For now webfinger is the place of authority for basically everyone, so it should support domain-only users.

I’m a bit skeptical about distributing authority between DNS and webfinger tbh, it’s yet another implementation surface and potential attack vector based on diffused responsibillity (what if webfinger and DNS are out of sync and a client only does webfinger? etc)

Several options have been discussed in this fediverse-ideas issue:

https://codeberg.org/fediverse/fediverse-ideas/issues/23

@mbajur

i'm currently using @domain.com@domain.com as a solution someone suggested to me a year ago but i find it a bit hacky and looking for a proper solution

It's not a bad solution IMO.

Maybe @snarfed.org has some ideas on how to do it better because domain handles are popular on Bluesky

It would be interesting to test whether mastodon links to people in replies by their href already, or whether it tries to do (cached) webfinger again when you hit reply, because if they use the href from the previous toot it could already work in replies.

I think what you want to do has a lot of value here … so I guess the steps are:

1) implement webfinger to resolve @domain to the one actor, and @user@domain to point *to the same actor* (so you can mention them on platforms that don’t yet implement the new style quotes)
2) Publish an FEP about this new webfinger extension