When the EBS wants to transmit realtime messages or state via PubSub, it will use the Send Extension PubSub Message endpoint. Using this endpoint, your EBS can broadcast to all viewers of a given channel or to specific user’ via a whisper.
Please be aware of the following technical guidelines for using Twitch PubSub:
- 1 message per second per channel
- 5 KB message size
You will need to send per channel. There has been some conversation about an extension-wide broadcast topic, but it does not yet exist.