TLCustomMessageHandler • tldraw Docs

Handler function for custom application messages sent through the sync protocol. These are user-defined messages that can be sent between clients via the sync server, separate from the standard document synchronization messages.

type TLCustomMessageHandler = (this: null, data: any) => void;

Example

const customMessageHandler: TLCustomMessageHandler = (data) => {
  if (data.type === "user_joined") {
    console.log(`${data.username} joined the session`);
    showToast(`${data.username} is now collaborating`);
  }
};

const syncClient = new TLSyncClient({
  // ... other config
  onCustomMessageReceived: customMessageHandler,
});

Parameters

Name	Description
`data`	Custom message payload (application-defined structure)