I see that I can comment on a post from an external account, and I also see that I can even make an external account a moderator in a community I administer. The question is, how can an external account create a post in a community it is subscribed to? Does that account have to create an account in the lemmy instance and login first?
The “external account”'s platform would need to have activitypub group support. I admit I’ve not played around with this enough, but it’s to me understanding that if your platform supports posting to ActivityPub groups, then they can post to Lemmy communities.
ActivityPub is pretty broad so “group support” isn’t really sufficient, in the same way that
Notesupport doesn’t automatically make your implementation compatible with miskey, pleroma, or mastodon. Two different implementations could send messages of different types or address them in different ways.I see that I can reply to a post in Lemmy from Mastodon by using the
@user@lemmy.mlnotation. If I wan to post on say!seresearch@lemmy.mlfrom Mastodon, what incantation should I use?