Connect clients

Use partysocket against a synkd host. The path shape matches PartyKit.

Minimal connection

import PartySocket from "partysocket";

const socket = new PartySocket({
  host: "127.0.0.1:8787",
  party: "main",
  room: "demo",
  query: { token: "dev-token" },
});

socket.addEventListener("message", (event) => {
  console.log(event.data);
});

socket.send(JSON.stringify({ text: "hello" }));

In Studio, Vite proxies /parties to the runtime, so the browser can use the Studio host instead of :8787.

Authentication

The lobby gate accepts:

• query token
• Authorization: Bearer …

Configure the shared guest secret in synkd.json:

{
  "auth": {
    "token": "dev-token"
  }
}

You can also use HS256 JWTs with auth.jwtSecret. Put claims such as sub, optional room / party, and name in the token.

Do not put the admin token in guest clients. Admin tokens are for Console and /v1 only. See Security.

Helpers

@synkd/client wraps common partysocket options for synkd hosts. Prefer partysocket directly if you already have a client stack.

Close code 1012

On hot reload, ownership move, or room unload, the server may close sockets with 1012. partysocket reconnects by default. Keep your UI ready for brief disconnects.

What to do next

• Try the Studio chat surface
• Add a Yjs pad