I've removed it here:

GitHub

Drop zapper support · rust-nostr/nostr@c2442d8

* Remove `nostr-zapper` * Remove `Client::zap` The zapper is too high level. This will also reduce a little bit the binary size of the bindings an...

At the moment, I think there are other things more important to focus on. We'll see if re-add it in the future, after the beta or release stage. Otherwise, if someone is interested in building a nostr-sdk extension library, could add it there.