@clacke Well, I don't think that it should be expected that the server delivers such a feed, but if it does you could always subscribe to it as with any other RSS/Atom feed if enabled on your server. For some reason we haven't enabled Atom links for !GNUsocial user tag feeds, but at least RSS 1.0 is linked: https://social.umeahackerspace.se/mmn/tag/hashtag

Note, this won't work for ActivityPub since it defies the long-established standards of feeds and requires various magic protocol specific mechanisms and artificial server intelligence .)