This topic is to shed a light on #software:mastodon 's abilities to work with #activitypub:c2s clients. Maybe someone has more info on supported C2S API, knows better on what we can or cannot expect in the upcoming Mastodon releases.
While experimenting #activitypub:c2s between #software:andstatus client and #software:pleroma server I started to receive Activities, created by Actors, having IDs at non-Pleroma hosts.
Client app cannot know if any concrete server supports #activitypub:c2s protocol or not, so it requests Actor’s profile from the Actor’s host (using Actor’s id) and fails or succeeds depending on the protocol’s support by that server.
And I was surprised that I’m getting valid ActivityPub responses from Mastodon servers. I can get Actor and Actor’s endpoints, and some of that endpoints work also: outbox, following, followers.
I even managed (using hackish way…) to login to Mastodon server as to “ActivityPub” type Social network (i.e. as if it really supports #activitypub:c2s), but “inbox” and posting new activities don’t work (I’m getting 404 Not found error).