Do you mean directly using the ActivityPub Plugin? If so, this is what you can currently federate:
Can be federated between Discourse instances
- Public topics can be federated when
- created in a specified Category or created with a specified tag
- Replies on those topics can also be federated in both directions
- this is super cool, but only works if both instances are public
- Deletions of these will also be federated
What can’t currently be federated between instances:
- edits aren’t federated
- this includes wiki edits
- old topics / replies can’t be federated
- this can be quite a challenge for legacy content
We are currently exploring federation between the pavilion tag here on meta.discourse.org and coop.pavilion.tech, so hopefully you’ll be able to see this in action in a real world setting shortly.