lenz.io valid

Lenz

Fact-checking API for AI-generated content — an independent verification layer that returns sourced verdicts with citations and a full reasoning trace.

Their llms.txt

The beginning of the file, from our validated copy saved 2026-10-23T06:01:11.825Z. Cached copy · Source on lenz.io

# Lenz

> Fact-checking API for AI-generated content — an independent verification layer that returns sourced verdicts with citations and a full reasoning trace.

Lenz verifies AI-generated content before it is published, returned to a customer, or passed to another agent. It is API-first: four primitives — extract, assess, verify, ask — with Python and TypeScript SDKs. extract pulls checkable claims out of AI output, or out of a public web page given its URL; assess returns a 3-model verdict in ~15 seconds; verify runs the full multi-model pipeline (Framing → Research → Debate → Panel Review → Conclusion) in ~90 seconds; ask answers grounded follow-up questions about a completed verification. Research grounds each claim in external sources scored for authority, and three independent reviewers on models from different vendors each check source quality, how directly the evidence bears on the claim, and claim precision; when enough quotes have been checked against their pages, one of them reads only those. Every verdict is structured — a conclusion label (True, Mostly True, Mixed, Mostly False, or False), a Lenz Score from 1 to 10, citations, and the reasoning trace — so workflows can block, publish, or escalate automatically. When no public record in the evidence settles a claim, the answer is "No Public Record" with no score (lenz_score is null), which does not make the claim false. Lenz is unaffiliated with any model vendor, and API-submitted claims are private.

## How It Works

- [About Lenz](https://lenz.io/about): The company — what Lenz is and who it fact-checks AI output for
- [How It Works](https://lenz.io/how-it-works): Five-step verification pipeline from claim framing to conclusion

## Research

- [Beyond Benchmarks: Disagreement Among Frontier LLMs on Real-World Fact-Checks](https://lenz.io/research/llm-disagreement): 5 frontier LLMs vs 997 user-submitted claims. Full methodology, breakdowns, and the per-claim CSV at https://lenz.io/research/llm-disagreement/data.csv. Permanent citation: https://doi.org/10.5281/zenodo.20344846 (resolves to the current version). Every version and every study: https://lenz.io/research

## Developer

- [Developers](https://lenz.io/developers): Fact-checking API for AI- and human-written documents — four primitives (/extract, /assess, /verify, /ask) with Python and TypeScript SDKs; /extract also reads a public web page given its URL
- [Plans & Pricing](https://lenz.io/plans): Self-serve plans from Free to Scale — per-tier /verify, /assess, and /ask quotas, monthly and annual billing
- [Warranty](https://lenz.io/warranty): What Lenz warrants, and when it pays
- [Product: fact-checking for AI-drafted text](https://lenz.io/product): What Lenz checks and where it runs — inside Claude or Cursor, from a script, or through the API — with one page per audience
- [For content teams](https://lenz.io/for/content-teams): Fact-check articles, briefs and posts before they go out — a result and the sources per statement
…

Machine-readable: GET /v1/resolve?q=lenz.io · GET /v1/domain/lenz.io · this page as Accept: application/json or text/markdown · MCP lookup_domain

Automatically discovered from public files. Inclusion does not imply endorsement or publisher participation.

Claim my listing on Agent Web Map for lenz.io:
1. POST https://agentwebmap.com/v1/sites/lenz.io/claims and keep claim_id and claim_secret private.
2. Publish the proof: add the line "AgentWebMap ownership: <token>" (token from step 1) to https://lenz.io/llms.txt, or use the DNS, meta-tag or well-known method the response describes.
3. POST https://agentwebmap.com/v1/sites/lenz.io/verify with {"claim_id": "...", "claim_secret": "..."}.
4. Save the api_key from the answer; it manages the listing (PATCH https://agentwebmap.com/v1/sites/lenz.io).
MCP equivalent: tools begin_ownership_claim, then verify_domain, at https://agentwebmap.com/mcp. Docs: https://agentwebmap.com/docs#verify

Corrections or removal requests: contact the directory.