I’m reading the ActivityPub spec here and it seems pretty fit for client-to-server communications. Yeah, it might be somewhat bulkier than your typical rest api, but it’s more universal, which begs the question: why do mastodon and lemmy both decided to implement custom (and incompatible) APIs for their clients to talk to the servers? Wouldn’t it be more straightforward if e.g. my voyager app talked ActivityPub to lemmy.world which then talked ActivityPub to lemmy.ml or something.
What am I missing?
Postel’s Law is relevant here. Conservative in what you send (simplify the schema of the data on the wire) and liberal in what you receive (put the complexity for interpreting that data in the client).