Hey @julian, congrats on the grant! I've been building the official ActivityPub plugin for Discourse(https://meta.discourse.org/t/activitypub-plugin/266794). To be clear, Pavilion (my cooperative) has been commissioned by CDCK (the company behind Discourse) to build it (I don't work for CDCK). With that throat clearing out of the way, I'd be keen to setup a test integration with your implementation when you're ready. Perhaps we could do it between a category here and a category on socialhub.activitypub.rocks, one of the primary ActivityPub forums? SocialHub is running both Discourse and the plugin (I'm also an admin there, which will help smooth things along). It'd be neat if we could get some NodeBB <> Discourse ActivityPub action happening.

Just a note, if anyone is wondering, that @julian and I have figured out why this topic didn't quite make it to [email protected] even though that actor is following this category. A fix will be coming soon.

@julian I've just sent a few follows from my local to @[email protected]. The code is again 400 and the error message is just "Bad request". I know our follows work with Mastodon (and other Discourse instances), but nevertheless there could be an issue on either end here. Lmk if you find anything in the logs about why it's being rejected.