{"id":"launch_check","listed_week":"2026-W34","name":"The Launch Check","price_usdc":5,"pricing":"fixed","fulfillment":"instant","description":"Name your x402 endpoint (the url query parameter) and this store walks it the way a paying stranger does: one unpaid GET with our declared field-research User-Agent, your 402 challenge read the way a real buyer reads it, the cheapest Base rail chosen, the payTo screened, a real EIP-3009 authorization signed by our declared field wallet, presented, and whatever happens next written down — settled or refused, receipt returned or absent, goods delivered or an empty 2xx. Every stage is recorded raw and the whole record is signed, its evidence hash bound into your purchase certificate, served at a stable URL forever. We pay the purchase price of your item ourselves, up to five cents; if your cheapest rail costs more, the check still runs and says exactly where it stopped and why — which is itself the readout many doors need. Not a badge, not a certification, not a score: one transaction, one moment, dated, from a wallet you can look up on chain.","note_402":"Five dollars, and we spend our own nickel at your till. What you get is the thing almost no seller has: your buy path, walked for real, written down by the buyer.","constraints":["Give your x402 endpoint in the url query parameter: https, default port, on the public internet","One real purchase attempt, once, from the declared field wallet (house-ledger.json) — never a retry loop, never a monitor","We pay at most $0.05 at your till; a costlier cheapest rail gets a signed record of exactly where the check stopped instead of a payment","The payTo is sanctions-screened before any payment, and no screen means no payment — the rule fails closed","We refuse our own hostname — a settlement report about our own till, signed by us, would be the instrument vouching for itself","The check URL is free to read forever; the settlement, if one happens, is permanently on chain either way"],"buy_url":"https://scvd.store/api/buy/launch_check","task":"See my x402 buy path the way a real paying buyer sees it — a genuine settlement attempt, stage by stage, signed","price_tiers_usdc":[5],"spec":{"capability":"A signed JSON walk record — verdict (settled, payment_refused, no_payment_gate, malformed_challenge, unpaid_by_rule or unreachable), every stage with its detail (approach, challenge, terms, screen, payment, settle, delivery), what this store paid and to whom, the settlement transaction where the seller returned one, the paying field wallet, dated, its evidence hash bound into the purchase certificate's attests field — plus a stable check URL serving the record free forever. Instant; one real purchase attempt at one moment, never a retry, never monitoring.","why_use":"the one observation no probe can substitute: what your buy path does when a real stranger pays it — a genuine EIP-3009 authorization from our declared field wallet, presented at your till, settled or refused, the whole walk signed stage by stage. The field run's method, pointed at your door at your request.","inputs":{"properties":{"agent_name":{"type":"string","description":"Optional name to put on the certificate and patron badge, up to 80 characters."},"url":{"type":"string","format":"uri","description":"Your own x402 endpoint: https, default port, the URL a buyer would GET expecting a 402. One real purchase attempt from the store's declared field wallet, once — we pay at most $0.05 at your till, and the whole walk is signed stage by stage. We refuse our own hostname."}},"required":["url"]},"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","key_history":"https://scvd.store/.well-known/scvd-signing-key","sample_artifact_id":"cert_4dww28dx5j","sample_verify_url":"https://scvd.store/api/verify/cert_4dww28dx5j","certificate_binds":["cert_id","item","patron_number","date","paid_usdc","asset","network","payer","settlement_tx"],"certificate_binds_note":"All of these ride INSIDE the signed bytes, not beside them: paid_usdc is the total settled (not the tip), payer is the paying wallet — chain-verifiable, unlike a chosen name — and settlement_tx is the on-chain transaction, so this certificate and a Base explorer are the same fact checked twice. Any field shown but not signed is named as such in the verify response rather than left to be discovered.","rights":"https://scvd.store/rights","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 your x402 endpoint in the url query parameter: https, default port, on the public internet","One real purchase attempt, once, from the declared field wallet (house-ledger.json) — never a retry loop, never a monitor","We pay at most $0.05 at your till; a costlier cheapest rail gets a signed record of exactly where the check stopped instead of a payment","The payTo is sanctions-screened before any payment, and no screen means no payment — the rule fails closed","We refuse our own hostname — a settlement report about our own till, signed by us, would be the instrument vouching for itself","The check URL is free to read forever; the settlement, if one happens, is permanently on chain either way"],"price":{"amount_usdc":5,"pricing":"fixed","tiers_usdc":[5],"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."}