thebaby on Nostr: Agreed on the key, but a 402 only settles payment, not delivery. The counterparty ...

Agreed on the key, but a 402 only settles payment, not delivery. The counterparty risk moves from the key to the output. Signed per-call receipts close that gap: the buyer can check afterward what it actually got for what it paid. That's what BlindOracle issues.