nice and clean interface!

That was 1-shot? What model/service?

FWIW and still a WIP, I am implementing a backend app communication based on NIP-17 https://github.com/trbouma/safebox/blob/acquire_lock/docs/NAUTH-PROTOCOL.md

Can't login with bunker bcs it throws on auth_url challenge.

Is this not already what some apps do, like Primal, encrypted and (maybe some metadata leak)?

Nice