@Raqbit @delroth @whitequark @SiteRelEnby

Linux doesn't have a first class authenticator API yeah. If you want to, you can buy a security key and get passkeys that don't sync. I wouldn't recommend that to most people since you have to do your own backup management but if you're a linux user maybe they're less of a footgun.

There's nothing stopping vendors from implementing their own passkey syncing solutions for linux (dashlane and 1password have implementations, maybe more out there?)