{"uid":"cap_hROkChALahtjRP6TbQE7S","slug":"code402-luhn-check-20b17c3c","name":"code402 Luhn Check","description":"Offline deterministic checks (no ML, no scraping) for business identifiers and rental due-diligence, paid per call via x402 (gasless EIP-3009 USDC on Base). Checksum-verifiable (IBAN, LEI, VAT, ABA, ISBN, SEDOL…) vs format-only (EIN, IFSC, SWIFT/BIC…) — every response returns a scope field. Non-custodial, signed receipts. First 3 calls/day free.","url":"https://hcrb.in/v1/tools/luhn-check/call?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"input":{"type":"object","required":["number"],"properties":{"number":{"type":"string","description":"12-19 digit number; spaces/dashes allowed."}}}}},"responseSchema":{"type":"json","schema":{"type":"object","required":["valid","reason"],"properties":{"tool":{"type":"string"},"scope":{"type":"string"},"valid":{"type":"boolean"},"reason":{"type":"string"},"country":{"type":"string"},"normalized":{"type":"string"}}},"example":{"valid":true,"reason":"checksum valid"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_1cW-z7xxcn-C4su1wXeUw","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a number using the Luhn algorithm (checksum) to detect transposition/typo errors in credit card numbers, IMEI numbers, and other Luhn-encoded identifiers","exampleAgentPrompt":"Can you run a Luhn checksum check on the card number 4539578763621486 to see if it's valid or if there's a typo?","exampleUseCases":[{"title":"Credit card number typo detection","prompt":"Check whether the credit card number 4111111111111111 passes the Luhn checksum — I want to know if the customer entered it correctly before we try to charge them."},{"title":"IMEI number validation before device registration","prompt":"Run a Luhn check on this IMEI number 490154203237518 — does it pass the checksum or is it malformed?"},{"title":"Batch identifier sanity check in onboarding flow","prompt":"I have a card number from our sign-up form: 3714496353984312 — can you do a Luhn validation on it and tell me if it's structurally valid?"}],"resultDescription":"A JSON object with a boolean 'valid' field indicating whether the number passes the Luhn checksum, a 'reason' string explaining the result (e.g. 'checksum valid' or 'checksum failed'), a 'scope' field indicating what kind of validation was performed (checksum vs format-only), and optionally a 'normalized' form of the identifier and a 'tool' name.","failureModes":["Malformed or missing input number returns valid:false with an explanatory reason","Non-numeric characters in input may cause a format rejection","After 3 free calls per day, a micropayment of $0.005 USDC is required via x402 protocol; missing payment returns 402 Payment Required","Input that is structurally a valid Luhn sequence but not a real card will still return valid:true — this is checksum-only, not account-existence validation","Very long or very short inputs may be rejected as out of spec for Luhn"],"whenToPreferThis":"Choose this endpoint when you need a fast, offline, deterministic Luhn checksum validation with no ML, no external lookups, and no data leaving the compute context — ideal for validating credit card numbers, IMEI numbers, or any Luhn-encoded identifier before submitting to a payment processor or device registry. Prefer this over regex-only validation when you need checksum verification (not just format), and over ML-based validators when you need deterministic, auditable results. The signed receipt and non-custodial payment model make it suitable for compliance-sensitive pipelines.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T06:33:12.904Z","isFirstParty":false,"canonicalSlug":"code402-luhn-check-20b17c3c"}