Bridge protocol

v0.js is a thin wrapper. If you prefer your own client — another framework, TypeScript types, a game engine compiled to WebAssembly — speak the protocol directly. It is JSON-RPC 2.0 over window.postMessage, the same transport as the MCP Apps standard.

Where the meeting is

ReMeet opens your page with two query parameters:

Parameter	Value
remeet_origin	The origin of the meeting page, for example https://remeet.video. Send messages only there and accept messages only from there.
remeet_surface	panel or stage

The meeting is window.parent.

Envelope

Every message is an object with remeet: 'v0' and jsonrpc: '2.0'.

Request from your app:

{ "remeet": "v0", "jsonrpc": "2.0", "id": 1, "method": "app.broadcast", "params": { "data": { "x": 3 } } }

parent.postMessage(request, remeetOrigin);

Response from the meeting — result or error:

{ "remeet": "v0", "jsonrpc": "2.0", "id": 1, "result": { "ok": true } }
{ "remeet": "v0", "jsonrpc": "2.0", "id": 2, "error": { "code": 403, "message": "Permission \"chat.send\" was not granted" } }

Event from the meeting — no id, method is always event:

{ "remeet": "v0", "jsonrpc": "2.0", "method": "event", "params": { "name": "speaking", "data": { "ids": ["p_…"] } } }

Check every incoming message: event.source === window.parent, event.origin === remeet_origin, remeet === 'v0'.

Methods

The first call must be ready; anything before it fails with 400.

Method	Params	Result	Permission
ready	{ sdk: '0.1.0' }	the context object, see app.context	—
participants.list	—	Participant[]	participants.read
app.broadcast	{ data }	{ ok: true }	app.broadcast
ui.notify	{ text }	{ ok: true }	—
chat.send	{ text }	{ ok: true }	chat.send
badges.set	{ participant, text | null }	{ ok: true }	badges.write
stage.open	{ everyone: boolean }	{ ok: true }	stage.start when everyone
stage.close	—	{ ok: true }	—
storage.get	{ key }	{ value }	storage
storage.set	{ key, value }	{ ok: true }	storage
storage.delete	{ key }	{ ok: true }	storage

Events and their data are listed in SDK API → Events.

Minimal client

const query = new URLSearchParams(location.search);
const origin = query.get('remeet_origin');
const pending = new Map();
let seq = 0;

function call(method, params = {}) {
  return new Promise((resolve, reject) => {
    const id = ++seq;
    pending.set(id, { resolve, reject });
    parent.postMessage({ remeet: 'v0', jsonrpc: '2.0', id, method, params }, origin);
  });
}

addEventListener('message', (event) => {
  const message = event.data;
  if (event.source !== parent || event.origin !== origin || message?.remeet !== 'v0') return;

  if (message.id != null && pending.has(message.id)) {
    const { resolve, reject } = pending.get(message.id);
    pending.delete(message.id);
    message.error ? reject(Object.assign(new Error(message.error.message), { code: message.error.code })) : resolve(message.result);
  } else if (message.method === 'event') {
    console.log('event', message.params.name, message.params.data);
  }
});

const context = await call('ready', { sdk: '0.1.0' });