Multiplayer API Logo Multiplayer API JavaScript SDK

JavaScript SDK — Getting Started

From install to a live room message in ~5 minutes. Works identically in Node.js ≥ 22 and modern browsers.

1. Install

npm install michitai-multiplayer

Or download SDK.zip and install the folder (npm install ./sdk-folder) — or copy src/ directly; the SDK is zero-dependency ESM.

2. Create the client

import { MultiplayerClient } from 'michitai-multiplayer';

const mp = new MultiplayerClient('YOUR_API_TOKEN');
// Browser: ship only the public token.
// Node: apiPrivateToken unlocks admin calls — server-side only.

3. Register a player

const reg = await mp.players.register('PlayerOne', {
  playerData: { level: 1 }
});
if (!reg.success) throw new Error(reg.error);
const playerToken = reg.private_key;   // persist: localStorage / file

4. Create a room and go realtime

await mp.rooms.create(playerToken, 'Lobby 1',
  { maxPlayers: 4, realtime: true });

const tok = await mp.realtime.get(playerToken);
const rt = mp.createRealtime({
  onReceive: (cmd, data, sender) => console.log(cmd, data),
});
await rt.connect(tok.token, tok.realtime_server);

rt.send('all', 'chat', { text: 'hello' });       // reliable
rt.sendUnreliable('others', 'pos', { x: 1 });    // UDP on Node, WS in browsers

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