Lemmy v1.0.0 is in open beta testing now, and has released the new API v4 for app developers
28d 23h ago by lemmy.ca/u/otter in photon@lemdro.id from lemmy.ml
A few of the features are also available in Piefed. It might be helpful to implement them both at once :)
I'll get to work on this around the end of May
Sounds great :)