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Agents confidently emit IBANs, phone numbers, domains, VAT numbers and crypto addresses that are subtly — and silently — wrong. Qiniso checks the structured facts an agent produces against checksums and curated authoritative data, so a bad value is caught instead of trusted.

It's the deterministic complement to the guardrail stack: security guardrails check whether output is safe, structure guardrails check it's well-formed, and hallucination guardrails ask another LLM if it's faithful to the prompt. None of them check whether a structured fact is actually correct against the real world — because that needs computation or curated data, not another model's opinion. That's Qiniso.

On arbitrary identifiers, a frontier LLM validates them wrong ~91% of the time, cold and silently. Qiniso: 0%.

Add it to Claude

Settings → Connectors → Add custom connector, and paste — no login, no key:

https://qiniso.qinisolabs.workers.dev/mcp

Stateless, reads no user data, requires no secrets.

Use it as a library

Every check is also a typed function — no MCP required:

npm i @qinisolabs/qiniso

import { validateIban, validateVat } from "@qinisolabs/qiniso";

validateIban("GB82 WEST 1234 5698 7654 32");
// { valid: true, country: "United Kingdom", ... }

What it verifies — 56 tools across 8 domains

Domain	Tools
Identifiers	IBAN, payment card (Luhn + brand), ISBN-13, VIN, GTIN/UPC/EAN barcodes (+ GS1 country)
Web / network	TLD & domain (IANA root zone), IP, UUID, URL, email
Finance	ISIN, CUSIP, SEDOL, LEI, US ABA routing
Crypto	Ethereum (EIP-55), Bitcoin (Base58Check / Bech32) addresses
National & tax IDs	Brazil CPF/CNPJ, South Africa ID, Spain DNI/NIE, India Aadhaar, Italy, Poland, Netherlands, Belgium, Nordics, Portugal, Turkey, China, Germany Steuer-IdNr, France NIR, Switzerland AHV, Mexico CURP, Croatia OIB, Romania CNP, Bulgaria EGN, Estonia, Czech/Slovak rodné číslo, EU/UK VAT
Academic	ISBN-10, ISSN, ORCID
Locale	Phone (global), date parsing, currency, holidays (~200 countries), UK VAT-by-date
Addresses	UK/US address parsing

Each tool wraps an authoritative method — a published checksum standard, an audited library (libphonenumber-js, jsvat, date-holidays, @noble/hashes), or curated reference data (the IANA root zone, UK VAT history).

What it is not

• Not a live-data provider. It verifies facts you give it; it does not return the current time, weather, or live exchange rates.
• Not a credential sink. It never asks for secrets or API keys. (For JWT signature verification, use a library in your own runtime so the secret never leaves your machine.)
• Not a registration check. It validates a VAT number's checksum, not whether it is live-registered (VIES); it confirms a domain's TLD is real, not that the domain is registered.

Architecture

A TypeScript monorepo. Each domain is a typed library in packages/*; the qiniso umbrella aggregates them and exposes one MCP server over three transports — stdio (local / npx), Streamable HTTP (self-host), and a Cloudflare Worker (the hosted edge endpoint). The same core powers the importable library.

npm install
npm run build
npm test

License

Apache-2.0