onelobby

Multiplayer for browser games. Players host a lobby, share a six-letter code, and join each other over peer-to-peer WebRTC. Includes lockstep sync, raw messages, text chat and voice chat. No runtime dependencies.

You need a OneLobby lobby server (the WebSocket URL, like wss://lobby.example.com/ws). See the docs to run one.

Use it from a <script> tag (no build tools)

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/onelobby.global.min.js"></script>
<script>
  const kit = new OneLobby.OneLobby({
    gameId: "com.you.yourgame",            // any unique name for your game
    netVersion: "1",
    lobbyServer: "wss://lobby.example.com/ws",
    mode: "raw",
  });
  // Host:  const lobby = await kit.host({ name: "My game", maxPlayers: 4 }); show OneLobby.formatCode(lobby.code)
  // Join:  const lobby = await kit.join("C5A FX8");
</script>

The file also works saved next to your page (<script src="onelobby.global.min.js">), including pages opened from disk.

No code at all

After the <script> tag above, this gives a complete lobby box (the sentence inside only shows if the script did not load):

<one-lobby server="https://your-name.onrender.com" game="my-game" max-players="4">
  If you can read this, the OneLobby script didn't load.
</one-lobby>

See the no-code guide.

Install with npm

npm install onelobby

import { OneLobby, formatCode } from "onelobby";

const kit = new OneLobby({ gameId: "com.you.yourgame", netVersion: "1", lobbyServer: "wss://lobby.example.com/ws" });
const lobby = await kit.host({ name: "My game", maxPlayers: 4 });
console.log("Tell your friend this code:", formatCode(lobby.code));

Without a bundler: import { OneLobby } from "https://cdn.jsdelivr.net/npm/[email protected]/dist/onelobby.bundle.mjs".

Made for players

• Lobbies are unlisted by default: friends join with the code or a link (OneLobby.shareUrl(lobby.code) makes https://your.game/?join=C5A-FX8; OneLobby.codeFromUrl() reads it back). Pass visibility: "public" to list it.
• Players without a name show as "Player 2", "Player 3", ...
• A joiner that can't connect gets an error after 15 s (readyTimeoutMs) instead of waiting forever: code ice_failed, and sessionEnded with that reason. One relay retry happens first when the server offers TURN.
• A page reload keeps the seat (rememberSeat, on by default): kit.join(sameCode) or kit.resume() takes it back; kit.rememberedCode says which lobby.
• OneLobby.describeError(err) turns any error into { message, hint } you can show as-is.
• Test seams go under advanced: { socketFactory, linkFactory, clock, storage, ... }.

Files

| Import | What | |---|---| | onelobby | the public API: OneLobby, Lobby, Lockstep, Chat, Voice, OneLobbyError, normalizeCode, formatCode, describeError, shareUrl, codeFromUrl | | onelobby/ui | the <one-lobby> drop-in element (host, join, invite link, players, start); also in the <script> build | | onelobby/testing | in-memory server, peer network and clock for your own tests | | onelobby/internals | low-level pieces (codec, chunking, migration, jitter buffer, ...); no stability promise | | dist/onelobby.global.min.js | the <script> build; sets window.OneLobby |

Guides, recipes and the API reference: OneLobby docs. MIT license.