.compact,
+              icon: const Icon(Icons.chevron_left),
+            ),
+          ],
+        ),
+        Expanded(
+          child: actions.isEmpty || !state.projection.phoneReachable ||
+                  state.connectionLost
+              ? Center(
+                  child: Text(
+                    state.projection.phoneReachable && !state.connectionLost
+                        ? 'Aucune action'
+                        : 'Connexion perdue',
+                    textAlign: TextAlign.center,
+                    style: Theme.of(context).textTheme.bodySmall,
+                  ),
+                )
+              : ListView.separated(
+                  padding: const EdgeInsets.only(top: 4, bottom: 12),
+                  itemBuilder: (context, index) {
+                    final action = actions[index];
+                    return OutlinedButton(
+                      onPressed: state.actionsEnabled
+                          ? () => onAction(action)
+                          : null,
+                      child: Text(_secondaryLabel(action)),
+                    );
+                  },
+                  separatorBuilder: (_, _) => const SizedBox(height: 8),
+                  itemCount: actions.length,
+                ),
+        ),
+      ],
+    );
+  }
+}
+
+final class _ConnectionLostView extends StatelessWidget {
+  const _ConnectionLostView({required this.onRetry});
+
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Text(
+          'Connexion perdue',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.titleSmall,
+        ),
+        const SizedBox(height: 8),
+        Text(
+          'Dernier état reçu il y a quelques secondes',
+          textAlign: TextAlign.center,
+          style: Theme.of(context).textTheme.bodySmall,
+        ),
+        const SizedBox(height: 16),
+        FilledButton(onPressed: onRetry, child: const Text('Réessayer')),
+      ],
+    );
+  }
+}
+
+String _primaryLabel(WatchSessionUiState state) {
+  if (state.commandPending) {
+    return state.waitingForPhone ? 'En attente du téléphone' : 'Envoi...';
+  }
+  return switch (state.projection.primaryAction) {
+    WatchPrimaryAction.none => 'Actualiser',
+    WatchPrimaryAction.startCurrentExercise => 'Démarrer l’exercice',
+    WatchPrimaryAction.pauseSession => 'Pause',
+    WatchPrimaryAction.resumeSession => 'Reprendre',
+    WatchPrimaryAction.startPreparedTimedStep => 'Démarrer le chrono',
+    WatchPrimaryAction.skipCurrentRest => 'Passer le repos',
+  };
+}
+
+String _secondaryLabel(WatchSecondaryAction action) {
+  return switch (action) {
+    WatchSecondaryAction.skipCurrentStep => 'Passer l’étape',
+    WatchSecondaryAction.skipCurrentPassage => 'Passer le passage',
+    WatchSecondaryAction.finishCurrentSet => 'Terminer la série',
+    WatchSecondaryAction.skipCurrentSet => 'Passer la série',
+    WatchSecondaryAction.skipCurrentRest => 'Passer le repos',
+  };
+}
+
+String? _contextLine(WatchSessionProjection projection) {
+  final parts = [
+    if (projection.passageIndex != null && projection.passageTotal != null)
+      'Passage ${projection.passageIndex} / ${projection.passageTotal}',
+    if (projection.stepIndex != null && projection.stepTotal != null)
+      'Étape ${projection.stepIndex} / ${projection.stepTotal}',
+  ];
+  if (parts.isEmpty) {
+    return null;
+  }
+  return parts.join(' · ');
+}
+
+String _timerText(WatchTimerProjection timer) {
+  final duration = _displayDuration(timer);
+  final totalSeconds = duration.inSeconds;
+  final minutes = (totalSeconds ~/ 60).toString().padLeft(2, '0');
+  final seconds = (totalSeconds % 60).toString().padLeft(2, '0');
+  return '$minutes:$seconds';
+}
+
+String _compactTimerText(WatchTimerProjection timer) {
+  return '${timer.label} ${_timerText(timer)}';
+}
+
+Duration _displayDuration(WatchTimerProjection timer) {
+  final elapsedMs = _interpolatedElapsedMs(timer);
+  final displayMs = switch (timer.displayMode) {
+    WatchTimerDisplayMode.elapsed => elapsedMs,
+    WatchTimerDisplayMode.countdown => (timer.targetMs ?? 0) - elapsedMs,
+  };
+  return Duration(milliseconds: displayMs < 0 ? 0 : displayMs);
+}
+
+int _interpolatedElapsedMs(WatchTimerProjection timer) {
+  if (timer.runState != WatchTimerRunState.running ||
+      timer.startedAtEpochMs == null) {
+    return timer.accumulatedMs;
+  }
+  final nowMs = DateTime.now().millisecondsSinceEpoch;
+  return timer.accumulatedMs + nowMs - timer.startedAtEpochMs!;
+}
diff --git a/watch_app/lib/presentation/watch_theme.dart b/watch_app/lib/presentation/watch_theme.dart
new file mode 100644
index 0000000..e1154d6
--- /dev/null
+++ b/watch_app/lib/presentation/watch_theme.dart
@@ -0,0 +1,71 @@
+import 'package:flutter/material.dart';
+
+ThemeData watchTheme() {
+  const background = Color(0xFF080A12);
+  const surface = Color(0xFF141824);
+  const text = Color(0xFFF5F1E8);
+  const muted = Color(0xFFA7ADBA);
+  const accent = Color(0xFFD72638);
+
+  final textTheme = Typography.whiteMountainView.copyWith(
+    labelSmall: const TextStyle(
+      fontSize: 10,
+      fontWeight: FontWeight.w800,
+      color: muted,
+    ),
+    bodySmall: const TextStyle(fontSize: 11, color: muted, height: 1.15),
+    bodyMedium: const TextStyle(fontSize: 13, color: text, height: 1.15),
+    titleSmall: const TextStyle(
+      fontSize: 16,
+      fontWeight: FontWeight.w800,
+      color: text,
+      height: 1.05,
+    ),
+    displayLarge: const TextStyle(
+      fontSize: 44,
+      fontWeight: FontWeight.w900,
+      color: text,
+      height: 0.95,
+      fontFeatures: [FontFeature.tabularFigures()],
+    ),
+  );
+
+  return ThemeData(
+    useMaterial3: true,
+    brightness: Brightness.dark,
+    scaffoldBackgroundColor: background,
+    colorScheme: const ColorScheme.dark(
+      primary: accent,
+      onPrimary: Colors.white,
+      secondary: Color(0xFFC9A24A),
+      surface: surface,
+      onSurface: text,
+      onSurfaceVariant: muted,
+      error: Color(0xFFFF4D5E),
+    ),
+    textTheme: textTheme,
+    filledButtonTheme: FilledButtonThemeData(
+      style: FilledButton.styleFrom(
+        minimumSize: const Size.fromHeight(38),
+        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+        textStyle: textTheme.labelLarge?.copyWith(
+          fontSize: 13,
+          fontWeight: FontWeight.w800,
+        ),
+      ),
+    ),
+    outlinedButtonTheme: OutlinedButtonThemeData(
+      style: OutlinedButton.styleFrom(
+        minimumSize: const Size.fromHeight(38),
+        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
+        side: const BorderSide(color: Color(0xFF303748)),
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
+        textStyle: textTheme.labelLarge?.copyWith(
+          fontSize: 13,
+          fontWeight: FontWeight.w800,
+        ),
+      ),
+    ),
+  );
+}
diff --git a/watch_app/pubspec.lock b/watch_app/pubspec.lock
new file mode 100644
index 0000000..33d9400
--- /dev/null
+++ b/watch_app/pubspec.lock
@@ -0,0 +1,78 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages:
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      sha256: faf38497bda5ead2a8c7615f4f7939df04333478bf32e4173fcb06d428b5716b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.1"
+  collection:
+    dependency: transitive
+    description:
+      name: collection
+      sha256: "2f5709ae4d3d59dd8f7cd309b4e023046b57d8a6c82130785d2b0e5868084e76"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.19.1"
+  flutter:
+    dependency: "direct main"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  flutter_lints:
+    dependency: "direct dev"
+    description:
+      name: flutter_lints
+      sha256: "3105dc8492f6183fb076ccf1f351ac3d60564bff92e20bfc4af9cc1651f4e7e1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.0"
+  lints:
+    dependency: transitive
+    description:
+      name: lints
+      sha256: "12f842a479589fea194fe5c5a3095abc7be0c1f2ddfa9a0e76aed1dbd26a87df"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.0"
+  material_color_utilities:
+    dependency: transitive
+    description:
+      name: material_color_utilities
+      sha256: "9c337007e82b1889149c82ed242ed1cb24a66044e30979c44912381e9be4c48b"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.13.0"
+  meta:
+    dependency: transitive
+    description:
+      name: meta
+      sha256: "1741988757a65eb6b36abe716829688cf01910bbf91c34354ff7ec1c3de2b349"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.18.0"
+  sky_engine:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  vector_math:
+    dependency: transitive
+    description:
+      name: vector_math
+      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  watch_bridge_contract:
+    dependency: "direct main"
+    description:
+      path: "../packages/watch_bridge_contract"
+      relative: true
+    source: path
+    version: "0.1.0"
+sdks:
+  dart: ">=3.10.0 <4.0.0"
diff --git a/watch_app/pubspec.yaml b/watch_app/pubspec.yaml
new file mode 100644
index 0000000..38b435c
--- /dev/null
+++ b/watch_app/pubspec.yaml
@@ -0,0 +1,20 @@
+name: gametime_watch
+description: Wear OS companion app for GameTime workout sessions.
+publish_to: 'none'
+
+version: 0.1.0+1
+
+environment:
+  sdk: ^3.10.0
+
+dependencies:
+  flutter:
+    sdk: flutter
+  watch_bridge_contract:
+    path: ../packages/watch_bridge_contract
+
+dev_dependencies:
+  flutter_lints: ^6.0.0
+
+flutter:
+  uses-material-design: true