When registering a handle at Handles Club we create a link between the Bluesky profile and the handle in our database using the Bluesky account's Decentralized ID (did) which is an immutable (never changing) value. The link remains in place forever. The database looks a little something like this:

When a user adds a handle to Bluesky via their account settings, Bluesky visits a special URL to find out which Bluesky profile (did) the handle belongs to. For example, if a Bluesky user tries to add example.on.computer to their Bluesky profile, Bluesky will visit example.on.computer/.well-known/atproto-did to compare the did (which is taken from our database) and if the values match, Bluesky will update the profile's handle.

Handles Club is powered by handles.net which provides a handle directory for every domain name. Visit the public directory for each Handles Club domain by clicking on the "registered" link for each domain on Handles Club.