Escrow Cancel (buyer refund) ($0.002/call)

Buyer reclaims the credits locked in an OPEN escrow: POST {id}. Full refund to the buyer, no fee. Buyer-only. If a notarized condition is already met, releases to the payee instead (you can't cancel out from under a met condition).

Paid endpoint: $0.002 per call via the x402 protocol (USDC on Base). An unpaid request returns 402 with payment requirements in the PAYMENT-REQUIRED response header; attach payment and retry.