About Lenz

Lenz is a fact-checking API for AI-generated content.

It checks AI output before it reaches users, customers or downstream systems, and returns a sourced verdict with the full trace behind it. Lenz is an independent third party: unaffiliated with any model vendor, and outside your own team.

Product

Verify AI output before it ships.

One escalation path, and a full verification that shows its work.

The path: extract → assess → verify → ask A full verification runs multiple models from multiple vendors through five stages: Framing → Research → Debate → Panel Review → Conclusion It returns the verdict with its citations and audit trail, so you can verify the verification.

Why we built it

We measured the models, then built the check.

Long before Lenz, we spent years following the skeptic movement — the podcasts, the books, the arguments — on one practical question: how do you know what’s true and what’s not?

It has only got harder to answer: more of what people read is written to persuade rather than to inform. And when AI started writing the documents, answers and reports people act on, that question became an operational one.

So we measured the frontier models against recent, real-world claims, chosen to keep their verdicts out of the models’ training data as far as possible. On 63% of those claims the models did not agree on the answer, and they reported high confidence while disagreeing. Read the study →

We built on the research literature on multi-agent adversarial debate, evidence-based fact verification and multi-model judging panels, and turned it into a product. A full Lenz verification runs multiple models from multiple vendors across five stages, keeps both sides of the argument in the record, and returns the full trace with the verdict. The API and the SDKs put that process inside any workflow, and the MCP server puts it inside Claude and ChatGPT with no code at all.

Our goal is to check more and more AI output before anyone acts on it, so that fewer false claims get out there. A truer world is a simpler and kinder one to live in.

Warranty

Vendors disclaim accuracy. Lenz warrants the verdict.

Nearly everyone who generates content with AI disclaims its accuracy in the terms. We put money behind our verdicts: the trace shows the work, and the warranty is what we are on the hook for.

On a paid Pro or Scale plan, every full verification that qualifies carries a contractual warranty, at no extra charge.

How the warranty works →

In the world

What we have built and published.

Customers

Built for teams shipping AI-drafted text.

Customers use the API for these jobs today, amongst others.

Company

Founded in 2026.

Lenz was founded in 2026 by Kosta Jordanov and Victoria Dodeva, and is venture-funded.

  • Kosta Jordanov, Founder and CEO. Lenz is his fourth company as founder and CEO, after Wiser (IPO), FITE (acquired by Triller) and Arexus (acquired by Framfab). LinkedIn ↗
  • Victoria Dodeva, Co-founder, go-to-market. Two decades in marketing, at software and media companies and at a digital agency serving top brands, most recently as VP of Marketing at FITE; a Chartered Marketer (CIM). LinkedIn ↗

Lenz is operated by Lenz IO DPK, registered in Bulgaria. EU VAT Identification Number (VATIN) BG208892119.

Ship verified AI output.