I started working on private groups in Mitra. Beginning with version 5.10.0, you can follow private communities on Lemmy 1.0 beta (test instance:
https://voyager.lemmy.ml/), post to them and leave comments on posts.
Local private groups are not supported yet, but I hope to finish this part soon.
I will also try to make Mitra at least partially compatible with
Shoot - an instant messenger built on ActivityPub that has private groupchats based on FEP-1b12.
