Meet: Android foreground service to survive screen lock

Samples~/Meet/Assets/Plugins/Android/AndroidManifest.xml

@@ -7,6 +7,8 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />
 
     <application>
         <activity android:name="com.unity3d.player.UnityPlayerActivity"
@@ -17,5 +19,11 @@
             </intent-filter>
             <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
         </activity>
+
+        <service
+            android:name="io.livekit.unity.sample.LiveKitForegroundService"
+            android:enabled="true"
+            android:exported="false"
+            android:foregroundServiceType="mediaPlayback" />
     </application>
 </manifest>

Samples~/Meet/Assets/Plugins/Android/LiveKitForegroundService.java

@@ -0,0 +1,75 @@
+package io.livekit.unity.sample;
+
+import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Build;
+import android.os.IBinder;
+
+public class LiveKitForegroundService extends Service {
+
+    private static final String CHANNEL_ID = "livekit_call";
+    private static final int NOTIFICATION_ID = 1701;
+
+    public static void start(Context context) {
+        Intent intent = new Intent(context, LiveKitForegroundService.class);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            context.startForegroundService(intent);
+        } else {
+            context.startService(intent);
+        }
+    }
+
+    public static void stop(Context context) {
+        Intent intent = new Intent(context, LiveKitForegroundService.class);
+        context.stopService(intent);
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        ensureChannel();
+        startForeground(NOTIFICATION_ID, buildNotification());
+    }
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        return START_STICKY;
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    private void ensureChannel() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return;
+        NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
+        if (nm == null) return;
+        if (nm.getNotificationChannel(CHANNEL_ID) != null) return;
+        NotificationChannel channel = new NotificationChannel(
+                CHANNEL_ID,
+                "Active call",
+                NotificationManager.IMPORTANCE_LOW);
+        channel.setShowBadge(false);
+        nm.createNotificationChannel(channel);
+    }
+
+    private Notification buildNotification() {
+        Notification.Builder builder;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            builder = new Notification.Builder(this, CHANNEL_ID);
+        } else {
+            builder = new Notification.Builder(this);
+        }
+        return builder
+                .setContentTitle("LiveKit call")
+                .setContentText("Connected — running in the background")
+                .setSmallIcon(android.R.drawable.ic_menu_call)
+                .setOngoing(true)
+                .build();
+    }
+}

Samples~/Meet/Assets/Runtime/AndroidBackgroundService.cs

@@ -0,0 +1,39 @@
+#if UNITY_ANDROID && !UNITY_EDITOR
+using UnityEngine;
+
+/// <summary>
+/// Starts/stops an Android foreground service so the OS keeps the process out of Doze
+/// while the user is in a LiveKit call. Without it, the screen lock pauses the network
+/// long enough for the SDK to exhaust its 10 reconnect attempts and disconnect.
+/// Call sites must guard with `#if UNITY_ANDROID && !UNITY_EDITOR`.
+/// </summary>
+public static class AndroidBackgroundService
+{
+    private const string ServiceClassName = "io.livekit.unity.sample.LiveKitForegroundService";
+
+    public static void Start()
+    {
+        WithActivity((cls, activity) => cls.CallStatic("start", activity));
+    }
+
+    public static void Stop()
+    {
+        WithActivity((cls, activity) => cls.CallStatic("stop", activity));
+    }
+
+    private static void WithActivity(System.Action<AndroidJavaClass, AndroidJavaObject> body)
+    {
+        try
+        {
+            using var player = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
+            using var activity = player.GetStatic<AndroidJavaObject>("currentActivity");
+            using var serviceClass = new AndroidJavaClass(ServiceClassName);
+            body(serviceClass, activity);
+        }
+        catch (System.Exception e)
+        {
+            Debug.LogWarning($"AndroidBackgroundService: {e.Message}");
+        }
+    }
+}
+#endif

Samples~/Meet/Assets/Runtime/MeetManager.cs

@@ -90,6 +90,9 @@ private void OnDestroy()
         }
         CleanUpAllTracks();
         _webCamTexture?.Stop();
+#if UNITY_ANDROID && !UNITY_EDITOR
+        AndroidBackgroundService.Stop();
+#endif
     }
 
     #endregion
@@ -110,6 +113,9 @@ private void OnEndCall()
         _room = null;
         _localId = null;
         buttonBar.SetConnected(false);
+#if UNITY_ANDROID && !UNITY_EDITOR
+        AndroidBackgroundService.Stop();
+#endif
     }
 
     private void OnToggleCamera()
@@ -183,6 +189,9 @@ private IEnumerator ConnectToRoom()
         Debug.Log($"Connected to {_room.Name}");
         _localId = _room.LocalParticipant.Identity;
         buttonBar.SetConnected(true);
+#if UNITY_ANDROID && !UNITY_EDITOR
+        AndroidBackgroundService.Start();
+#endif
 
         EnsureParticipantTile(_localId);
         foreach (var remote in _room.RemoteParticipants.Values)