NIP-42

Relay authentication

NIP-42 lets a relay ask a client to prove which Nostr key it controls. This supports private relays, paid relays, and relay features that require identity.

NIP-42 is one of the small agreements that lets different Nostr apps understand the same kind of activity. In everyday terms, it is like agreeing on the shape of a form: once everyone uses the same form for relay authentication, people can move between apps without losing the meaning of what they created.

Read more in the official 42.md NIP document.