Thinking about an on chain zap…
Thinking about an on chain zap spec:
Nostr addresses are bitcoin addresses
Alice zaps Bob 100,000 sats for note N
Output 1: Bob - 100,000 sats
Output 2: OP_RETURN Zap - Version=1 - N (32 bytes) - 4 bytes empty OR note/npub
Output 3: Alice - change