# Identifier Validators

Check digits and structure for ISBN, UPC/EAN, VIN, ISSN, ORCID, ISIN, CUSIP, LEI and MAC addresses.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://id-validators.x402tookit.com/openapi.json
- x402 manifest: https://id-validators.x402tookit.com/.well-known/x402
- Catalog (free): https://id-validators.x402tookit.com/catalog
- Health (free): https://id-validators.x402tookit.com/health
- Uptime (free): https://id-validators.x402tookit.com/uptime

## Endpoints (9)

### GET /cusip-check — $0.02
Validate a 9-character CUSIP security identifier check digit and split issuer and issue codes.
Params: id: string
Example: https://id-validators.x402tookit.com/cusip-check?id=037833100

### GET /gtin-check — $0.02
Validate a UPC-A, EAN-8, EAN-13 or GTIN-14 barcode check digit and name its format.
Params: id: string
Example: https://id-validators.x402tookit.com/gtin-check?id=036000291452

### GET /isbn-check — $0.02
Validate an ISBN-10 or ISBN-13 check digit and convert between the two forms.
Params: id: string
Example: https://id-validators.x402tookit.com/isbn-check?id=978-0-306-40615-7

### GET /isin-check — $0.02
Validate a securities ISIN check digit and split it into country code and national security number.
Params: id: string
Example: https://id-validators.x402tookit.com/isin-check?id=US0378331005

### GET /issn-check — $0.02
Validate an ISSN (journal or serial number) check digit and format it with the hyphen.
Params: id: string
Example: https://id-validators.x402tookit.com/issn-check?id=0378-5955

### GET /lei-check — $0.02
Validate a 20-character Legal Entity Identifier with the ISO 7064 mod 97-10 check and split its parts.
Params: id: string
Example: https://id-validators.x402tookit.com/lei-check?id=HWUPKR0MPOU8FGXBT394

### GET /mac-parse — $0.02
Parse a MAC address in any common notation: canonical forms, OUI, unicast or multicast, universal or local.
Params: id: string
Example: https://id-validators.x402tookit.com/mac-parse?id=00-1A-2B-3C-4D-5E

### GET /orcid-check — $0.02
Validate an ORCID iD (researcher identifier) with its ISO 7064 check character and give the canonical form.
Params: id: string
Example: https://id-validators.x402tookit.com/orcid-check?id=0000-0002-1825-0097

### GET /vin-check — $0.02
Validate a 17-character vehicle VIN check digit and decode region, manufacturer code and model-year candidates.
Params: id: string
Example: https://id-validators.x402tookit.com/vin-check?id=1M8GDM9AXKP042788

## Terms

Identifier checks are computed locally from published check-digit algorithms. A valid check digit proves the identifier is well formed, not that it is issued, assigned or belongs to anyone. This tool does not validate payment cards, bank accounts or government IDs.