Authentication

The RTM SDK comes with built-in support for authentication. This ensures that only authenticated users can call into specific remote functions.

Setting up authentication with the RTM Server as easy as defining a single function. Here's an example to authenticate a user with a hard-coded password.

Enable Authentication on Server

note

Consider using Firebase Admin SDK, Auth0, or similar for authentication. The example below does not represent any real-world scenarios.

Provide the authHandler handler to the RtmServer options to enable authentication. The function parameters will contain whatever data sent by the RtmClient when connecting (e.g. a token).

Note: Any data returned by authHandler will be available to all RtmRemoteClient objects on RPC functions as RtmRemoteClient.authentication. You can use this to retrieve and store additional user info about the connected clients. This is also useful in a multi-server setup where you need unique IDs of connected clients for sending events.

src/server.ts

const server = new RtmServer(undefined, {
  port: 70,
  onOpen(port) {
    console.log("Server started on port " + port);
    resolve(server);
  },
  // Provide a callback for authHandler to enable authentication. Any data returned by this
  // function will be available on client.authentication object passed to RPC functions.
  authHandler(...params) {
    console.log(`Authenticating, input: ${JSON.stringify(params)}`);
    return params[0];
  },
  onAuthTimeout(connection) {
    console.log("A connection timed out authentication.");
  },
});

Authenticating from Client Side

The RtmClientOptions allows you to pass authentication data (e.g. token) to the server that is processed by the authHandler function. Here's an example of client sending authentication data to the server:

src/client.ts

const token = getIdToken();
client = new RtmClient("ws://localhost:70/", {
  // Pass authentication data to the server.
  authenticationData: token,

  // Delay between reconnect attempts when connection fails.
  reconnectDelayMs: 5000,
  // Callback for when the client is attempting to reconnect.
  onReconnecting(attempt) {
    console.log(`Trying to reconnect for ${attempt} time...`);
  },
  // Callback for when the client successfully connects.
  async onOpen() {
    console.log("Connected to the RTM server.");
    resolve(client);
  },

  // Callback for when the client has been disconnected.
  onClose() {
    console.log("Connection with the RTM server was closed.");
  },

  // Callback for errors during connection.
  onError() {
    console.log("Error connecting to the RTM server");
    reject();
  },
});