Some notes, specially in case I can’t attend the live session (should be fine but who knows).
Pleroma was thinking on getting WebSocket-based Federation (still HTTP in a way but still) and we’re doing the stabilization part of it currently. I haven’t worked on it.
This reminds me of https://socialhub.activitypub.rocks/t/documenting-federation-behavior-in-a-semi-standard-way/453/6 aka federation.md, I don’t know if it went further, we have yet to use it ourselves.
I’m going to extract the documentation into a proper document (it’s currently in https://git.pleroma.social/pleroma/pleroma/-/blob/241f7cb1ed91a8d6855dbd03517e85c98c08edb7/lib/pleroma/web/activity_pub/activity_pub_controller.ex#L526-538) but we got it to work between Pleroma and AndStatus.
(if you wonder why we don’t have the object parameter: https://git.pleroma.social/pleroma/pleroma/-/merge_requests/1810, could be re-evaluated for standardization)