**I Built My Own Nostr Signer and Discovered a Different Security Problem**
I started building my own Nostr signer for a simple reason: I wanted to understand what actually happens between a Nostr client and my private key.
Nip07
NIP-07
NIP-07 defines the browser interface that lets Nostr web apps talk to user signers. It standardizes the optional window.nostr object, usually provided by a browser extension, so websites can request a user’s public key and ask the signer to sign Nostr events without ever handling the user’s private key directly.