fix(jellyfin): keep remote websocket alive

- Respond to keep-alive requests and reconnect when the socket goes silent
- Warn when playback reports fail

changes/fix-jellyfin-modern-auth.md

@@ -0,0 +1,5 @@
+type: fixed
+area: jellyfin
+
+- Authenticate Jellyfin playback, subtitle, artwork, and remote-control socket URLs with the `ApiKey` query parameter and stop sending the legacy `X-Emby-Token` and `X-Emby-Authorization` headers, so the integration keeps working on Jellyfin 12 where legacy authorization is disabled by default.
+- Keep the cast-target websocket alive by answering Jellyfin keep-alive requests and reconnect when the server stops replying, so "Play on SubMiner" keeps working on Jellyfin 12 instead of silently dying about a minute after connecting. Failed playback progress and stop reports are now logged as warnings.

docs-site/jellyfin-integration.md

@@ -12,7 +12,7 @@ This is the recommended way to use Jellyfin with SubMiner. A terminal-only optio
 
 ## Requirements
 
-- A Jellyfin server plus your username and password
+- A Jellyfin server plus your username and password (Jellyfin 12, which disables legacy authorization by default, is supported)
 - SubMiner installed and running (see [Installation](/installation))
 - On Linux, the session token is stored with `gnome-libsecret` by default
 

launcher/jellyfin.ts

@@ -89,7 +89,6 @@ export async function jellyfinApiRequest<T>(
   const url = `${session.serverUrl}${requestPath}`;
   const response = await fetch(url, {
     headers: {
-      'X-Emby-Token': session.accessToken,
       Authorization: `MediaBrowser Token="${session.accessToken}"`,
     },
   });
@@ -103,7 +102,7 @@ export async function jellyfinApiRequest<T>(
 }
 
 function itemPreviewUrl(session: JellyfinSessionConfig, id: string): string {
-  return `${session.serverUrl}/Items/${id}/Images/Primary?maxHeight=720&quality=85&api_key=${encodeURIComponent(session.accessToken)}`;
+  return `${session.serverUrl}/Items/${id}/Images/Primary?maxHeight=720&quality=85&ApiKey=${encodeURIComponent(session.accessToken)}`;
 }
 
 function jellyfinIconCacheDir(session: JellyfinSessionConfig): string {

launcher/picker.ts

@@ -228,7 +228,7 @@ export function pickLibrary(
     commandExists('chafa') && commandExists('curl')
       ? `
 id={1}
-url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&api_key=${escapeShellSingle(session.accessToken)}
+url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&ApiKey=${escapeShellSingle(session.accessToken)}
 curl -fsSL "$url" 2>/dev/null | chafa --format=symbols --symbols=vhalf+wide --size=${'${FZF_PREVIEW_COLUMNS}'}x${'${FZF_PREVIEW_LINES}'} - 2>/dev/null
 `.trim()
       : 'echo "Install curl + chafa for image preview"';
@@ -266,7 +266,7 @@ export function pickItem(
     commandExists('chafa') && commandExists('curl')
       ? `
 id={1}
-url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&api_key=${escapeShellSingle(session.accessToken)}
+url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&ApiKey=${escapeShellSingle(session.accessToken)}
 curl -fsSL "$url" 2>/dev/null | chafa --format=symbols --symbols=vhalf+wide --size=${'${FZF_PREVIEW_COLUMNS}'}x${'${FZF_PREVIEW_LINES}'} - 2>/dev/null
 `.trim()
       : 'echo "Install curl + chafa for image preview"';
@@ -304,7 +304,7 @@ export function pickGroup(
     commandExists('chafa') && commandExists('curl')
       ? `
 id={1}
-url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&api_key=${escapeShellSingle(session.accessToken)}
+url=${escapeShellSingle(session.serverUrl)}/Items/$id/Images/Primary?maxHeight=720\\&quality=85\\&ApiKey=${escapeShellSingle(session.accessToken)}
 curl -fsSL "$url" 2>/dev/null | chafa --format=symbols --symbols=vhalf+wide --size=${'${FZF_PREVIEW_COLUMNS}'}x${'${FZF_PREVIEW_LINES}'} - 2>/dev/null
 `.trim()
       : 'echo "Install curl + chafa for image preview"';

src/anki-integration.test.ts

@@ -1545,3 +1545,25 @@ test('Anki metadata rejects a credential-bearing media title before metadata arr
   const result = privateApi.formatMiscInfoPattern('stream?api_key=test-secret', 426);
   assert.equal(result, '[SubMiner] Unknown media | Unknown media (00:07:06)');
 });
+
+test('AnkiIntegration.formatMiscInfoPattern treats ApiKey stream paths like legacy api_key ones', () => {
+  const integration = new AnkiIntegration(
+    { metadata: { pattern: '[SubMiner] %f (%t)' } } as never,
+    {} as never,
+    {
+      currentSubText: '',
+      currentVideoPath: 'stream?static=true&ApiKey=secret-token&MediaSourceId=ms-1',
+      currentTimePos: 426,
+      currentSubStart: 426,
+      currentSubEnd: 428,
+      currentMediaTitle: '[Jellyfin/direct] Bocchi the Rock! - S01E02',
+      send: () => true,
+    } as unknown as never,
+  );
+  const privateApi = integration as unknown as {
+    formatMiscInfoPattern: (fallbackFilename: string, startTimeSeconds?: number) => string;
+  };
+  const result = privateApi.formatMiscInfoPattern('audio_123.mp3', 426);
+  assert.equal(result, '[SubMiner] [Jellyfin/direct] Bocchi the Rock! - S01E02 (00:07:06)');
+  assert.equal(result.includes('ApiKey='), false);
+});

src/anki-integration.ts

@@ -185,7 +185,7 @@ function extractFilenameFromMediaPath(rawPath: string): string {
 function shouldPreferMediaTitleForMiscInfo(rawPath: string, filename: string): boolean {
   const loweredPath = rawPath.toLowerCase();
   const loweredFilename = filename.toLowerCase();
-  if (loweredPath.includes('api_key=')) {
+  if (loweredPath.includes('api_key=') || loweredPath.includes('apikey=')) {
     return true;
   }
   if (loweredPath.startsWith('http://') || loweredPath.startsWith('https://')) {

src/core/services/immersion-tracker-service.test.ts

@@ -3174,6 +3174,7 @@ test('Jellyfin metadata cleanup requires both an API key and a stream marker', a
       { filename: 'stream?api_key=secret', leaked: true },
       { filename: '/STREAM?API_KEY=secret', leaked: true },
       { filename: '/Videos/item?api_key=secret', leaked: true },
+      { filename: '/Videos/item?ApiKey=secret', leaked: true },
       { filename: 'MediaSourceId=item api key secret', leaked: true },
       { filename: 'An API Key Story', leaked: false },
       { filename: 'api_key=ordinary-metadata', leaked: false },

src/core/services/immersion-tracker-service.ts

@@ -376,6 +376,7 @@ function buildJellyfinStatsMediaPath(mediaPath: string, itemId: string): string
 
 const JELLYFIN_MEDIA_ALIAS_QUERY_KEYS = [
   'api_key',
+  'ApiKey',
   'StartTimeTicks',
   'AudioStreamIndex',
   'SubtitleStreamIndex',

src/core/services/immersion-tracker/jellyfin-link-repair.ts

@@ -82,7 +82,7 @@ function parseLegacyJellyfinStreamUrl(value: string | null): URL | null {
     ) {
       return null;
     }
-    if (!url.searchParams.has('api_key')) {
+    if (!url.searchParams.has('api_key') && !url.searchParams.has('ApiKey')) {
       return null;
     }
     return url;
@@ -130,13 +130,13 @@ function repairLeakedJellyfinAnimeTitles(db: DatabaseSync, currentTimestamp: str
               SELECT v.canonical_title
               FROM imm_videos v
               WHERE v.anime_id = a.anime_id
-                AND v.canonical_title NOT LIKE '%api_key=%'
+                AND v.canonical_title NOT LIKE '%api_key=%' AND v.canonical_title NOT LIKE '%ApiKey=%'
                 AND lower(v.canonical_title) NOT LIKE '%api key%'
               ORDER BY v.LAST_UPDATE_DATE DESC, v.video_id DESC
               LIMIT 1
             ) AS linked_video_title
           FROM imm_anime a
-          WHERE a.canonical_title LIKE '%api_key=%'
+          WHERE a.canonical_title LIKE '%api_key=%' OR a.canonical_title LIKE '%ApiKey=%'
              OR lower(a.canonical_title) LIKE '%api key%'
              OR lower(a.normalized_title_key) LIKE '%api key%'
         `,
@@ -244,11 +244,11 @@ function repairLeakedJellyfinVideoParseMetadata(
           LAST_UPDATE_DATE = ?
         WHERE source_type = 2
           AND (
-            parsed_basename LIKE '%api_key=%'
+            parsed_basename LIKE '%api_key=%' OR parsed_basename LIKE '%ApiKey=%'
             OR lower(parsed_basename) LIKE '%api key%'
-            OR parsed_title LIKE '%api_key=%'
+            OR parsed_title LIKE '%api_key=%' OR parsed_title LIKE '%ApiKey=%'
             OR lower(parsed_title) LIKE '%api key%'
-            OR parse_metadata_json LIKE '%api_key=%'
+            OR parse_metadata_json LIKE '%api_key=%' OR parse_metadata_json LIKE '%ApiKey=%'
             OR lower(parse_metadata_json) LIKE '%api key%'
           )
       `,
@@ -267,7 +267,7 @@ function repairLeakedJellyfinAnimeParseMetadata(
     UPDATE imm_anime
     SET metadata_json = NULL, LAST_UPDATE_DATE = ?
     WHERE (
-      metadata_json LIKE '%api_key=%'
+      metadata_json LIKE '%api_key=%' OR metadata_json LIKE '%ApiKey=%'
       OR lower(metadata_json) LIKE '%api key%'
     ) AND (
       lower(metadata_json) LIKE '%stream?%'
@@ -295,11 +295,11 @@ export function repairJellyfinStreamVideoLinks(db: DatabaseSync): JellyfinLinkRe
         FROM imm_videos
         WHERE source_type = 2
           AND (
-            video_key LIKE '%api_key=%'
+            video_key LIKE '%api_key=%' OR video_key LIKE '%ApiKey=%'
             OR lower(video_key) LIKE '%api key%'
-            OR source_url LIKE '%api_key=%'
+            OR source_url LIKE '%api_key=%' OR source_url LIKE '%ApiKey=%'
             OR lower(source_url) LIKE '%api key%'
-            OR canonical_title LIKE '%api_key=%'
+            OR canonical_title LIKE '%api_key=%' OR canonical_title LIKE '%ApiKey=%'
             OR lower(canonical_title) LIKE '%api key%'
           )
       `,

src/core/services/jellyfin-remote.test.ts

@@ -4,6 +4,17 @@ import { buildJellyfinTimelinePayload, JellyfinRemoteSessionService } from './je
 
 class FakeWebSocket {
   private listeners: Record<string, Array<(...args: unknown[]) => void>> = {};
+  sent: string[] = [];
+  terminated = false;
+
+  send(data: string): void {
+    this.sent.push(data);
+  }
+
+  terminate(): void {
+    this.terminated = true;
+    this.emit('close');
+  }
 
   on(event: string, listener: (...args: unknown[]) => void): this {
     if (!this.listeners[event]) {
@@ -58,7 +69,7 @@ test('start posts capabilities on socket connect', async () => {
     accessToken: 'token-1',
     deviceId: 'device-1',
     webSocketFactory: (url) => {
-      assert.equal(url, 'ws://jellyfin.local:8096/socket?api_key=token-1&deviceId=device-1');
+      assert.equal(url, 'ws://jellyfin.local:8096/socket?ApiKey=token-1&deviceId=device-1');
       const socket = new FakeWebSocket();
       sockets.push(socket);
       return socket as unknown as any;
@@ -99,7 +110,8 @@ test('socket headers include jellyfin authorization metadata', () => {
   assert.equal(seenHeaders.length, 1);
   assert.ok(seenHeaders[0]!['Authorization']!.includes('Client="SubMiner"'));
   assert.ok(seenHeaders[0]!['Authorization']!.includes('DeviceId="device-auth"'));
-  assert.ok(seenHeaders[0]!['X-Emby-Authorization']);
+  assert.equal('X-Emby-Authorization' in seenHeaders[0]!, false);
+  assert.equal('X-Emby-Token' in seenHeaders[0]!, false);
 });
 
 test('dispatches inbound Play, Playstate, and GeneralCommand messages', () => {
@@ -355,3 +367,114 @@ test('advertiseNow validates server registration using Sessions endpoint', async
   assert.equal(ok, true);
   assert.ok(calls.some((url) => url.endsWith('/Sessions')));
 });
+
+test('answers ForceKeepAlive with KeepAlive messages on the advertised cadence', () => {
+  const sockets: FakeWebSocket[] = [];
+  const timers: Array<{ handler: () => void; delay: number }> = [];
+
+  const service = new JellyfinRemoteSessionService({
+    serverUrl: 'http://jellyfin.local',
+    accessToken: 'token-ka',
+    deviceId: 'device-ka',
+    webSocketFactory: () => {
+      const socket = new FakeWebSocket();
+      sockets.push(socket);
+      return socket as unknown as any;
+    },
+    fetchImpl: (async () => new Response(null, { status: 200 })) as typeof fetch,
+    setTimer: ((handler: () => void, delay?: number) => {
+      timers.push({ handler, delay: Number(delay) });
+      return timers.length as unknown as ReturnType<typeof setTimeout>;
+    }) as typeof setTimeout,
+    clearTimer: (() => undefined) as typeof clearTimeout,
+  });
+
+  service.start();
+  sockets[0]!.emit('open');
+  assert.deepEqual(sockets[0]!.sent, ['{"MessageType":"KeepAlive"}']);
+  assert.equal(timers[0]!.delay, 30_000);
+
+  sockets[0]!.emit('message', JSON.stringify({ MessageType: 'ForceKeepAlive', Data: 20 }));
+  assert.equal(sockets[0]!.sent.length, 2);
+  assert.equal(timers.at(-1)!.delay, 10_000);
+
+  timers.at(-1)!.handler();
+  assert.equal(sockets[0]!.sent.length, 3);
+});
+
+test('reconnects when the server stops answering keep-alives', () => {
+  let now = 1_000_000;
+  const sockets: FakeWebSocket[] = [];
+  const timers: Array<() => void> = [];
+  const warnings: string[] = [];
+
+  const service = new JellyfinRemoteSessionService({
+    serverUrl: 'http://jellyfin.local',
+    accessToken: 'token-lost',
+    deviceId: 'device-lost',
+    webSocketFactory: () => {
+      const socket = new FakeWebSocket();
+      sockets.push(socket);
+      return socket as unknown as any;
+    },
+    fetchImpl: (async () => new Response(null, { status: 200 })) as typeof fetch,
+    getNow: () => now,
+    logWarn: (message) => {
+      warnings.push(message);
+    },
+    reconnectBaseDelayMs: 100,
+    setTimer: ((handler: () => void) => {
+      timers.push(handler);
+      return timers.length as unknown as ReturnType<typeof setTimeout>;
+    }) as typeof setTimeout,
+    clearTimer: (() => undefined) as typeof clearTimeout,
+  });
+
+  service.start();
+  sockets[0]!.emit('open');
+
+  // Two silent ticks are still within the 90s tolerance; the third marks the socket lost.
+  now += 30_000;
+  timers.shift()!();
+  now += 30_000;
+  timers.shift()!();
+  assert.equal(sockets[0]!.sent.length, 3);
+  assert.equal(sockets[0]!.terminated, false);
+
+  now += 30_000;
+  timers.shift()!();
+  assert.equal(sockets[0]!.terminated, true);
+  assert.equal(service.isConnected(), false);
+  assert.equal(warnings.length, 1);
+
+  timers.shift()!();
+  assert.equal(sockets.length, 2);
+});
+
+test('warns once per failing timeline endpoint until it recovers', async () => {
+  const warnings: string[] = [];
+  let status = 400;
+
+  const service = new JellyfinRemoteSessionService({
+    serverUrl: 'http://jellyfin.local',
+    accessToken: 'token-warn',
+    deviceId: 'device-warn',
+    webSocketFactory: () => new FakeWebSocket() as unknown as any,
+    fetchImpl: (async () => new Response(null, { status })) as typeof fetch,
+    logWarn: (message) => {
+      warnings.push(message);
+    },
+  });
+  const state = { itemId: 'item-1', positionTicks: 10, playMethod: 'DirectPlay' };
+
+  assert.equal(await service.reportStopped(state), false);
+  assert.equal(await service.reportStopped(state), false);
+  assert.equal(warnings.length, 1);
+  assert.match(warnings[0]!, /Sessions\/Playing\/Stopped/);
+
+  status = 200;
+  assert.equal(await service.reportStopped(state), true);
+  status = 500;
+  assert.equal(await service.reportStopped(state), false);
+  assert.equal(warnings.length, 2);
+});

src/core/services/jellyfin-remote.ts

@@ -45,9 +45,22 @@ interface JellyfinRemoteSocket {
   on(event: 'close', listener: () => void): this;
   on(event: 'error', listener: (error: Error) => void): this;
   on(event: 'message', listener: (data: unknown) => void): this;
+  send(data: string): void;
+  terminate?(): void;
   close(): void;
 }
 
+// Jellyfin advertises its keep-alive timeout in the ForceKeepAlive message (60s by default),
+// drops sockets that stay silent past it, and since 12.0 also detaches the session's remote
+// controller when that happens. The drop never reaches the client as a close frame, so the
+// client has to keep sending KeepAlive and treat missing replies as a dead connection.
+const DEFAULT_KEEP_ALIVE_TIMEOUT_MS = 60_000;
+const KEEP_ALIVE_LOST_FACTOR = 1.5;
+
+function unrefTimer(timer: ReturnType<typeof setTimeout>): void {
+  (timer as unknown as { unref?: () => void }).unref?.();
+}
+
 type JellyfinRemoteSocketHeaders = Record<string, string>;
 
 export interface JellyfinRemoteSessionServiceOptions {
@@ -77,6 +90,9 @@ export interface JellyfinRemoteSessionServiceOptions {
   deviceName?: string;
   onConnected?: () => void;
   onDisconnected?: () => void;
+  logWarn?: (message: string, details?: unknown) => void;
+  keepAliveTimeoutMs?: number;
+  getNow?: () => number;
 }
 
 function normalizeServerUrl(serverUrl: string): string {
@@ -196,6 +212,12 @@ export class JellyfinRemoteSessionService {
   private readonly authHeader: string;
   private readonly onConnected?: () => void;
   private readonly onDisconnected?: () => void;
+  private readonly logWarn?: (message: string, details?: unknown) => void;
+  private readonly now: () => number;
+  private keepAliveTimeoutMs: number;
+  private keepAliveTimer: ReturnType<typeof setTimeout> | null = null;
+  private lastInboundAtMs = 0;
+  private readonly failedRequestPaths = new Set<string>();
 
   private readonly reconnectBaseDelayMs: number;
   private readonly reconnectMaxDelayMs: number;
@@ -233,6 +255,12 @@ export class JellyfinRemoteSessionService {
     });
     this.onConnected = options.onConnected;
     this.onDisconnected = options.onDisconnected;
+    this.logWarn = options.logWarn;
+    this.now = options.getNow ?? Date.now;
+    this.keepAliveTimeoutMs = Math.max(
+      1000,
+      options.keepAliveTimeoutMs ?? DEFAULT_KEEP_ALIVE_TIMEOUT_MS,
+    );
     this.reconnectBaseDelayMs = Math.max(100, options.reconnectBaseDelayMs ?? 500);
     this.reconnectMaxDelayMs = Math.max(
       this.reconnectBaseDelayMs,
@@ -250,6 +278,7 @@ export class JellyfinRemoteSessionService {
   public stop(): void {
     this.running = false;
     this.connected = false;
+    this.stopKeepAlive();
     if (this.reconnectTimer) {
       this.clearTimer(this.reconnectTimer);
       this.reconnectTimer = null;
@@ -298,12 +327,15 @@ export class JellyfinRemoteSessionService {
       if (this.socket !== socket || !this.running) return;
       this.connected = true;
       this.reconnectAttempt = 0;
+      this.lastInboundAtMs = this.now();
+      this.startKeepAlive(socket, this.keepAliveTimeoutMs);
       this.onConnected?.();
       void this.postCapabilities();
     });
 
     socket.on('message', (rawData) => {
-      this.handleInboundMessage(rawData);
+      this.lastInboundAtMs = this.now();
+      this.handleInboundMessage(socket, rawData);
     });
 
     const handleDisconnect = () => {
@@ -311,6 +343,7 @@ export class JellyfinRemoteSessionService {
       disconnected = true;
       if (this.socket === socket) {
         this.socket = null;
+        this.stopKeepAlive();
       }
       this.connected = false;
       this.onDisconnected?.();
@@ -323,6 +356,51 @@ export class JellyfinRemoteSessionService {
     socket.on('error', handleDisconnect);
   }
 
+  private startKeepAlive(socket: JellyfinRemoteSocket, timeoutMs: number): void {
+    this.stopKeepAlive();
+    this.keepAliveTimeoutMs = timeoutMs;
+    this.sendKeepAlive(socket);
+    this.scheduleKeepAliveTick(socket);
+  }
+
+  private scheduleKeepAliveTick(socket: JellyfinRemoteSocket): void {
+    const intervalMs = Math.max(1000, Math.floor(this.keepAliveTimeoutMs / 2));
+    const timer = this.setTimer(() => {
+      this.keepAliveTimer = null;
+      if (this.socket !== socket || !this.running) return;
+      const silentForMs = this.now() - this.lastInboundAtMs;
+      if (silentForMs >= this.keepAliveTimeoutMs * KEEP_ALIVE_LOST_FACTOR) {
+        this.logWarn?.('Jellyfin remote websocket stopped answering keep-alives; reconnecting.');
+        // Dropping the socket raises 'close', which schedules the reconnect.
+        if (socket.terminate) {
+          socket.terminate();
+        } else {
+          socket.close();
+        }
+        return;
+      }
+      this.sendKeepAlive(socket);
+      this.scheduleKeepAliveTick(socket);
+    }, intervalMs);
+    unrefTimer(timer);
+    this.keepAliveTimer = timer;
+  }
+
+  private stopKeepAlive(): void {
+    if (this.keepAliveTimer) {
+      this.clearTimer(this.keepAliveTimer);
+      this.keepAliveTimer = null;
+    }
+  }
+
+  private sendKeepAlive(socket: JellyfinRemoteSocket): void {
+    try {
+      socket.send(JSON.stringify({ MessageType: 'KeepAlive' }));
+    } catch (error) {
+      this.logWarn?.('Failed to send Jellyfin remote keep-alive.', error);
+    }
+  }
+
   private scheduleReconnect(): void {
     const delay = Math.min(
       this.reconnectMaxDelayMs,
@@ -342,7 +420,7 @@ export class JellyfinRemoteSessionService {
     const baseUrl = new URL(`${this.serverUrl}/`);
     const socketUrl = new URL('/socket', baseUrl);
     socketUrl.protocol = baseUrl.protocol === 'https:' ? 'wss:' : 'ws:';
-    socketUrl.searchParams.set('api_key', this.accessToken);
+    socketUrl.searchParams.set('ApiKey', this.accessToken);
     socketUrl.searchParams.set('deviceId', this.deviceId);
     return socketUrl.toString();
   }
@@ -350,8 +428,6 @@ export class JellyfinRemoteSessionService {
   private createSocket(url: string): JellyfinRemoteSocket {
     const headers: JellyfinRemoteSocketHeaders = {
       Authorization: this.authHeader,
-      'X-Emby-Authorization': this.authHeader,
-      'X-Emby-Token': this.accessToken,
     };
     if (this.socketHeadersFactory) {
       return this.socketHeadersFactory(url, headers);
@@ -375,8 +451,6 @@ export class JellyfinRemoteSessionService {
         method: 'GET',
         headers: {
           Authorization: this.authHeader,
-          'X-Emby-Authorization': this.authHeader,
-          'X-Emby-Token': this.accessToken,
         },
       });
       if (!response.ok) return false;
@@ -398,21 +472,41 @@ export class JellyfinRemoteSessionService {
         headers: {
           'Content-Type': 'application/json',
           Authorization: this.authHeader,
-          'X-Emby-Authorization': this.authHeader,
-          'X-Emby-Token': this.accessToken,
         },
         body: JSON.stringify(payload),
       });
+      this.noteRequestOutcome(path, response.ok ? null : `HTTP ${response.status}`);
       return response.ok;
-    } catch {
+    } catch (error) {
+      this.noteRequestOutcome(path, error);
       return false;
     }
   }
 
-  private handleInboundMessage(rawData: unknown): void {
+  // Warn once per path while it keeps failing so a rejected stop report is visible in the
+  // log without a warning per progress tick.
+  private noteRequestOutcome(path: string, failure: unknown): void {
+    if (failure === null) {
+      this.failedRequestPaths.delete(path);
+      return;
+    }
+    if (this.failedRequestPaths.has(path)) return;
+    this.failedRequestPaths.add(path);
+    this.logWarn?.(`Jellyfin remote request failed: POST ${path}`, failure);
+  }
+
+  private handleInboundMessage(socket: JellyfinRemoteSocket, rawData: unknown): void {
     const message = parseInboundMessage(rawData);
     if (!message) return;
     const messageType = message.MessageType;
+    if (messageType === 'ForceKeepAlive') {
+      const seconds = Number(message.Data);
+      const timeoutMs =
+        Number.isFinite(seconds) && seconds > 0 ? seconds * 1000 : this.keepAliveTimeoutMs;
+      this.startKeepAlive(socket, timeoutMs);
+      return;
+    }
+    if (messageType === 'KeepAlive') return;
     const payload = parseMessageData(message.Data);
     if (messageType === 'Play') {
       this.onPlay?.(payload);

src/core/services/jellyfin.test.ts

@@ -279,7 +279,7 @@ test('resolvePlaybackPlan prefers transcode when directPlayPreferred is disabled
     assert.equal(plan.mode, 'transcode');
     const url = new URL(plan.url);
     assert.match(url.pathname, /\/Videos\/movie-2\/master\.m3u8$/);
-    assert.equal(url.searchParams.get('api_key'), 'token');
+    assert.equal(url.searchParams.get('ApiKey'), 'token');
     assert.equal(url.searchParams.get('AudioStreamIndex'), '4');
     assert.equal(url.searchParams.get('StartTimeTicks'), '10000000');
   } finally {
@@ -365,7 +365,7 @@ test('listSubtitleTracks returns all subtitle streams with delivery urls', async
                 IsForced: true,
                 IsExternal: true,
                 DeliveryMethod: 'External',
-                DeliveryUrl: '/Videos/movie-1/ms-1/Subtitles/3/Stream.srt',
+                DeliveryUrl: '/Videos/movie-1/ms-1/Subtitles/3/Stream.srt?api_key=server-token',
                 IsExternalUrl: false,
               },
               {
@@ -402,11 +402,11 @@ test('listSubtitleTracks returns all subtitle streams with delivery urls', async
     );
     assert.equal(
       tracks[0]!.deliveryUrl,
-      'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/2/Stream.srt?api_key=token',
+      'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/2/Stream.srt?ApiKey=token',
     );
     assert.equal(
       tracks[1]!.deliveryUrl,
-      'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/3/Stream.srt?api_key=token',
+      'http://jellyfin.local/Videos/movie-1/ms-1/Subtitles/3/Stream.srt?ApiKey=token',
     );
     assert.equal(tracks[2]!.deliveryUrl, 'https://cdn.example.com/subs.srt');
   } finally {
@@ -505,7 +505,7 @@ test('resolvePlaybackPlan reuses server transcoding url and appends missing para
     const url = new URL(plan.url);
     assert.match(url.pathname, /\/Videos\/movie-4\/master\.m3u8$/);
     assert.equal(url.searchParams.get('VideoCodec'), 'hevc');
-    assert.equal(url.searchParams.get('api_key'), 'token');
+    assert.equal(url.searchParams.get('ApiKey'), 'token');
     assert.equal(url.searchParams.get('AudioStreamIndex'), '3');
     assert.equal(url.searchParams.get('SubtitleStreamIndex'), '8');
     assert.equal(url.searchParams.get('StartTimeTicks'), '50000000');
@@ -626,7 +626,7 @@ test('listSubtitleTracks falls back from PlaybackInfo to item media sources', as
     assert.equal(tracks[0]!.index, 11);
     assert.equal(
       tracks[0]!.deliveryUrl,
-      'http://jellyfin.local/Videos/movie-fallback/ms-fallback/Subtitles/11/Stream.srt?api_key=token',
+      'http://jellyfin.local/Videos/movie-fallback/ms-fallback/Subtitles/11/Stream.srt?ApiKey=token',
     );
   } finally {
     globalThis.fetch = originalFetch;
@@ -789,3 +789,67 @@ test('resolvePlaybackPlan surfaces no-source and no-stream fallback errors', asy
     globalThis.fetch = originalFetch;
   }
 });
+
+test('API requests authenticate with the MediaBrowser header only (no legacy X-Emby-Token)', async () => {
+  const originalFetch = globalThis.fetch;
+  const seenHeaders: Headers[] = [];
+  globalThis.fetch = (async (_input, init) => {
+    seenHeaders.push(new Headers(init?.headers));
+    return new Response(JSON.stringify({ Items: [] }), { status: 200 });
+  }) as typeof fetch;
+
+  try {
+    await listLibraries(
+      { serverUrl: 'http://jellyfin.local', accessToken: 'token', userId: 'u1', username: 'kyle' },
+      clientInfo,
+    );
+    assert.equal(seenHeaders.length, 1);
+    const headers = seenHeaders[0]!;
+    const authorization = headers.get('authorization') ?? '';
+    assert.match(authorization, /^MediaBrowser /);
+    assert.match(authorization, /Token="token"/);
+    assert.match(authorization, /DeviceId="subminer-test"/);
+    assert.equal(headers.has('x-emby-token'), false);
+    assert.equal(headers.has('x-emby-authorization'), false);
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});
+
+test('resolvePlaybackPlan replaces a legacy api_key on the server transcoding url with ApiKey', async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = (async () =>
+    new Response(
+      JSON.stringify({
+        Id: 'movie-legacy',
+        Name: 'Movie Legacy',
+        MediaSources: [
+          {
+            Id: 'ms-legacy',
+            Container: 'mkv',
+            SupportsDirectStream: false,
+            SupportsTranscoding: true,
+            TranscodingUrl: '/Videos/movie-legacy/master.m3u8?VideoCodec=hevc&api_key=server-token',
+          },
+        ],
+      }),
+      { status: 200 },
+    )) as typeof fetch;
+
+  try {
+    const plan = await resolvePlaybackPlan(
+      { serverUrl: 'http://jellyfin.local', accessToken: 'token', userId: 'u1', username: 'kyle' },
+      clientInfo,
+      { enabled: true, directPlayPreferred: true },
+      { itemId: 'movie-legacy' },
+    );
+
+    assert.equal(plan.mode, 'transcode');
+    const url = new URL(plan.url);
+    assert.equal(url.searchParams.get('ApiKey'), 'token');
+    assert.equal(url.searchParams.has('api_key'), false);
+    assert.equal(url.searchParams.get('VideoCodec'), 'hevc');
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});

src/core/services/jellyfin.ts

@@ -136,6 +136,16 @@ function getErrorMessage(error: unknown): string {
   return String(error || 'unknown error');
 }
 
+// Jellyfin reads query keys case-insensitively and older servers embed the token as
+// `api_key` in the URLs they hand back, so drop every spelling before setting the one
+// form Jellyfin 12 still accepts with legacy authorization disabled.
+function setApiKeyParam(url: URL, accessToken: string): void {
+  for (const key of [...url.searchParams.keys()]) {
+    if (/^api_?key$/i.test(key)) url.searchParams.delete(key);
+  }
+  url.searchParams.set('ApiKey', accessToken);
+}
+
 function resolveDeliveryUrl(
   session: JellyfinAuthSession,
   stream: JellyfinMediaStream,
@@ -146,9 +156,7 @@ function resolveDeliveryUrl(
   if (deliveryUrl) {
     if (stream.IsExternalUrl === true) return deliveryUrl;
     const resolved = new URL(deliveryUrl, `${session.serverUrl}/`);
-    if (!resolved.searchParams.has('api_key')) {
-      resolved.searchParams.set('api_key', session.accessToken);
-    }
+    setApiKeyParam(resolved, session.accessToken);
     return resolved.toString();
   }
 
@@ -171,9 +179,7 @@ function resolveDeliveryUrl(
     `/Videos/${encodeURIComponent(itemId)}/${encodeURIComponent(mediaSourceId)}/Subtitles/${streamIndex}/Stream.${ext}`,
     `${session.serverUrl}/`,
   );
-  if (!fallback.searchParams.has('api_key')) {
-    fallback.searchParams.set('api_key', session.accessToken);
-  }
+  setApiKeyParam(fallback, session.accessToken);
   return fallback.toString();
 }
 
@@ -197,7 +203,6 @@ async function jellyfinRequestJson<T>(
   const headers = new Headers(init.headers ?? {});
   headers.set('Content-Type', 'application/json');
   headers.set('Authorization', createAuthorizationHeader(client, session.accessToken));
-  headers.set('X-Emby-Token', session.accessToken);
 
   const response = await fetch(`${session.serverUrl}${path}`, {
     ...init,
@@ -221,7 +226,7 @@ function createDirectPlayUrl(
 ): string {
   const query = new URLSearchParams({
     static: 'true',
-    api_key: session.accessToken,
+    ApiKey: session.accessToken,
     MediaSourceId: ensureString(mediaSource.Id),
   });
   if (mediaSource.LiveStreamId) {
@@ -245,9 +250,7 @@ function createTranscodeUrl(
 ): string {
   if (mediaSource.TranscodingUrl) {
     const url = new URL(`${session.serverUrl}${mediaSource.TranscodingUrl}`);
-    if (!url.searchParams.has('api_key')) {
-      url.searchParams.set('api_key', session.accessToken);
-    }
+    setApiKeyParam(url, session.accessToken);
     if (!url.searchParams.has('AudioStreamIndex') && plan.audioStreamIndex !== null) {
       url.searchParams.set('AudioStreamIndex', String(plan.audioStreamIndex));
     }
@@ -261,7 +264,7 @@ function createTranscodeUrl(
   }
 
   const query = new URLSearchParams({
-    api_key: session.accessToken,
+    ApiKey: session.accessToken,
     MediaSourceId: ensureString(mediaSource.Id),
     VideoCodec: ensureString(config.transcodeVideoCodec, 'h264'),
     TranscodingContainer: 'ts',

src/main/runtime/composers/jellyfin-remote-composer.ts

@@ -91,6 +91,7 @@ export function composeJellyfinRemoteHandlers(
       getNow: options.getNow,
       ticksPerSecond: options.ticksPerSecond,
       logDebug: options.logDebug,
+      logWarn: options.logWarn,
     });
   const reportJellyfinRemoteProgress = createReportJellyfinRemoteProgressHandler(
     buildReportJellyfinRemoteProgressMainDepsHandler(),

src/main/runtime/jellyfin-remote-main-deps.ts

@@ -75,5 +75,6 @@ export function createBuildReportJellyfinRemoteStoppedMainDepsHandler(
     getNow: deps.getNow ? () => deps.getNow?.() ?? Date.now() : undefined,
     ticksPerSecond: deps.ticksPerSecond,
     logDebug: (message: string, error: unknown) => deps.logDebug(message, error),
+    ...(deps.logWarn ? { logWarn: (message: string) => deps.logWarn?.(message) } : {}),
   });
 }

src/main/runtime/jellyfin-remote-playback.ts

@@ -203,6 +203,7 @@ export type JellyfinRemoteStoppedReporterDeps = {
   getNow?: () => number;
   ticksPerSecond: number;
   logDebug: (message: string, error: unknown) => void;
+  logWarn?: (message: string) => void;
 };
 
 export function createReportJellyfinRemoteStoppedHandler(deps: JellyfinRemoteStoppedReporterDeps) {
@@ -244,7 +245,7 @@ export function createReportJellyfinRemoteStoppedHandler(deps: JellyfinRemoteSto
       } catch (error) {
         deps.logDebug('Failed to report Jellyfin remote final progress', error);
       }
-      await session.reportStopped({
+      const reported = await session.reportStopped({
         itemId: playback.itemId,
         mediaSourceId: playback.mediaSourceId,
         positionTicks,
@@ -254,6 +255,11 @@ export function createReportJellyfinRemoteStoppedHandler(deps: JellyfinRemoteSto
         subtitleStreamIndex: playback.subtitleStreamIndex,
         eventName: 'stop',
       });
+      if (reported === false) {
+        deps.logWarn?.(
+          `Jellyfin did not accept the playback stop report for item ${playback.itemId}; the server may keep showing it as playing.`,
+        );
+      }
     } catch (error) {
       deps.logDebug('Failed to report Jellyfin remote stop', error);
     } finally {

src/main/runtime/jellyfin-remote-session-lifecycle.ts

@@ -38,6 +38,7 @@ type JellyfinRemoteServiceOptions = {
   };
   onConnected: () => void;
   onDisconnected: () => void;
+  logWarn?: (message: string, details?: unknown) => void;
   onPlay: (payload: JellyfinRemoteEventPayload) => void;
   onPlaystate: (payload: JellyfinRemoteEventPayload) => void;
   onGeneralCommand: (payload: JellyfinRemoteEventPayload) => void;
@@ -110,6 +111,7 @@ export function createStartJellyfinRemoteSessionHandler(deps: {
       onDisconnected: () => {
         deps.logWarn('Jellyfin remote websocket disconnected; retrying.');
       },
+      logWarn: (message, details) => deps.logWarn(message, details),
       onPlay: (payload) => {
         void deps.handlePlay(payload).catch((error) => {
           deps.logWarn('Failed handling Jellyfin remote Play event', error);