I should really implement negentropy user sync for grain...
How does this sound?
https://github.com/0ceanSlim/grain/issues/20#issuecomment-2586113672
Discussion
Have you checked out rust-nostr? They have an example for negentropy. Not sure how that works myself.
https://github.com/rust-nostr/nostr/blob/master/bindings/nostr-sdk-js/examples/negentropy.js