{"id":"good_buyer","listed_week":"2026-W35","name":"The Good Buyer","price_usdc":0.99,"pricing":"fixed","fulfillment":"instant","description":"Name an x402 door you are about to pay (the url query parameter) and the store knocks once, writes down the accepts exactly as that door served them, and replays the stock x402 client's own selection over them — the default-asset filter, the per-payment ceiling, prefer-authorization, then the first survivor. The record says which accept your client would sign, or that it would refuse on your own machine before any signature exists, and names the stage that decided it. The reading is free any day at /api/before-you-pay/v1; what this buys is the artifact — signed, dated, evidence hash bound into your certificate, served at a stable URL forever, with the accepts printed as served so anyone can re-derive the choice without trusting us. For the human who later asks why the money went where it went. Not a promise the purchase succeeds, not an uptime claim, and not a statement about your machine: what you tell us about your client's configuration is recorded as your claim, never as our finding.","note_402":"Under a dollar, deliberately — the whole point is that a client which cannot pay a dollar can still afford to be told why.","constraints":["Give the door in the url query parameter: https, default port, on the public internet, the URL a buyer would GET expecting a 402","Optional: max_usd, your client's maxAmountPerPayment in dollars, and no_spend_controls=true if you pass spendControls: false. Leave both off and you get the reading for a client configured with nothing","Your client's configuration is recorded as YOUR declaration and never verified — we cannot see your machine","One GET at one moment, signed; nothing is signed on your behalf and no wallet is touched","The simulation models @x402/core at the version this store has installed, named on the record; a different version is a different answer","We refuse our own hostname — the platform kills self-fetch, and a reading we sign about our own door is worth nothing to whoever you would show it to","The report URL is free to read forever"],"buy_url":"https://scvd.store/api/buy/good_buyer","task":"Find out whether my own x402 client will actually pay a door before I spend a round trip on it, and get that dated and signed","price_tiers_usdc":[0.99],"spec":{"capability":"A signed JSON reading — verdict (would_sign, would_throw, cannot_simulate, unreachable or refused), the accepts exactly as that door served them, the buyer's declared client configuration recorded as theirs, and the replay: the accept a stock client selects or the stage that made it refuse, everything dropped and why, the hazards on the chosen accept, and what the simulation cannot see. Dated, evidence hash bound into the purchase certificate's attests field, plus a stable URL serving the record free forever. Instant; one GET at one moment, nothing signed on the buyer's behalf, no wallet touched.","why_use":"a dated, signed record of the accepts one door served and what a stock x402 client would do with them — free at POST /api/before-you-pay/v1; this buys the signature, the certificate binding and a permanent URL. The accepts print verbatim, so the selection re-derives without us.","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":"The x402 door you are about to pay: https, default port, on the public internet, the URL a buyer would GET expecting a 402. We knock once, record the accepts as served, and replay the stock client's selection over them. We refuse our own hostname."},"max_usd":{"type":"string","description":"Optional. Your client's spendControls.maxAmountPerPayment, in dollars. Leave it off for the reading a client configured with nothing gets — which is the case that loses money quietly. Recorded as your declaration, never verified."},"no_spend_controls":{"type":"string","description":"Optional, \"true\" if you pass spendControls: false — the one escape from the whole filter. Recorded as your declaration, never verified."}},"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 the door in the url query parameter: https, default port, on the public internet, the URL a buyer would GET expecting a 402","Optional: max_usd, your client's maxAmountPerPayment in dollars, and no_spend_controls=true if you pass spendControls: false. Leave both off and you get the reading for a client configured with nothing","Your client's configuration is recorded as YOUR declaration and never verified — we cannot see your machine","One GET at one moment, signed; nothing is signed on your behalf and no wallet is touched","The simulation models @x402/core at the version this store has installed, named on the record; a different version is a different answer","We refuse our own hostname — the platform kills self-fetch, and a reading we sign about our own door is worth nothing to whoever you would show it to","The report URL is free to read forever"],"price":{"amount_usdc":0.99,"pricing":"fixed","tiers_usdc":[0.99],"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."}