lobbylink

Instant lobby-based multiplayer connectivity via WebRTC DataChannels with coturn fallback: a Go signaling/lobby server plus TypeScript (browser) and Rust (native) client libraries. Full design spec: lobbylink_implementation_guide.md.

Status

• Go server (cmd/p2p-lobby-server, internal/): implemented, with unit + integration tests.
• TypeScript client (clients/ts): implemented — zero runtime dependencies, built by plain tsc (make in clients/ts), browser test suite passes against production including forced-TURN relay. See clients/ts/README.md for the API and the wire/framing contract.
• Rust client (clients/rust): next.

Build & test

CGO_ENABLED=0 go build -trimpath -ldflags "-s -w -X main.version=$(git rev-parse --short HEAD)" \
  -o dist/p2p-lobby-server ./cmd/p2p-lobby-server
go test -race ./...

The binary embeds web/ (demo page + browser client bundle). Build the TypeScript client first when you want the real web/p2p-client.js instead of the placeholder.

Run (dev)

./dist/p2p-lobby-server \
  --listen-http 127.0.0.1:8787 \
  --allowed-origin http://localhost:8787,http://127.0.0.1:8787 \
  --public-url http://127.0.0.1:8787

Then open http://127.0.0.1:8787/ for the demo page, or check /healthz and /config.json.

Configuration

Defaults < --config /etc/p2p-lobby/config.toml < CLI flags. See the config example in the implementation guide §2.3; every key there is supported, and unknown keys are rejected so typos fail fast.

Key server behaviors:

• WebSocket Origin must be on the global allowlist (or an app allowlist for appId joins); native clients without an Origin header are only accepted with --allow-no-origin / allow_no_origin = true.
• Stable player IDs 0..maxPlayers-1; disconnects preserve slots.
• Hidden resume tokens (rotated on every resume/claim; only hashes are stored server-side) plus timeout-based slot claiming (claim_after, default 40s of silence; any WS message counts as liveness).
• TURN credentials are minted per player with coturn's REST-secret scheme (use-auth-secret).

Embedding as a library

Other binaries can link the lobby in and mount their own HTTP routes next to it ("plugins") through the public lobbyserver package — the stock cmd/p2p-lobby-server runs through the same package, so embedders get the exact production serving behavior. The lobby stays game-agnostic; anything game-specific lives in the embedding module.

cfg, _ := lobbyserver.LoadConfig("server.toml") // or DefaultConfig()
cfg.SetListenHTTP("127.0.0.1:8787")
srv, _ := lobbyserver.New(cfg, version)
mux := http.NewServeMux()
mux.Handle("/mygame/", myGameRoutes(cfg.AllowedOrigins()))
mux.Handle("/", srv.Handler())
err := srv.Run(ctx, mux) // listeners + room GC + graceful shutdown

Deployment

Recommended: the self-contained kit — everything in ~/lobbylink on the server, run as a systemd user service, with dual entry points (Apache subpath proxy + standalone :4443). Step-by-step guide and all scripts: deploy/selfcontained/README.md.

Alternative system-wide shapes from the guide (§10–11):

1. Apache reverse proxy — Apache owns :443, proxies / and /ws to Go on 127.0.0.1:8787: scripts/setup-apache-proxy.sh <domain>.
2. Direct HTTPS on :4443 — Go serves TLS itself with copied Let's Encrypt certs: scripts/setup-direct-4443.sh <domain>.

Common steps first:

sudo scripts/install-common.sh <domain>       # user, dirs, secret, config
sudo scripts/copy-certs.sh <domain>           # also a certbot deploy hook
sudo scripts/setup-coturn.sh <domain> <ip>    # coturn with shared secret

Templates for systemd/Apache/coturn live in deploy/.