{"name":"checksum","title":"Checksum Validator","category":"developer","description":"Validate or compute check digits for IBAN, ISBN-10, and ISBN-13 identifiers.","price_usd":0.001,"input_schema":{"type":"object","properties":{"scheme":{"type":"string","description":"Checksum scheme","enum":["iban","isbn10","isbn13"]},"value":{"type":"string","description":"Value to check (spaces/dashes ignored)"},"mode":{"type":"string","description":"validate or check_digit","enum":["validate","check_digit"]}},"additionalProperties":false,"required":["value"]}}