silverpillFEP-ae97: Client-side activity signing has been updated: https://codeberg.org/fediverse/fep/pulls/682
I added a new section describing Media API after implementing it in Mitra v4.10.0.
The API is somewhat similar to Blossom API used by Nostr apps: media objects are identified by their SHA-256 digests, and can be mirrored to other gateways.
I also specified status codes for error responses.