Right now Datasette authentication is provided exclusively by plugins:

• https://github.com/simonw/datasette-auth-github
• https://github.com/simonw/datasette-auth-existing-cookies

This is an all-or-nothing approach: either your Datasette instance requires authentication at the top level or it does not.

But... as I build new plugins like https://github.com/simonw/datasette-configure-fts and https://github.com/simonw/datasette-edit-tables I increasingly have individual features which should be reserved for logged-in users while still wanting other parts of Datasette to be open to all.

This is too much for plugins to own independently of Datasette core. Datasette needs to ship a single "user is authenticated" concept (independent of how users actually sign in) so that different plugins can integrate with it.