# Settlement Attestation

An independent signed observation of whether an x402 payment settled — on Base, Polygon or Solana, and the identifier's own shape picks the rail: a 0x hash names an EVM transaction rather than a chain, so it is read on Base and then on Polygon; a base58 signature reads Solana. Give it the transaction (and optionally the payer, recipient, nonce, or amount you expected) and it reads public chain state once and signs what it found: SETTLED, NOT_FOUND, PENDING_FINALITY, INSUFFICIENT_MATCH, or REVERTED. Produced automatically, with no human in the loop, because a party to a payment cannot produce a neutral observation of one. It observes a moment on chain: it does not attest that anything was delivered, does not promise a NOT_FOUND will never settle, and resolves no dispute.

- **id:** `settlement_attestation`
- **price:** $0.004 fixed, one-off; nothing here charges again by itself, ever — there is no mechanism that could
- **fulfillment:** delivered instantly
- **buy:** `GET https://scvd.store/api/buy/settlement_attestation` (x402 v2; USDC on a network offered in the current quote)
- **sample:** https://scvd.store/samples/settlement-attestation.json
- **does not prove:** That goods or services were delivered, that a NOT_FOUND will never settle later, or that the payment was legitimate. That the transaction was the settlement of any particular request: binding says what it ties, and authorization_nonce ties one EIP-3009 authorization, not one 402 challenge — whether the door tied that nonce to a single request is the door's work and unobserved. Anything a facilitator's settlement response says: it is received, not observed, and an agreement row that reads disagrees is a finding about the response, not a verdict on anyone. One RPC read of public state, at one moment, signed by a party with no interest in the answer.

House rules: give the transaction in the tx_hash query parameter: an evm hash (0x + 64 hex, read on base and then polygon) or a solana signature (base58) — the shape picks the rail; optional narrowing: payer, recipient, nonce (evm rails only — refused beside a solana signature), amount_usdc, or payment_payload (the base64 payment-signature you sent, read with the store's own replay-guard code). the artifact's binding field says what the answer ties the transaction to: a matched nonce binds it to one authorization, never to one request; optional payment_response: the payment-response header you received, verbatim. received, not observed — its bytes are digested into the signature and echoed outside it, and each claimed field (transaction, network, payer, success) is set beside what the chain showed: agrees, disagrees, not claimed, or not observed; observes settlement only, never delivery; one read at one moment; no polling, no retry, no second look.

> Four tenths of a cent, friend. The chain read is free; the signed, disinterested receipt is what you are buying. An EVM hash (read on Base, then Polygon) or a Solana signature — the shape picks the rail. No transaction of your own yet? Buy anything here — the half-cent blessing counts — and the purchase response hands you this door's URL with your own settlement transaction already filled in, whichever rail you paid on.