Can the EBS listen to the "broadcast" topic on PubSub?

The EBS can broadcast messages through PubSub for the extension clients to receive. Is the reverse possible? Or is the only way to implement many-to-one communication to have the extension clients directly talk to the EBS?

I tried listening to PubSub the traditional way, through a web socket connection, but wasn’t able to find the right topic to listen to.

From the docs: and

  • 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).

Pubsub is a fan-out messaging solution. It is not a fan-in messaging solution. An extension can communicate with an EBS. All that is needed is a public endpoint on the EBS.

1 Like

Hey everyone, I stumbled upon the same. I want to offer a polling extension and I would like to have an easy back-channel to the EBS. E.g. the EBS in my case should take control of the poll.
However, I don’t like that each viewer has to establish their own connection to the EBS.

I would really like to see a solution where the EBS can listen to a channel’s broadcast topic - why is this not possible yet?
It will get broadcasted to the broadcaster’s dashboard anyway.

Any chance that we see a mechanism to allow EBS to listen to the broadcast topic? From what I have reverse engineered, it is just a topic, however, it uses a JWT for auth, instead of an oauth token. Can’t you just share how this token is generated?

Best, Robert

As @rbartlet said PubSub is:

For FanOut messages, one source many listeners
Not FanIn Messages, Many Source, one listener.

Twitch doesn’t want to pay for your EBS operations, in the bandwidth and potential abuse and server load on the PubSub from allowing FanIn.

They don’t want someones extension to attempt to bring down PubSub by spamming in a tonne of events when five large broadcasters start a poll on your extension at the same time. And 200,000 people vote at the same time

There is a future, where EBSs are not needed, as Twitch provides scalable services for developers, that for many use cases, eliminate the need for/of an EBS. We are working towards this future. Quite clearly, we are not yet there.