sync_replay_project/README.md

sync_relay_project

Watch-together desktop app (working title). One binary, three modes:

• Client — GUI Join, sync WS + mpv. No server code runs.
• Server+Client (Host) — GUI Host starts packages/server in-process, listens on a port, self-connects via loopback. Host must open ports. Clients never open ports.
• Headless — watch.exe --headless, same server package, no window.

v1 order: links support (shared http(s) media URL, Syncplay-style sync) first, file relay (server-proxied bytes, whitelist case) after. Jellyfin native + auto-update are deferred as their own undertakings.

Layout:

/packages/core      protocol, sync engine, messages (pure Dart, no Flutter)
/packages/server    room + media HTTP endpoint (pure Dart, no Flutter)
/apps/desktop       Flutter app embedding packages/server (the ONE binary)
/tool               spikes + harnesses (range_logger, shaper, fake_viewer, e2e_check)
/deploy             systemd unit, notes
/docs               PROTOCOL.md, ARCHITECTURE.md, mpv-http-contract.md, ROADMAP.md

Phases + status: docs/ROADMAP.md. Session handoff: HANDOFF.md (root).

Enforcement: core and server must have zero Flutter imports (tested).