Lenz
AIAudit-grade fact-checking API that runs claims through an eight-model, five-stage adversarial pipeline and returns a cited verdict.
Lenz
Audit-grade fact-checking API that runs claims through an eight-model, five-stage adversarial pipeline and returns a cited verdict.
About Lenz
Lenz is a fact-checking API built for AI products that cannot afford to hallucinate. Instead of asking one model whether a statement is true, it runs each claim through a five-stage pipeline across eight models from multiple vendors: evidence is gathered from real sources, an opposing side argues the counter-position, and three independent reviewers score the result, producing a verdict with a confidence rating and a full citation trail rather than a bare yes or no. Four API primitives form a depth ladder — /extract pulls verifiable claims out of arbitrary text, /assess returns a fast multi-model verdict cheap enough for synchronous UX, /verify runs the full adversarial pipeline with citations, and /ask handles grounded follow-up questions about a completed verification. The API ships as OpenAPI 3.1 with Python and TypeScript SDKs and a CLI, and drops into Claude, Cursor, n8n and Zapier for incident triage, async runtime verification of model output, and pre-release CI gates. A public workbench and research library let anyone paste a single statement, link or question and see the sourced reasoning, and Lenz publishes open evaluations of how frontier models disagree on real user-submitted fact-checks.
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Key Features
Use Cases
Frequently asked questions about Lenz
What is Lenz?
Audit-grade fact-checking API that runs claims through an eight-model, five-stage adversarial pipeline and returns a cited verdict.
How does Lenz work?
Lenz works by combining Five-Stage Adversarial Pipeline: Eight models across five stages gather evidence, argue the opposing side, and pass through three independent reviewers before a verdict is issued., Multi-Vendor Independence: Verdicts come from LLMs across several vendors rather than one provider, so a single model's blind spot cannot decide the outcome., Full Citation Trail: Every verdict ships with the real sources it rests on and the reasoning shown, so a human can audit why the answer came out the way it did., Depth Ladder of Primitives: /extract, /assess, /verify and /ask let you trade latency against rigor — a fast multi-model check for live UX, the full pipeline for anything that will be published., Claim Extraction from Free Text: /extract pulls the individually verifiable claims out of any document or model output so each can be checked separately. to help users with Runtime Output Verification: Check what your LLM feature just produced against real sources before it reaches a user, asynchronously or inline., Pre-Release CI Gates: Run generated content, docs or marketing copy through /verify in CI so unsupported claims fail the build., Incident Triage: Verify claims circulating during a live incident and get a verdict with sources instead of a confident guess., Editorial and Newsroom Checking: Extract the checkable claims from a draft and get each one scored with citations before publication., Compliance and Risk Review: Produce an auditable trail showing what was verified, against which sources, for regulated or high-liability content..
What are the main features of Lenz?
Key features include Five-Stage Adversarial Pipeline: Eight models across five stages gather evidence, argue the opposing side, and pass through three independent reviewers before a verdict is issued., Multi-Vendor Independence: Verdicts come from LLMs across several vendors rather than one provider, so a single model's blind spot cannot decide the outcome., Full Citation Trail: Every verdict ships with the real sources it rests on and the reasoning shown, so a human can audit why the answer came out the way it did., Depth Ladder of Primitives: /extract, /assess, /verify and /ask let you trade latency against rigor — a fast multi-model check for live UX, the full pipeline for anything that will be published., Claim Extraction from Free Text: /extract pulls the individually verifiable claims out of any document or model output so each can be checked separately..
Who is Lenz for?
Lenz is useful for anyone interested in Runtime Output Verification: Check what your LLM feature just produced against real sources before it reaches a user, asynchronously or inline., Pre-Release CI Gates: Run generated content, docs or marketing copy through /verify in CI so unsupported claims fail the build., Incident Triage: Verify claims circulating during a live incident and get a verdict with sources instead of a confident guess., Editorial and Newsroom Checking: Extract the checkable claims from a draft and get each one scored with citations before publication., Compliance and Risk Review: Produce an auditable trail showing what was verified, against which sources, for regulated or high-liability content..
How much does Lenz cost?
Lenz offers a free tier with paid plans for advanced features.
How do I get started with Lenz?
Visit https://lenz.io to sign up and explore Lenz.
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