Kind 3 is a replaceable event, there's no changelog
So I think it would have to be done client-side
The client would compare any kind 3 events containing your npub it retrieves against a cached list of all such events it has ever found
OR
We need a notification event kind representing a new follow, so when following someone the client publishes two events: the updated kind 3 list and the notification
quotingOne thing about #nostr is the apps are endless and the functionality is wild as hell, but when it comes to simple things, like seeing whose actually a new follower and following them back if I want, seems to be a game of maybe
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