Veridigit

Name: Veridigit
Author: qinisolabs

@qinisolabs

About Veridigit

Verified IBAN, payment card, ISBN-13 and VIN validation for AI agents — runs the real checksum algorithms (mod-97, Luhn, mod-10, ISO 3779) instead of letting the model guess, and returns structured results with clear errors.

#validation #iban #credit-card #isbn #vin #checksum #fintech #identifiers

Basic information

Config

Add this server to your MCP-compatible client using the configuration below.

{
  "mcpServers": {
    "veridigit": {
      "command": "npx",
      "args": [
        "-y",
        "veridigit"
      ]
    }
  }
}

Tools

ISO 7064 mod-97 checksum + country-specific length (75+ countries)

Luhn checksum, brand detection from the BIN, length rules

ISBN-13: 978/979 prefix + mod-10 weighted check digit

ISO 3779 alphabet (no I/O/Q) + position-9 transliteration check digit

Overview

What is Veridigit?

Veridigit is a tool that validates structured identifiers (IBAN, credit card, ISBN, VIN) using real checksum algorithms, returning parsed parts and clear reasons when something is wrong. It is designed for AI agents that otherwise invent or mistype check digits.

How to use Veridigit?

Install as an MCP server by adding veridigit to your mcpServers config: {"command": "npx", "args": ["-y", "veridigit"]}. Alternatively, import it as a typed TypeScript library via npm install veridigit. No API key is required.

Key features of Veridigit

validate_iban: ISO 7064 mod-97 checksum + country-specific length (75+ countries)
validate_card: Luhn checksum, brand detection from BIN, length rules
validate_isbn: ISBN‑13 978/979 prefix + mod‑10 weighted check digit
validate_vin: ISO 3779 alphabet (no I/O/Q) + position‑9 transliteration check digit
Validates structure only; no network calls made

Use cases of Veridigit

Preventing an AI agent from accepting malformed IBANs
Correcting credit card check digits that LLMs invent
Validating ISBN‑13 numbers generated by a language model
Checking VIN check digits against the ISO 3779 standard

FAQ from Veridigit

What does Veridigit validate?

It validates the structure (format + checksum) of IBANs, credit card numbers, ISBN‑13, and VINs. It does not confirm whether an account, card, book, or vehicle actually exists or is active.

How does Veridigit compare to a language model guessing check digits?

In a benchmark of 32 randomly generated identifiers, a frontier model without Veridigit got the check digit wrong 91% of the time, while Veridigit had 0% error.

Does Veridigit require an API key or make network calls?

No. Veridigit is free, requires no API key, and makes no network calls. It runs entirely locally.

What dependencies or runtime are needed?

It runs as an MCP server via npx (Node.js) or can be imported as a TypeScript library. No other runtime dependencies are mentioned.

Are there any known limitations?

Veridigit validates only the structural correctness of an identifier. It does not confirm ownership, activity, or real-world existence of the referenced item.