> Can't we build a social network with a simple protocol:

> 1: Each user has a private key that they use to sign their messages.

> 2: Each user keeps a list of instances who announced that one of their members follows them. When the user posts something, they broadcast the post to those instances.

> Shouldn't this be enough?

> It could all be url based. One user, one url.

I might be misremembering how it works, but this sounds conceptually similar to how Ghost (the blog platform) works after their recent 6.0 update. They now support federation, posting on Bluesky and Mastodon, etc.