My friend is working on adding ActivityPub support to his blog platform (BDServer) so people can follow/comment from Mastodon, Lemmy, etc.
Current status: Lemmy and Misskey can find and follow his account (@blenderdumbass@blenderdumbass.org), but Mastodon can’t find it at all, even though he sees proper ActivityPub requests hitting his server.
The technical details are pretty gnarly - RSA signature verification, HTTP header recreation, multi-threading issues. He wrote up the full journey here: Please Help Me With Activity Pub
If anyone has ActivityPub experience or wants to take a look at the code (Python), we have a Matrix room for BDServer development. Any insights on why different platforms behave differently would be super helpful.
https://matrix.to/#/#bdserver:tchncs.de
Source code: ActivityPub.py
It’s for django, but take a look into my ActivityPub Toolkit. It is designed to be compliant with ActivityPub and not with any particular implementation, so it should be easy for you to adapt to your own needs.
This doesn’t have any link to code. And all the other buttons say that the docs are not implemented yet.
The menu has a link to the repository.