{"id":"settlement_attestation","listed_week":"2026-W31","name":"Settlement Attestation","price_usdc":0.004,"pricing":"fixed","fulfillment":"instant","description":"An independent signed observation of whether an x402 payment settled on Base. Give it a transaction hash (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.","note_402":"Four tenths of a cent, friend. The chain read is free; the signed, disinterested receipt is what you are buying.","constraints":["Give the transaction hash in the tx_hash query parameter","Optional narrowing: payer, recipient, nonce, amount_usdc, or payment_payload (the base64 PAYMENT-SIGNATURE you sent, read with the store's own replay-guard code)","Observes settlement only, never delivery","One read at one moment; no polling, no retry, no second look"],"buy_url":"https://scvd.store/api/buy/settlement_attestation","price_tiers_usdc":[0.004],"spec":{"capability":"A signed JSON observation of one Base transaction — status (SETTLED, NOT_FOUND, PENDING_FINALITY, INSUFFICIENT_MATCH or REVERTED), block height, confirmations, chain head, the query echoed back, and an evidence hash — verifiable against the store's published key without asking the store. Instant.","why_use":"independent signed observation of settlement state — an interested party can't produce a neutral one; the RPC read is free, the independent signed receipt is the product.","inputs":{"properties":{"agent_name":{"type":"string","description":"Optional name to put on the certificate and patron badge, up to 80 characters."},"tx_hash":{"type":"string","pattern":"^0x[0-9a-fA-F]{64}$","description":"The Base transaction hash to observe. Read once, at one moment; never polled."},"payer":{"type":"string","description":"Optional. Narrow the match to transfers from this address."},"recipient":{"type":"string","description":"Optional. Narrow the match to transfers to this address."},"nonce":{"type":"string","description":"Optional. Require this EIP-3009 authorization nonce to have been burned in the transaction."},"amount_usdc":{"type":"number","description":"Optional. Require a transfer of exactly this many USDC. Unstated fields widen the match, which is why the query is echoed onto the artifact."},"payment_payload":{"type":"string","description":"Optional. The base64 PAYMENT-SIGNATURE you sent, verbatim. The nonce is read out of it with the same code the store's replay guard uses, so you do not have to dig it out yourself."}},"required":["tx_hash"]},"outputs":{"delivery":"delivered in the purchase response, same request","always_included":["signed certificate (ed25519)","sequential patron number","badge_url","verify_url"]},"verification":{"verify_url":"https://scvd.store/api/verify/{id}","cost":"free, unlimited, forever","signing_key":"https://scvd.store/.well-known/scvd-signing-key","sample_artifact_id":"cert_4dww28dx5j","sample_verify_url":"https://scvd.store/api/verify/cert_4dww28dx5j","attestation":"Signed by the store's key, not yours: a claim the certificate carries can be checked by a third party without trusting your self-report."},"constraints":["Give the transaction hash in the tx_hash query parameter","Optional narrowing: payer, recipient, nonce, amount_usdc, or payment_payload (the base64 PAYMENT-SIGNATURE you sent, read with the store's own replay-guard code)","Observes settlement only, never delivery","One read at one moment; no polling, no retry, no second look"],"price":{"amount_usdc":0.004,"pricing":"fixed","tiers_usdc":[0.004],"currency":"USDC","network":"Base (eip155:8453)","protocol":"x402 v2"}},"guaranteed":["signature validity forever","verification free forever","price as displayed","delivery format as specified"],"not_guaranteed":["fitness for your particular task","future protocol compatibility beyond stated interfaces","human-labor turnaround faster than posted SLA"],"fulfillment_state":{"class":"instant","shutter":"open"},"markdown_note":"This same URL serves markdown when the Accept header prefers text/markdown."}