From the docs: https://dev.twitch.tv/docs/extensions/reference#send-extension-pubsub-message and https://dev.twitch.tv/docs/extensions/reference#send-functiontarget-contenttype-message
- EBS can broadcast to all clients
- EBS can broadcast to specific clients
- Clients can broadcast to all clients
- Clients can broadcast to specific clients
I’ve not seen anything in the docs about Clients sending to EBS via PubSub/EBS listening to broadcast (officially at least).