Veridigit

io.github.qinisolabsPublished by GitHub account qinisolabsv0.1.0Updated Oct 24, 2026

Verified IBAN, card, ISBN-13 & VIN validation for AI agents — checksums, not guesses.

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Overview

AI-generated overview

Lets an assistant validate IBAN, payment card, ISBN-13 and VIN identifiers using real checksum algorithms instead of guessing.

What you can do
Exposes four tools — validate_iban, validate_card, validate_isbn and validate_vin — that run the actual checksum algorithms (ISO 7064 mod-97, Luhn/ISO 7812, ISBN-13 mod-10, ISO 3779 VIN) and return structured results with parsed parts and error reasons. Card validation also detects the brand from the BIN and checks length rules; IBAN validation covers country-specific lengths for 75+ countries. It also ships as a typed TypeScript library for direct import.
When to use it
Useful when an assistant handles structured identifiers and must not accept malformed ones — checking IBANs, card numbers, ISBN-13s or VINs before acting on them. It replaces confident but wrong model guesses with a deterministic answer.
Requirements
Runs locally as a stdio MCP server, typically started with npx, so Node.js and npm are needed. No accounts, API keys, environment variables or headers are declared, and it performs no network calls.
Before you install
It validates structure only: format and checksum. It does not confirm that an account, card, book or vehicle exists, is active, or belongs to anyone. No credentials are requested and no data is sent to third parties.

Installation

In SourceWeft

  1. Open Veridigit in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

veridigit

Verified validation of structured identifiers for AI agents — checksums, not guesses.

LLMs cheerfully accept malformed IBANs, mistype card check digits, invent ISBN and VIN check digits, and guess a card's brand wrong. veridigit gives an agent a deterministic, authoritative answer instead: it runs the real checksum algorithms and returns structured results with the parsed parts and clear error reasons.

It ships as both an MCP server (for agents to call live) and a typed TypeScript library (for apps to import).

Supported in v1:

  • IBAN — ISO 7064 mod-97 checksum + country-specific length, for 75+ countries.
  • Payment cards — Luhn (ISO/IEC 7812) checksum, brand detection from the BIN (Visa, Mastercard, Amex, Discover, Diners, JCB, UnionPay), and length rules.
  • ISBN-13 — 978/979 prefix and mod-10 weighted check digit.
  • VIN — ISO 3779 alphabet (no I/O/Q) and the position-9 transliteration check digit.

Why

On 32 randomly generated, non-memorised identifiers, a frontier model with no tool got the check digit wrong 91% of the time — IBAN 100%, VIN 100%, ISBN-13 88%, card/Luhn 75% — versus 0% for veridigit. The failure is invisible: the model returns a confident, well-formatted answer that happens to be wrong. veridigit replaces the guess with the algorithm.

Benchmark and reproducible harness: https://qinisolabs.github.io/veridigit

The 91% figure is one frontier model, tool-free, at temperature 0. Run it on any model yourself with the harness in bench/.

Use as an MCP server

jsonc
// in your MCP client config{  "mcpServers": {    "veridigit": { "command": "npx", "args": ["-y", "veridigit"] }  }}

Tools exposed: validate_iban, validate_card, validate_isbn, validate_vin.

Use as a library

bash
npm install veridigit
ts
import { validateIban, validateCard, validateIsbn13, validateVin } from "veridigit";
validateIban("GB82 WEST 1234 5698 7654 32");// { valid: true, countryCode: "GB", country: "United Kingdom", checkDigits: "82", ... }
validateCard("4111 1111 1111 1111");// { valid: true, luhnValid: true, brand: "Visa", lengthValid: true, ... }
validateIsbn13("978-0-306-40615-7"); // { valid: true, type: "ISBN-13", checkDigit: "7", ... }validateVin("1HGCM82633A004352");    // { valid: true, checkDigit: "3", ... }

Helper exports are also available: ibanCheckDigits, luhnValid, luhnCheckDigit, detectBrand, isbn13CheckDigit, vinCheckDigit, supportedIbanCountries.

Scope

veridigit validates the structure of an identifier — its format and checksum. It does not confirm that a bank account, card, book or vehicle actually exists, is active, or belongs to anyone. It performs no network calls.

Development

bash
npm installnpm run build   # tsc -> dist/npm test        # parity/known-answer tests via tsx

The curated reference data (IBAN country specs, card BIN ranges) lives in data/.

License

Apache-2.0

Source: README.md at commit bc7fedd

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

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  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts