Client Messages

In addition to publishing messages server-side, connected WebSocket clients can also publish messages if they're authorized to do so.

Publish Permissions

A connected client can publish messages, but only if they have explicit publish permissions to do so for a given event in a particular channel.

Let's take a chat room example. Assume each person in the room.123 channel need to send two types of events - one to indicate to other subscribers that they are typing and another to pass each sent chat message.

Your token must authorize subscribe access to the channel and grant publish access to both the is-typing and chat events. Setting echo to true on chat events allows the sender to receive a copy of those messages despite also being the sender. There's no need for the sender to also know that they are typing, so is-typing is not echoed.

{
  "channels": {
    "room.123": {
      "subscribe": true,
      "messages": {
        "is-typing": {
          "publish": true
        },
        "chat": {
          "publish": true,
          "echo": true
        }
      }
    }
  }
}

On the WebSocket, the client can now send a message when they begin typing.

> {"channel":"room.123","event":"is-typing"}

Other members of the channel will receive a copy. All client-initiated messages include the sender uid and umd in the meta attribute.

< {"id":"01J663WM0781SKS3FDWVV0G884","event":"is-typing","channel":"room.123","data":null,"meta":{"uid":"Jim","umd":null}}

Similarly the client can publish chat messages on the WebSocket.

> {"channel":"room.123","event":"chat","data":"Hello! I just wanted to say hi ❤️"}

All channel subscribers will receive a copy of this message. But this one will also send a copy to the sender (because of the echo directive).

< {"id":"01J664PF9MFZPADFA0N5AJB42R","event":"chat","channel":"room.123","data":"Hello! I just wanted to say hi ❤️","meta":{"uid":"Jim","umd":null}}

You can see this chat example in action in the Real-Time Chat demo.