NIP-77: Negentropy syncing

[fiatjaf]

This is a copy of @hoytech's https://github.com/hoytech/strfry/blob/nextneg/docs/negentropy.md with some small tweaks in the text (not in the protocol) just to have it here somewhere.

https://github.com/nostr-protocol/nips/blob/negentropy/77.md

[vitorpamplona]

IMHO, In the long run, sync will have to become a mandatory part of the protocol. I just don't see Nostr taking over everything without robust syncing operations. Yes, we can sync via REQs but that is so bad that I don't actually consider it a viable solution.

That means that the sync protocol must be extremely well defined such that we can actually have 100s of different implementations in all possible languages, with all possible database options, working together. We need to simplify and clarify this NIP to the extreme. It needs to become so good that it is fine if we add it to 01.md

Libraries can help, but the ability to code it from near scratch is a MUST to me.

[kehiy]

These new message types must be added to readme as well.

[fiatjaf]

Let's not do it for now.

[kehiy]

ok.

[jb55]

sync will have to become a mandatory part of the protocol

I hope so

[braydonf]

A great one to add, this will be great for mobile clients and for relay to relay syncing. Lots of potential. Let's go! :)