Earlier quoted context omitted.
I've been looking into hacking ActivityPub into some projects that I run but there are a lot of caveats. For one, there's "ActivityPub" and there's "ActivityPub that Mastodon (and therefore most of the Fediverse) can interoperate with reliably". For example, Mastodon has some artifical requirements that add signature requirements to public APIs to reduce bot and spam load. This isn't in the spec as a mandatory requir…
"that add signature requirements to public APIs to reduce bot and spam load" Hmm? Are you talking about AUTHORIZED_FETCH? That's specifically an opt-in (and discouraged) feature that's meant to reduce the possibility of blocked instances retrieving your posts and displaying/replying to them on their own servers, it has nothing to do with bot or spam load. "This isn't in the spec as a mandatory requirement, but if you…
Enabling authorised fetch breaks federation with several other servers and some apps as well. Previously valid post IDs may suddenly become unavailable or break, which some services trying to backfill posts absolutely cannot deal with.
I believe actors are available as barebones actor information not to break federation completely, but I don't believe this type of compatibility is available for individual statuses.
Personally, I don't see why I shouldn't enable the setting on my own servers because the extra control it provides is probably worth it for the few exotic broken servers out there, but it's a gotcha if you expect the protocol to work as described in the spec alone.