@evan Hi, I've filed an issue on tags.pub regarding RFC 9421 HTTP Message Signatures compatibility. tags.pub rejects Content-Digest headers with “No digest provided,” which prevents Fedify 2.1+ servers from following tags.pub accounts.

https://github.com/social-web-foundation/tags.pub/issues/22

@hongminhee awesome! Thanks for the detective work. I'll catch us right up.