Scope fence – read before use
This tool is a verifier only – it takes an already-produced x402 envelope as input and checks it. It never originates, funds, signs, or settles a payment, never calls a facilitator or any wallet API, and never holds custody of anything. A PASS verdict proves the envelope is structurally well-formed against the x402 spec and (if provided) internally consistent with the paired
PaymentRequirements; it does not prove the signature cryptographically recovers to the claimed payer – that recovery is art-591-x402-signer-recovery-verifier's job, cited here and not duplicated. It also makes no settlement or scope-of-mandate claim – see the "see also" panel below. N/A determination (CONTRACT §38): this tool verifies envelope structure and signature format against the published x402 protocol spec; no regulation, standard, or accounting pronouncement prescribes the arithmetic here, so no clause citation applies.
See also – do not duplicate
T277 · x402 Header Decoder, Payload Linter & Flow Simulator decodes/lints headers and simulates the 402 flow – no crypto check, no correctness proof; this tool is downstream of it. ·
art-591 · x402 Signer Recovery Verifier performs the actual ECDSA signer recovery this tool does not attempt. ·
art-565 · KYA×x402 Scope Verifier verifies a payload's claimed scope against a KYA mandate – this tool makes no scope claim. ·
art-03 · x402 Settlement Modeler projects settlement outcomes – this tool verifies a produced artifact, it does not model one.
🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Verify an x402 Payment Envelope
Paste a PaymentPayload, optionally paired with a PaymentRequirements