{"uid":"cap_p8jqX_OPtKCehWa5QsCXW","slug":"isbn-validator-isbn-10-and-isbn-13-f885cefd","name":"ISBN Validator (ISBN-10 and ISBN-13)","description":"Validate an ISBN-10 (mod-11, trailing X allowed) or ISBN-13 (GTIN mod-10) book number. Length after removing spaces/hyphens selects the scheme.","url":"https://checkdigit.openverbs.com/v1/isbn","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["isbn"],"properties":{"isbn":{"type":"string","maxLength":32,"minLength":1,"description":"ISBN-10 or ISBN-13 (spaces/hyphens allowed)."}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_yrCha1F2eznodathSaG25","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates an ISBN-10 or ISBN-13 book number using mod-11 or GTIN mod-10 checksum algorithms respectively, with automatic scheme selection based on digit length.","exampleAgentPrompt":"Can you check whether this ISBN is valid: 978-0-306-40615-7?","exampleUseCases":[{"title":"Bookstore inventory data cleanup","prompt":"I'm importing a batch of book records and want to make sure this ISBN is legitimate before saving it — can you validate 0-306-40615-2 for me?"},{"title":"Publisher catalog submission check","prompt":"Before I submit this book entry to our catalog system, can you verify that ISBN-13 9780140449136 has a valid check digit?"},{"title":"Second-hand book listing verification","prompt":"I'm listing a used book on a marketplace and want to confirm the ISBN printed on the back cover is correct — can you validate 0-19-853453-1?"}],"resultDescription":"Returns whether the supplied ISBN passes its checksum: valid (true/false), the scheme detected (ISBN-10 or ISBN-13), and optionally details about why it failed if the check digit is incorrect or the length is invalid.","failureModes":["ISBN string is empty or missing — returns validation error","Length after stripping hyphens/spaces is not 10 or 13 — scheme cannot be determined, returns error","Check digit does not match computed checksum — returns invalid result","ISBN-10 check digit is not a digit or 'X' — returns invalid","Non-numeric characters other than hyphens, spaces, or trailing X present — returns error","Network or payment failure may prevent the call from completing"],"whenToPreferThis":"Choose this endpoint when you need to validate the check digit of a specific ISBN-10 or ISBN-13 book identifier. It automatically selects the correct algorithm (mod-11 for ISBN-10, GTIN mod-10 for ISBN-13) based on length, and handles hyphens and spaces natively. Prefer this over a generic Luhn or GTIN validator when you know the identifier is specifically a book ISBN and want ISBN-aware validation including the trailing 'X' allowed for ISBN-10.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:34:25.656Z","isFirstParty":false}