Final touches

app/(auth)/(tabs)/(home)/_layout.tsx

@@ -7,6 +7,9 @@ import { nestedTabPageScreenOptions } from "@/components/stacks/NestedTabPageSta
 import useRouter from "@/hooks/useAppRouter";
 
 const Chromecast = Platform.isTV ? null : require("@/components/Chromecast");
+const SyncPlayButtonComponent = Platform.isTV
+  ? null
+  : require("@/components/syncplay/SyncPlayButton").SyncPlayButton;
 
 import { useAtom } from "jotai";
 import { HeaderBackButton } from "@/components/common/HeaderBackButton";
@@ -33,6 +36,7 @@ export default function IndexLayout() {
               {!Platform.isTV && (
                 <>
                   <Chromecast.Chromecast background='transparent' />
+                  {SyncPlayButtonComponent && <SyncPlayButtonComponent />}
                   {user?.Policy?.IsAdministrator && <SessionsButton />}
                   <SettingsButton />
                 </>

app/(auth)/player/direct-player.tsx

@@ -31,9 +31,11 @@ import {
 } from "@/components/video-player/controls/utils/playback-speed-settings";
 import useRouter from "@/hooks/useAppRouter";
 import { useHaptic } from "@/hooks/useHaptic";
+import { useKeepWebSocketAlive } from "@/hooks/useKeepWebSocketAlive";
 import { useOrientation } from "@/hooks/useOrientation";
 import { usePlaybackManager } from "@/hooks/usePlaybackManager";
 import usePlaybackSpeed from "@/hooks/usePlaybackSpeed";
+import { usePlayerItemNavigation } from "@/hooks/usePlayerItemNavigation";
 import { useInvalidatePlaybackProgressCache } from "@/hooks/useRevalidatePlaybackProgressCache";
 import { useWebSocket } from "@/hooks/useWebsockets";
 import {
@@ -49,10 +51,10 @@ import { DownloadedItem } from "@/providers/Downloads/types";
 import { useInactivity } from "@/providers/InactivityProvider";
 import { apiAtom, userAtom } from "@/providers/JellyfinProvider";
 import { OfflineModeProvider } from "@/providers/OfflineModeProvider";
-
+import { useSyncPlay } from "@/providers/SyncPlay";
+import type { PlayerControls } from "@/providers/SyncPlay/types";
 import { getSubtitlesForItem } from "@/utils/atoms/downloadedSubtitles";
 import { useSettings } from "@/utils/atoms/settings";
-import { getDefaultPlaySettings } from "@/utils/jellyfin/getDefaultPlaySettings";
 import { getPrimaryImageUrl } from "@/utils/jellyfin/image/getPrimaryImageUrl";
 import { getStreamUrl } from "@/utils/jellyfin/media/getStreamUrl";
 import {
@@ -77,6 +79,11 @@ export default function DirectPlayerPage() {
   const [isPlaybackStopped, setIsPlaybackStopped] = useState(false);
   const [showControls, _setShowControls] = useState(true);
   const [isPipMode, setIsPipMode] = useState(false);
+
+  // Keep the global WebSocket open while in PiP so SyncPlay commands
+  // (and any other server pushes) keep flowing while iOS treats the
+  // app as backgrounded. See `WebSocketProvider.acquireKeepAlive`.
+  useKeepWebSocketAlive(isPipMode);
   const [aspectRatio] = useState<"default" | "16:9" | "4:3" | "1:1" | "21:9">(
     "default",
   );
@@ -128,6 +135,7 @@ export default function DirectPlayerPage() {
     bitrateValue: bitrateValueStr,
     offline: offlineStr,
     playbackPosition: playbackPositionFromUrl,
+    syncPlay: syncPlayStr,
   } = useLocalSearchParams<{
     itemId: string;
     audioIndex: string;
@@ -137,9 +145,23 @@ export default function DirectPlayerPage() {
     offline: string;
     /** Playback position in ticks. */
     playbackPosition?: string;
+    /** Whether playback was initiated by SyncPlay */
+    syncPlay?: string;
   }>();
+
+  // When opened via SyncPlay, don't auto-play - let SyncPlay commands control playback
+  const openedViaSyncPlay = syncPlayStr === "true";
   const { lockOrientation, unlockOrientation } = useOrientation();
 
+  // SyncPlay integration
+  const syncPlay = useSyncPlay();
+  const {
+    isEnabled: isSyncPlayEnabled,
+    controller: syncPlayController,
+    setPlayerControls,
+    notifyBuffering,
+  } = syncPlay;
+
   const offline = offlineStr === "true";
 
   // Audio index: use URL param if provided, otherwise use stored index for offline playback
@@ -415,8 +437,72 @@ export default function DirectPlayerPage() {
     reportPlaybackStart();
   }, [stream, api, offline]);
 
+  // SyncPlay: Connect player controls when video is ready
+  useEffect(() => {
+    if (!isVideoLoaded || !videoRef.current || offline) {
+      setPlayerControls(null);
+      return;
+    }
+
+    const controls: PlayerControls = {
+      play: () => videoRef.current?.play(),
+      pause: () => videoRef.current?.pause(),
+      seekTo: (positionMs: number) => {
+        const positionSec = positionMs / 1000;
+        console.log(
+          `PlayerControls.seekTo: ${positionMs}ms = ${positionSec}s, videoRef exists: ${!!videoRef.current}`,
+        );
+        videoRef.current?.seekTo(positionSec);
+      },
+      setSpeed: (speed: number) => videoRef.current?.setSpeed?.(speed),
+      getSpeed: () => currentPlaybackSpeed,
+      getCurrentPosition: () => progress.get(),
+      isPlaying: () => isPlaying,
+      isBuffering: () => isBuffering,
+    };
+
+    setPlayerControls(controls);
+
+    return () => {
+      setPlayerControls(null);
+    };
+  }, [
+    isVideoLoaded,
+    offline,
+    isPlaying,
+    isBuffering,
+    currentPlaybackSpeed,
+    progress,
+    setPlayerControls,
+  ]);
+
+  // SyncPlay: Report buffering/ready state to server.
+  //
+  // CRITICAL: We must report `buffering` to the server *during* initial
+  // load (before `isVideoLoaded`), otherwise the server treats us as ready
+  // and proceeds without waiting for us. jellyfin-web reports this for
+  // free via the HTML5 video element's `waiting` event; for us, the
+  // initial load itself is the buffering window.
+  useEffect(() => {
+    if (!isSyncPlayEnabled) {
+      return;
+    }
+
+    const isLocallyReady = isVideoLoaded && !isBuffering;
+    // notifyBuffering routes through the debouncer in PlaybackCore so
+    // re-renders during a stall don't spam the server.
+    notifyBuffering(!isLocallyReady);
+  }, [isSyncPlayEnabled, isVideoLoaded, isBuffering, notifyBuffering]);
+
   const togglePlay = async () => {
     lightHapticFeedback();
+
+    // Route through SyncPlay when active
+    if (isSyncPlayEnabled && syncPlayController) {
+      syncPlayController.playPause();
+      return;
+    }
+
     setIsPlaying(!isPlaying);
     if (isPlaying) {
       await videoRef.current?.pause();
@@ -645,10 +731,12 @@ export default function DirectPlayerPage() {
     const startPos = ticksToSeconds(startTicks);
 
     // Build source config - headers only needed for online streaming
+    // When opened via SyncPlay, don't auto-play - SyncPlay commands control playback
+    const shouldAutoplay = !openedViaSyncPlay;
     const source: MpvVideoSource = {
       url: stream.url,
       startPosition: startPos,
-      autoplay: true,
+      autoplay: shouldAutoplay,
       initialSubtitleId,
       initialAudioId,
       // Pass cache/buffer settings from user preferences
@@ -843,6 +931,41 @@ export default function DirectPlayerPage() {
     [],
   );
 
+  // PiP playback controls. When SyncPlay is active, the native side
+  // is told to *delegate* these via `syncPlayDelegated`, so the OS
+  // play/pause/skip buttons emit these events instead of poking MPV
+  // directly. We route them through the SyncPlay controller so the
+  // server broadcasts a command to every group member (including us).
+  const _onPipPlayRequest = useCallback(() => {
+    if (isSyncPlayEnabled && syncPlayController) {
+      console.log("SyncPlay: PiP play → controller.playPause()");
+      syncPlayController.playPause();
+    }
+  }, [isSyncPlayEnabled, syncPlayController]);
+
+  const _onPipPauseRequest = useCallback(() => {
+    if (isSyncPlayEnabled && syncPlayController) {
+      console.log("SyncPlay: PiP pause → controller.playPause()");
+      syncPlayController.playPause();
+    }
+  }, [isSyncPlayEnabled, syncPlayController]);
+
+  const _onPipSkipRequest = useCallback(
+    (e: {
+      nativeEvent: { targetSeconds: number; intervalSeconds: number };
+    }) => {
+      if (!isSyncPlayEnabled || !syncPlayController) return;
+      const { targetSeconds } = e.nativeEvent;
+      // SyncPlay seek takes ticks (1 s = 10_000_000 ticks).
+      const ticks = Math.max(0, Math.round(targetSeconds * 10_000_000));
+      console.log(
+        `SyncPlay: PiP skip → controller.seek(${targetSeconds}s = ${ticks} ticks)`,
+      );
+      syncPlayController.seek(ticks);
+    },
+    [isSyncPlayEnabled, syncPlayController],
+  );
+
   const [isMounted, setIsMounted] = useState(false);
 
   // Add useEffect to handle mounting
@@ -867,10 +990,21 @@ export default function DirectPlayerPage() {
     videoRef.current?.pause?.();
   }, []);
 
-  const seek = useCallback((position: number) => {
-    // MPV expects seconds, convert from ms
-    videoRef.current?.seekTo?.(position / 1000);
-  }, []);
+  const seek = useCallback(
+    (position: number) => {
+      // Route through SyncPlay when active. `position` is in ms; the
+      // controller takes ticks (1 ms = 10000 ticks).
+      if (isSyncPlayEnabled && syncPlayController) {
+        console.log("SyncPlay: seek requested via SyncPlay", position);
+        syncPlayController.seek(Math.round(position * 10000));
+        return;
+      }
+
+      // MPV expects seconds, convert from ms
+      videoRef.current?.seekTo?.(position / 1000);
+    },
+    [isSyncPlayEnabled, syncPlayController],
+  );
 
   // TV audio track change handler
   const handleAudioIndexChange = useCallback(
@@ -1010,44 +1144,6 @@ export default function DirectPlayerPage() {
     }
   }, [isZoomedToFill, stream?.mediaSource, screenWidth, screenHeight]);
 
-  // TV: Navigate to previous item
-  const goToPreviousItem = useCallback(() => {
-    if (!previousItem || !settings) return;
-
-    const {
-      mediaSource: newMediaSource,
-      audioIndex: defaultAudioIndex,
-      subtitleIndex: defaultSubtitleIndex,
-    } = getDefaultPlaySettings(previousItem, settings, {
-      indexes: {
-        // Use the live selection, not the stale URL params (see goToNextItem).
-        subtitleIndex: currentSubtitleIndex,
-        audioIndex: currentAudioIndex,
-      },
-      source: stream?.mediaSource ?? undefined,
-    });
-
-    const queryParams = new URLSearchParams({
-      itemId: previousItem.Id ?? "",
-      audioIndex: defaultAudioIndex?.toString() ?? "",
-      subtitleIndex: defaultSubtitleIndex?.toString() ?? "",
-      mediaSourceId: newMediaSource?.Id ?? "",
-      bitrateValue: bitrateValue?.toString() ?? "",
-      playbackPosition:
-        previousItem.UserData?.PlaybackPositionTicks?.toString() ?? "",
-    }).toString();
-
-    router.replace(`player/direct-player?${queryParams}` as any);
-  }, [
-    previousItem,
-    settings,
-    currentSubtitleIndex,
-    currentAudioIndex,
-    stream?.mediaSource,
-    bitrateValue,
-    router,
-  ]);
-
   // TV: Add subtitle file to player (for client-side downloaded subtitles)
   const addSubtitleFile = useCallback(async (path: string) => {
     await videoRef.current?.addSubtitleFile?.(path, true);
@@ -1077,45 +1173,25 @@ export default function DirectPlayerPage() {
     return [];
   }, [isMounted]);
 
-  // TV: Navigate to next item
-  const goToNextItem = useCallback(() => {
-    if (!nextItem || !settings || isPlaybackStopped) return;
-
-    const {
-      mediaSource: newMediaSource,
-      audioIndex: defaultAudioIndex,
-      subtitleIndex: defaultSubtitleIndex,
-    } = getDefaultPlaySettings(nextItem, settings, {
-      indexes: {
-        // Use the live selection (updated when the user changes tracks
-        // mid-playback), not the stale URL params the episode started with.
-        subtitleIndex: currentSubtitleIndex,
-        audioIndex: currentAudioIndex,
-      },
-      source: stream?.mediaSource ?? undefined,
-    });
-
-    const queryParams = new URLSearchParams({
-      itemId: nextItem.Id ?? "",
-      audioIndex: defaultAudioIndex?.toString() ?? "",
-      subtitleIndex: defaultSubtitleIndex?.toString() ?? "",
-      mediaSourceId: newMediaSource?.Id ?? "",
-      bitrateValue: bitrateValue?.toString() ?? "",
-      playbackPosition:
-        nextItem.UserData?.PlaybackPositionTicks?.toString() ?? "",
-    }).toString();
-
-    router.replace(`player/direct-player?${queryParams}` as any);
-  }, [
+  /*
+   * Item-level navigation (next / previous). Wraps SyncPlay dispatch,
+   * platform-appropriate local navigation (replace on TV), and offline
+   * param injection in a single hook so the in-player buttons and any
+   * future entry points (autoplay overlay, episode picker, etc.) share
+   * one implementation.
+   */
+  const {
+    goToNextItem: dispatchNextItem,
+    goToPreviousItem: dispatchPreviousItem,
+  } = usePlayerItemNavigation({
     nextItem,
-    settings,
-    currentSubtitleIndex,
+    previousItem,
+    mediaSource: stream?.mediaSource,
     currentAudioIndex,
-    stream?.mediaSource,
+    currentSubtitleIndex,
     bitrateValue,
-    router,
-    isPlaybackStopped,
-  ]);
+    isDisabled: isPlaybackStopped,
+  });
 
   // Apply subtitle settings when video loads
   useEffect(() => {
@@ -1262,6 +1338,10 @@ export default function DirectPlayerPage() {
                 onProgress={onProgress}
                 onPlaybackStateChange={onPlaybackStateChanged}
                 onPictureInPictureChange={_onPictureInPictureChange}
+                syncPlayDelegated={isSyncPlayEnabled}
+                onPipPlayRequest={_onPipPlayRequest}
+                onPipPauseRequest={_onPipPauseRequest}
+                onPipSkipRequest={_onPipSkipRequest}
                 onLoad={() => setIsVideoLoaded(true)}
                 onError={(e: { nativeEvent: MpvOnErrorEventPayload }) => {
                   console.error("Video Error:", e.nativeEvent);
@@ -1316,8 +1396,8 @@ export default function DirectPlayerPage() {
                   onSubtitleIndexChange={handleSubtitleIndexChange}
                   previousItem={previousItem}
                   nextItem={nextItem}
-                  goToPreviousItem={goToPreviousItem}
-                  goToNextItem={goToNextItem}
+                  goToPreviousItem={dispatchPreviousItem}
+                  goToNextItem={dispatchNextItem}
                   onRefreshSubtitleTracks={handleRefreshSubtitleTracks}
                   addSubtitleFile={addSubtitleFile}
                   showTechnicalInfo={showTechnicalInfo}

app/_layout.tsx

@@ -25,6 +25,7 @@ import { MusicPlayerProvider } from "@/providers/MusicPlayerProvider";
 import { NetworkStatusProvider } from "@/providers/NetworkStatusProvider";
 import { PlaySettingsProvider } from "@/providers/PlaySettingsProvider";
 import { ServerUrlProvider } from "@/providers/ServerUrlProvider";
+import { SyncPlayProvider } from "@/providers/SyncPlay";
 import { WebSocketProvider } from "@/providers/WebSocketProvider";
 import { useSettings } from "@/utils/atoms/settings";
 import {
@@ -409,133 +410,136 @@ function Layout() {
               <PlaySettingsProvider>
                 <LogProvider>
                   <WebSocketProvider>
-                    <DownloadProvider>
-                      <MusicPlayerProvider>
-                        <GlobalModalProvider>
-                          <BottomSheetModalProvider>
-                            <IntroSheetProvider>
-                              <ThemeProvider value={DarkTheme}>
-                                <SystemBars style='light' hidden={false} />
-                                <Stack initialRouteName='(auth)/(tabs)'>
-                                  <Stack.Screen
-                                    name='(auth)/(tabs)'
-                                    options={{
-                                      headerShown: false,
-                                      title: "",
-                                      header: () => null,
+                    <SyncPlayProvider>
+                      <DownloadProvider>
+                        <MusicPlayerProvider>
+                          <GlobalModalProvider>
+                            <BottomSheetModalProvider>
+                              <IntroSheetProvider>
+                                <ThemeProvider value={DarkTheme}>
+                                  <SystemBars style='light' hidden={false} />
+                                  <Stack initialRouteName='(auth)/(tabs)'>
+                                    <Stack.Screen
+                                      name='(auth)/(tabs)'
+                                      options={{
+                                        headerShown: false,
+                                        title: "",
+                                        header: () => null,
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/player'
+                                      options={{
+                                        headerShown: false,
+                                        title: "",
+                                        header: () => null,
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/now-playing'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "modal",
+                                        gestureEnabled: true,
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='login'
+                                      options={{
+                                        headerShown: true,
+                                        title: "",
+                                        headerTransparent:
+                                          Platform.OS === "ios",
+                                      }}
+                                    />
+                                    <Stack.Screen name='+not-found' />
+                                    <Stack.Screen
+                                      name='(auth)/tv-option-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/tv-subtitle-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/tv-request-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/tv-season-select-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/tv-series-season-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='tv-account-action-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='tv-account-select-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                    <Stack.Screen
+                                      name='(auth)/tv-user-switch-modal'
+                                      options={{
+                                        headerShown: false,
+                                        presentation: "transparentModal",
+                                        animation: "fade",
+                                      }}
+                                    />
+                                  </Stack>
+                                  <Toaster
+                                    duration={4000}
+                                    toastOptions={{
+                                      style: {
+                                        backgroundColor: "#262626",
+                                        borderColor: "#363639",
+                                        borderWidth: 1,
+                                      },
+                                      titleStyle: {
+                                        color: "white",
+                                      },
                                     }}
+                                    closeButton
                                   />
-                                  <Stack.Screen
-                                    name='(auth)/player'
-                                    options={{
-                                      headerShown: false,
-                                      title: "",
-                                      header: () => null,
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/now-playing'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "modal",
-                                      gestureEnabled: true,
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='login'
-                                    options={{
-                                      headerShown: true,
-                                      title: "",
-                                      headerTransparent: Platform.OS === "ios",
-                                    }}
-                                  />
-                                  <Stack.Screen name='+not-found' />
-                                  <Stack.Screen
-                                    name='(auth)/tv-option-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/tv-subtitle-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/tv-request-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/tv-season-select-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/tv-series-season-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='tv-account-action-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='tv-account-select-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                  <Stack.Screen
-                                    name='(auth)/tv-user-switch-modal'
-                                    options={{
-                                      headerShown: false,
-                                      presentation: "transparentModal",
-                                      animation: "fade",
-                                    }}
-                                  />
-                                </Stack>
-                                <Toaster
-                                  duration={4000}
-                                  toastOptions={{
-                                    style: {
-                                      backgroundColor: "#262626",
-                                      borderColor: "#363639",
-                                      borderWidth: 1,
-                                    },
-                                    titleStyle: {
-                                      color: "white",
-                                    },
-                                  }}
-                                  closeButton
-                                />
-                                {!Platform.isTV && <GlobalModal />}
-                              </ThemeProvider>
-                            </IntroSheetProvider>
-                          </BottomSheetModalProvider>
-                        </GlobalModalProvider>
-                      </MusicPlayerProvider>
-                    </DownloadProvider>
+                                  {!Platform.isTV && <GlobalModal />}
+                                </ThemeProvider>
+                              </IntroSheetProvider>
+                            </BottomSheetModalProvider>
+                          </GlobalModalProvider>
+                        </MusicPlayerProvider>
+                      </DownloadProvider>
+                    </SyncPlayProvider>
                   </WebSocketProvider>
                 </LogProvider>
               </PlaySettingsProvider>

bun.lock

@@ -1,6 +1,5 @@
 {
   "lockfileVersion": 1,
-  "configVersion": 1,
   "workspaces": {
     "": {
       "name": "streamyfin",

components/PlayButton.tsx

@@ -23,9 +23,8 @@ import Animated, {
   useSharedValue,
   withTiming,
 } from "react-native-reanimated";
-import useRouter from "@/hooks/useAppRouter";
-import { useHaptic } from "@/hooks/useHaptic";
 import type { ThemeColors } from "@/hooks/useImageColorsReturn";
+import { usePlayerItemNavigation } from "@/hooks/usePlayerItemNavigation";
 import { getDownloadedItemById } from "@/providers/Downloads/database";
 import { useGlobalModal } from "@/providers/GlobalModalProvider";
 import { apiAtom, userAtom } from "@/providers/JellyfinProvider";
@@ -67,47 +66,44 @@ export const PlayButton: React.FC<Props> = ({
   const api = useAtomValue(apiAtom);
   const user = useAtomValue(userAtom);
 
+  // Single source of truth for all player navigation — SyncPlay,
+  // offline-vs-stream resolution, and the autoplay counter reset all
+  // live inside `playItem`.
+  const { playItem } = usePlayerItemNavigation();
+
   // Use colors prop if provided, otherwise fallback to global atom
   const effectiveColors = colors || globalColorAtom;
 
-  const router = useRouter();
-
   const startWidth = useSharedValue(0);
   const targetWidth = useSharedValue(0);
   const endColor = useSharedValue(effectiveColors);
   const startColor = useSharedValue(effectiveColors);
   const widthProgress = useSharedValue(0);
   const colorChangeProgress = useSharedValue(0);
-  const { settings, updateSettings } = useSettings();
-  const lightHapticFeedback = useHaptic("light");
+  const { settings } = useSettings();
 
   const goToPlayer = useCallback(
-    (q: string) => {
-      if (settings.maxAutoPlayEpisodeCount.value !== -1) {
-        updateSettings({ autoPlayEpisodeCount: 0 });
-      }
-      router.push(`/player/direct-player?${q}`);
+    (opts: Parameters<typeof playItem>[1]) => {
+      void playItem(item, opts);
     },
-    [router, isOffline],
+    [item, playItem],
   );
 
   const handleNormalPlayFlow = useCallback(async () => {
     if (!item) return;
 
-    const queryParams = new URLSearchParams({
-      itemId: item.Id!,
-      audioIndex: selectedOptions.audioIndex?.toString() ?? "",
-      subtitleIndex: selectedOptions.subtitleIndex?.toString() ?? "",
-      mediaSourceId: selectedOptions.mediaSource?.Id ?? "",
-      bitrateValue: selectedOptions.bitrate?.value?.toString() ?? "",
-      playbackPosition: item.UserData?.PlaybackPositionTicks?.toString() ?? "0",
-      offline: isOffline ? "true" : "false",
-    });
-
-    const queryString = queryParams.toString();
+    // Default play options derived from the page's track / source / bitrate
+    // pickers. `playItem` handles SyncPlay broadcasting and offline-vs-online
+    // routing; we just need to pick a destination (device vs Chromecast).
+    const defaultOpts = {
+      audioIndex: selectedOptions.audioIndex,
+      subtitleIndex: selectedOptions.subtitleIndex,
+      mediaSourceId: selectedOptions.mediaSource?.Id ?? undefined,
+      bitrateValue: selectedOptions.bitrate?.value,
+    };
 
     if (!client) {
-      goToPlayer(queryString);
+      goToPlayer(defaultOpts);
       return;
     }
 
@@ -270,7 +266,7 @@ export const PlayButton: React.FC<Props> = ({
             });
             break;
           case 1:
-            goToPlayer(queryString);
+            goToPlayer(defaultOpts);
             break;
           case cancelButtonIndex:
             break;
@@ -280,35 +276,24 @@ export const PlayButton: React.FC<Props> = ({
   }, [
     item,
     client,
-    settings,
     api,
     user,
-    router,
     showActionSheetWithOptions,
     mediaStatus,
     selectedOptions,
     goToPlayer,
-    isOffline,
     t,
   ]);
 
   const onPress = useCallback(async () => {
     if (!item) return;
 
-    lightHapticFeedback();
-
     // Check if item is downloaded
     const downloadedItem = item.Id ? getDownloadedItemById(item.Id) : undefined;
 
     // If already in offline mode, play downloaded file directly
     if (isOffline && downloadedItem) {
-      const queryParams = new URLSearchParams({
-        itemId: item.Id!,
-        offline: "true",
-        playbackPosition:
-          item.UserData?.PlaybackPositionTicks?.toString() ?? "0",
-      });
-      goToPlayer(queryParams.toString());
+      goToPlayer({ forceOffline: true });
       return;
     }
 
@@ -331,13 +316,7 @@ export const PlayButton: React.FC<Props> = ({
                 <Button
                   onPress={() => {
                     hideModal();
-                    const queryParams = new URLSearchParams({
-                      itemId: item.Id!,
-                      offline: "true",
-                      playbackPosition:
-                        item.UserData?.PlaybackPositionTicks?.toString() ?? "0",
-                    });
-                    goToPlayer(queryParams.toString());
+                    goToPlayer({ forceOffline: true });
                   }}
                   color='purple'
                 >
@@ -374,13 +353,7 @@ export const PlayButton: React.FC<Props> = ({
             {
               text: t("player.downloaded_file_yes"),
               onPress: () => {
-                const queryParams = new URLSearchParams({
-                  itemId: item.Id!,
-                  offline: "true",
-                  playbackPosition:
-                    item.UserData?.PlaybackPositionTicks?.toString() ?? "0",
-                });
-                goToPlayer(queryParams.toString());
+                goToPlayer({ forceOffline: true });
               },
               isPreferred: true,
             },
@@ -404,13 +377,12 @@ export const PlayButton: React.FC<Props> = ({
     handleNormalPlayFlow();
   }, [
     item,
-    lightHapticFeedback,
+    isOffline,
     handleNormalPlayFlow,
     goToPlayer,
     t,
     showModal,
     hideModal,
-    effectiveColors,
   ]);
 
   const derivedTargetWidth = useDerivedValue(() => {

components/syncplay/GroupSelectionMenu.tsx

@@ -0,0 +1,259 @@
+/**
+ * GroupSelectionMenu
+ *
+ * Content rendered inside the SyncPlay bottom sheet (the sheet itself is
+ * owned by SyncPlayButton). Calls `onClose` after successful actions to
+ * dismiss the parent sheet.
+ */
+
+import { Ionicons } from "@expo/vector-icons";
+import { useCallback, useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
+import { ActivityIndicator, TouchableOpacity, View } from "react-native";
+import { useSafeAreaInsets } from "react-native-safe-area-context";
+import { Button } from "@/components/Button";
+import { Text } from "@/components/common/Text";
+import { useSyncPlay } from "@/providers/SyncPlay";
+import type { GroupInfoDto } from "@/providers/SyncPlay/types";
+
+interface GroupSelectionMenuProps {
+  onClose: () => void;
+}
+
+export function GroupSelectionMenu({ onClose }: GroupSelectionMenuProps) {
+  const { t } = useTranslation();
+  const insets = useSafeAreaInsets();
+
+  const {
+    isEnabled,
+    groupInfo,
+    canCreateGroups,
+    joinGroup,
+    createGroup,
+    leaveGroup,
+    getGroups,
+    resumeGroupPlayback,
+  } = useSyncPlay();
+
+  const [groups, setGroups] = useState<GroupInfoDto[]>([]);
+  const [isLoading, setIsLoading] = useState(false);
+  const [isCreating, setIsCreating] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+    (async () => {
+      setIsLoading(true);
+      try {
+        const fetchedGroups = await getGroups();
+        if (!cancelled) {
+          setGroups(fetchedGroups);
+        }
+      } catch (error) {
+        console.error("Failed to fetch groups", error);
+      } finally {
+        if (!cancelled) {
+          setIsLoading(false);
+        }
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [getGroups]);
+
+  const handleJoinGroup = useCallback(
+    async (groupId: string) => {
+      try {
+        await joinGroup(groupId);
+        onClose();
+      } catch (error) {
+        console.error("Failed to join group", error);
+      }
+    },
+    [joinGroup, onClose],
+  );
+
+  const handleCreateGroup = useCallback(async () => {
+    setIsCreating(true);
+    try {
+      await createGroup();
+      onClose();
+    } catch (error) {
+      console.error("Failed to create group", error);
+    } finally {
+      setIsCreating(false);
+    }
+  }, [createGroup, onClose]);
+
+  const handleLeaveGroup = useCallback(async () => {
+    try {
+      await leaveGroup();
+      onClose();
+    } catch (error) {
+      console.error("Failed to leave group", error);
+    }
+  }, [leaveGroup, onClose]);
+
+  // Jump (back) into the group's current item. Mirrors jellyfin-web's
+  // "Resume playback" menu entry — close the sheet and navigate to
+  // the player; SyncPlayProvider handles the re-follow + URL build.
+  const handleResumePlayback = useCallback(async () => {
+    try {
+      await resumeGroupPlayback();
+      onClose();
+    } catch (error) {
+      console.error("Failed to resume group playback", error);
+    }
+  }, [resumeGroupPlayback, onClose]);
+
+  const containerStyle = {
+    paddingLeft: Math.max(16, insets.left),
+    paddingRight: Math.max(16, insets.right),
+    paddingBottom: Math.max(16, insets.bottom),
+    paddingTop: 8,
+  };
+
+  if (isEnabled && groupInfo) {
+    return (
+      <View style={containerStyle}>
+        <View className='mb-4'>
+          <View className='flex-row items-center mb-2'>
+            <Ionicons name='people' size={24} color='#00a4dc' />
+            <Text className='font-bold text-xl text-neutral-100 ml-2'>
+              {t("syncplay.title")}
+            </Text>
+          </View>
+          <Text className='text-neutral-400'>{t("syncplay.my_group")}</Text>
+        </View>
+
+        <View className='bg-neutral-800 rounded-xl p-4 mb-4'>
+          <View className='flex-row items-center justify-between mb-3'>
+            <Text className='text-neutral-100 font-semibold text-lg'>
+              {groupInfo.GroupName}
+            </Text>
+            <View className='bg-[#00a4dc] px-2 py-1 rounded'>
+              <Text className='text-white text-xs font-medium'>
+                {groupInfo.State}
+              </Text>
+            </View>
+          </View>
+
+          {groupInfo.Participants && groupInfo.Participants.length > 0 && (
+            <View className='flex-row items-center'>
+              <Ionicons name='person' size={16} color='#9ca3af' />
+              <Text className='text-neutral-400 ml-2'>
+                {groupInfo.Participants.length} {t("syncplay.members")}
+              </Text>
+            </View>
+          )}
+        </View>
+
+        <View className='mb-3'>
+          <Button onPress={handleResumePlayback} color='black'>
+            <View className='flex-row items-center justify-center'>
+              <Ionicons name='play-circle-outline' size={20} color='white' />
+              <Text className='text-white font-semibold ml-2'>
+                {t("syncplay.resume_playback")}
+              </Text>
+            </View>
+          </Button>
+        </View>
+
+        <Button onPress={handleLeaveGroup} color='red'>
+          <View className='flex-row items-center justify-center'>
+            <Ionicons name='exit-outline' size={20} color='white' />
+            <Text className='text-white font-semibold ml-2'>
+              {t("syncplay.leave_group")}
+            </Text>
+          </View>
+        </Button>
+      </View>
+    );
+  }
+
+  return (
+    <View style={containerStyle}>
+      <View className='mb-4'>
+        <View className='flex-row items-center mb-2'>
+          <Ionicons name='people-outline' size={24} color='white' />
+          <Text className='font-bold text-xl text-neutral-100 ml-2'>
+            {t("syncplay.title")}
+          </Text>
+        </View>
+        <Text className='text-neutral-400'>{t("syncplay.join_group")}</Text>
+      </View>
+
+      {isLoading && (
+        <View className='py-8 items-center'>
+          <ActivityIndicator color='#00a4dc' />
+        </View>
+      )}
+
+      {!isLoading && groups.length > 0 && (
+        <View className='mb-4'>
+          <Text className='text-neutral-400 text-sm mb-2 ml-1'>
+            {t("syncplay.available_groups")}
+          </Text>
+          <View className='bg-neutral-800 rounded-xl overflow-hidden'>
+            {groups.map((group, index) => (
+              <TouchableOpacity
+                key={group.GroupId ?? index}
+                onPress={() => group.GroupId && handleJoinGroup(group.GroupId)}
+                className={`flex-row items-center p-4 ${
+                  index < groups.length - 1 ? "border-b border-neutral-700" : ""
+                }`}
+              >
+                <View className='w-10 h-10 bg-[#00a4dc]/20 rounded-full items-center justify-center mr-3'>
+                  <Ionicons name='people' size={20} color='#00a4dc' />
+                </View>
+
+                <View className='flex-1'>
+                  <Text className='text-neutral-100 font-medium'>
+                    {group.GroupName}
+                  </Text>
+                  <Text className='text-neutral-500 text-sm'>
+                    {group.Participants?.length ?? 0} {t("syncplay.members")} •{" "}
+                    {group.State}
+                  </Text>
+                </View>
+
+                <Ionicons name='chevron-forward' size={20} color='#9ca3af' />
+              </TouchableOpacity>
+            ))}
+          </View>
+        </View>
+      )}
+
+      {!isLoading && groups.length === 0 && (
+        <View className='bg-neutral-800/50 rounded-xl p-6 mb-4 items-center'>
+          <Ionicons name='people-outline' size={40} color='#6b7280' />
+          <Text className='text-neutral-400 text-center mt-3'>
+            {t("syncplay.available_groups")}: 0{"\n"}
+            {t("syncplay.create_new_group")}
+          </Text>
+        </View>
+      )}
+
+      {canCreateGroups && (
+        <Button
+          onPress={handleCreateGroup}
+          color='purple'
+          disabled={isCreating}
+        >
+          <View className='flex-row items-center justify-center'>
+            {isCreating ? (
+              <ActivityIndicator size='small' color='white' />
+            ) : (
+              <>
+                <Ionicons name='add' size={20} color='white' />
+                <Text className='text-white font-semibold ml-2'>
+                  {t("syncplay.create_new_group")}
+                </Text>
+              </>
+            )}
+          </View>
+        </Button>
+      )}
+    </View>
+  );
+}

components/syncplay/SyncPlayActionIcon.tsx

@@ -0,0 +1,206 @@
+/**
+ * SyncPlayActionIcon
+ *
+ * In-button SyncPlay status indicator — drops into the player's
+ * play/pause button slot and replaces the normal play/pause/loader
+ * graphic while SyncPlay is mid-transition. Mirrors jellyfin-web's
+ * `#syncPlayIcon` element (see `showIcon()` in
+ * `jellyfin-web/src/controllers/playback/video/index.js`).
+ *
+ * Icon vocabulary (matched 1:1 with jellyfin-web's `showIcon` switch):
+ *
+ *   action          primary       secondary         pulse      spin
+ *   --------------- ------------- ----------------- ---------- ----
+ *   schedule-play   sync          play (centered)   infinite   yes
+ *   unpause         play-circle   —                 one-shot   no
+ *   pause           pause-circle  —                 one-shot   no
+ *   seek            refresh       —                 infinite   no
+ *   buffering       clock         —                 infinite   no
+ *   wait-pause      clock         pause (shifted)   infinite   no
+ *   wait-unpause    clock         play (shifted)    infinite   no
+ *
+ * Material → Ionicons mapping used here:
+ *   sync → sync, schedule → time-outline, update → refresh-outline,
+ *   play_arrow → play, pause → pause,
+ *   play_circle_outline → play-circle-outline,
+ *   pause_circle_outline → pause-circle-outline.
+ *
+ * When no SyncPlay action is active the component renders `fallback`
+ * so callers can keep the normal play/pause/loader graphic.
+ */
+
+import { Ionicons } from "@expo/vector-icons";
+import { type ReactNode, useEffect } from "react";
+import { StyleSheet, View } from "react-native";
+import Animated, {
+  cancelAnimation,
+  Easing,
+  useAnimatedStyle,
+  useSharedValue,
+  withRepeat,
+  withSequence,
+  withTiming,
+} from "react-native-reanimated";
+import type { SyncPlayOsdAction } from "@/providers/SyncPlay";
+import { useSyncPlay } from "@/providers/SyncPlay";
+
+// SyncPlay cyan (matches jellyfin-web's `.syncPlayIconCircle` color)
+const SYNC_PLAY_COLOR = "#00a4dc";
+
+type IoniconName = keyof typeof Ionicons.glyphMap;
+
+type SecondaryPosition = "centered" | "shifted";
+
+interface SecondaryIcon {
+  icon: IoniconName;
+  position: SecondaryPosition;
+}
+
+interface OsdConfig {
+  /** Primary icon — fills the available size. */
+  icon: IoniconName;
+  /** Optional smaller overlay (~42% size). */
+  secondary?: SecondaryIcon;
+  /** Wrapper-level scale animation. */
+  pulse: "infinite" | "oneshot";
+  /** Rotate the primary icon continuously (secondary stays still). */
+  spin?: boolean;
+}
+
+const CONFIG: Record<SyncPlayOsdAction, OsdConfig> = {
+  "schedule-play": {
+    icon: "sync",
+    secondary: { icon: "play", position: "centered" },
+    pulse: "infinite",
+    spin: true,
+  },
+  unpause: { icon: "play-circle-outline", pulse: "oneshot" },
+  pause: { icon: "pause-circle-outline", pulse: "oneshot" },
+  seek: { icon: "refresh-outline", pulse: "infinite" },
+  buffering: { icon: "time-outline", pulse: "infinite" },
+  "wait-pause": {
+    icon: "time-outline",
+    secondary: { icon: "pause", position: "shifted" },
+    pulse: "infinite",
+  },
+  "wait-unpause": {
+    icon: "time-outline",
+    secondary: { icon: "play", position: "shifted" },
+    pulse: "infinite",
+  },
+};
+
+interface SyncPlayActionIconProps {
+  size: number;
+  color?: string;
+  /** Rendered when no SyncPlay action is active. */
+  fallback?: ReactNode;
+}
+
+export function SyncPlayActionIcon({
+  size,
+  color = SYNC_PLAY_COLOR,
+  fallback = null,
+}: SyncPlayActionIconProps) {
+  const { osdAction } = useSyncPlay();
+
+  const rotation = useSharedValue(0);
+  const scale = useSharedValue(1);
+
+  useEffect(() => {
+    cancelAnimation(rotation);
+    cancelAnimation(scale);
+    rotation.value = 0;
+    scale.value = 1;
+
+    if (!osdAction) return;
+
+    const config = CONFIG[osdAction];
+
+    if (config.spin) {
+      rotation.value = withRepeat(
+        withTiming(360, { duration: 1200, easing: Easing.linear }),
+        -1,
+        false,
+      );
+    }
+
+    if (config.pulse === "infinite") {
+      scale.value = withRepeat(
+        withSequence(
+          withTiming(1.1, {
+            duration: 700,
+            easing: Easing.inOut(Easing.quad),
+          }),
+          withTiming(0.95, {
+            duration: 700,
+            easing: Easing.inOut(Easing.quad),
+          }),
+        ),
+        -1,
+        true,
+      );
+    } else {
+      // one-shot: single scale flash; the provider clears the action
+      // ~1500ms later (transient OSD) so the icon then unmounts.
+      scale.value = withSequence(
+        withTiming(1.2, { duration: 220, easing: Easing.out(Easing.quad) }),
+        withTiming(1, { duration: 220, easing: Easing.inOut(Easing.quad) }),
+      );
+    }
+  }, [osdAction, rotation, scale]);
+
+  const pulseStyle = useAnimatedStyle(() => ({
+    transform: [{ scale: scale.value }],
+  }));
+
+  const spinStyle = useAnimatedStyle(() => ({
+    transform: [{ rotate: `${rotation.value}deg` }],
+  }));
+
+  if (!osdAction) return <>{fallback}</>;
+
+  const config = CONFIG[osdAction];
+  const secondarySize = Math.round(size * 0.42);
+
+  // centered: geometric middle of the primary (e.g. play arrow inside
+  // the spinning `sync` ring for schedule-play).
+  // shifted: bottom-right corner (e.g. play/pause badge on the clock
+  // for wait-unpause / wait-pause).
+  const secondaryPosStyle =
+    config.secondary?.position === "centered"
+      ? {
+          top: (size - secondarySize) / 2,
+          left: (size - secondarySize) / 2,
+        }
+      : { bottom: 0, right: 0 };
+
+  return (
+    <Animated.View style={pulseStyle}>
+      <View style={{ width: size, height: size }}>
+        <Animated.View style={[StyleSheet.absoluteFill, spinStyle]}>
+          <Ionicons name={config.icon} size={size} color={color} />
+        </Animated.View>
+
+        {config.secondary && (
+          <View
+            pointerEvents='none'
+            style={[styles.secondary, secondaryPosStyle]}
+          >
+            <Ionicons
+              name={config.secondary.icon}
+              size={secondarySize}
+              color={color}
+            />
+          </View>
+        )}
+      </View>
+    </Animated.View>
+  );
+}
+
+const styles = StyleSheet.create({
+  secondary: {
+    position: "absolute",
+  },
+});

components/syncplay/SyncPlayButton.tsx

@@ -0,0 +1,97 @@
+/**
+ * SyncPlayButton
+ *
+ * Header button for accessing SyncPlay functionality.
+ * Shows group status and opens the group selection sheet.
+ *
+ * Uses the @expo/ui drop-in BottomSheetModal (SwiftUI sheet on iOS, Jetpack
+ * Compose ModalBottomSheet on Android). Because it presents natively, it
+ * works correctly even when triggered from `headerRight` — no portal or
+ * provider context is required (unlike @gorhom/bottom-sheet, which fails
+ * silently from detached UINavigationItem subtrees).
+ *
+ * Safe to import statically: this whole module is lazy-required only on
+ * non-TV platforms by app/(auth)/(tabs)/(home)/_layout.tsx.
+ */
+
+import {
+  type BottomSheetMethods,
+  BottomSheetModal,
+  BottomSheetView,
+} from "@expo/ui/community/bottom-sheet";
+import { Ionicons } from "@expo/vector-icons";
+import { useCallback, useRef } from "react";
+import { Platform, View } from "react-native";
+import { Pressable } from "react-native-gesture-handler";
+import { useCastDevice } from "react-native-google-cast";
+import { toast } from "sonner-native";
+import { useNetworkStatus } from "@/providers/NetworkStatusProvider";
+import { useSyncPlay } from "@/providers/SyncPlay";
+import { GroupSelectionMenu } from "./GroupSelectionMenu";
+
+interface SyncPlayButtonProps {
+  size?: number;
+}
+
+export function SyncPlayButton({ size = 22 }: SyncPlayButtonProps) {
+  const { isEnabled, canJoinGroups } = useSyncPlay();
+  const { isConnected } = useNetworkStatus();
+  const castDevice = useCastDevice();
+  const sheetRef = useRef<BottomSheetMethods>(null);
+
+  const isCasting = !!castDevice;
+
+  const handlePress = useCallback(() => {
+    if (isCasting) {
+      toast("SyncPlay not available while casting");
+      return;
+    }
+    sheetRef.current?.present();
+  }, [isCasting]);
+
+  const handleDismiss = useCallback(() => {
+    sheetRef.current?.dismiss();
+  }, []);
+
+  if (Platform.isTV) return null;
+  if (!canJoinGroups) return null;
+  if (!isConnected) return null;
+
+  const iconColor = isCasting ? "#6b7280" : isEnabled ? "#00a4dc" : "white";
+
+  return (
+    <>
+      <Pressable
+        className='mr-4'
+        onPress={handlePress}
+        hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}
+      >
+        <View className='relative'>
+          <Ionicons
+            name={isEnabled ? "people" : "people-outline"}
+            size={size}
+            color={iconColor}
+          />
+          {isEnabled && !isCasting && (
+            <View
+              className='absolute -top-0.5 -right-0.5 w-2.5 h-2.5 rounded-full bg-[#00a4dc]'
+              style={{
+                borderWidth: 1,
+                borderColor: "#171717",
+              }}
+            />
+          )}
+        </View>
+      </Pressable>
+      <BottomSheetModal
+        ref={sheetRef}
+        snapPoints={Platform.OS === "android" ? ["100%"] : ["60%"]}
+        enablePanDownToClose
+      >
+        <BottomSheetView>
+          <GroupSelectionMenu onClose={handleDismiss} />
+        </BottomSheetView>
+      </BottomSheetModal>
+    </>
+  );
+}

components/syncplay/SyncPlaySpinner.tsx

@@ -0,0 +1,53 @@
+/**
+ * SyncPlaySpinner
+ *
+ * Compact rotating SyncPlay icon shown in place of the play/pause button
+ * while a play/pause command is in flight to the server (the "schedule-play"
+ * indicator from jellyfin-web).
+ */
+
+import { Ionicons } from "@expo/vector-icons";
+import { useEffect } from "react";
+import Animated, {
+  Easing,
+  useAnimatedStyle,
+  useSharedValue,
+  withRepeat,
+  withTiming,
+} from "react-native-reanimated";
+
+// SyncPlay cyan color (matches jellyfin-web)
+const SYNC_PLAY_COLOR = "#00a4dc";
+
+interface SyncPlaySpinnerProps {
+  size: number;
+  color?: string;
+}
+
+export function SyncPlaySpinner({
+  size,
+  color = SYNC_PLAY_COLOR,
+}: SyncPlaySpinnerProps) {
+  const rotation = useSharedValue(0);
+
+  useEffect(() => {
+    rotation.value = withRepeat(
+      withTiming(360, {
+        duration: 1200,
+        easing: Easing.linear,
+      }),
+      -1,
+      false,
+    );
+  }, [rotation]);
+
+  const animatedStyle = useAnimatedStyle(() => ({
+    transform: [{ rotate: `${rotation.value}deg` }],
+  }));
+
+  return (
+    <Animated.View style={animatedStyle}>
+      <Ionicons name='sync' size={size} color={color} />
+    </Animated.View>
+  );
+}

components/syncplay/index.ts

@@ -0,0 +1,8 @@
+/**
+ * SyncPlay UI Components
+ */
+
+export { GroupSelectionMenu } from "./GroupSelectionMenu";
+export { SyncPlayActionIcon } from "./SyncPlayActionIcon";
+export { SyncPlayButton } from "./SyncPlayButton";
+export { SyncPlaySpinner } from "./SyncPlaySpinner";

components/video-player/controls/CenterControls.tsx

@@ -3,6 +3,7 @@ import type { FC } from "react";
 import { Platform, TouchableOpacity, View } from "react-native";
 import { Text } from "@/components/common/Text";
 import { Loader } from "@/components/Loader";
+import { SyncPlayActionIcon } from "@/components/syncplay/SyncPlayActionIcon";
 import { useControlsSafeAreaInsets } from "@/hooks/useControlsSafeAreaInsets";
 import { useSettings } from "@/utils/atoms/settings";
 import AudioSlider from "./AudioSlider";
@@ -121,15 +122,20 @@ export const CenterControls: FC<CenterControlsProps> = ({
 
       <View style={Platform.isTV ? { flex: 1, alignItems: "center" } : {}}>
         <TouchableOpacity onPress={togglePlay}>
-          {!isBuffering ? (
-            <Ionicons
-              name={isPlaying ? "pause" : "play"}
-              size={ICON_SIZES.CENTER}
-              color='white'
-            />
-          ) : (
-            <Loader size={"large"} />
-          )}
+          <SyncPlayActionIcon
+            size={ICON_SIZES.CENTER}
+            fallback={
+              !isBuffering ? (
+                <Ionicons
+                  name={isPlaying ? "pause" : "play"}
+                  size={ICON_SIZES.CENTER}
+                  color='white'
+                />
+              ) : (
+                <Loader size={"large"} />
+              )
+            }
+          />
         </TouchableOpacity>
       </View>
 

components/video-player/controls/ContinueWatchingOverlay.tsx

@@ -7,14 +7,12 @@ import useRouter from "@/hooks/useAppRouter";
 import { useSettings } from "@/utils/atoms/settings";
 
 export interface ContinueWatchingOverlayProps {
-  goToNextItem: (options: {
-    isAutoPlay: boolean;
-    resetWatchCount: boolean;
-  }) => void;
+  /** Invoked when the user confirms they want to keep watching. */
+  onContinue: () => void;
 }
 
 const ContinueWatchingOverlay: React.FC<ContinueWatchingOverlayProps> = ({
-  goToNextItem,
+  onContinue,
 }) => {
   const { settings } = useSettings();
   const router = useRouter();
@@ -29,13 +27,7 @@ const ContinueWatchingOverlay: React.FC<ContinueWatchingOverlayProps> = ({
       <Text className='text-2xl font-bold text-white py-4 '>
         Are you still watching ?
       </Text>
-      <Button
-        onPress={() => {
-          goToNextItem({ isAutoPlay: false, resetWatchCount: true });
-        }}
-        color={"purple"}
-        className='my-4 w-2/3'
-      >
+      <Button onPress={onContinue} color={"purple"} className='my-4 w-2/3'>
         {t("player.continue_watching")}
       </Button>
 

components/video-player/controls/Controls.tsx

@@ -15,17 +15,15 @@ import Animated, {
   withTiming,
 } from "react-native-reanimated";
 import ContinueWatchingOverlay from "@/components/video-player/controls/ContinueWatchingOverlay";
-import useRouter from "@/hooks/useAppRouter";
 import { useCreditSkipper } from "@/hooks/useCreditSkipper";
-import { useHaptic } from "@/hooks/useHaptic";
 import { useIntroSkipper } from "@/hooks/useIntroSkipper";
 import { usePlaybackManager } from "@/hooks/usePlaybackManager";
+import { usePlayerItemNavigation } from "@/hooks/usePlayerItemNavigation";
 import { useTrickplay } from "@/hooks/useTrickplay";
 import type { TechnicalInfo } from "@/modules/mpv-player";
 import { DownloadedItem } from "@/providers/Downloads/types";
 import { useOfflineMode } from "@/providers/OfflineModeProvider";
 import { useSettings } from "@/utils/atoms/settings";
-import { getDefaultPlaySettings } from "@/utils/jellyfin/getDefaultPlaySettings";
 import { ticksToMs } from "@/utils/time";
 import { BottomControls } from "./BottomControls";
 import { CenterControls } from "./CenterControls";
@@ -104,9 +102,7 @@ export const Controls: FC<Props> = ({
   transcodeReasons,
 }) => {
   const offline = useOfflineMode();
-  const { settings, updateSettings } = useSettings();
-  const router = useRouter();
-  const lightHapticFeedback = useHaptic("light");
+  const { settings } = useSettings();
 
   const [episodeView, setEpisodeView] = useState(false);
   const [showAudioSlider, setShowAudioSlider] = useState(false);
@@ -338,130 +334,27 @@ export const Controls: FC<Props> = ({
       maxMs,
     );
 
-  const goToItemCommon = useCallback(
-    (item: BaseItemDto) => {
-      if (!item || !settings) {
-        return;
-      }
-      lightHapticFeedback();
-      const previousIndexes = {
-        subtitleIndex: subtitleIndex
-          ? Number.parseInt(subtitleIndex, 10)
-          : undefined,
-        audioIndex: audioIndex ? Number.parseInt(audioIndex, 10) : undefined,
-      };
-
-      const {
-        mediaSource: newMediaSource,
-        audioIndex: defaultAudioIndex,
-        subtitleIndex: defaultSubtitleIndex,
-      } = getDefaultPlaySettings(
-        item,
-        settings,
-        {
-          indexes: previousIndexes,
-          source: mediaSource ?? undefined,
-        },
-        { applyLanguagePreferences: true },
-      );
-
-      // Use setParams instead of replace to avoid unmounting/remounting the player,
-      // which would create a new MPV native view and crash with "mp_initialize already initialized".
-      router.setParams({
-        ...(offline && { offline: "true" }),
-        itemId: item.Id ?? "",
-        audioIndex: defaultAudioIndex?.toString() ?? "",
-        subtitleIndex: defaultSubtitleIndex?.toString() ?? "",
-        mediaSourceId: newMediaSource?.Id ?? "",
-        bitrateValue: bitrateValue?.toString(),
-        playbackPosition:
-          item.UserData?.PlaybackPositionTicks?.toString() ?? "",
-      });
-    },
-    [
-      settings,
-      subtitleIndex,
-      audioIndex,
-      mediaSource,
-      bitrateValue,
-      router,
-      offline,
-    ],
-  );
-
-  const goToPreviousItem = useCallback(() => {
-    if (!previousItem) {
-      return;
-    }
-    goToItemCommon(previousItem);
-  }, [previousItem, goToItemCommon]);
-
-  const goToNextItem = useCallback(
-    ({
-      isAutoPlay,
-      resetWatchCount,
-    }: {
-      isAutoPlay?: boolean;
-      resetWatchCount?: boolean;
-    }) => {
-      if (!nextItem) {
-        return;
-      }
-
-      if (!isAutoPlay) {
-        // if we are not autoplaying, we won't update anything, we just go to the next item
-        goToItemCommon(nextItem);
-        if (resetWatchCount) {
-          updateSettings({
-            autoPlayEpisodeCount: 0,
-          });
-        }
-        return;
-      }
-
-      // Skip autoplay logic if maxAutoPlayEpisodeCount is -1
-      if (settings.maxAutoPlayEpisodeCount.value === -1) {
-        goToItemCommon(nextItem);
-        return;
-      }
-
-      if (
-        settings.autoPlayEpisodeCount + 1 <
-        settings.maxAutoPlayEpisodeCount.value
-      ) {
-        goToItemCommon(nextItem);
-      }
-
-      // Check if the autoPlayEpisodeCount is less than maxAutoPlayEpisodeCount for the autoPlay
-      if (
-        settings.autoPlayEpisodeCount < settings.maxAutoPlayEpisodeCount.value
-      ) {
-        // update the autoPlayEpisodeCount in settings
-        updateSettings({
-          autoPlayEpisodeCount: settings.autoPlayEpisodeCount + 1,
-        });
-      }
-    },
-    [nextItem, goToItemCommon],
-  );
-
-  // Add a memoized handler for autoplay next episode
-  const handleNextEpisodeAutoPlay = useCallback(() => {
-    goToNextItem({ isAutoPlay: true });
-  }, [goToNextItem]);
-
-  // Add a memoized handler for manual next episode
-  const handleNextEpisodeManual = useCallback(() => {
-    goToNextItem({ isAutoPlay: false });
-  }, [goToNextItem]);
-
-  // Add a memoized handler for ContinueWatchingOverlay
-  const handleContinueWatching = useCallback(
-    (options: { isAutoPlay?: boolean; resetWatchCount?: boolean }) => {
-      goToNextItem(options);
-    },
-    [goToNextItem],
-  );
+  /*
+   * Single source of truth for next / previous / picker / autoplay
+   * navigation. Handles SyncPlay dispatch, autoplay count gating,
+   * platform-appropriate local navigation, and offline param injection.
+   */
+  const {
+    goToNextItem: handleNextEpisodeManual,
+    goToPreviousItem: handlePreviousItem,
+    goToItem: handleGoToItem,
+    handleAutoPlayNext: handleNextEpisodeAutoPlay,
+    handleContinueWatching,
+  } = usePlayerItemNavigation({
+    nextItem,
+    previousItem,
+    mediaSource,
+    currentAudioIndex: audioIndex ? Number.parseInt(audioIndex, 10) : undefined,
+    currentSubtitleIndex: subtitleIndex
+      ? Number.parseInt(subtitleIndex, 10)
+      : undefined,
+    bitrateValue: bitrateValue ? Number.parseInt(bitrateValue, 10) : undefined,
+  });
 
   const hideControls = useCallback(() => {
     setShowControls(false);
@@ -490,7 +383,7 @@ export const Controls: FC<Props> = ({
         <EpisodeList
           item={item}
           close={() => setEpisodeView(false)}
-          goToItem={goToItemCommon}
+          goToItem={handleGoToItem}
         />
       ) : (
         <>
@@ -524,8 +417,8 @@ export const Controls: FC<Props> = ({
               mediaSource={mediaSource}
               startPictureInPicture={startPictureInPicture}
               switchOnEpisodeMode={switchOnEpisodeMode}
-              goToPreviousItem={goToPreviousItem}
-              goToNextItem={goToNextItem}
+              goToPreviousItem={handlePreviousItem}
+              goToNextItem={handleNextEpisodeManual}
               previousItem={previousItem}
               nextItem={nextItem}
               aspectRatio={aspectRatio}
@@ -597,7 +490,7 @@ export const Controls: FC<Props> = ({
         </>
       )}
       {settings.maxAutoPlayEpisodeCount.value !== -1 && (
-        <ContinueWatchingOverlay goToNextItem={handleContinueWatching} />
+        <ContinueWatchingOverlay onContinue={handleContinueWatching} />
       )}
     </View>
   );

components/video-player/controls/HeaderControls.tsx

@@ -24,7 +24,7 @@ interface HeaderControlsProps {
   startPictureInPicture?: () => Promise<void>;
   switchOnEpisodeMode: () => void;
   goToPreviousItem: () => void;
-  goToNextItem: (options: { isAutoPlay?: boolean }) => void;
+  goToNextItem: () => void;
   previousItem?: BaseItemDto | null;
   nextItem?: BaseItemDto | null;
   aspectRatio?: AspectRatio;
@@ -172,7 +172,7 @@ export const HeaderControls: FC<HeaderControlsProps> = ({
         )}
         {nextItem && (
           <TouchableOpacity
-            onPress={() => goToNextItem({ isAutoPlay: false })}
+            onPress={() => goToNextItem()}
             className='aspect-square flex flex-col rounded-xl items-center justify-center p-2'
           >
             <Ionicons

hooks/useKeepWebSocketAlive.ts

@@ -0,0 +1,22 @@
+import { useEffect } from "react";
+import { useWebSocketContext } from "@/providers/WebSocketProvider";
+
+/**
+ * While `active` is true, hold a keep-alive token on the global
+ * WebSocket so it is NOT closed when the app moves to
+ * background/inactive. Releases automatically when `active` flips
+ * false or the component unmounts.
+ *
+ * Used by the video player while in Picture-in-Picture so SyncPlay
+ * commands (and any other server pushes) keep flowing while the OS
+ * thinks the app is backgrounded.
+ */
+export function useKeepWebSocketAlive(active: boolean): void {
+  const { acquireKeepAlive } = useWebSocketContext();
+
+  useEffect(() => {
+    if (!active) return;
+    const release = acquireKeepAlive();
+    return release;
+  }, [active, acquireKeepAlive]);
+}

hooks/usePlayerItemNavigation.ts

@@ -0,0 +1,405 @@
+/**
+ * Single source of truth for *all* item-level navigation inside the
+ * player (next / previous / picked-from-episode-list / autoplay-next).
+ *
+ * This hook encapsulates three orthogonal concerns so callers don't
+ * have to:
+ *
+ *  1. **SyncPlay** — when a group is active, every advance/rewind
+ *     dispatches through `Controller`. `SyncPlayProvider` handles the
+ *     resulting `localPlay` / `localSetCurrentPlaylistItem` events and
+ *     navigates the local screen.
+ *  2. **Autoplay gating** — `maxAutoPlayEpisodeCount` limits how many
+ *     episodes auto-play before stopping. Manual presses bypass this.
+ *     SyncPlay bypasses it too (the server drives the queue).
+ *  3. **Platform navigation** — mobile uses `router.setParams` so the
+ *     player view stays mounted (avoids a full re-mount + bitrate /
+ *     stream re-pick cycle). TV uses `router.replace` because MPV's
+ *     native view can't be re-initialized in place. Offline state is
+ *     preserved automatically by `useAppRouter`.
+ */
+
+import type {
+  BaseItemDto,
+  MediaSourceInfo,
+} from "@jellyfin/sdk/lib/generated-client";
+import { useCallback } from "react";
+import { useTranslation } from "react-i18next";
+import { Alert, Platform } from "react-native";
+import useAppRouter from "@/hooks/useAppRouter";
+import { useHaptic } from "@/hooks/useHaptic";
+import { getDownloadedItemById } from "@/providers/Downloads";
+import { useOfflineMode } from "@/providers/OfflineModeProvider";
+import { useSyncPlay } from "@/providers/SyncPlay";
+import { useSettings } from "@/utils/atoms/settings";
+import { getDefaultPlaySettings } from "@/utils/jellyfin/getDefaultPlaySettings";
+
+interface UsePlayerItemNavigationParams {
+  /**
+   * The adjacent item that "next" should target (from `usePlaybackManager`).
+   * Only needed by callers that use the in-session nav methods.
+   */
+  nextItem?: BaseItemDto | null;
+  /** The adjacent item that "previous" should target. */
+  previousItem?: BaseItemDto | null;
+  /** The active media source for the *current* item; used to seed track defaults. */
+  mediaSource?: MediaSourceInfo | null;
+  /** Live audio track index (may differ from the URL param after the user changed tracks). */
+  currentAudioIndex?: number;
+  /** Live subtitle track index. */
+  currentSubtitleIndex?: number;
+  /** Currently-active bitrate cap. */
+  bitrateValue?: number;
+  /**
+   * Optional guard for "we're already stopping the player". TV passes
+   * `isPlaybackStopped` here to drop spurious next-item dispatches that
+   * fire during teardown.
+   */
+  isDisabled?: boolean;
+}
+
+/** Options for `playItem` — the entry-point method used by PlayButton et al. */
+export interface PlayItemOptions {
+  audioIndex?: number;
+  subtitleIndex?: number;
+  mediaSourceId?: string;
+  bitrateValue?: number;
+  /** Defaults to `item.UserData?.PlaybackPositionTicks`. */
+  playbackPosition?: number;
+  /**
+   * Force local-file playback even outside the offline UI context, and
+   * skip SyncPlay broadcasting. Used when the user explicitly picks the
+   * downloaded copy from a "play downloaded?" prompt.
+   */
+  forceOffline?: boolean;
+}
+
+export interface PlayerItemNavigation {
+  /** SyncPlay-aware previous. No-op when there's no previous item. */
+  goToPreviousItem: () => void;
+  /**
+   * Manual next (e.g. user tapped the skip-forward / next button).
+   * Autoplay gating is bypassed.
+   */
+  goToNextItem: () => void;
+  /** Jump to an arbitrary item (episode picker). */
+  goToItem: (item: BaseItemDto) => void;
+  /**
+   * Autoplay next (e.g. "Up Next" overlay countdown completed). Respects
+   * `maxAutoPlayEpisodeCount`. Bypassed when SyncPlay is active.
+   */
+  handleAutoPlayNext: () => void;
+  /**
+   * Helper for the "Keep Watching" overlay button — advances and resets
+   * the auto-play counter so the next stretch of episodes can autoplay.
+   */
+  handleContinueWatching: () => void;
+  /**
+   * Entry-point: start playback of an item from outside the player
+   * (PlayButton, Continue Watching, episode picker on the item page).
+   * SyncPlay-aware. Resets the autoplay counter.
+   */
+  playItem: (item: BaseItemDto, opts?: PlayItemOptions) => Promise<void>;
+}
+
+export function usePlayerItemNavigation(
+  params: UsePlayerItemNavigationParams = {},
+): PlayerItemNavigation {
+  const {
+    nextItem,
+    previousItem,
+    mediaSource,
+    currentAudioIndex,
+    currentSubtitleIndex,
+    bitrateValue,
+    isDisabled,
+  } = params;
+
+  const router = useAppRouter();
+  const { t } = useTranslation();
+  const { settings, updateSettings } = useSettings();
+  const { isEnabled: isSyncPlayEnabled, controller: syncPlayController } =
+    useSyncPlay();
+  const lightHapticFeedback = useHaptic("light");
+  // Note: "offline mode" is a *UI context* flag (set by pages entered from
+  // the downloads tab), not a network-connectivity status. A user may be
+  // in offline mode with perfect internet, watching a downloaded copy.
+  const inOfflineContext = useOfflineMode();
+
+  /*
+   * Compute the destination URL params for a given target item, using
+   * the live selection state (which may differ from the URL params the
+   * episode started with — the user may have switched tracks mid-play).
+   */
+  const buildNavigationParams = useCallback(
+    (target: BaseItemDto) => {
+      if (!settings) return null;
+      const {
+        mediaSource: newMediaSource,
+        audioIndex: defaultAudioIndex,
+        subtitleIndex: defaultSubtitleIndex,
+      } = getDefaultPlaySettings(
+        target,
+        settings,
+        {
+          indexes: {
+            subtitleIndex: currentSubtitleIndex,
+            audioIndex: currentAudioIndex,
+          },
+          source: mediaSource ?? undefined,
+        },
+        { applyLanguagePreferences: true },
+      );
+      return {
+        itemId: target.Id ?? "",
+        audioIndex: defaultAudioIndex?.toString() ?? "",
+        subtitleIndex: defaultSubtitleIndex?.toString() ?? "",
+        mediaSourceId: newMediaSource?.Id ?? "",
+        bitrateValue: bitrateValue?.toString() ?? "",
+        playbackPosition:
+          target.UserData?.PlaybackPositionTicks?.toString() ?? "",
+      };
+    },
+    [
+      settings,
+      currentSubtitleIndex,
+      currentAudioIndex,
+      mediaSource,
+      bitrateValue,
+    ],
+  );
+
+  /*
+   * Stamp the `offline` URL param onto a params object based on whether
+   * the target item is actually downloaded.
+   *
+   * - Online (no offline UI context) → pass through unchanged; the
+   *   `offline` key is absent so `useAppRouter` doesn't touch it.
+   * - Offline context, target IS downloaded → `offline: "true"` (play
+   *   the local copy).
+   * - Offline context, target is NOT downloaded → `offline: ""` (force
+   *   online streaming; the key's presence blocks `useAppRouter` from
+   *   auto-injecting `"true"`, and direct-player only treats the value
+   *   `"true"` as offline).
+   *
+   * That last case is the important one: a user can be in the offline
+   * UI context with perfect internet (e.g. navigated in from downloads)
+   * and pick an episode they never downloaded. Without this the player
+   * would hang waiting for a local file that doesn't exist.
+   */
+  const withOfflineParam = useCallback(
+    (params: Record<string, string>, target: BaseItemDto) => {
+      if (!inOfflineContext) return params;
+      const isDownloaded = !!(target.Id && getDownloadedItemById(target.Id));
+      return { ...params, offline: isDownloaded ? "true" : "" };
+    },
+    [inOfflineContext],
+  );
+
+  /*
+   * Platform-appropriate local navigation. Mobile keeps the same player
+   * view mounted via setParams; TV swaps the whole route via replace.
+   */
+  const localNavigate = useCallback(
+    (target: BaseItemDto) => {
+      if (isDisabled) return;
+      const navParams = buildNavigationParams(target);
+      if (!navParams) return;
+      lightHapticFeedback();
+
+      const finalParams = withOfflineParam(navParams, target);
+
+      if (Platform.isTV) {
+        const queryString = new URLSearchParams(finalParams).toString();
+        router.replace(`/player/direct-player?${queryString}`);
+      } else {
+        router.setParams(finalParams);
+      }
+    },
+    [
+      isDisabled,
+      buildNavigationParams,
+      router,
+      lightHapticFeedback,
+      withOfflineParam,
+    ],
+  );
+
+  const goToPreviousItem = useCallback(() => {
+    if (isSyncPlayEnabled && syncPlayController) {
+      syncPlayController.previousItem();
+      return;
+    }
+    if (!previousItem) return;
+    localNavigate(previousItem);
+  }, [isSyncPlayEnabled, syncPlayController, previousItem, localNavigate]);
+
+  const goToNextItem = useCallback(() => {
+    if (isSyncPlayEnabled && syncPlayController) {
+      syncPlayController.nextItem();
+      return;
+    }
+    if (!nextItem) return;
+    localNavigate(nextItem);
+  }, [isSyncPlayEnabled, syncPlayController, nextItem, localNavigate]);
+
+  const goToItem = useCallback(
+    (target: BaseItemDto) => {
+      if (isSyncPlayEnabled && syncPlayController && target.Id) {
+        syncPlayController.goToItem(target);
+        return;
+      }
+      localNavigate(target);
+    },
+    [isSyncPlayEnabled, syncPlayController, localNavigate],
+  );
+
+  const handleAutoPlayNext = useCallback(() => {
+    // SyncPlay always advances unconditionally — the server is the source
+    // of truth for queue progression and per-client gating would desync us.
+    if (isSyncPlayEnabled && syncPlayController) {
+      syncPlayController.nextItem();
+      return;
+    }
+    if (!nextItem) return;
+
+    const maxCount = settings?.maxAutoPlayEpisodeCount.value ?? 0;
+    const currentCount = settings?.autoPlayEpisodeCount ?? 0;
+
+    // -1 means "no limit"
+    if (maxCount === -1) {
+      localNavigate(nextItem);
+      return;
+    }
+
+    if (currentCount + 1 < maxCount) {
+      localNavigate(nextItem);
+    }
+
+    if (currentCount < maxCount) {
+      updateSettings({ autoPlayEpisodeCount: currentCount + 1 });
+    }
+  }, [
+    isSyncPlayEnabled,
+    syncPlayController,
+    nextItem,
+    settings,
+    updateSettings,
+    localNavigate,
+  ]);
+
+  const handleContinueWatching = useCallback(() => {
+    if (isSyncPlayEnabled && syncPlayController) {
+      syncPlayController.nextItem();
+      return;
+    }
+    if (!nextItem) return;
+    updateSettings({ autoPlayEpisodeCount: 0 });
+    localNavigate(nextItem);
+  }, [
+    isSyncPlayEnabled,
+    syncPlayController,
+    nextItem,
+    updateSettings,
+    localNavigate,
+  ]);
+
+  /*
+   * Entry-point: start playback of an item from outside the player.
+   *
+   * Used by PlayButton, Continue Watching cards, episode pickers on the
+   * item page, etc. Unlike the in-session methods, this always uses
+   * `router.push` (we're entering the player, not navigating within it)
+   * and runs on both mobile and TV with the same shape.
+   *
+   * SyncPlay: when in a group and the user *didn't* explicitly request
+   * local playback, we route through `controller.play()` so every group
+   * member gets the same `PlayQueue: NewPlaylist` update and navigates
+   * together. Errors surface as an Alert and abort the local navigation
+   * (matches `PlayButton`'s previous behavior).
+   */
+  const playItem = useCallback(
+    async (item: BaseItemDto, opts: PlayItemOptions = {}) => {
+      if (!item.Id) return;
+      lightHapticFeedback();
+
+      const startPositionTicks =
+        opts.playbackPosition ?? item.UserData?.PlaybackPositionTicks ?? 0;
+
+      // Fresh playback start — reset the autoplay budget so the next
+      // stretch of episodes can autoplay.
+      if (settings && settings.maxAutoPlayEpisodeCount.value !== -1) {
+        updateSettings({ autoPlayEpisodeCount: 0 });
+      }
+
+      // SyncPlay: broadcast to the group instead of navigating locally.
+      // Skipped when the user explicitly picked the downloaded copy — a
+      // local file can't be part of a synced session.
+      if (!opts.forceOffline && isSyncPlayEnabled && syncPlayController) {
+        try {
+          await syncPlayController.play({
+            items: [item],
+            ids: [item.Id],
+            startPositionTicks,
+          });
+        } catch (error) {
+          console.error("SyncPlay: failed to start group playback", error);
+          Alert.alert(
+            t("player.client_error"),
+            t("syncplay.failed_to_start", {
+              defaultValue: "Failed to start SyncPlay group playback",
+            }),
+          );
+        }
+        return;
+      }
+
+      // Build a string-record so we can run it through `withOfflineParam`
+      // and `URLSearchParams` uniformly.
+      const baseParams: Record<string, string> = {
+        itemId: item.Id,
+        playbackPosition: String(startPositionTicks),
+      };
+      if (opts.audioIndex !== undefined) {
+        baseParams.audioIndex = String(opts.audioIndex);
+      }
+      if (opts.subtitleIndex !== undefined) {
+        baseParams.subtitleIndex = String(opts.subtitleIndex);
+      }
+      if (opts.mediaSourceId) {
+        baseParams.mediaSourceId = opts.mediaSourceId;
+      }
+      if (opts.bitrateValue !== undefined) {
+        baseParams.bitrateValue = String(opts.bitrateValue);
+      }
+
+      const finalParams = opts.forceOffline
+        ? { ...baseParams, offline: "true" }
+        : withOfflineParam(baseParams, item);
+
+      const queryString = new URLSearchParams(finalParams).toString();
+      router.push(`/player/direct-player?${queryString}`);
+    },
+    [
+      lightHapticFeedback,
+      settings,
+      updateSettings,
+      isSyncPlayEnabled,
+      syncPlayController,
+      withOfflineParam,
+      router,
+      t,
+    ],
+  );
+
+  return {
+    goToPreviousItem,
+    goToNextItem,
+    goToItem,
+    handleAutoPlayNext,
+    handleContinueWatching,
+    playItem,
+  };
+}
+
+export default usePlayerItemNavigation;

hooks/useWebsockets.ts

@@ -2,6 +2,7 @@ import { useEffect } from "react";
 import { useTranslation } from "react-i18next";
 import { Alert } from "react-native";
 import useRouter from "@/hooks/useAppRouter";
+import { useSyncPlay } from "@/providers/SyncPlay/SyncPlayProvider";
 import { useWebSocketContext } from "@/providers/WebSocketProvider";
 
 interface UseWebSocketProps {
@@ -80,9 +81,9 @@ export const useWebSocket = ({
   playTrailers,
 }: UseWebSocketProps) => {
   const router = useRouter();
-  const { lastMessage } = useWebSocketContext();
+  const { lastMessage, clearLastMessage } = useWebSocketContext();
   const { t } = useTranslation();
-  const { clearLastMessage } = useWebSocketContext();
+  const { isEnabled: isSyncPlayEnabled } = useSyncPlay();
 
   useEffect(() => {
     if (!lastMessage) return;
@@ -96,6 +97,25 @@ export const useWebSocket = ({
       | Record<string, string>
       | undefined; // Arguments are Dictionary<string, string>
 
+    // Skip playback commands when SyncPlay is enabled - SyncPlay handles these
+    const isSyncPlayCommand =
+      lastMessage.MessageType === "SyncPlayCommand" ||
+      lastMessage.MessageType === "SyncPlayGroupUpdate";
+    const isPlaybackCommand = [
+      "PlayPause",
+      "Pause",
+      "Unpause",
+      "Stop",
+      "Seek",
+      "NextTrack",
+      "PreviousTrack",
+    ].includes(command ?? "");
+
+    if (isSyncPlayEnabled && (isSyncPlayCommand || isPlaybackCommand)) {
+      console.log(`Command ~ ${command} - skipping, SyncPlay handles playback`);
+      return;
+    }
+
     if (command === "PlayPause") {
       console.log("Command ~ PlayPause");
       togglePlay();

modules/mpv-player/android/src/main/java/expo/modules/mpvplayer/MpvPlayerModule.kt

@@ -50,6 +50,13 @@ class MpvPlayerModule : Module() {
                 // No-op on Android - media session integration would require MediaSessionCompat
             }
 
+            // When true, PiP play/pause/skip controls emit JS events
+            // instead of driving MPV directly, so the host app can route
+            // through SyncPlay (server -> group broadcast -> all clients).
+            Prop("syncPlayDelegated") { view: MpvPlayerView, delegated: Boolean ->
+                view.syncPlayDelegated = delegated
+            }
+
             // Async function to play video
             AsyncFunction("play") { view: MpvPlayerView ->
                 view.play()
@@ -198,7 +205,7 @@ class MpvPlayerModule : Module() {
             }
 
             // Defines events that the view can send to JavaScript
-            Events("onLoad", "onPlaybackStateChange", "onProgress", "onError", "onTracksReady", "onPictureInPictureChange")
+            Events("onLoad", "onPlaybackStateChange", "onProgress", "onError", "onTracksReady", "onPictureInPictureChange", "onPipPlayRequest", "onPipPauseRequest", "onPipSkipRequest")
         }
     }
 }

modules/mpv-player/android/src/main/java/expo/modules/mpvplayer/MpvPlayerView.kt

@@ -47,6 +47,16 @@ class MpvPlayerView(context: Context, appContext: AppContext) : ExpoView(context
     val onError by EventDispatcher()
     val onTracksReady by EventDispatcher()
     val onPictureInPictureChange by EventDispatcher()
+    // SyncPlay: when `syncPlayDelegated == true`, PiP playback controls
+    // (play / pause / skip) emit these events instead of driving MPV
+    // directly, so JS can route the action through the SyncPlay
+    // controller (server -> group broadcast -> all clients). Default
+    // behavior (non-SyncPlay) is unchanged.
+    val onPipPlayRequest by EventDispatcher()
+    val onPipPauseRequest by EventDispatcher()
+    val onPipSkipRequest by EventDispatcher()
+
+    var syncPlayDelegated: Boolean = false
 
     private var textureView: TextureView
     private var renderer: MPVLayerRenderer? = null
@@ -85,14 +95,32 @@ class MpvPlayerView(context: Context, appContext: AppContext) : ExpoView(context
         pipController?.setPlayerView(textureView)
         pipController?.delegate = object : PiPController.Delegate {
             override fun onPlay() {
+                if (syncPlayDelegated) {
+                    onPipPlayRequest(mapOf<String, Any>())
+                    return
+                }
                 play()
             }
 
             override fun onPause() {
+                if (syncPlayDelegated) {
+                    onPipPauseRequest(mapOf<String, Any>())
+                    return
+                }
                 pause()
             }
 
             override fun onSeekBy(seconds: Double) {
+                if (syncPlayDelegated) {
+                    val target = (cachedPosition + seconds).coerceAtLeast(0.0)
+                    onPipSkipRequest(
+                        mapOf(
+                            "targetSeconds" to target,
+                            "intervalSeconds" to seconds
+                        )
+                    )
+                    return
+                }
                 seekBy(seconds)
             }
 

modules/mpv-player/ios/MpvPlayerModule.swift

@@ -65,6 +65,13 @@ public class MpvPlayerModule: Module {
         }
       }
 
+      // When true, PiP play/pause/skip controls emit JS events instead
+      // of driving MPV directly, so the host app can route through
+      // SyncPlay (server -> group broadcast -> all clients).
+      Prop("syncPlayDelegated") { (view: MpvPlayerView, delegated: Bool) in
+        view.syncPlayDelegated = delegated
+      }
+
       // Async function to play video
       AsyncFunction("play") { (view: MpvPlayerView) in
         view.play()
@@ -213,7 +220,7 @@ public class MpvPlayerModule: Module {
       }
 
       // Defines events that the view can send to JavaScript
-      Events("onLoad", "onPlaybackStateChange", "onProgress", "onError", "onTracksReady", "onPictureInPictureChange")
+      Events("onLoad", "onPlaybackStateChange", "onProgress", "onError", "onTracksReady", "onPictureInPictureChange", "onPipPlayRequest", "onPipPauseRequest", "onPipSkipRequest")
     }
   }
 }

modules/mpv-player/ios/MpvPlayerView.swift

@@ -62,6 +62,16 @@ class MpvPlayerView: ExpoView {
 	let onError = EventDispatcher()
 	let onTracksReady = EventDispatcher()
 	let onPictureInPictureChange = EventDispatcher()
+	// SyncPlay: when `syncPlayDelegated == true`, PiP playback controls
+	// (play / pause / skip) emit these events instead of driving MPV
+	// directly, so JS can route the action through the SyncPlay
+	// controller (server → group broadcast → all clients). Default
+	// behavior (non-SyncPlay) is unchanged.
+	let onPipPlayRequest = EventDispatcher()
+	let onPipPauseRequest = EventDispatcher()
+	let onPipSkipRequest = EventDispatcher()
+
+	var syncPlayDelegated: Bool = false
 
 	private var currentURL: URL?
 	private var cachedPosition: Double = 0
@@ -671,6 +681,12 @@ extension MpvPlayerView: PiPControllerDelegate {
 	
 	func pipControllerPlay(_ controller: PiPController) {
 		print("PiP play requested")
+		if syncPlayDelegated {
+			// Let JS route through SyncPlay. We deliberately do NOT touch
+			// MPV here; the WS command coming back will drive playback.
+			onPipPlayRequest([:])
+			return
+		}
 		intendedPlayState = true
 		renderer?.play()
 		pipController?.setPlaybackRate(1.0)
@@ -678,6 +694,10 @@ extension MpvPlayerView: PiPControllerDelegate {
 	
 	func pipControllerPause(_ controller: PiPController) {
 		print("PiP pause requested")
+		if syncPlayDelegated {
+			onPipPauseRequest([:])
+			return
+		}
 		intendedPlayState = false
 		renderer?.pausePlayback()
 		pipController?.setPlaybackRate(0.0)
@@ -687,6 +707,16 @@ extension MpvPlayerView: PiPControllerDelegate {
 		let seconds = CMTimeGetSeconds(interval)
 		print("PiP skip by interval: \(seconds)")
 		let target = max(0, cachedPosition + seconds)
+		if syncPlayDelegated {
+			// `targetSeconds` lets JS convert to ticks and call
+			// syncPlayController.seek(). `intervalSeconds` is also sent
+			// for telemetry / debug.
+			onPipSkipRequest([
+				"targetSeconds": target,
+				"intervalSeconds": seconds
+			])
+			return
+		}
 		seekTo(position: target)
 	}
 	

modules/mpv-player/src/MpvPlayer.types.ts

@@ -29,6 +29,21 @@ export type OnPictureInPictureChangePayload = {
   isActive: boolean;
 };
 
+/**
+ * Emitted when the user taps a PiP playback control while the view
+ * was rendered with `syncPlayDelegated`. The host app should route
+ * the action through the SyncPlay controller instead of acting
+ * locally.
+ */
+export type OnPipPlayRequestPayload = Record<string, never>;
+export type OnPipPauseRequestPayload = Record<string, never>;
+export type OnPipSkipRequestPayload = {
+  /** Absolute target position the user wants to seek to, in seconds. */
+  targetSeconds: number;
+  /** Skip interval requested by the OS (signed seconds). Debug only. */
+  intervalSeconds: number;
+};
+
 export type NowPlayingMetadata = {
   title?: string;
   artist?: string;
@@ -84,6 +99,18 @@ export type MpvPlayerViewProps = {
   onPictureInPictureChange?: (event: {
     nativeEvent: OnPictureInPictureChangePayload;
   }) => void;
+  /**
+   * When true, PiP play/pause/skip controls emit the corresponding
+   * `onPipPlayRequest` / `onPipPauseRequest` / `onPipSkipRequest`
+   * events instead of driving MPV directly. Used to route PiP control
+   * actions through SyncPlay.
+   */
+  syncPlayDelegated?: boolean;
+  onPipPlayRequest?: (event: { nativeEvent: OnPipPlayRequestPayload }) => void;
+  onPipPauseRequest?: (event: {
+    nativeEvent: OnPipPauseRequestPayload;
+  }) => void;
+  onPipSkipRequest?: (event: { nativeEvent: OnPipSkipRequestPayload }) => void;
 };
 
 export interface MpvPlayerViewRef {

providers/SyncPlay/Controller.ts

@@ -0,0 +1,191 @@
+/**
+ * SyncPlay Controller — public playback API exposed to consumers.
+ *
+ * Methods are fire-and-forget by design: SyncPlay HTTP responses don't
+ * carry useful info (the real state arrives via WebSocket broadcast).
+ * Wrap calls in try/catch so transient network errors don't reach the UI.
+ */
+
+import type { BaseItemDto } from "@jellyfin/sdk/lib/generated-client/models";
+import { getSyncPlayApi } from "@jellyfin/sdk/lib/utils/api";
+import type { SyncPlayManager } from "./Manager";
+import {
+  getItemsForPlayback,
+  type TranslateOptions,
+  translateItemsForPlayback,
+} from "./transport/queueTranslation";
+
+export interface PlayOptions extends TranslateOptions {
+  items?: BaseItemDto[];
+  ids?: string[];
+  startIndex?: number;
+  startPositionTicks?: number;
+}
+
+export class Controller {
+  private manager!: SyncPlayManager;
+
+  init(manager: SyncPlayManager): void {
+    this.manager = manager;
+  }
+
+  /** Toggle play/pause for the whole group. */
+  playPause(): void {
+    if (this.manager.isPlaying()) {
+      this.pause();
+    } else {
+      this.unpause();
+    }
+  }
+
+  /** Resume the group's playback. */
+  unpause(): void {
+    this.manager.markPendingPlaybackCommand("Unpause");
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlayUnpause();
+    } catch (error) {
+      console.error("SyncPlay Controller.unpause failed", error);
+    }
+  }
+
+  /** Pause the group's playback. */
+  pause(): void {
+    this.manager.markPendingPlaybackCommand("Pause");
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlayPause();
+    } catch (error) {
+      console.error("SyncPlay Controller.pause failed", error);
+    }
+    // Pause locally too so the user sees instant feedback.
+    this.manager.getPlayerWrapper().localPause();
+  }
+
+  /** Seek the group's playback. `positionTicks` is in ticks (1ms = 10000 ticks). */
+  seek(positionTicks: number): void {
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlaySeek({
+        seekRequestDto: { PositionTicks: positionTicks },
+      });
+    } catch (error) {
+      console.error("SyncPlay Controller.seek failed", error);
+    }
+  }
+
+  /**
+   * Start playback in the group. Expands containers (Series, Season,
+   * BoxSet, Playlist, single Episode w/ autoplay) into the real
+   * playable queue before broadcasting.
+   *
+   * Resolves once the SetNewQueue request completes; the server then
+   * broadcasts a PlayQueue update and Play command to every member.
+   */
+  async play(options: PlayOptions): Promise<void> {
+    const api = this.manager.getApiClient();
+
+    const sendPlayRequest = async (items: BaseItemDto[]) => {
+      const queue = items
+        .map((item) => item.Id)
+        .filter((id): id is string => typeof id === "string");
+      await getSyncPlayApi(api).syncPlaySetNewQueue({
+        playRequestDto: {
+          PlayingQueue: queue,
+          PlayingItemPosition: options.startIndex ?? 0,
+          StartPositionTicks: options.startPositionTicks ?? 0,
+        },
+      });
+    };
+
+    try {
+      const sourceItems = options.items
+        ? options.items
+        : await getItemsForPlayback(api, options.ids ?? []);
+      const items = await translateItemsForPlayback(api, sourceItems, options);
+      await sendPlayRequest(items);
+    } catch (error) {
+      console.error("SyncPlay Controller.play failed", error);
+      throw error;
+    }
+  }
+
+  /** Stop the group's playback. */
+  stop(): void {
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlayStop();
+    } catch (error) {
+      console.error("SyncPlay Controller.stop failed", error);
+    }
+  }
+
+  /** Jump to the next item in the group's queue. */
+  nextItem(): void {
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlayNextItem({
+        nextItemRequestDto: {
+          PlaylistItemId: this.manager
+            .getQueueCore()
+            .getCurrentPlaylistItemId(),
+        } as unknown as Parameters<
+          ReturnType<typeof getSyncPlayApi>["syncPlayNextItem"]
+        >[0]["nextItemRequestDto"],
+      });
+    } catch (error) {
+      console.error("SyncPlay Controller.nextItem failed", error);
+    }
+  }
+
+  /** Jump to the previous item in the group's queue. */
+  previousItem(): void {
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlayPreviousItem({
+        previousItemRequestDto: {
+          PlaylistItemId: this.manager
+            .getQueueCore()
+            .getCurrentPlaylistItemId(),
+        } as unknown as Parameters<
+          ReturnType<typeof getSyncPlayApi>["syncPlayPreviousItem"]
+        >[0]["previousItemRequestDto"],
+      });
+    } catch (error) {
+      console.error("SyncPlay Controller.previousItem failed", error);
+    }
+  }
+
+  /** Jump to a specific item in the queue by playlist item id. */
+  setCurrentPlaylistItem(playlistItemId: string): void {
+    try {
+      getSyncPlayApi(this.manager.getApiClient()).syncPlaySetPlaylistItem({
+        setPlaylistItemRequestDto: { PlaylistItemId: playlistItemId },
+      });
+    } catch (error) {
+      console.error("SyncPlay Controller.setCurrentPlaylistItem failed", error);
+    }
+  }
+
+  /**
+   * Jump the group to `item`. If the item is already in the current queue
+   * (by `Id`), dispatches a cheap `SetPlaylistItem` so the queue stays
+   * intact. Otherwise starts a new playback request, which replaces the
+   * group's queue (matches jellyfin-web's playbackManager.play behavior
+   * when picking an episode from a different series/season).
+   */
+  goToItem(item: BaseItemDto): void {
+    if (!item.Id) {
+      console.warn("SyncPlay Controller.goToItem called without item.Id");
+      return;
+    }
+    const queueEntry = this.manager
+      .getQueueCore()
+      .getPlaylist()
+      .find((q) => q.Id === item.Id);
+    if (queueEntry?.PlaylistItemId) {
+      this.setCurrentPlaylistItem(queueEntry.PlaylistItemId);
+      return;
+    }
+    void this.play({
+      ids: [item.Id],
+      startPositionTicks: item.UserData?.PlaybackPositionTicks ?? 0,
+    });
+  }
+}
+
+export default Controller;

providers/SyncPlay/EventEmitter.ts

@@ -0,0 +1,93 @@
+/**
+ * Per-instance event emitter — replaces jellyfin-web's global `Events.trigger`
+ * bus. Listeners that throw are caught and logged so one bad listener can't
+ * break the rest.
+ */
+
+import { WaitForEventDefaultTimeout } from "./constants";
+
+export class EventEmitter {
+  private listeners: Map<string, Set<(...args: unknown[]) => void>> = new Map();
+
+  on(event: string, callback: (...args: unknown[]) => void): void {
+    if (!this.listeners.has(event)) {
+      this.listeners.set(event, new Set());
+    }
+    this.listeners.get(event)!.add(callback);
+  }
+
+  off(event: string, callback: (...args: unknown[]) => void): void {
+    this.listeners.get(event)?.delete(callback);
+  }
+
+  emit(event: string, ...args: unknown[]): void {
+    this.listeners.get(event)?.forEach((callback) => {
+      try {
+        callback(...args);
+      } catch (error) {
+        console.error(
+          `SyncPlay EventEmitter: handler for "${event}" threw`,
+          error,
+        );
+      }
+    });
+  }
+
+  removeAllListeners(event?: string): void {
+    if (event) {
+      this.listeners.delete(event);
+    } else {
+      this.listeners.clear();
+    }
+  }
+}
+
+/**
+ * Resolve on the next emission of `event`, or reject after `timeoutMs`
+ * (or any event in `rejectEventTypes`). Cleans up every listener.
+ */
+export function waitForEventOnce(
+  emitter: EventEmitter,
+  event: string,
+  timeoutMs: number = WaitForEventDefaultTimeout,
+  rejectEventTypes?: string[],
+): Promise<unknown[]> {
+  return new Promise((resolve, reject) => {
+    let timer: ReturnType<typeof setTimeout> | null = null;
+
+    const clearAll = () => {
+      emitter.off(event, handler);
+      if (timer) clearTimeout(timer);
+      if (Array.isArray(rejectEventTypes)) {
+        for (const eventName of rejectEventTypes) {
+          emitter.off(eventName, rejectCallback);
+        }
+      }
+    };
+
+    const handler = (...args: unknown[]) => {
+      clearAll();
+      resolve(args);
+    };
+
+    const rejectCallback = (...args: unknown[]) => {
+      clearAll();
+      reject(args[0] ?? new Error("rejected"));
+    };
+
+    if (timeoutMs) {
+      timer = setTimeout(() => {
+        clearAll();
+        reject(new Error("Timed out."));
+      }, timeoutMs);
+    }
+
+    emitter.on(event, handler);
+
+    if (Array.isArray(rejectEventTypes)) {
+      for (const eventName of rejectEventTypes) {
+        emitter.on(eventName, rejectCallback);
+      }
+    }
+  });
+}

providers/SyncPlay/Manager.ts

@@ -0,0 +1,383 @@
+/**
+ * SyncPlayManager — central orchestrator for a SyncPlay session.
+ *
+ * Owns the three "cores" (TimeSync, PlaybackCore, QueueCore) and the
+ * PlayerWrapper, and routes WebSocket events between them.
+ *
+ * Lifecycle:
+ *   constructor → init() → (joinGroup → group-state-change "Idle"+) →
+ *   group-state-change "Playing" → group-state-change "Paused" → ...
+ *   → (leaveGroup) → destroy()
+ *
+ * Events emitted (provider listens):
+ *   - `group-info-update`     `(GroupInfoDto | null)`
+ *   - `group-state-change`    `(state: string, oldState: string)`
+ *   - `enabled`               `(isEnabled: boolean)`
+ *   - `play-state-change`     `(isFollowing: boolean)`
+ *   - `playbackstart` / `playbackerror` — from PlayerWrapper hooks
+ *   - `osd`                   `(action: SyncPlayOsdAction)`
+ *   - `toast`                 `(messageKey: string)`
+ *
+ * The manager exposes a per-instance `EventEmitter` rather than upstream
+ * `Events.on(manager, ...)` — replaces the global Events bus pattern.
+ */
+
+import type { Api } from "@jellyfin/sdk";
+import { Controller } from "./Controller";
+import { PlaybackCore } from "./cores/PlaybackCore";
+import { QueueCore } from "./cores/QueueCore";
+import { TimeSync } from "./cores/TimeSync";
+import { EventEmitter } from "./EventEmitter";
+import { PendingPlaybackTracker } from "./player/PendingPlaybackTracker";
+import { PlayerWrapper } from "./player/PlayerWrapper";
+import { reconcileToGroupOnAttach } from "./player/reconcileToGroupOnAttach";
+import type {
+  GroupInfoDto,
+  GroupUpdate,
+  PlayerControls,
+  PlayQueueUpdate,
+  SendCommand,
+} from "./types";
+
+/** Raw WebSocket message data shapes (already unwrapped by the hook). */
+
+export class SyncPlayManager extends EventEmitter {
+  private apiClient: Api;
+  private playerWrapper: PlayerWrapper;
+  private timeSync: TimeSync;
+  private playbackCore: PlaybackCore;
+  private queueCore: QueueCore;
+  private pendingPlaybackTracker: PendingPlaybackTracker;
+  private controller: Controller;
+
+  /** Current group info. `null` when not in a group. */
+  private groupInfo: GroupInfoDto | null = null;
+  /** Is SyncPlay actively enabled (i.e., we're in a group)? */
+  private syncPlayEnabledAtPlayer = false;
+  /** Are we mirroring the group's commands locally? */
+  private followingGroupPlayback = true;
+
+  constructor(api: Api) {
+    super();
+    this.apiClient = api;
+    this.playerWrapper = new PlayerWrapper();
+    this.timeSync = new TimeSync(api);
+    this.playbackCore = new PlaybackCore();
+    this.queueCore = new QueueCore();
+    this.pendingPlaybackTracker = new PendingPlaybackTracker();
+    this.controller = new Controller();
+  }
+
+  /** Wire up cores. Called once after construction. */
+  init(): void {
+    this.playbackCore.init(this);
+    this.queueCore.init(this);
+    this.controller.init(this);
+
+    // Forward PlaybackCore OSD events to provider listeners.
+    this.playbackCore.on("osd", (...args) => {
+      this.emit("osd", ...args);
+    });
+
+    // Bridge optimistic pending Pause/Unpause → React state.
+    this.pendingPlaybackTracker.setChangeHandler((cmd) => {
+      this.emit("pending-playback-change", cmd);
+    });
+
+    this.timeSync.startPing();
+  }
+
+  /** Public controller for callers. */
+  getController(): Controller {
+    return this.controller;
+  }
+
+  /** Called by SyncPlayProvider when the user switches Jellyfin servers. */
+  updateApiClient(api: Api): void {
+    this.apiClient = api;
+    this.timeSync.updateApiClient(api);
+  }
+
+  getApiClient(): Api {
+    return this.apiClient;
+  }
+
+  getPlayerWrapper(): PlayerWrapper {
+    return this.playerWrapper;
+  }
+
+  getTimeSync(): TimeSync {
+    return this.timeSync;
+  }
+
+  getPlaybackCore(): PlaybackCore {
+    return this.playbackCore;
+  }
+
+  getQueueCore(): QueueCore {
+    return this.queueCore;
+  }
+
+  getPendingPlaybackTracker(): PendingPlaybackTracker {
+    return this.pendingPlaybackTracker;
+  }
+
+  // ===========================================================================
+  // WebSocket message handlers (called by useSyncPlayWebSocket)
+  // ===========================================================================
+
+  /**
+   * Handle a `SyncPlayGroupUpdate` WebSocket message.
+   *
+   * Cast: the SDK's `GroupUpdate.Type` union is narrower than what the
+   * server actually emits (it omits `SyncPlayIsDisabled`, `GroupUpdate`,
+   * `CreateGroupDenied`, `JoinGroupDenied`). Wire format is the source
+   * of truth here.
+   */
+  processGroupUpdate(rawUpdate: GroupUpdate): void {
+    if (!rawUpdate) {
+      console.warn("SyncPlay processGroupUpdate: empty update");
+      return;
+    }
+    const update = rawUpdate as unknown as {
+      Type: string;
+      Data: unknown;
+    };
+
+    switch (update.Type) {
+      case "PlayQueue":
+        this.queueCore.updatePlayQueue(
+          this.apiClient,
+          update.Data as unknown as PlayQueueUpdate,
+        );
+        break;
+
+      case "UserJoined":
+      case "UserLeft":
+        // Group membership notifications — current group will follow
+        // via GroupUpdate, but emit a toast for friendliness.
+        this.emit("toast", `MessageSyncPlay${update.Type}`, update.Data);
+        break;
+
+      case "GroupJoined": {
+        this.groupInfo = update.Data as GroupInfoDto;
+        this.enableSyncPlay(this.groupInfo);
+        this.emit("group-update", this.groupInfo);
+        this.emit("toast", "MessageSyncPlayGroupJoined");
+        break;
+      }
+
+      case "GroupLeft":
+      case "NotInGroup":
+      case "SyncPlayIsDisabled": {
+        const previousState = this.groupInfo?.State;
+        this.groupInfo = null;
+        this.disableSyncPlay();
+        this.emit("group-update", null);
+        if (update.Type === "GroupLeft") {
+          this.emit("toast", "MessageSyncPlayGroupLeft");
+        }
+        if (previousState) {
+          this.emit("group-state-change", "Idle", previousState);
+        }
+        break;
+      }
+
+      case "GroupUpdate": {
+        const previousState = this.groupInfo?.State;
+        this.groupInfo = update.Data as GroupInfoDto;
+        this.emit("group-update", this.groupInfo);
+        const newState = this.groupInfo.State;
+        if (newState && newState !== previousState) {
+          this.emit("group-state-change", newState, previousState ?? "Idle");
+        }
+        break;
+      }
+
+      case "StateUpdate": {
+        const stateData = update.Data as {
+          State?: string;
+          PreviousState?: string;
+          Reason?: string;
+        };
+        const newState = stateData.State ?? "Idle";
+        const previousState = stateData.PreviousState ?? "Idle";
+        const reason = stateData.Reason;
+        if (this.groupInfo) {
+          this.groupInfo.State = newState as GroupInfoDto["State"];
+          this.emit("group-update", this.groupInfo);
+        }
+        this.emit("group-state-change", newState, previousState, reason);
+        // Server signals "Playing" or "Paused" → clear any in-flight
+        // optimistic tap state.
+        if (newState === "Playing" || newState === "Paused") {
+          this.pendingPlaybackTracker.clear();
+        }
+        break;
+      }
+
+      case "CreateGroupDenied":
+        this.emit("toast", "MessageSyncPlayCreateGroupDenied");
+        break;
+      case "JoinGroupDenied":
+        this.emit("toast", "MessageSyncPlayJoinGroupDenied");
+        break;
+      case "LibraryAccessDenied":
+        this.emit("toast", "MessageSyncPlayLibraryAccessDenied");
+        break;
+      case "GroupDoesNotExist":
+        this.emit("toast", "MessageSyncPlayGroupDoesNotExist");
+        break;
+
+      default:
+        console.warn("SyncPlay processGroupUpdate: unknown type", update.Type);
+        break;
+    }
+  }
+
+  /** Handle a `SyncPlayCommand` WebSocket message. */
+  processCommand(command: SendCommand): void {
+    if (!command) {
+      console.warn("SyncPlay processCommand: empty command");
+      return;
+    }
+    this.playbackCore.applyCommand(command);
+    // Server told us the new playing state — clear optimistic UI.
+    if (command.Command === "Unpause" || command.Command === "Pause") {
+      this.pendingPlaybackTracker.clear();
+    }
+  }
+
+  // ===========================================================================
+  // Enable / disable SyncPlay
+  // ===========================================================================
+
+  private enableSyncPlay(_group: GroupInfoDto): void {
+    if (this.syncPlayEnabledAtPlayer) return;
+    this.syncPlayEnabledAtPlayer = true;
+    this.followingGroupPlayback = true;
+    this.timeSync.forceUpdate();
+    this.emit("enabled", true);
+    this.emit("play-state-change", true);
+  }
+
+  private disableSyncPlay(): void {
+    if (!this.syncPlayEnabledAtPlayer) return;
+    this.syncPlayEnabledAtPlayer = false;
+    this.followingGroupPlayback = false;
+    this.playbackCore.clearScheduledCommand();
+    this.queueCore.clear();
+    this.pendingPlaybackTracker.clear();
+    this.emit("enabled", false);
+    this.emit("play-state-change", false);
+  }
+
+  /**
+   * Resume following group playback after the user temporarily took
+   * local control (e.g. scrubbed the seek bar).
+   */
+  async followGroupPlayback(_api: Api): Promise<void> {
+    this.followingGroupPlayback = true;
+    this.emit("play-state-change", true);
+  }
+
+  /** Stop following group playback (e.g., user takes local control). */
+  haltGroupPlayback(_api: Api): void {
+    this.followingGroupPlayback = false;
+    this.emit("play-state-change", false);
+  }
+
+  isFollowingGroupPlayback(): boolean {
+    return this.followingGroupPlayback;
+  }
+
+  isSyncPlayEnabled(): boolean {
+    return this.syncPlayEnabledAtPlayer;
+  }
+
+  // ===========================================================================
+  // Player attach + provider bridges
+  // ===========================================================================
+
+  /**
+   * Bind the RN player controls.
+   * Called from the player screen's `useEffect`. Triggers a reconcile
+   * if a group is active and the player is late-arriving.
+   */
+  setPlayerControls(controls: PlayerControls | null): void {
+    this.playerWrapper.bindToControls(controls);
+    if (controls && this.syncPlayEnabledAtPlayer) {
+      const lastCommand = this.playbackCore.getLastCommand();
+      reconcileToGroupOnAttach(controls, lastCommand, (local) =>
+        this.timeSync.localDateToRemote(local),
+      );
+    }
+  }
+
+  /** Player-side notify hook: media is ready to play. */
+  notifyReady(): void {
+    this.emit("playbackstart");
+    if (this.syncPlayEnabledAtPlayer) {
+      this.playbackCore.onReady(this.apiClient);
+    }
+  }
+
+  /** Player-side notify hook: buffering state changed. */
+  notifyBuffering(isBuffering: boolean): void {
+    if (!this.syncPlayEnabledAtPlayer) return;
+    if (isBuffering) {
+      this.playbackCore.onBuffering(this.apiClient);
+    } else {
+      this.playbackCore.onReady(this.apiClient);
+    }
+  }
+
+  /** Player-side notify hook: local playback started. */
+  notifyPlaybackStart(): void {
+    this.emit("playbackstart");
+    if (this.syncPlayEnabledAtPlayer) {
+      this.playbackCore.onPlaybackStart(this.apiClient);
+    }
+  }
+
+  // ===========================================================================
+  // Pending playback (optimistic UI for play/pause taps)
+  // ===========================================================================
+
+  /** Called by Controller before sending an Unpause/Pause request. */
+  markPendingPlaybackCommand(command: "Unpause" | "Pause"): void {
+    this.pendingPlaybackTracker.mark(command);
+  }
+
+  /** Is the group currently playing? Used by Controller.playPause. */
+  isPlaying(): boolean {
+    const pending = this.pendingPlaybackTracker.get();
+    if (pending === "Unpause") return true;
+    if (pending === "Pause") return false;
+    return this.groupInfo?.State === "Playing";
+  }
+
+  /** Group info for consumers. */
+  getGroupInfo(): GroupInfoDto | null {
+    return this.groupInfo;
+  }
+
+  /** Last playback command (for QueueCore.startPlayback resumption). */
+  getLastPlaybackCommand(): SendCommand | null {
+    return this.playbackCore.getLastCommand();
+  }
+
+  // ===========================================================================
+  // Teardown
+  // ===========================================================================
+
+  destroy(): void {
+    this.timeSync.destroy();
+    this.playbackCore.destroy();
+    this.queueCore.destroy();
+    this.playerWrapper.bindToControls(null);
+    this.removeAllListeners();
+  }
+}
+
+export default SyncPlayManager;

providers/SyncPlay/SyncPlayProvider.tsx

@@ -0,0 +1,600 @@
+/**
+ * SyncPlayProvider — React glue around `SyncPlayManager`.
+ *
+ * Responsibilities:
+ *  - Manager lifecycle (construct on api change, destroy on unmount)
+ *  - React mirrors of manager state (`isEnabled`, `groupInfo`,
+ *    `pendingPlaybackCommand`) so components re-render
+ *  - Navigation handlers wired into `PlayerWrapper.localPlay` /
+ *    `localSetCurrentPlaylistItem` — these are what jellyfin-web does
+ *    synchronously via `playbackManager.play`; on RN they navigate
+ *    to the player screen instead
+ *  - AppState foreground re-join (we may miss broadcasts while
+ *    suspended)
+ *
+ * External API surface (`useSyncPlay`) is stable; components don't
+ * change when the internals do.
+ */
+
+import { getSyncPlayApi } from "@jellyfin/sdk/lib/utils/api";
+import { usePathname } from "expo-router";
+import { useAtomValue } from "jotai";
+import {
+  createContext,
+  type ReactNode,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from "react";
+import { AppState, type AppStateStatus } from "react-native";
+import { toast } from "sonner-native";
+import { useAppRouter } from "@/hooks/useAppRouter";
+import { useKeepWebSocketAlive } from "@/hooks/useKeepWebSocketAlive";
+import i18n from "@/i18n";
+import { getDownloadedItemById } from "@/providers/Downloads";
+import { apiAtom, userAtom } from "@/providers/JellyfinProvider";
+import { useWebSocketContext } from "@/providers/WebSocketProvider";
+import type { Controller as SyncPlayController } from "./Controller";
+import { SyncPlayManager } from "./Manager";
+import { useSyncPlayWebSocket } from "./transport/useSyncPlayWebSocket";
+import type { GroupInfoDto, PlayerControls, SyncPlayOsdAction } from "./types";
+
+interface SyncPlayContextValue {
+  isEnabled: boolean;
+  groupInfo: GroupInfoDto | null;
+  canJoinGroups: boolean;
+  canCreateGroups: boolean;
+
+  joinGroup: (groupId: string) => Promise<void>;
+  createGroup: (groupName?: string) => Promise<void>;
+  leaveGroup: () => Promise<void>;
+  getGroups: () => Promise<GroupInfoDto[]>;
+
+  /**
+   * Re-attach to the group's command stream and jump back to the
+   * group's currently-playing item. Mirrors jellyfin-web's "Resume
+   * playback" menu entry: in jellyfin-web it just calls
+   * `playbackManager.play` on the group's current queue position.
+   * Here we navigate to direct-player with the same params our
+   * `localSetCurrentItem` bridge would use, so the player picks up
+   * mid-group with `syncPlay=true` and the right offset.
+   */
+  resumeGroupPlayback: () => Promise<void>;
+
+  controller: SyncPlayController | null;
+
+  setPlayerControls: (controls: PlayerControls | null) => void;
+  notifyReady: () => void;
+  notifyBuffering: (isBuffering: boolean) => void;
+  notifyPlaybackStart: () => void;
+
+  pendingPlaybackCommand: "Unpause" | "Pause" | null;
+  /**
+   * Current SyncPlay OSD overlay state. Drives the animated icon over the
+   * video that mirrors jellyfin-web's `#syncPlayIcon`. `null` means hidden.
+   */
+  osdAction: SyncPlayOsdAction | null;
+}
+
+const SyncPlayContext = createContext<SyncPlayContextValue | null>(null);
+
+interface SyncPlayProviderProps {
+  children: ReactNode;
+}
+
+export function SyncPlayProvider({ children }: SyncPlayProviderProps) {
+  const api = useAtomValue(apiAtom);
+  const user = useAtomValue(userAtom);
+  const router = useAppRouter();
+  const { isConnected: isWsConnected } = useWebSocketContext();
+
+  const [manager, setManager] = useState<SyncPlayManager | null>(null);
+  const isNavigatingToPlayerRef = useRef(false);
+
+  // Keep a live ref of the current route pathname so the
+  // navigateToPlayer helper (wired up once inside the manager-lifecycle
+  // effect) can read the *current* page without stale-closure issues.
+  const pathname = usePathname();
+  const pathnameRef = useRef(pathname);
+  useEffect(() => {
+    pathnameRef.current = pathname;
+  }, [pathname]);
+
+  const [isEnabled, setIsEnabled] = useState(false);
+  const [groupInfo, setGroupInfo] = useState<GroupInfoDto | null>(null);
+  const [pendingPlaybackCommand, setPendingPlaybackCommand] = useState<
+    "Unpause" | "Pause" | null
+  >(null);
+
+  // While in a SyncPlay group, hold a keep-alive token on the global
+  // WebSocket so backgrounding the app does NOT cleanly close the
+  // socket. A clean close is interpreted by the Jellyfin server as
+  // leaving the group and is broadcast to every other member as
+  // "<user> has left the group". Keeping the socket open across a
+  // short suspend lets us stay in the group while quickly switching
+  // apps; if the OS eventually tears the TCP connection down anyway,
+  // the app-foreground rejoin effect below will pull us back in.
+  useKeepWebSocketAlive(isEnabled);
+
+  const [osdAction, setOsdAction] = useState<SyncPlayOsdAction | null>(null);
+  const osdTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  /**
+   * Set the OSD overlay action.
+   *
+   * `transient` mirrors jellyfin-web's `iconVisibilityTime = 1500` for the
+   * Unpause / Pause / Seek command-confirmation flashes. Persistent actions
+   * (schedule-play, buffering, wait-*) stay until cleared by a state
+   * transition or a subsequent call with `null`.
+   */
+  const showOsd = useCallback(
+    (action: SyncPlayOsdAction | null, transient = false) => {
+      if (osdTimeoutRef.current) {
+        clearTimeout(osdTimeoutRef.current);
+        osdTimeoutRef.current = null;
+      }
+      setOsdAction(action);
+      if (transient && action !== null) {
+        osdTimeoutRef.current = setTimeout(() => {
+          osdTimeoutRef.current = null;
+          setOsdAction((cur) => (cur === action ? null : cur));
+        }, 1500);
+      }
+    },
+    [],
+  );
+
+  // Pending play/pause tap → optimistic schedule-play overlay (unless another
+  // overlay reason has already taken precedence).
+  useEffect(() => {
+    if (pendingPlaybackCommand) {
+      setOsdAction((cur) => cur ?? "schedule-play");
+    } else {
+      setOsdAction((cur) => (cur === "schedule-play" ? null : cur));
+    }
+  }, [pendingPlaybackCommand]);
+
+  // Clear the OSD auto-expire timeout on unmount.
+  useEffect(() => {
+    return () => {
+      if (osdTimeoutRef.current) {
+        clearTimeout(osdTimeoutRef.current);
+        osdTimeoutRef.current = null;
+      }
+    };
+  }, []);
+
+  const canJoinGroups = useMemo(() => {
+    const access = user?.Policy?.SyncPlayAccess;
+    return access !== "None" && access !== undefined;
+  }, [user?.Policy?.SyncPlayAccess]);
+
+  const canCreateGroups = useMemo(
+    () => user?.Policy?.SyncPlayAccess === "CreateAndJoinGroups",
+    [user?.Policy?.SyncPlayAccess],
+  );
+
+  // Latch: `true` once we've fired the per-attach `playbackstart` event.
+  const playbackStartFiredRef = useRef(false);
+
+  // ---------------------------------------------------------------------------
+  // Navigation to the player screen
+  // ---------------------------------------------------------------------------
+
+  /*
+   * Single navigate-to-direct-player helper, used by every code path
+   * that needs to (re-)open the player while in a SyncPlay group:
+   *  - localPlay (group's leader started a new queue / we just joined)
+   *  - localSetCurrentPlaylistItem (group advanced to next episode)
+   *  - resumeGroupPlayback (user tapped "Resume playback" in the menu)
+   *
+   * Both jellyfin-web's playbackManager.play and its setCurrentPlaylistItem
+   * collapse to "point the player at this item / position" — RN is the
+   * same shape, just a router navigation instead of an in-page DOM swap.
+   *
+   * Note: no "joining playback" toast here — the `GroupJoined`
+   * WebSocket event already triggers a "Joined group" toast via
+   * `Manager.ts`, and showing both on a fresh join was redundant.
+   */
+  const navigateToPlayer = useCallback(
+    (itemId: string, startPositionTicks: number) => {
+      if (isNavigatingToPlayerRef.current) {
+        console.debug("SyncPlay: already navigating to player");
+        return;
+      }
+      isNavigatingToPlayerRef.current = true;
+
+      // Opportunistic local playback: if we have a downloaded copy of
+      // the target item, use it instead of streaming. Matters most when
+      // the group advances to an episode you've downloaded — the local
+      // file starts instantly and survives spotty wifi. SyncPlay's
+      // position/pause/seek commands keep flowing normally; only the
+      // source changes.
+      const isDownloaded = !!getDownloadedItemById(itemId);
+      const queryParams = new URLSearchParams({
+        itemId,
+        playbackPosition: String(startPositionTicks),
+        syncPlay: "true",
+        ...(isDownloaded && { offline: "true" }),
+      }).toString();
+      // Use `replace` when we're already on the player screen so queue
+      // advances don't stack a second player on the nav stack; `push`
+      // otherwise so the user can back out to where they came from.
+      const onPlayerScreen =
+        pathnameRef.current?.startsWith("/player/direct-player") ?? false;
+      if (onPlayerScreen) {
+        router.replace(`/player/direct-player?${queryParams}`);
+      } else {
+        router.push(`/player/direct-player?${queryParams}`);
+      }
+
+      setTimeout(() => {
+        isNavigatingToPlayerRef.current = false;
+      }, 2000);
+    },
+    [router],
+  );
+
+  // ---------------------------------------------------------------------------
+  // Manager lifecycle
+  // ---------------------------------------------------------------------------
+
+  useEffect(() => {
+    if (!api) return;
+
+    const mgr = new SyncPlayManager(api);
+    mgr.init();
+    setManager(mgr);
+
+    const playerWrapper = mgr.getPlayerWrapper();
+
+    // localPlay → navigate to direct-player with syncPlay=true
+    playerWrapper.setLocalPlayHandler((options) => {
+      const itemId = options.ids[0];
+      if (!itemId) {
+        console.warn("SyncPlay: localPlay called with no ids");
+        return;
+      }
+      navigateToPlayer(itemId, options.startPositionTicks ?? 0);
+    });
+
+    // localSetCurrentPlaylistItem → navigate to the new playlist item
+    playerWrapper.setLocalSetCurrentItemHandler((playlistItemId) => {
+      if (!playlistItemId) return;
+      const queueCore = mgr.getQueueCore();
+      const target = queueCore
+        .getPlaylist()
+        .find((i) => i.PlaylistItemId === playlistItemId);
+      const itemId = target?.Id;
+      if (!itemId) {
+        console.warn(
+          "SyncPlay: localSetCurrentPlaylistItem — item not in playlist",
+          playlistItemId,
+        );
+        return;
+      }
+      navigateToPlayer(itemId, queueCore.getStartPositionTicks());
+    });
+
+    mgr.on("enabled", (...args: unknown[]) => {
+      const enabled = args[0] as boolean;
+      setIsEnabled(enabled);
+      if (!enabled) setGroupInfo(null);
+    });
+
+    mgr.on("group-update", (...args: unknown[]) => {
+      setGroupInfo((args[0] as GroupInfoDto | null | undefined) ?? null);
+    });
+
+    mgr.on("pending-playback-change", (...args: unknown[]) => {
+      setPendingPlaybackCommand(args[0] as "Unpause" | "Pause" | null);
+    });
+
+    // group-state-change → on "Waiting", pause locally so we don't drift
+    // ahead of the group while the server is reconciling buffering/seek
+    // state. Position resync is *only* done from the explicit Pause /
+    // Unpause / Seek SendCommands that follow (`PlaybackCore.applyCommand`
+    // → `scheduleUnpause` etc.) — those commands carry the canonical
+    // `PositionTicks` for the action's `When`. The old code here also
+    // called `wrapper.localSeek(lastCommand.PositionTicks)`, but
+    // `lastCommand` is the *previous* Pause/Unpause and can be many
+    // seconds stale, so it rewound the user every time someone else
+    // buffered. Don't put a seek back here.
+    mgr.on("group-state-change", (...args: unknown[]) => {
+      const state = args[0] as string | undefined;
+      const reason = args[2] as string | undefined;
+      const wrapper = mgr.getPlayerWrapper();
+      if (!wrapper.isPlaybackActive()) return;
+      if (state === "Waiting") {
+        wrapper.localPause();
+      }
+
+      // Drive the persistent OSD overlay from (state, reason).
+      // Mirrors jellyfin-web's `group-state-update` → `showIcon` mapping.
+      if (state === "Waiting") {
+        if (reason === "Buffer") showOsd("buffering");
+        else if (reason === "Unpause") showOsd("wait-unpause");
+        else if (reason === "Pause") showOsd("wait-pause");
+        else if (reason === "Seek") showOsd("seek");
+      } else if (state === "Playing" || state === "Paused") {
+        // Stable state — clear any persistent overlay; transient flashes
+        // come from the `osd` event below and self-expire.
+        setOsdAction((cur) => {
+          if (
+            cur === "schedule-play" ||
+            cur === "buffering" ||
+            cur === "wait-pause" ||
+            cur === "wait-unpause"
+          ) {
+            return null;
+          }
+          return cur;
+        });
+      }
+    });
+
+    // PlaybackCore-emitted OSD events. Transient ones auto-expire in 1.5s.
+    mgr.on("osd", (...args: unknown[]) => {
+      const action = args[0] as SyncPlayOsdAction;
+      const transient =
+        action === "unpause" || action === "pause" || action === "seek";
+      showOsd(action, transient);
+    });
+
+    mgr.on("toast", (...args: unknown[]) => {
+      const key = args[0] as string;
+      const arg = args[1] as string | undefined;
+      const message = arg
+        ? i18n.t(`syncplay.toasts.${key}`, { user: arg })
+        : i18n.t(`syncplay.toasts.${key}`);
+      toast(message);
+    });
+
+    return () => {
+      mgr.destroy();
+      setManager(null);
+    };
+  }, [api, navigateToPlayer]);
+
+  // Initial join race: once `enabled` flips true, snapshot the current group.
+  useEffect(() => {
+    if (isEnabled && manager) {
+      setGroupInfo(manager.getGroupInfo());
+    }
+  }, [isEnabled, manager]);
+
+  // Wire WebSocket messages → manager
+  useSyncPlayWebSocket(manager);
+
+  // ---------------------------------------------------------------------------
+  // Group management
+  // ---------------------------------------------------------------------------
+
+  const getGroups = useCallback(async (): Promise<GroupInfoDto[]> => {
+    if (!api) return [];
+    try {
+      const response = await getSyncPlayApi(api).syncPlayGetGroups();
+      return (response.data as unknown as GroupInfoDto[]) ?? [];
+    } catch (error) {
+      console.error("SyncPlay: failed to get groups", error);
+      return [];
+    }
+  }, [api]);
+
+  const joinGroup = useCallback(
+    async (groupId: string): Promise<void> => {
+      if (!api) return;
+      try {
+        await getSyncPlayApi(api).syncPlayJoinGroup({
+          joinGroupRequestDto: { GroupId: groupId },
+        });
+      } catch (error) {
+        console.error("SyncPlay: failed to join group", error);
+        throw error;
+      }
+    },
+    [api],
+  );
+
+  const createGroup = useCallback(
+    async (groupName?: string): Promise<void> => {
+      if (!api || !user) return;
+      const name = groupName || `${user.Name}'s Group`;
+      try {
+        await getSyncPlayApi(api).syncPlayCreateGroup({
+          newGroupRequestDto: { GroupName: name },
+        });
+      } catch (error) {
+        console.error("SyncPlay: failed to create group", error);
+        throw error;
+      }
+    },
+    [api, user],
+  );
+
+  const leaveGroup = useCallback(async (): Promise<void> => {
+    if (!api) return;
+    try {
+      await getSyncPlayApi(api).syncPlayLeaveGroup();
+    } catch (error) {
+      console.error("SyncPlay: failed to leave group", error);
+      throw error;
+    }
+  }, [api]);
+
+  /*
+   * Resume playback: re-follow the group's command stream and jump
+   * the local player to the group's current item + position. This is
+   * the only entry point a user needs from the menu — there is no
+   * separate "halt" UI; the player exit/back already detaches us.
+   */
+  const resumeGroupPlayback = useCallback(async (): Promise<void> => {
+    if (!api || !manager) return;
+    await manager.followGroupPlayback(api);
+    const queueCore = manager.getQueueCore();
+    const index = queueCore.getCurrentPlaylistIndex();
+    const itemId =
+      index >= 0 ? (queueCore.getPlaylist()[index]?.Id ?? null) : null;
+    if (!itemId) {
+      console.warn("SyncPlay: resumeGroupPlayback — no current group item");
+      return;
+    }
+    navigateToPlayer(itemId, queueCore.getStartPositionTicks());
+  }, [api, manager, navigateToPlayer]);
+
+  // ---------------------------------------------------------------------------
+  // App foreground re-join (idempotent; gets us a fresh GroupJoined snapshot)
+  // ---------------------------------------------------------------------------
+
+  const lastGroupIdRef = useRef<string | null>(null);
+  useEffect(() => {
+    lastGroupIdRef.current = groupInfo?.GroupId ?? null;
+  }, [groupInfo?.GroupId]);
+
+  // Track whether the WebSocket got torn down while the app was
+  // backgrounded. If it survived (keep-alive worked), the server
+  // still has us in the group and we must NOT call JoinGroup again —
+  // doing so would trigger a redundant "X joined the group" broadcast
+  // to every other member every time we briefly leave the app.
+  const wsClosedWhileBackgroundedRef = useRef(false);
+  const appStateRef = useRef<AppStateStatus>(AppState.currentState);
+  useEffect(() => {
+    if (!isWsConnected && appStateRef.current !== "active") {
+      wsClosedWhileBackgroundedRef.current = true;
+    }
+  }, [isWsConnected]);
+
+  useEffect(() => {
+    if (!api) return;
+
+    const subscription = AppState.addEventListener("change", (nextAppState) => {
+      const previousAppState = appStateRef.current;
+      appStateRef.current = nextAppState;
+
+      const becameActive =
+        (previousAppState === "background" ||
+          previousAppState === "inactive") &&
+        nextAppState === "active";
+      if (!becameActive) return;
+
+      const groupId = lastGroupIdRef.current;
+      if (!groupId) return;
+
+      // Happy path: keep-alive held the socket open across the
+      // suspend. Server still considers us a member — nothing to do.
+      if (!wsClosedWhileBackgroundedRef.current) {
+        console.log(
+          "SyncPlay: app foregrounded with WS still alive, skipping rejoin",
+        );
+        return;
+      }
+      wsClosedWhileBackgroundedRef.current = false;
+
+      // Small delay so the WebSocket has a moment to reconnect.
+      setTimeout(() => {
+        console.log(
+          `SyncPlay: app foregrounded after WS drop, rejoining group ${groupId}`,
+        );
+        getSyncPlayApi(api)
+          .syncPlayJoinGroup({ joinGroupRequestDto: { GroupId: groupId } })
+          .catch((error) => {
+            console.error("SyncPlay: failed to rejoin group", error);
+          });
+      }, 1000);
+    });
+
+    return () => subscription.remove();
+  }, [api]);
+
+  // ---------------------------------------------------------------------------
+  // Player attach bridges
+  // ---------------------------------------------------------------------------
+
+  const setPlayerControls = useCallback(
+    (controls: PlayerControls | null) => {
+      // Reset the playbackstart latch on each new attach.
+      playbackStartFiredRef.current = false;
+      manager?.setPlayerControls(controls);
+    },
+    [manager],
+  );
+
+  const notifyReady = useCallback(() => {
+    manager?.notifyReady();
+  }, [manager]);
+
+  const notifyBuffering = useCallback(
+    (isBuffering: boolean) => {
+      manager?.notifyBuffering(isBuffering);
+      if (!isBuffering && !playbackStartFiredRef.current) {
+        playbackStartFiredRef.current = true;
+        manager?.notifyPlaybackStart();
+      }
+    },
+    [manager],
+  );
+
+  const notifyPlaybackStart = useCallback(() => {
+    manager?.notifyPlaybackStart();
+  }, [manager]);
+
+  // ---------------------------------------------------------------------------
+  // Context value
+  // ---------------------------------------------------------------------------
+
+  const contextValue: SyncPlayContextValue = useMemo(
+    () => ({
+      isEnabled,
+      groupInfo,
+      canJoinGroups,
+      canCreateGroups,
+      joinGroup,
+      createGroup,
+      leaveGroup,
+      getGroups,
+      resumeGroupPlayback,
+      controller: manager?.getController() ?? null,
+      setPlayerControls,
+      notifyReady,
+      notifyBuffering,
+      notifyPlaybackStart,
+      pendingPlaybackCommand,
+      osdAction,
+    }),
+    [
+      isEnabled,
+      groupInfo,
+      canJoinGroups,
+      canCreateGroups,
+      joinGroup,
+      createGroup,
+      leaveGroup,
+      getGroups,
+      resumeGroupPlayback,
+      manager,
+      setPlayerControls,
+      notifyReady,
+      notifyBuffering,
+      notifyPlaybackStart,
+      pendingPlaybackCommand,
+      osdAction,
+    ],
+  );
+
+  return (
+    <SyncPlayContext.Provider value={contextValue}>
+      {children}
+    </SyncPlayContext.Provider>
+  );
+}
+
+export function useSyncPlay(): SyncPlayContextValue {
+  const context = useContext(SyncPlayContext);
+  if (!context) {
+    throw new Error("useSyncPlay must be used within a SyncPlayProvider");
+  }
+  return context;
+}

providers/SyncPlay/constants.ts

@@ -0,0 +1,23 @@
+/**
+ * Constants — shared timing/threshold values used across SyncPlay files.
+ * Kept separate from `types.ts` because these are implementation tuning
+ * values, not the public protocol/types surface.
+ */
+
+import { TicksPerMillisecond } from "./types";
+
+export { TicksPerMillisecond };
+
+/** Default timeout for `waitForEventOnce` (matches jellyfin-web). */
+export const WaitForEventDefaultTimeout = 30000;
+
+/** Short-lived timeout for player events (matches jellyfin-web). */
+export const WaitForPlayerEventTimeout = 500;
+
+export function ticksToMs(ticks: number): number {
+  return ticks / TicksPerMillisecond;
+}
+
+export function msToTicks(ms: number): number {
+  return Math.round(ms * TicksPerMillisecond);
+}

providers/SyncPlay/cores/PlaybackCore.ts

@@ -0,0 +1,381 @@
+/**
+ * SyncPlay PlaybackCore — schedules unpauses/pauses/seeks/stops to fire
+ * at the precise group-wide moment and keeps the player drift-corrected.
+ *
+ * Design choices that diverge from jellyfin-web:
+ *  - **No SpeedToSync**. Our RN players' `setPlaybackSpeed` is unreliable
+ *    across platforms (mpv/VLC/expo-video each behave differently for
+ *    fractional speeds). We always seek to catch up.
+ *  - **No `MessageSyncPlayDuplicateMedia` detection**. Web's detection
+ *    used HTML element identity; on RN we don't have a stable handle
+ *    and the false-positive rate would be much higher than the value.
+ *  - **No syncMethod / showSyncIcon**. We don't surface the sync
+ *    technique to the UI.
+ */
+
+import type { Api } from "@jellyfin/sdk";
+import { getSyncPlayApi } from "@jellyfin/sdk/lib/utils/api";
+import {
+  TicksPerMillisecond,
+  ticksToMs,
+  WaitForPlayerEventTimeout,
+} from "../constants";
+import { EventEmitter, waitForEventOnce } from "../EventEmitter";
+import type { SyncPlayManager } from "../Manager";
+import { type SendCommand, SYNC_PLAY_TUNING } from "../types";
+
+export class PlaybackCore extends EventEmitter {
+  private manager!: SyncPlayManager;
+  private lastCommand: SendCommand | null = null;
+  private scheduledCommand: ReturnType<typeof setTimeout> | null = null;
+
+  init(manager: SyncPlayManager): void {
+    this.manager = manager;
+  }
+
+  /** Local "playback started" hook — fires the initial Ready request. */
+  onPlaybackStart(apiClient: Api): void {
+    try {
+      const playerWrapper = this.manager.getPlayerWrapper();
+      const positionMs = playerWrapper.currentTime();
+      const positionTicks = Math.round(positionMs * TicksPerMillisecond);
+      const isPlaying = playerWrapper.isPlaying();
+      const playlistItemId =
+        this.manager.getQueueCore().getCurrentPlaylistItemId() ?? undefined;
+      const now = this.manager.getTimeSync().localDateToRemote(new Date());
+
+      getSyncPlayApi(apiClient).syncPlayReady({
+        readyRequestDto: {
+          When: now.toISOString(),
+          PositionTicks: positionTicks,
+          IsPlaying: isPlaying,
+          PlaylistItemId: playlistItemId,
+        },
+      });
+    } catch (error) {
+      console.error("SyncPlay onPlaybackStart:", error);
+    }
+  }
+
+  /** Local pause → tell the server. */
+  onPause(apiClient: Api): void {
+    try {
+      getSyncPlayApi(apiClient).syncPlayPause();
+    } catch (error) {
+      console.error("SyncPlay onPause:", error);
+    }
+  }
+
+  /** Local unpause → tell the server. */
+  onUnpause(apiClient: Api): void {
+    try {
+      getSyncPlayApi(apiClient).syncPlayUnpause();
+    } catch (error) {
+      console.error("SyncPlay onUnpause:", error);
+    }
+  }
+
+  /** Local "ready" hook — server uses this to know we've finished buffering. */
+  onReady(apiClient: Api): void {
+    this.sendBufferingRequest(apiClient, false);
+  }
+
+  /** Local "buffering" hook — server uses this to (optionally) pause the group. */
+  onBuffering(apiClient: Api): void {
+    this.sendBufferingRequest(apiClient, true);
+  }
+
+  /** Send a Ready or Buffering request. */
+  sendBufferingRequest(apiClient: Api, isBuffering: boolean): void {
+    const playerWrapper = this.manager.getPlayerWrapper();
+    const positionMs = playerWrapper.currentTime();
+    const positionTicks = Math.round(positionMs * TicksPerMillisecond);
+    const isPlaying = playerWrapper.isPlaying();
+    const playlistItemId =
+      this.manager.getQueueCore().getCurrentPlaylistItemId() ?? undefined;
+    const now = this.manager.getTimeSync().localDateToRemote(new Date());
+
+    try {
+      if (isBuffering) {
+        getSyncPlayApi(apiClient).syncPlayBuffering({
+          bufferRequestDto: {
+            When: now.toISOString(),
+            PositionTicks: positionTicks,
+            IsPlaying: isPlaying,
+            PlaylistItemId: playlistItemId,
+          },
+        });
+      } else {
+        getSyncPlayApi(apiClient).syncPlayReady({
+          readyRequestDto: {
+            When: now.toISOString(),
+            PositionTicks: positionTicks,
+            IsPlaying: isPlaying,
+            PlaylistItemId: playlistItemId,
+          },
+        });
+      }
+    } catch (error) {
+      console.error("SyncPlay sendBufferingRequest:", error);
+    }
+  }
+
+  /**
+   * Apply a group command (Unpause, Pause, Stop, Seek). Times the
+   * execution to fire at the group-wide instant the server selected.
+   */
+  applyCommand(command: SendCommand): void {
+    (command as unknown as { EmittedAt: Date }).EmittedAt = new Date(
+      command.EmittedAt as unknown as string,
+    );
+    (command as unknown as { When: Date }).When = new Date(
+      command.When as unknown as string,
+    );
+
+    // Duplicate-detection — mirrors jellyfin-web's PlaybackCore.applyCommand.
+    // The server can redeliver the same command (WebSocket reconnect, multiple
+    // group-state transitions referencing the same instant, etc). If every
+    // identifying field matches the previously applied command, we don't
+    // re-schedule — we just verify player state still matches and bail.
+    //
+    // IMPORTANT: this is NOT a monotonic-clock check. `When` is the scheduled
+    // execution time and can legitimately move backward between commands
+    // (e.g. a Pause emitted now with `When = now` arriving after an earlier
+    // Unpause whose `When` was scheduled 10s in the future). An earlier
+    // version of this code rejected anything whose `When` or `EmittedAt`
+    // wasn't strictly greater than `lastCommand`'s — that silently locked
+    // out every subsequent pause/unpause whenever group playback first
+    // started with a future-scheduled Unpause.
+    if (
+      this.lastCommand &&
+      (this.lastCommand as unknown as { When: Date }).When.getTime() ===
+        (command as unknown as { When: Date }).When.getTime() &&
+      this.lastCommand.PositionTicks === command.PositionTicks &&
+      this.lastCommand.Command === command.Command &&
+      this.lastCommand.PlaylistItemId === command.PlaylistItemId
+    ) {
+      console.debug("SyncPlay applyCommand: duplicate command", command);
+      return;
+    }
+
+    this.lastCommand = command;
+    if (!this.manager.isFollowingGroupPlayback()) {
+      console.debug(
+        "SyncPlay applyCommand: dropping command (not following playback)",
+        command,
+      );
+      return;
+    }
+
+    const playerWrapper = this.manager.getPlayerWrapper();
+    if (!playerWrapper.isPlaybackActive()) {
+      console.debug(
+        "SyncPlay applyCommand: dropping command (playback not active)",
+        command,
+      );
+      return;
+    }
+
+    const enqueuedAt = new Date();
+    const remoteEnqueuedAt = this.manager
+      .getTimeSync()
+      .localDateToRemote(enqueuedAt);
+    const localCommandWhen = this.manager
+      .getTimeSync()
+      .remoteDateToLocal(command.When as unknown as Date);
+
+    switch (command.Command) {
+      case "Unpause":
+        this.scheduleUnpause(localCommandWhen, command.PositionTicks ?? 0);
+        this.emit("osd", "unpause");
+        break;
+      case "Pause":
+        this.schedulePause(localCommandWhen, command.PositionTicks ?? 0);
+        this.emit("osd", "pause");
+        break;
+      case "Stop":
+        this.scheduleStop(localCommandWhen);
+        break;
+      case "Seek":
+        this.scheduleSeek(localCommandWhen, command.PositionTicks ?? 0);
+        this.emit("osd", "seek");
+        break;
+      default:
+        console.warn("SyncPlay applyCommand: unknown command", command);
+        break;
+    }
+
+    if (
+      (command as unknown as { When: Date }).When.getTime() <
+      remoteEnqueuedAt.getTime()
+    ) {
+      console.debug(
+        "SyncPlay applyCommand: command was scheduled for the past",
+        command,
+      );
+    }
+  }
+
+  /** Pre-Unpause hook: emit a wait OSD while we wait for the moment. */
+  scheduleUnpause(when: Date, positionTicks: number): void {
+    this.clearScheduledCommand();
+    const now = Date.now();
+    const playAtTime = when.getTime();
+    const currentPositionMs = this.manager.getPlayerWrapper().currentTime();
+    const currentPositionTicks = Math.round(
+      currentPositionMs * TicksPerMillisecond,
+    );
+
+    if (playAtTime > now) {
+      // Future: seek now, then play at the right moment.
+      this.localSeek(positionTicks);
+      this.scheduledCommand = setTimeout(() => {
+        this.localUnpause();
+        // After playback resumes, the player position will need a
+        // small bump to land on the group target. waitForPlayerEvent
+        // is best-effort.
+        waitForEventOnce(
+          this.manager,
+          "unpause",
+          WaitForPlayerEventTimeout,
+        ).catch(() => undefined);
+      }, playAtTime - now);
+      this.emit("osd", "wait-unpause");
+    } else {
+      // Past: catch up now.
+      const targetMs = ticksToMs(positionTicks);
+      const delayMs = now - playAtTime;
+      this.localSeek(Math.round((targetMs + delayMs) * TicksPerMillisecond));
+      this.localUnpause();
+      void currentPositionTicks;
+    }
+  }
+
+  schedulePause(when: Date, positionTicks: number): void {
+    this.clearScheduledCommand();
+    const now = Date.now();
+    const pauseAtTime = when.getTime();
+
+    const callback = () => {
+      this.localUnpause();
+      this.localSeek(positionTicks);
+      this.localPause();
+    };
+
+    if (pauseAtTime > now) {
+      this.scheduledCommand = setTimeout(callback, pauseAtTime - now);
+      this.emit("osd", "wait-pause");
+    } else {
+      callback();
+    }
+  }
+
+  scheduleStop(when: Date): void {
+    this.clearScheduledCommand();
+    const now = Date.now();
+    const stopAtTime = when.getTime();
+    if (stopAtTime > now) {
+      this.scheduledCommand = setTimeout(() => {
+        this.localStop();
+      }, stopAtTime - now);
+    } else {
+      this.localStop();
+    }
+  }
+
+  scheduleSeek(when: Date, positionTicks: number): void {
+    this.applyCommand({
+      ...this.lastCommand!,
+      Command: "Pause",
+      PositionTicks: positionTicks,
+      When: when as unknown as string,
+      EmittedAt: new Date().toISOString(),
+    });
+  }
+
+  clearScheduledCommand(): void {
+    if (this.scheduledCommand) {
+      clearTimeout(this.scheduledCommand);
+      this.scheduledCommand = null;
+    }
+  }
+
+  // -- local player ops ------------------------------------------------------
+
+  localUnpause(): void {
+    this.manager.getPlayerWrapper().localUnpause();
+  }
+
+  localPause(): void {
+    this.manager.getPlayerWrapper().localPause();
+  }
+
+  localSeek(positionTicks: number): void {
+    this.manager.getPlayerWrapper().localSeek(positionTicks);
+  }
+
+  localStop(): void {
+    this.manager.getPlayerWrapper().localStop();
+  }
+
+  // -- queries ---------------------------------------------------------------
+
+  getLastCommand(): SendCommand | null {
+    return this.lastCommand;
+  }
+
+  /**
+   * Estimate where the group should be in ticks, given a known
+   * starting position and the time the position was valid at.
+   */
+  estimateCurrentTicks(positionTicks: number, when: Date): number {
+    const lastCommand = this.lastCommand;
+    if (!lastCommand) return positionTicks;
+    const remoteNow = this.manager.getTimeSync().localDateToRemote(new Date());
+    const elapsedMs = remoteNow.getTime() - when.getTime();
+    if (lastCommand.Command === "Unpause") {
+      return positionTicks + elapsedMs * TicksPerMillisecond;
+    }
+    return positionTicks;
+  }
+
+  /**
+   * Drift correction tick — called on every player time update. Skips
+   * to the group's expected position if drift exceeds the threshold.
+   * SpeedToSync is intentionally not implemented (see file header).
+   */
+  syncPlaybackTime(): void {
+    const lastCommand = this.lastCommand;
+    if (lastCommand?.Command !== "Unpause") return;
+
+    const playerWrapper = this.manager.getPlayerWrapper();
+    if (!playerWrapper.isPlaying()) return;
+
+    const currentMs = playerWrapper.currentTime();
+    const expectedTicks = this.estimateCurrentTicks(
+      lastCommand.PositionTicks ?? 0,
+      lastCommand.When as unknown as Date,
+    );
+    const expectedMs = ticksToMs(expectedTicks);
+    const driftMs = Math.abs(currentMs - expectedMs);
+
+    if (driftMs > SYNC_PLAY_TUNING.minDelaySkipToSync) {
+      console.log(
+        `SyncPlay syncPlaybackTime: drift ${driftMs.toFixed(
+          0,
+        )}ms exceeds threshold, seeking to ${expectedMs.toFixed(0)}ms`,
+      );
+      this.localSeek(expectedTicks);
+    }
+  }
+
+  // -- teardown --------------------------------------------------------------
+
+  destroy(): void {
+    this.clearScheduledCommand();
+    this.lastCommand = null;
+    this.removeAllListeners();
+  }
+}
+
+export default PlaybackCore;

providers/SyncPlay/cores/QueueCore.ts

@@ -0,0 +1,332 @@
+/**
+ * SyncPlay QueueCore — tracks the group's playlist.
+ *
+ * Responsibilities:
+ *  - Handle `PlayQueue` group updates (NewPlaylist, SetCurrentItem,
+ *    NextItem, PreviousItem, RemoveItems, etc.)
+ *  - Resolve the server's flat list of ItemIds into full `BaseItemDto`s
+ *    (with PlaylistItemId glued on for SyncPlay requests)
+ *  - Expose `currentPlaylistItemId` — required by every SyncPlay
+ *    request (Ready, Buffering, Seek) so the server can ignore stale
+ *    ones from before the playlist moved
+ *  - On NewPlaylist, ask the server we're ready by sending a Buffering
+ *    request after the local player emits `playbackstart`
+ */
+
+import type { Api } from "@jellyfin/sdk";
+import type { BaseItemDto } from "@jellyfin/sdk/lib/generated-client";
+import { getSyncPlayApi } from "@jellyfin/sdk/lib/utils/api";
+import { TicksPerMillisecond, WaitForEventDefaultTimeout } from "../constants";
+import { EventEmitter, waitForEventOnce } from "../EventEmitter";
+import type { SyncPlayManager } from "../Manager";
+import {
+  getItemsForPlayback,
+  translateItemsForPlayback,
+} from "../transport/queueTranslation";
+import type {
+  PlayQueueUpdate,
+  PlayQueueUpdateReason,
+  SyncPlayQueueItem,
+} from "../types";
+
+export class QueueCore extends EventEmitter {
+  private manager!: SyncPlayManager;
+  private lastPlayQueueUpdate: PlayQueueUpdate | null = null;
+  /** Playable items with `PlaylistItemId` glued on. */
+  private playlist: BaseItemDto[] = [];
+
+  init(manager: SyncPlayManager): void {
+    this.manager = manager;
+  }
+
+  /** Handle a PlayQueue group update from the server. */
+  updatePlayQueue(apiClient: Api, newPlayQueue: PlayQueueUpdate): void {
+    (newPlayQueue as unknown as { LastUpdate: Date }).LastUpdate = new Date(
+      newPlayQueue.LastUpdate as unknown as string,
+    );
+
+    if (
+      (newPlayQueue.LastUpdate as unknown as Date).getTime() <=
+      this.getLastUpdateTime()
+    ) {
+      console.debug("SyncPlay updatePlayQueue: ignoring old update");
+      return;
+    }
+
+    this.onPlayQueueUpdate(apiClient, newPlayQueue)
+      .then(() => {
+        if (
+          (newPlayQueue.LastUpdate as unknown as Date).getTime() <
+          this.getLastUpdateTime()
+        ) {
+          console.warn("SyncPlay updatePlayQueue: trying to apply old update");
+          return;
+        }
+
+        const reason = newPlayQueue.Reason as PlayQueueUpdateReason;
+        switch (reason) {
+          case "NewPlaylist": {
+            if (!this.manager.isFollowingGroupPlayback()) {
+              this.manager.followGroupPlayback(apiClient).then(() => {
+                this.startPlayback(apiClient);
+              });
+            } else {
+              this.startPlayback(apiClient);
+            }
+            break;
+          }
+          case "SetCurrentItem":
+          case "NextItem":
+          case "PreviousItem": {
+            const playlistItemId = this.getCurrentPlaylistItemId();
+            this.setCurrentPlaylistItem(apiClient, playlistItemId);
+            break;
+          }
+          case "RemoveItems":
+          case "MoveItem":
+          case "Queue":
+          case "QueueNext":
+          case "RepeatMode":
+          case "ShuffleMode":
+            // Video-focused: we don't expose repeat/shuffle/queue mutation
+            // controls in the RN UI yet, so these reasons just update our
+            // local snapshot (already done by onPlayQueueUpdate) without
+            // triggering any local action.
+            break;
+          default:
+            console.warn(
+              "SyncPlay updatePlayQueue: unknown reason",
+              newPlayQueue.Reason,
+            );
+            break;
+        }
+      })
+      .catch((error) => {
+        console.warn("SyncPlay updatePlayQueue:", error);
+      });
+  }
+
+  /** Apply a play-queue update to local state. */
+  async onPlayQueueUpdate(
+    apiClient: Api,
+    playQueueUpdate: PlayQueueUpdate,
+  ): Promise<void> {
+    const itemIds = (playQueueUpdate.Playlist ?? [])
+      .map((queueItem: SyncPlayQueueItem) => queueItem.ItemId)
+      .filter((id): id is string => typeof id === "string");
+
+    if (!itemIds.length) {
+      this.lastPlayQueueUpdate = playQueueUpdate;
+      this.playlist = [];
+      return;
+    }
+
+    const fetched = await getItemsForPlayback(apiClient, itemIds);
+    const items = await translateItemsForPlayback(apiClient, fetched, {
+      ids: itemIds,
+    });
+
+    if (
+      this.lastPlayQueueUpdate &&
+      (playQueueUpdate.LastUpdate as unknown as Date).getTime() <=
+        this.getLastUpdateTime()
+    ) {
+      throw new Error("Trying to apply old update");
+    }
+
+    // Glue PlaylistItemId from the server's playlist entries onto each
+    // resolved item. The server-assigned IDs are what every SyncPlay
+    // request needs to identify the queue slot.
+    const playlistItems = playQueueUpdate.Playlist ?? [];
+    for (let i = 0; i < items.length && i < playlistItems.length; i++) {
+      items[i].PlaylistItemId = playlistItems[i].PlaylistItemId;
+    }
+
+    this.lastPlayQueueUpdate = playQueueUpdate;
+    this.playlist = items;
+  }
+
+  /**
+   * Send a Ready request once the local player begins playback. The
+   * server uses this to wait until every member is buffered before
+   * issuing the next Unpause.
+   *
+   * On timeout (player never starts), halt group playback so the rest
+   * of the group can proceed without us.
+   */
+  scheduleReadyRequestOnPlaybackStart(apiClient: Api, origin: string): void {
+    waitForEventOnce(
+      this.manager,
+      "playbackstart",
+      WaitForEventDefaultTimeout,
+      ["playbackerror"],
+    )
+      .then(() => {
+        console.debug(
+          "SyncPlay scheduleReadyRequestOnPlaybackStart: notifying server",
+        );
+        const playerWrapper = this.manager.getPlayerWrapper();
+        playerWrapper.localPause();
+
+        const currentPosition = playerWrapper.currentTime();
+        const currentPositionTicks = Math.round(
+          currentPosition * TicksPerMillisecond,
+        );
+        const isPlaying = playerWrapper.isPlaying();
+        const now = this.manager.getTimeSync().localDateToRemote(new Date());
+
+        try {
+          getSyncPlayApi(apiClient).syncPlayReady({
+            readyRequestDto: {
+              When: now.toISOString(),
+              PositionTicks: currentPositionTicks,
+              IsPlaying: isPlaying,
+              PlaylistItemId: this.getCurrentPlaylistItemId() ?? undefined,
+            },
+          });
+        } catch (error) {
+          console.error("SyncPlay syncPlayReady failed", error);
+        }
+      })
+      .catch((error) => {
+        console.error(
+          "Timed out waiting for 'playbackstart' event!",
+          origin,
+          error,
+        );
+        if (!this.manager.isSyncPlayEnabled()) {
+          this.manager.emit("toast", "MessageSyncPlayErrorMedia");
+        }
+        this.manager.haltGroupPlayback(apiClient);
+      });
+  }
+
+  /** Start local playback by navigating to the player screen for the current item. */
+  startPlayback(apiClient: Api): void {
+    if (!this.manager.isFollowingGroupPlayback()) {
+      console.debug("SyncPlay startPlayback: ignoring, not following playback");
+      return;
+    }
+
+    if (this.isPlaylistEmpty()) {
+      console.debug("SyncPlay startPlayback: empty playlist");
+      return;
+    }
+
+    // Estimate where to start playback from. Prefer the last playback
+    // command if newer than the queue update (playback ticks change
+    // more often than queue position).
+    const playbackCommand = this.manager.getLastPlaybackCommand();
+    let startPositionTicks = 0;
+
+    if (
+      playbackCommand &&
+      (
+        playbackCommand as unknown as { EmittedAt: Date }
+      ).EmittedAt?.getTime() >= this.getLastUpdateTime()
+    ) {
+      startPositionTicks = this.manager
+        .getPlaybackCore()
+        .estimateCurrentTicks(
+          playbackCommand.PositionTicks ?? 0,
+          (playbackCommand as unknown as { When: Date }).When,
+        );
+    } else {
+      startPositionTicks = this.manager
+        .getPlaybackCore()
+        .estimateCurrentTicks(
+          this.getStartPositionTicks(),
+          (this.getLastUpdate() ?? new Date()) as Date,
+        );
+    }
+
+    const serverId = apiClient.deviceInfo?.id ?? "";
+
+    this.scheduleReadyRequestOnPlaybackStart(apiClient, "startPlayback");
+
+    this.manager
+      .getPlayerWrapper()
+      .localPlay({
+        ids: this.getPlaylistAsItemIds(),
+        startPositionTicks,
+        startIndex: this.getCurrentPlaylistIndex(),
+        serverId,
+      })
+      .catch((error: unknown) => {
+        console.error("SyncPlay startPlayback: localPlay failed", error);
+        this.manager.emit("toast", "MessageSyncPlayErrorMedia");
+      });
+  }
+
+  /** Navigate to a specific item in the queue. */
+  setCurrentPlaylistItem(apiClient: Api, playlistItemId: string | null): void {
+    if (!this.manager.isFollowingGroupPlayback()) {
+      console.debug(
+        "SyncPlay setCurrentPlaylistItem: ignoring, not following playback",
+      );
+      return;
+    }
+
+    this.scheduleReadyRequestOnPlaybackStart(
+      apiClient,
+      "setCurrentPlaylistItem",
+    );
+
+    this.manager.getPlayerWrapper().localSetCurrentPlaylistItem(playlistItemId);
+  }
+
+  // -- getters ---------------------------------------------------------------
+
+  getCurrentPlaylistIndex(): number {
+    return this.lastPlayQueueUpdate?.PlayingItemIndex ?? -1;
+  }
+
+  getCurrentPlaylistItemId(): string | null {
+    if (!this.lastPlayQueueUpdate) return null;
+    const index = this.lastPlayQueueUpdate.PlayingItemIndex ?? -1;
+    if (index === -1) return null;
+    return this.playlist[index]?.PlaylistItemId ?? null;
+  }
+
+  getPlaylist(): BaseItemDto[] {
+    return this.playlist.slice(0);
+  }
+
+  isPlaylistEmpty(): boolean {
+    return this.playlist.length === 0;
+  }
+
+  getLastUpdate(): Date | null {
+    if (!this.lastPlayQueueUpdate) return null;
+    return this.lastPlayQueueUpdate.LastUpdate as unknown as Date;
+  }
+
+  getLastUpdateTime(): number {
+    if (!this.lastPlayQueueUpdate) return 0;
+    return (this.lastPlayQueueUpdate.LastUpdate as unknown as Date).getTime();
+  }
+
+  getStartPositionTicks(): number {
+    return this.lastPlayQueueUpdate?.StartPositionTicks ?? 0;
+  }
+
+  getPlaylistAsItemIds(): (string | undefined)[] {
+    if (!this.lastPlayQueueUpdate) return [];
+    return (this.lastPlayQueueUpdate.Playlist ?? []).map((q) => q.ItemId);
+  }
+
+  // -- teardown --------------------------------------------------------------
+
+  /** Clear cached playlist. Called on group disable so a re-join starts clean. */
+  clear(): void {
+    this.lastPlayQueueUpdate = null;
+    this.playlist = [];
+  }
+
+  destroy(): void {
+    this.clear();
+    this.removeAllListeners();
+  }
+}
+
+export default QueueCore;

providers/SyncPlay/cores/TimeSync.ts

@@ -0,0 +1,220 @@
+/**
+ * TimeSync — NTP-style time synchronisation with the Jellyfin server.
+ *
+ * Merged port of jellyfin-web's `core/timeSync/{TimeSync,TimeSyncServer,
+ * TimeSyncCore}.js` — three classes that exist on web because the
+ * abstract layer supports syncing against other group members, not just
+ * the server. RN only syncs against the server, so it's one class.
+ *
+ * Algorithm: repeatedly time a round-trip request to `getUtcTime`,
+ * compute `offset = ((requestReceived - requestSent) + (responseSent -
+ * responseReceived)) / 2`, keep the minimum-delay measurement out of
+ * the last 8. This is the standard NTP outlier-rejection trick — the
+ * measurement with the shortest delay is the most accurate because
+ * less network jitter could have skewed the timestamps.
+ *
+ * Polling: greedy mode at 1s intervals for the first 3 pings to warm
+ * up the offset, then low-profile at 60s intervals for steady-state.
+ * `forceUpdate()` resets to greedy mode (called on group join).
+ */
+
+import type { Api } from "@jellyfin/sdk";
+import { getTimeSyncApi } from "@jellyfin/sdk/lib/utils/api";
+import { EventEmitter } from "../EventEmitter";
+
+const NumberOfTrackedMeasurements = 8;
+const PollingIntervalGreedy = 1000; // ms
+const PollingIntervalLowProfile = 60000; // ms
+const GreedyPingCount = 3;
+
+class Measurement {
+  requestSent: number;
+  requestReceived: number;
+  responseSent: number;
+  responseReceived: number;
+
+  constructor(
+    requestSent: Date,
+    requestReceived: Date,
+    responseSent: Date,
+    responseReceived: Date,
+  ) {
+    this.requestSent = requestSent.getTime();
+    this.requestReceived = requestReceived.getTime();
+    this.responseSent = responseSent.getTime();
+    this.responseReceived = responseReceived.getTime();
+  }
+
+  /** Time offset (ms): positive means server clock is ahead of ours. */
+  getOffset(): number {
+    return (
+      (this.requestReceived -
+        this.requestSent +
+        (this.responseSent - this.responseReceived)) /
+      2
+    );
+  }
+
+  /** Round-trip delay (ms), excluding server processing. */
+  getDelay(): number {
+    return (
+      this.responseReceived -
+      this.requestSent -
+      (this.responseSent - this.requestReceived)
+    );
+  }
+
+  /** One-way ping (ms). */
+  getPing(): number {
+    return this.getDelay() / 2;
+  }
+}
+
+/**
+ * Tracks the offset between this client's clock and the Jellyfin server's
+ * clock, and exposes conversions between local and remote Dates.
+ *
+ * Listeners:
+ *   - `"update"` (timeOffset: number, ping: number) — fires on every
+ *     successful ping. Errors are logged but not emitted; consumers
+ *     should treat absence of updates as transient.
+ */
+export class TimeSync extends EventEmitter {
+  private api: Api;
+  private pingStop = true;
+  private pollingInterval = PollingIntervalGreedy;
+  private poller: ReturnType<typeof setTimeout> | null = null;
+  private pings = 0;
+  private measurement: Measurement | null = null;
+  private measurements: Measurement[] = [];
+
+  constructor(api: Api) {
+    super();
+    this.api = api;
+  }
+
+  /** Called when the user switches Jellyfin servers. */
+  updateApiClient(api: Api): void {
+    this.api = api;
+  }
+
+  /** Whether we've completed at least one successful measurement. */
+  isReady(): boolean {
+    return !!this.measurement;
+  }
+
+  /** Current best-estimate time offset (ms). */
+  getTimeOffset(): number {
+    return this.measurement ? this.measurement.getOffset() : 0;
+  }
+
+  /** Current best-estimate one-way ping (ms). */
+  getPing(): number {
+    return this.measurement ? this.measurement.getPing() : 0;
+  }
+
+  /** Convert a server-time Date to local time. */
+  remoteDateToLocal(remote: Date): Date {
+    return new Date(remote.getTime() - this.getTimeOffset());
+  }
+
+  /** Convert a local Date to server time. */
+  localDateToRemote(local: Date): Date {
+    return new Date(local.getTime() + this.getTimeOffset());
+  }
+
+  /** Start polling. Idempotent. */
+  startPing(): void {
+    this.pingStop = false;
+    this.scheduleNextPing();
+  }
+
+  /** Stop polling. Idempotent. */
+  stopPing(): void {
+    this.pingStop = true;
+    if (this.poller) {
+      clearTimeout(this.poller);
+      this.poller = null;
+    }
+  }
+
+  /** Reset to greedy polling and force a fresh measurement immediately. */
+  forceUpdate(): void {
+    this.stopPing();
+    this.pollingInterval = PollingIntervalGreedy;
+    this.pings = 0;
+    this.startPing();
+  }
+
+  /** Drop all measurements. Used on group leave. */
+  resetMeasurements(): void {
+    this.measurement = null;
+    this.measurements = [];
+  }
+
+  /** Full teardown on provider unmount. */
+  destroy(): void {
+    this.stopPing();
+    this.resetMeasurements();
+    this.removeAllListeners();
+  }
+
+  private scheduleNextPing(): void {
+    if (this.poller || this.pingStop) return;
+    this.poller = setTimeout(() => {
+      this.poller = null;
+      this.requestPing()
+        .then((result) => this.onPingResponse(result))
+        .catch((error) => {
+          console.error("SyncPlay TimeSync: ping failed", error);
+        })
+        .finally(() => this.scheduleNextPing());
+    }, this.pollingInterval);
+  }
+
+  private async requestPing() {
+    const requestSent = new Date();
+    const response = await getTimeSyncApi(this.api).getUtcTime();
+    const responseReceived = new Date();
+    const data = response.data;
+    const requestReceived = new Date(data.RequestReceptionTime as string);
+    const responseSent = new Date(data.ResponseTransmissionTime as string);
+    return { requestSent, requestReceived, responseSent, responseReceived };
+  }
+
+  private onPingResponse(result: {
+    requestSent: Date;
+    requestReceived: Date;
+    responseSent: Date;
+    responseReceived: Date;
+  }): void {
+    const measurement = new Measurement(
+      result.requestSent,
+      result.requestReceived,
+      result.responseSent,
+      result.responseReceived,
+    );
+
+    this.measurements.push(measurement);
+    if (this.measurements.length > NumberOfTrackedMeasurements) {
+      this.measurements.shift();
+    }
+
+    // Outlier rejection: pick the measurement with the shortest delay.
+    const sorted = [...this.measurements].sort(
+      (a, b) => a.getDelay() - b.getDelay(),
+    );
+    this.measurement = sorted[0];
+
+    // Throttle once we've warmed up.
+    if (this.pings >= GreedyPingCount) {
+      this.pollingInterval = PollingIntervalLowProfile;
+    } else {
+      this.pings++;
+    }
+
+    this.emit("update", this.getTimeOffset(), this.getPing());
+  }
+}
+
+export default TimeSync;

providers/SyncPlay/index.ts

@@ -0,0 +1,13 @@
+/**
+ * SyncPlay — public exports.
+ *
+ * Only what external consumers (components, hooks, screens) need.
+ * Internal modules (PlaybackCore, QueueCore, TimeSync, PlayerWrapper,
+ * queueTranslation, EventEmitter, etc.) stay package-private.
+ */
+
+export { Controller as SyncPlayController } from "./Controller";
+export { msToTicks, ticksToMs } from "./constants";
+export { SyncPlayManager } from "./Manager";
+export { SyncPlayProvider, useSyncPlay } from "./SyncPlayProvider";
+export * from "./types";

providers/SyncPlay/player/PendingPlaybackTracker.ts

@@ -0,0 +1,58 @@
+/**
+ * PendingPlaybackTracker — tracks an in-flight `Unpause` / `Pause` request
+ * that we've sent to the server but haven't seen echoed back via
+ * `SyncPlayCommand`.
+ *
+ * Drives three things:
+ *  1. Drop duplicate rapid taps
+ *  2. Provide an optimistic-UI hint for the in-flight state
+ *  3. Override "current play state" when deciding pause-vs-unpause
+ *     for the next tap
+ *
+ * Auto-clears after `pendingPlaybackTimeoutMs` so a lost broadcast
+ * doesn't freeze the UI forever.
+ */
+
+import { SYNC_PLAY_TUNING } from "../types";
+
+export class PendingPlaybackTracker {
+  private command: "Unpause" | "Pause" | null = null;
+  private timeout: ReturnType<typeof setTimeout> | null = null;
+  private onChange: ((cmd: "Unpause" | "Pause" | null) => void) | null = null;
+
+  setChangeHandler(
+    handler: ((cmd: "Unpause" | "Pause" | null) => void) | null,
+  ): void {
+    this.onChange = handler;
+  }
+
+  get(): "Unpause" | "Pause" | null {
+    return this.command;
+  }
+
+  mark(command: "Unpause" | "Pause"): void {
+    this.command = command;
+    if (this.timeout) clearTimeout(this.timeout);
+    this.timeout = setTimeout(() => {
+      console.debug(
+        "SyncPlay PendingPlaybackTracker: timed out waiting for broadcast",
+        command,
+      );
+      this.command = null;
+      this.timeout = null;
+      this.onChange?.(null);
+    }, SYNC_PLAY_TUNING.pendingPlaybackTimeoutMs);
+    this.onChange?.(command);
+  }
+
+  clear(): void {
+    if (this.timeout) {
+      clearTimeout(this.timeout);
+      this.timeout = null;
+    }
+    if (this.command !== null) {
+      this.command = null;
+      this.onChange?.(null);
+    }
+  }
+}

providers/SyncPlay/player/PlayerWrapper.ts

@@ -0,0 +1,87 @@
+/**
+ * PlayerWrapper — adapter between jellyfin's tick-based playerWrapper API
+ * and our millisecond-based `PlayerControls`. Methods that have no RN
+ * analog (queue mutation hooks) delegate to provider-supplied handlers
+ * which navigate to the player screen.
+ */
+
+import { TicksPerMillisecond } from "../constants";
+import type { PlayerControls } from "../types";
+
+/** Options passed to `playerWrapper.localPlay` — provider navigates to the player screen. */
+export interface LocalPlayOptions {
+  ids: (string | undefined)[];
+  startPositionTicks: number;
+  startIndex: number;
+  serverId?: string;
+}
+
+export class PlayerWrapper {
+  private controls: PlayerControls | null = null;
+  private localPlayHandler: ((options: LocalPlayOptions) => void) | null = null;
+  private setCurrentItemHandler:
+    | ((playlistItemId: string | null) => void)
+    | null = null;
+
+  /** Attach / detach the underlying player. */
+  bindToControls(controls: PlayerControls | null): void {
+    this.controls = controls;
+  }
+
+  /** Provider wires this to navigate to the player screen. */
+  setLocalPlayHandler(handler: ((options: LocalPlayOptions) => void) | null) {
+    this.localPlayHandler = handler;
+  }
+
+  /** Provider wires this to navigate to a different queue item. */
+  setLocalSetCurrentItemHandler(
+    handler: ((playlistItemId: string | null) => void) | null,
+  ) {
+    this.setCurrentItemHandler = handler;
+  }
+
+  localUnpause(): void {
+    this.controls?.play();
+  }
+
+  localPause(): void {
+    this.controls?.pause();
+  }
+
+  /** Upstream takes ticks; RN's `seekTo` takes ms. */
+  localSeek(positionTicks: number): void {
+    this.controls?.seekTo(positionTicks / TicksPerMillisecond);
+  }
+
+  /** RN: pause instead of teardown — leaving the player screen is the navigator's job. */
+  localStop(): void {
+    this.controls?.pause();
+  }
+
+  /** Position in ms. */
+  currentTime(): number {
+    return this.controls?.getCurrentPosition() ?? 0;
+  }
+
+  isPlaying(): boolean {
+    return this.controls?.isPlaying() ?? false;
+  }
+
+  isPlaybackActive(): boolean {
+    return this.controls !== null;
+  }
+
+  /** RN never runs as a remote-managed player. */
+  isRemote(): boolean {
+    return false;
+  }
+
+  localPlay(options: LocalPlayOptions): Promise<void> {
+    this.localPlayHandler?.(options);
+    return Promise.resolve();
+  }
+
+  localSetCurrentPlaylistItem(playlistItemId: string | null): void {
+    this.setCurrentItemHandler?.(playlistItemId);
+  }
+}

providers/SyncPlay/player/bufferingDebouncer.ts

@@ -0,0 +1,64 @@
+/**
+ * bufferingDebouncer — wrap an `isBuffering: boolean → void` notify callback
+ * with three RN-only guards. Web gets these for free from HTML `waiting`/
+ * `canplay`; our `PlayerControls` exposes state (not events) and the React
+ * effect that polls it can fire many times per second.
+ *
+ *  - **dedup**: drop redundant calls when state hasn't changed
+ *  - **debounce buffering→true**: only escalate after the threshold;
+ *    going back to ready cancels the pending escalation
+ *  - **coalesce inflight**: serialize concurrent sends
+ *
+ * Returns `{ notify, dispose }`.
+ */
+
+import { SYNC_PLAY_TUNING } from "../types";
+
+export function createBufferingDebouncer(
+  send: (isBuffering: boolean) => Promise<void>,
+) {
+  let lastSent: boolean | null = null;
+  let inflight: Promise<void> | null = null;
+  let pendingTimeout: ReturnType<typeof setTimeout> | null = null;
+
+  const flush = async (isBuffering: boolean) => {
+    if (lastSent === isBuffering) return;
+    if (inflight) {
+      try {
+        await inflight;
+      } catch {
+        // ignore — used only for ordering
+      }
+      if (lastSent === isBuffering) return;
+    }
+    lastSent = isBuffering;
+    inflight = send(isBuffering).finally(() => {
+      inflight = null;
+    });
+    return inflight;
+  };
+
+  return {
+    notify(isBuffering: boolean): void {
+      if (pendingTimeout) {
+        clearTimeout(pendingTimeout);
+        pendingTimeout = null;
+      }
+      if (!isBuffering) {
+        // Ready always fires immediately.
+        void flush(false);
+        return;
+      }
+      pendingTimeout = setTimeout(() => {
+        pendingTimeout = null;
+        void flush(true);
+      }, SYNC_PLAY_TUNING.minBufferingThresholdMs);
+    },
+    dispose(): void {
+      if (pendingTimeout) {
+        clearTimeout(pendingTimeout);
+        pendingTimeout = null;
+      }
+    },
+  };
+}

providers/SyncPlay/player/reconcileToGroupOnAttach.ts

@@ -0,0 +1,58 @@
+/**
+ * reconcileToGroupOnAttach — estimate the group's current position from
+ * the last play/pause broadcast and seek the freshly-attached player
+ * there if drift exceeds the threshold.
+ *
+ * Web's player binds at group-join, so this race doesn't exist there.
+ * On RN the player mounts in a separate route after the join, so
+ * commands arrive before controls attach. Without this, the player
+ * resumes from its local position and is silently behind the group.
+ */
+
+import { TicksPerMillisecond } from "../constants";
+import {
+  type PlayerControls,
+  type SendCommand,
+  SYNC_PLAY_TUNING,
+} from "../types";
+
+export function reconcileToGroupOnAttach(
+  controls: PlayerControls,
+  lastCommand: SendCommand | null,
+  localToRemote: (local: Date) => Date,
+): void {
+  if (
+    !lastCommand ||
+    (lastCommand.Command !== "Unpause" && lastCommand.Command !== "Pause") ||
+    !lastCommand.When ||
+    lastCommand.PositionTicks == null
+  ) {
+    return;
+  }
+
+  try {
+    const commandWhen = new Date(lastCommand.When);
+    let targetTicks = lastCommand.PositionTicks;
+    if (lastCommand.Command === "Unpause") {
+      const remoteNow = localToRemote(new Date());
+      targetTicks +=
+        (remoteNow.getTime() - commandWhen.getTime()) * TicksPerMillisecond;
+    }
+    const targetMs = Math.max(0, targetTicks / TicksPerMillisecond);
+    const currentMs = controls.getCurrentPosition();
+    if (
+      Math.abs(currentMs - targetMs) >
+      SYNC_PLAY_TUNING.positionReconcileThresholdMs
+    ) {
+      console.log(
+        `SyncPlay: player attached — seeking to estimated group position ${targetMs}ms (was ${currentMs}ms)`,
+      );
+      controls.seekTo(targetMs);
+    }
+  } catch (error) {
+    console.warn(
+      "SyncPlay: failed to estimate group position on attach",
+      error,
+    );
+  }
+}

providers/SyncPlay/transport/queueTranslation.ts

@@ -0,0 +1,183 @@
+/**
+ * queueTranslation — expand container items into a real playable queue.
+ *
+ * The server takes the queue we send via `syncPlaySetNewQueue` and
+ * rebroadcasts it verbatim to every group member. Sending a container
+ * ID (Series, Season, BoxSet, Playlist) means every receiver fails to
+ * open the player because they can't directly play a container. We must
+ * expand to real playable item IDs before sending the queue.
+ *
+ * Video-focused: music (MusicArtist/MusicGenre) and photo branches are
+ * intentionally omitted. Live TV (Program), Episode auto-advance, and
+ * folder expansion are preserved because they're the common video flows.
+ */
+
+import type { Api } from "@jellyfin/sdk";
+import type { BaseItemDto } from "@jellyfin/sdk/lib/generated-client";
+import {
+  getItemsApi,
+  getTvShowsApi,
+  getUserApi,
+  getUserLibraryApi,
+} from "@jellyfin/sdk/lib/utils/api";
+
+export interface TranslateOptions {
+  ids?: string[];
+  shuffle?: boolean;
+  queryOptions?: Record<string, unknown>;
+}
+
+const PLAYBACK_FIELDS = ["Chapters", "Trickplay"] as const;
+
+async function getCurrentUser(api: Api) {
+  const user = (await getUserApi(api).getCurrentUser()).data;
+  if (!user?.Id) {
+    throw new Error("SyncPlay queueTranslation: no authenticated user");
+  }
+  return user;
+}
+
+async function queryItems(
+  api: Api,
+  userId: string,
+  params: Record<string, unknown>,
+): Promise<BaseItemDto[]> {
+  const res = await getItemsApi(api).getItems({
+    limit: 300,
+    fields: PLAYBACK_FIELDS as unknown as never,
+    excludeLocationTypes: ["Virtual"] as unknown as never,
+    enableTotalRecordCount: false,
+    collapseBoxSetItems: false,
+    ...params,
+    userId,
+  });
+  return res.data.Items ?? [];
+}
+
+function fetchFolderChildren(
+  api: Api,
+  userId: string,
+  params: Record<string, unknown>,
+): Promise<BaseItemDto[]> {
+  return queryItems(api, userId, {
+    filters: ["IsNotFolder"],
+    recursive: true,
+    ...params,
+  });
+}
+
+/**
+ * Resolve item IDs into full `BaseItemDto`s.
+ *
+ *  - single ID → `getItem` (cheap, no Items wrapper)
+ *  - multi ID → `getItems` with playback defaults
+ */
+export async function getItemsForPlayback(
+  api: Api,
+  ids: string[],
+): Promise<BaseItemDto[]> {
+  if (!ids.length) return [];
+  const userId = (await getCurrentUser(api)).Id as string;
+  if (ids.length === 1) {
+    const res = await getUserLibraryApi(api).getItem({
+      userId,
+      itemId: ids[0],
+    });
+    return res.data ? [res.data] : [];
+  }
+  return queryItems(api, userId, { ids });
+}
+
+/**
+ * Expand a "first item" into a real playable queue.
+ *
+ *  - Program → channel items
+ *  - Playlist → playlist children
+ *  - IsFolder (Series, Season, BoxSet, MusicAlbum, ...) → recursive descendants
+ *  - single Episode (when `EnableNextEpisodeAutoPlay`) → remaining series episodes
+ *  - everything else → passthrough (Movies, Audio, single Episode w/ autoplay off)
+ *
+ * Preserves the caller's `ids` order so the receiver sees the same
+ * queue order the sender intended.
+ */
+export async function translateItemsForPlayback(
+  api: Api,
+  items: BaseItemDto[],
+  options: TranslateOptions = {},
+): Promise<BaseItemDto[]> {
+  if (!items.length) return [];
+
+  const workingItems =
+    items.length > 1 && options.ids
+      ? [...items].sort(
+          (a, b) =>
+            (options.ids ?? []).indexOf(a.Id ?? "") -
+            (options.ids ?? []).indexOf(b.Id ?? ""),
+        )
+      : items;
+
+  const firstItem = workingItems[0];
+
+  if (firstItem.Type === "Program" && firstItem.ChannelId) {
+    return getItemsForPlayback(api, [firstItem.ChannelId]);
+  }
+
+  const user = await getCurrentUser(api);
+  const userId = user.Id as string;
+
+  if (firstItem.Type === "Playlist") {
+    return queryItems(api, userId, {
+      parentId: firstItem.Id,
+      sortBy: options.shuffle ? ["Random"] : undefined,
+    });
+  }
+
+  if (firstItem.IsFolder) {
+    // Series, Season, BoxSet, MusicAlbum, etc.
+    const sortBy = options.shuffle
+      ? ["Random"]
+      : firstItem.Type === "BoxSet"
+        ? ["SortName"]
+        : undefined;
+    return fetchFolderChildren(api, userId, {
+      parentId: firstItem.Id,
+      mediaTypes: ["Audio", "Video"],
+      sortBy,
+      ...(options.queryOptions ?? {}),
+    });
+  }
+
+  if (firstItem.Type === "Episode" && workingItems.length === 1) {
+    // Single-episode auto-next: load all remaining episodes in the
+    // series, starting at this one. Gated on the user preference so we
+    // don't surprise users who disabled autoplay.
+    if (!user.Configuration?.EnableNextEpisodeAutoPlay || !firstItem.SeriesId) {
+      return workingItems;
+    }
+    const res = await getTvShowsApi(api).getEpisodes({
+      seriesId: firstItem.SeriesId,
+      userId,
+      isMissing: false,
+      fields: PLAYBACK_FIELDS as unknown as never,
+      // SDK omits `isVirtualUnaired` from typed request; server honours
+      // it. Cast keeps wire payload identical to jellyfin-web.
+      ...({ isVirtualUnaired: false } as Record<string, unknown>),
+    } as Parameters<ReturnType<typeof getTvShowsApi>["getEpisodes"]>[0]);
+    const all = res.data.Items ?? [];
+    // Drop everything before firstItem; keep firstItem and everything
+    // after. Empty list if firstItem isn't in the series (shouldn't
+    // happen, but matches upstream's behaviour).
+    let foundItem = false;
+    return all.filter((e) => {
+      if (foundItem) return true;
+      if (e.Id === firstItem.Id) {
+        foundItem = true;
+        return true;
+      }
+      return false;
+    });
+  }
+
+  // Movies, Audio, single Episode w/ autoplay off, etc.
+  return workingItems;
+}

providers/SyncPlay/transport/useSyncPlayWebSocket.ts

@@ -0,0 +1,94 @@
+/**
+ * useSyncPlayWebSocket
+ *
+ * Hook that connects the SyncPlay manager to WebSocket messages.
+ * Listens for SyncPlayCommand and SyncPlayGroupUpdate messages.
+ *
+ * IMPORTANT: We subscribe directly to the WebSocket via `addEventListener`
+ * rather than reading WebSocketProvider's `lastMessage` state. That state
+ * only holds the most recent message, so when the server emits bursts
+ * after a join (GroupJoined + StateUpdate + UserJoined + PlayQueue, all
+ * within a few ms), React's batching causes earlier messages to be
+ * overwritten before our effect can read them — most notably the
+ * GroupJoined message, which left the joining client thinking it hadn't
+ * joined while other members already saw it as a participant.
+ *
+ * Listening on the raw socket guarantees we see every frame in order.
+ */
+
+import { useEffect } from "react";
+import { useWebSocketContext } from "@/providers/WebSocketProvider";
+import type { SyncPlayManager } from "../Manager";
+import type { GroupUpdate, SendCommand } from "../types";
+
+/**
+ * Hook to connect SyncPlay manager to WebSocket
+ */
+export function useSyncPlayWebSocket(manager: SyncPlayManager | null): void {
+  const { ws } = useWebSocketContext();
+
+  useEffect(() => {
+    if (!ws || !manager) return;
+
+    const handleMessage = (event: WebSocketMessageEvent) => {
+      let parsed: { MessageType?: string; Data?: unknown };
+      try {
+        parsed = JSON.parse(event.data as string);
+      } catch (error) {
+        console.error("SyncPlay: failed to parse WebSocket message", error);
+        return;
+      }
+
+      const { MessageType, Data } = parsed;
+
+      // Only handle SyncPlay messages here; everything else is handled
+      // elsewhere via WebSocketProvider's lastMessage.
+      if (!MessageType?.startsWith("SyncPlay")) return;
+
+      console.log(
+        `SyncPlay WebSocket [${MessageType}]:`,
+        JSON.stringify(Data).substring(0, 300),
+      );
+
+      switch (MessageType) {
+        case "SyncPlayCommand": {
+          const command = Data as SendCommand;
+          console.log(
+            `SyncPlay: COMMAND received - ${command.Command} at ${command.When}`,
+            command.Command === "Seek"
+              ? `position=${command.PositionTicks}`
+              : "",
+          );
+
+          // Note: it's normal for controls to be missing here during the
+          // join → navigate → load window. Manager stashes the command and
+          // replays it on attach.
+          manager.processCommand(command);
+          break;
+        }
+
+        case "SyncPlayGroupUpdate": {
+          // SDK's `GroupUpdate` type is a discriminated union with a
+          // narrower `Type` enum than the wire format. Cast through
+          // unknown so upstream `Manager.processGroupUpdate` can switch
+          // on the real string.
+          const update = Data as unknown as GroupUpdate;
+          console.debug(
+            "SyncPlay: group update -",
+            (update as { Type?: string }).Type,
+          );
+          manager.processGroupUpdate(update);
+          break;
+        }
+
+        default:
+          break;
+      }
+    };
+
+    ws.addEventListener("message", handleMessage);
+    return () => {
+      ws.removeEventListener("message", handleMessage);
+    };
+  }, [ws, manager]);
+}

providers/SyncPlay/types.ts

@@ -0,0 +1,88 @@
+/**
+ * SyncPlay — public types and tuning constants.
+ *
+ * Re-exports the SDK types we use, defines the small RN-specific
+ * extensions (PlayerControls, OSD actions), and centralises the magic
+ * numbers that govern sync behaviour.
+ */
+
+import type { BaseItemDto } from "@jellyfin/sdk/lib/generated-client";
+
+// SDK type re-exports — kept narrow on purpose, only what callers
+// actually reach for.
+export type {
+  GroupInfoDto,
+  GroupQueueMode,
+  GroupRepeatMode,
+  GroupShuffleMode,
+  GroupStateType,
+  GroupUpdate,
+  PlayQueueUpdate,
+  PlayQueueUpdateReason,
+  SendCommand,
+  SendCommandType,
+  SyncPlayQueueItem,
+  SyncPlayUserAccessType,
+} from "@jellyfin/sdk/lib/generated-client/models";
+
+/** Jellyfin's tick unit. 1ms = 10000 ticks. */
+export const TicksPerMillisecond = 10000;
+
+/**
+ * Player controls SyncPlay drives. The provider wires this up against
+ * the active RN player (mpv / VLC / expo-video).
+ */
+export interface PlayerControls {
+  play: () => void;
+  pause: () => void;
+  /** Seek to absolute position in milliseconds. */
+  seekTo: (positionMs: number) => void;
+  setSpeed: (speed: number) => void;
+  getSpeed: () => number;
+  /** Current position in milliseconds. */
+  getCurrentPosition: () => number;
+  isPlaying: () => boolean;
+  isBuffering: () => boolean;
+}
+
+/** OSD action types — drive optional player-overlay feedback. */
+export type SyncPlayOsdAction =
+  /** transient — 1.5s pulse, the unpause command fired locally */
+  | "unpause"
+  /** transient — 1.5s pulse, the pause command fired locally */
+  | "pause"
+  /** transient — 1.5s pulse, a seek command applied locally */
+  | "seek"
+  /** persistent — group is about to play (Waiting+Unpause / pending Unpause) */
+  | "schedule-play"
+  /** persistent — another client is buffering (Waiting+Buffer) */
+  | "buffering"
+  /** persistent — group transitioning to pause (Waiting+Pause) */
+  | "wait-pause"
+  /** persistent — group transitioning to unpause; sibling of schedule-play */
+  | "wait-unpause";
+
+/**
+ * Tuning constants. These mirror jellyfin-web's defaults; tweak with
+ * care — they affect perceived sync quality across all clients.
+ */
+export const SYNC_PLAY_TUNING = {
+  /** Drift threshold (ms) above which we hard-seek to catch up. */
+  minDelaySkipToSync: 400,
+  /** Drift beyond this (ms) is always corrected by seeking. */
+  maxDelaySync: 3000,
+  /** Don't escalate buffering to the group for blips shorter than this (ms). */
+  minBufferingThresholdMs: 3000,
+  /** Player-attach drift (ms) above which we reconcile to group position. */
+  positionReconcileThresholdMs: 500,
+  /** Safety timeout (ms) for in-flight Pause/Unpause optimistic UI. */
+  pendingPlaybackTimeoutMs: 1500,
+} as const;
+
+/** Options accepted by `Controller.play`. */
+export interface PlayOptions {
+  ids?: string[];
+  items?: BaseItemDto[];
+  startIndex?: number;
+  startPositionTicks?: number;
+}

providers/WebSocketProvider.tsx

@@ -44,6 +44,15 @@ interface WebSocketContextType {
   lastMessage: WebSocketMessage | null;
   sendMessage: (message: any) => void;
   clearLastMessage: () => void;
+  /**
+   * Acquire a keep-alive token. While at least one token is held the
+   * WebSocket will NOT be closed on AppState background/inactive. Used
+   * by the video player while in Picture-in-Picture so SyncPlay (and
+   * any other server-pushed events) keep flowing. Returns a release
+   * function — call it (or rely on the React effect cleanup) when the
+   * keep-alive is no longer needed.
+   */
+  acquireKeepAlive: () => () => void;
 }
 
 const WebSocketContext = createContext<WebSocketContextType | null>(null);
@@ -63,6 +72,21 @@ export const WebSocketProvider = ({ children }: WebSocketProviderProps) => {
   const libraryChangeDebounceRef = useRef<ReturnType<typeof setTimeout> | null>(
     null,
   );
+  // Ref-counted keep-alive: while > 0 we skip the AppState→background
+  // close so the socket survives PiP / brief OS suspensions. iOS keeps
+  // the audio session (and therefore networking) alive while PiP is
+  // active, so the WS can continue to receive SyncPlay commands.
+  const keepAliveCountRef = useRef(0);
+
+  const acquireKeepAlive = useCallback((): (() => void) => {
+    keepAliveCountRef.current += 1;
+    let released = false;
+    return () => {
+      if (released) return;
+      released = true;
+      keepAliveCountRef.current = Math.max(0, keepAliveCountRef.current - 1);
+    };
+  }, []);
 
   const connectWebSocket = useCallback(() => {
     if (!deviceId || !api?.accessToken || !isNetworkConnected) {
@@ -235,9 +259,20 @@ export const WebSocketProvider = ({ children }: WebSocketProviderProps) => {
   useEffect(() => {
     const handleAppStateChange = (state: AppStateStatus) => {
       if (state === "background" || state === "inactive") {
+        if (keepAliveCountRef.current > 0) {
+          console.log(
+            `App backgrounded but WS keep-alive held (${keepAliveCountRef.current}); leaving socket open`,
+          );
+          return;
+        }
         console.log("App moving to background, closing WebSocket...");
         ws?.close();
       } else if (state === "active") {
+        // Only reconnect if we actually lost the socket (we may have
+        // skipped the close above because of a keep-alive token).
+        if (ws?.readyState === WebSocket.OPEN) {
+          return;
+        }
         console.log("App coming to foreground, reconnecting WebSocket...");
         connectWebSocket();
       }
@@ -267,7 +302,14 @@ export const WebSocketProvider = ({ children }: WebSocketProviderProps) => {
   }, []);
   return (
     <WebSocketContext.Provider
-      value={{ ws, isConnected, lastMessage, sendMessage, clearLastMessage }}
+      value={{
+        ws,
+        isConnected,
+        lastMessage,
+        sendMessage,
+        clearLastMessage,
+        acquireKeepAlive,
+      }}
     >
       {children}
     </WebSocketContext.Provider>

translations/en.json

@@ -1003,6 +1003,28 @@
       "all": "All media (default)"
     }
   },
+  "syncplay": {
+    "title": "SyncPlay",
+    "my_group": "My Group",
+    "join_group": "Join Group",
+    "leave_group": "Leave Group",
+    "create_new_group": "Create New Group",
+    "available_groups": "Available Groups",
+    "members": "members",
+    "failed_to_start": "Failed to start SyncPlay group playback",
+    "resume_playback": "Resume playback",
+    "toasts": {
+      "MessageSyncPlayGroupJoined": "Joined group",
+      "MessageSyncPlayGroupLeft": "Left group",
+      "MessageSyncPlayUserJoined": "{{user}} joined the group",
+      "MessageSyncPlayUserLeft": "{{user}} left the group",
+      "MessageSyncPlayCreateGroupDenied": "Permission denied to create a group",
+      "MessageSyncPlayJoinGroupDenied": "Permission denied to join group",
+      "MessageSyncPlayLibraryAccessDenied": "Access to the content has been denied",
+      "MessageSyncPlayGroupDoesNotExist": "Failed to join group because it does not exist",
+      "MessageSyncPlayErrorMedia": "SyncPlay error during media playback"
+    }
+  },
   "companion_login": {
     "title": "Pair with TV",
     "align_qr": "Align the QR code within the frame",