ActivityPub C2S is part of our roadmap.

Concerning federation and APIs, this is the current tasks sequence:

- TheFreeNetworkModule: a layer that will ensure data integrity and proper federation with more than one protocol enabled (OStatus and ActivityPub, for instance);
- ActivityPubPlugin S2S: It seems to be working properly with Pleroma already, yet some issues with Mastodon were reported. Furthermore, there's still a couple of things to implement, namely: Groups, attachment retrieval, proper deletion and some minor issues;
- ActivityPub C2S: unfortunately, this one wasn't even started yet, we've just done some planning about it, sorry, but we want it to be part of v2;
- Pleroma API: We want to release this one in v3.

I can advanced that TheFreeNetworkModule is having good results already and will soon be merged! :)

cc: @tenma