watchparty/README.md

Watch Party for Emby

A standalone web app for watching the same title, in sync, with other users of the same Emby server. It reads your Emby catalog and streams your Emby media, but it's its own app with its own player — not an Emby plugin.

See docs/architecture.md for the full design, including why this replaced an earlier Emby-plugin attempt (still in src/WatchParty/ for reference — see below).

How it works

1. Sign in with your Emby account (just username/password — the server address is fixed server-side, see Deploying below).
2. A sidebar lists your Emby libraries; the home page shows every ongoing watch party live (host, how long it's been running, member count) plus a "recently added" row per library, Emby-style. No join codes — if a party is running, it's already on the list, updating in real time.
3. Pick a movie/episode tile and hit "Lancer une watch party" (or drill into a Series' seasons/episodes first) — you become the host — or hit "Rejoindre" on any party already listed on the home page.
4. The host's play/pause/seek drives everyone else's player automatically; starting from an episode queues the rest of the series so the host can just hit "Épisode suivant" instead of restarting a party each time. If the host leaves, the party hands off to another member automatically (their player unlocks live, no reload needed) — only closing once everyone's gone.
5. Everyone present shows up as a small avatar overlay on the video (their initials, on the player itself). If you're not the host, clicking your own avatar asks the host to pause — everyone sees the request, including the host, without needing chat.

Everything — catalog, images, video, sync — flows through this app's own backend, which proxies whatever it needs from Emby server-side. The browser never talks to Emby directly and never holds an Emby access token; it only ever has a session cookie for this app.

Music isn't part of this yet — it needs its own player and a collaborative playlist, different enough to be its own pass. The sidebar already lists a Music library if you have one; the page just says so for now.

Status

Login, and the rendering/navigation logic for the sidebar/home/library/series pages, have been exercised end to end (login against the real Emby server with intentionally-wrong credentials; the pages against mocked API responses). See docs/architecture.md for exactly what that does and doesn't confirm — the real Emby response shapes this now depends on (library CollectionType, seasons/episodes, PlaybackInfo's media streams) and actual HLS playback are still unverified.

Project layout

server/           Node.js backend: proxies ALL Emby access (auth, catalog,
                  images, HLS streaming) and coordinates party/room state +
                  realtime sync. The browser only ever talks to this.
  src/index.js       Express app + REST endpoints
  src/embyAuth.js    server-side login against Emby + session cookies
  src/embyProxy.js   generic Emby request/response proxying (incl. HLS)
  src/socketHandler.js  Socket.IO protocol (see comments in the file)
  src/partyManager.js  in-memory room state

client/           Static frontend (plain JS, ES modules, no build step).
                  Talks only to server/ - never to Emby directly.
  js/shell.js        persistent sidebar + #mainContent the router swaps
  js/tiles.js        poster-tile rendering shared by home.js and library.js
  js/embyApi.js      calls our own /api/* routes (auth, catalog, playback options)
  js/party.js        our own backend's party REST + Socket.IO client
  js/views/          one file per screen: login, home, library, series, player

src/WatchParty/   The earlier Emby-plugin attempt. Builds fine and installs,
                  but Emby has no supported extension point for a player
                  button, and even menu integration required reverse-
                  engineering undocumented internals - see
                  docs/architecture.md for the full story. Kept for
                  reference; not the active direction.

docs/architecture.md   full design doc for the standalone app

Running locally

cd server
npm install
EMBY_SERVER_URL=https://your-emby-server npm start

Then open http://localhost:3000.

Deploying

Build the Docker image from the repo root (it needs both server/ and client/):

docker build -f server/Dockerfile -t watchparty .
docker run -d --name watchparty -p 3000:3000 -e EMBY_SERVER_URL=https://theater.media.kyuno.fr watchparty

Then put it behind your existing reverse proxy like everything else (theater.media.kyuno.fr, git.dev.kyuno.fr, ...), e.g. watchparty.kyuno.fr → http://<container>:3000.

Roadmap

• Design + scaffold the standalone app
• Proxy all Emby access server-side; Emby-themed UI (sidebar, carousels)
• TV show navigation (Series → Seasons → Episodes) + episode auto-queue
• Player language/subtitle/quality pickers
• Socket.IO instead of raw WebSockets; fixed two real memory leaks (dead-connection cleanup server-side, view teardown on navigation client-side) — see docs/architecture.md
• Live "watch parties en cours" list (host, elapsed time, member count), live host handoff, no join codes
• Presence overlay (avatars) + "request pause" in the player
• Try a full party end-to-end with two real accounts (still the main gap)
• Music: dedicated player, artist/album browsing, collaborative playlist
• Tune transcoding target / support direct play when possible

No chat, no OIDC — deliberately out of scope (Emby-only auth was the explicit choice; see docs/architecture.md).

License

MIT — see LICENSE.