Watch Party for Emby

An Emby Server plugin that lets a group of users on the same server watch the same title together. Nobody switches players: everyone keeps using their normal Emby app (web, mobile, TV, whatever), and the plugin nudges playback back in sync using the same remote-control commands Emby already uses for casting / "play on another device".

See docs/architecture.md for the full design, including which parts are solidly confirmed against Emby's SDK docs and which still need verification against your exact server build.

How it's meant to work

1. You start playing a title in your normal Emby app.
2. You open the Watch Party control panel (a small web page the plugin serves) and start a party. You get a 6-character join code.
3. Friends open the control panel, sign in with their own Emby account, start playing the same title in their own Emby app, and enter the code to join.
4. The server treats one member (the host, by default) as the reference position, and periodically nudges everyone else's session back in sync (seek correction, and mirroring pause/unpause) — see docs/architecture.md.

The control panel is a companion page, not a video player — it never touches the actual video stream.

Status

Early scaffold, not yet built or run against a real server. It's structured around Emby's documented plugin patterns (BasePlugin<T>, IServerEntryPoint, the IService/[Route] API style) and the confirmed ISessionManager.SendPlaystateCommand remote-control API, but several SDK details are marked TODO(verify) in the code — see docs/architecture.md before expecting it to compile as-is.

Requirements

• Emby Server (developed against 4.9.5.0; should work on nearby 4.9.x/4.8.x builds, but the plugin ABI does shift between versions)
• .NET SDK to build (not currently installed in this environment — dotnet --version came back empty)

Project layout

src/WatchParty/          the plugin itself (C#, netstandard2.0)
  Plugin.cs              plugin registration + admin settings page
  Configuration/         plugin settings + the dashboard config page HTML
  Parties/               Party / PartyMember model + in-memory PartyManager
  Sync/                  the drift-correction background loop
  Api/                   REST endpoints + serving the control panel's static files
web/control-panel/       the user-facing page (plain HTML/JS/CSS, no build step)
docs/architecture.md     full design doc

Building

dotnet build src/WatchParty/WatchParty.csproj

To have a build drop the DLL straight into a local Emby Server's plugin folder, set EMBY_PLUGINS_DIR before building, e.g.:

EMBY_PLUGINS_DIR="C:/ProgramData/Emby-Server/programdata/plugins" dotnet build src/WatchParty/WatchParty.csproj

Adjust the path for however your server is installed (Windows service vs. portable install vs. Docker volume).

Roadmap

• Design doc + scaffold
• Build against the real SDK, fix whatever the TODO(verify) spots got wrong
• Try it against a real Emby Server + two clients
• Live (WebSocket) updates in the control panel instead of polling
• Optional text chat, reusing the same realtime channel
• Per-party override of sync settings instead of only server-wide defaults

License

MIT — see LICENSE.