{"uid":"cap_gzmm4sQDh5Hd7W4-1dJ6N","slug":"duo-data-utilities-financial-security-identifier-validator-isin-builder-36870be4","name":"Duo Data Utilities – Financial Security Identifier Validator & ISIN Builder","description":"Validate the check digit of a financial security identifier: ISIN (ISO 6166), CUSIP, SEDOL and FIGI. Returns the verdict, the computed correct check character, and for an ISIN the issuing country prefix and the embedded NSIN. Also builds an ISIN from a country code plus a 9-character NSIN. Format and checksum only, no security master lookup.","url":"https://api.duoleads.com/v1/id/security?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"op":{"enum":["validate","build-isin"],"type":"string","default":"validate","maxLength":64,"description":"validate (default) or build-isin."},"nsin":{"type":"string","maxLength":64,"description":"Exactly 9 alphanumeric characters. Required when op=build-isin."},"value":{"type":"string","maxLength":24,"description":"ISIN, CUSIP, SEDOL or FIGI to validate. Required when op=validate."},"country":{"type":"string","maxLength":16,"description":"ISO 3166-1 alpha-2 code or XS. Required when op=build-isin."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["ok","route","version","data","meta"],"properties":{"ok":{"const":true},"data":{"type":"object","properties":{"isin":{"type":"string"},"nsin":{"type":["string","null"]},"type":{"type":"string"},"valid":{"type":"boolean"},"reason":{"type":["string","null"]},"country":{"type":["string","null"]},"algorithm":{"type":["string","null"]},"check_char":{"type":["string","null"]},"normalised":{"type":"string"},"check_char_ok":{"type":"boolean"}}},"meta":{"type":"object","required":["request_id","computed_at","price_usd","deterministic","disclaimer"],"properties":{"sources":{"type":"array","items":{"type":"object","required":["id","version","published"]}},"price_usd":{"type":"string"},"disclaimer":{"type":"string"},"request_id":{"type":"string"},"computed_at":{"type":"string","description":"RFC 3339 UTC with milliseconds"},"deterministic":{"type":"boolean"}}},"route":{"const":"/v1/id/security"},"version":{"type":"string"}}}}}}},"responseSchema":{"type":"json","example":{"ok":true,"data":{"nsin":"037833100","type":"isin","valid":true,"reason":null,"country":"US","algorithm":"luhn-mod10-alpha","check_char":"5","normalised":"US0378331005","check_char_ok":true},"meta":{"price_usd":"0.05","disclaimer":"Factual output of a deterministic computation over public data. Provided as is, with no warranty of accuracy, completeness or availability. Not investment, financial, legal, tax, medical or any other professional advice, and not a recommendation. Verify before relying on it. Terms: https://api.duoleads.com/terms","request_id":"01K6B7Q4ZC8H3F2M9WXR5TYN0D","computed_at":"2026-09-28T12:00:00.000Z","deterministic":true},"route":"/v1/id/security","version":"1.0.0"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_DTEWMLlCjsK9aL0fe14-_","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates the check digit of ISIN, CUSIP, SEDOL, and FIGI identifiers, returning validity verdict and computed check character; also builds an ISIN from a country code and NSIN.","exampleAgentPrompt":"Can you validate whether US0378331005 is a correctly formatted ISIN with a valid check digit, and tell me the embedded country code and NSIN?","exampleUseCases":[{"title":"Pre-trade ISIN integrity check","prompt":"Before I submit this trade, can you verify that the ISIN GB0002634946 has a valid check digit and tell me if it's correctly formatted?"},{"title":"Build ISIN from NSIN for new issuance","prompt":"I need to construct a proper ISIN for a US security — use country code US and NSIN 037833100 to build it for me."},{"title":"Validate CUSIP before database ingestion","prompt":"I'm about to load a batch of security records — can you check whether the CUSIP 037833100 has a valid check digit so I know it's not corrupted?"}],"resultDescription":"Returns a JSON object with: a boolean validity flag, the identifier type detected (isin/cusip/sedol/figi), the computed correct check character, whether the provided check character matches, a normalised form of the identifier, the algorithm used (e.g. luhn-mod10-alpha), a human-readable reason if invalid, and for ISINs the embedded country prefix and NSIN. Also includes metadata: request ID, computation timestamp, price, and a deterministic flag.","failureModes":["Missing required 'value' parameter when op=validate returns an error","Missing 'nsin' or 'country' when op=build-isin returns an error","NSIN not exactly 9 alphanumeric characters causes rejection","Unrecognised identifier type returns an error or null type","Invalid ISO 3166-1 alpha-2 country code causes build-isin to fail","Value exceeding maxLength of 24 characters is rejected"],"whenToPreferThis":"Use this endpoint when you need purely algorithmic, deterministic check-digit validation and format parsing for ISIN, CUSIP, SEDOL, or FIGI — with no latency or cost of a security master database lookup. Ideal for data-pipeline integrity checks, pre-trade validation, ETL ingestion hygiene, or constructing ISINs programmatically from known country codes and NSINs. Not suitable if you need to resolve the identifier to real security metadata (issuer name, price, exchange listing).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T02:16:06.747Z","isFirstParty":false,"canonicalSlug":"duo-data-utilities-financial-security-identifier-validator-isin-builder-36870be4"}