{"x402Version":2,"name":"Check Digit Validator","description":"Validate common check-digit schemes — Luhn (cards), ISBN-10/13, EAN/UPC/GTIN, IMEI and US ABA routing numbers. Malformed input is rejected, a wrong check digit returns valid:false.","version":"0.1.0","openapi":"https://checkdigit.openverbs.com/openapi.json","resources":[{"url":"https://checkdigit.openverbs.com/v1/luhn","method":"POST","description":"Validate a number by the Luhn (mod-10) algorithm — the scheme behind credit/debit card numbers and many IDs. Spaces and hyphens are ignored. A mismatched check digit is a successful { valid: false }.","tags":["luhn validation","validate credit card number","mod 10 check digit","luhn checksum api","check card number","validate luhn number"],"accepts":[{"scheme":"exact","network":"eip155:8453","price":"$0.002","payTo":"0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A","asset":"USDC"}]},{"url":"https://checkdigit.openverbs.com/v1/isbn","method":"POST","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.","tags":["isbn validation","validate isbn","isbn check digit","isbn 10 isbn 13","book number lookup","isbn checksum api"],"accepts":[{"scheme":"exact","network":"eip155:8453","price":"$0.002","payTo":"0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A","asset":"USDC"}]},{"url":"https://checkdigit.openverbs.com/v1/ean","method":"POST","description":"Validate a GTIN barcode number — EAN-8, UPC-A (12), EAN-13 or GTIN-14 — by the standard mod-10 check digit. Length selects the scheme.","tags":["gtin validation","validate barcode number","ean upc check digit","upc validation","ean 13 checksum","barcode check digit"],"accepts":[{"scheme":"exact","network":"eip155:8453","price":"$0.002","payTo":"0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A","asset":"USDC"}]},{"url":"https://checkdigit.openverbs.com/v1/imei","method":"POST","description":"Validate a 15-digit mobile device IMEI by its Luhn check digit. Spaces and hyphens are ignored.","tags":["imei validation","validate imei number","mobile device imei","imei check digit","imei luhn check","phone imei validator"],"accepts":[{"scheme":"exact","network":"eip155:8453","price":"$0.002","payTo":"0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A","asset":"USDC"}]},{"url":"https://checkdigit.openverbs.com/v1/routing","method":"POST","description":"Validate a 9-digit US ABA bank routing number by its weighted (3,7,1) mod-10 checksum. Spaces and hyphens are ignored.","tags":["aba routing validation","validate routing number","bank routing checksum","us routing number lookup","aba check digit","routing number api"],"accepts":[{"scheme":"exact","network":"eip155:8453","price":"$0.002","payTo":"0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A","asset":"USDC"}]}]}