> > that, and they don't even have /.well-known/host-meta set up to properly redirect it.
I don't think www
will cause problems, their webfinger works, request to https://threads.net/.well-known/webfinger?resource=acct:mosseri@threads.net
returns {"subject":"acct:mosseri@threads.net","links":[{"href":"https://www.threads.net/ap/users/mosseri/","rel":"self","type":"application/activity+json"}]}
@top @dansup @grishka
WebFinger lets us take an ID like name@domain.example and get an actor endpoint https://domain.example/some/path/to/idnumber.jsonld . The format of the actor endpoint is implementation-dependent, so the WebFinger lets us have a nice little ID that is easily recognizable.