httppayai

Duplicate payment batch

Duplicate payment batch: up to 20 fingerprints in one call. Pass ?items= as a JSON array of {resource, payee, amount, nonce}. Optional &window= applies when an item omits it (default 600 seconds, clamped from 60 to 86400). Each row is its own EIP-712 DuplicateVerdict (domain APEX DuplicateGuard). The same fingerprint inside the batch is FRESH once, then DUPLICATE. A 21st item is refused before anything is recorded and before any charge.