Great question! ActivityStreams 2 does support tagging posts with their language. I don't know of a way in AS2/AP to indicate a user's language, apart from proprietary ways like in Mastodon's API. Mastodon and other servers do let you translate posts automatically though, which Bridgy Fed already supports. And I'm open to other ideas!
@snarfed.org @wysteriary
Auto-translation isn’t super commonly enabled in Mastodon, unfortunately. Normally I’d say infer by TLD, but considering all these funny domain names here…
If you keep the info ephemeral, you could check if the account has an
"outbox"and if so if there’s an original post that has the language set in the first 10 or so (if the service doesn’t hand you a page of inline objects anyway). It would be inefficient and slow, but hopefully the path is cold enough that that doesn’t really matter, and it’s likely the only mostly-reliable way currently (aside from trying to infer a language from the profile text). Would need to be able to fail and default in a bunch of places for AP, like if there’s no (accessible) outbox present.Also note that AT posts can be tagged in multiple languages at once.
(Side-note, I don’t think Mastodon notifies users about replies to their posts unless those replies also still @ them. There’s no ‘reply’ notification type/category here.)