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Add fact-checking to any Zap.

The Lenz app for Zapier adds a verification step to any Zap: before the send, before the publish, before the row is written. A sourced verdict with score and citations comes back as mapped fields you can branch on. No HTTP configuration, just your API key.

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  • AppIn Zapier’s directory
  • SetupAPI key only
  • StepsOne trigger, four actions
  • OutputMapped fields

01How Verify runs in a Zap

Verify a Claim waits for a signed callback.

How the Verify step waitsThe full pipeline takes ~90 seconds, which is longer than a Zap step is allowed to block. So Verify a Claim doesn’t block. It hands Lenz a Zapier-managed callback URL, Zapier parks the Zap as waiting, and the step resumes when Lenz posts back, at which point the app fetches the finished result and hands your Zap the fields below. Assess (Fast) is a plain synchronous step: it returns in seconds, well inside the step timeout.
Webhook secretBecause the callback is a signed webhook, Verify a Claim needs a webhook secret on your API key: a one-time click under API key settings → Webhooks → Generate webhook secret. Assess, Extract Claims, and Ask Follow-Up work without one. If the secret is missing, the app says so when you test the step rather than failing silently on the first live run.

02What you can build

Any Zap that moves content has a place to verify it.

Check AI-drafted copy before the Zap sends it

Use the verdict to route to publish, revise, or your reviewers.

Screen claims pulled out of documents, forms or pages

Check claims from documents, form submissions, or scraped pages before they reach a downstream system.

Assess a batch of claims cheaply

Then escalate only the uncertain ones to the full pipeline.

Start a Zap when a verification finishes

Fan the result out to Slack, a sheet, or a review queue.

03Trigger and actions

One trigger and four actions, each with its own fields.

StepTimeReturns
New Verification CompletedTrigger · polling—Fires once a claim submitted with this API key finishes. verification_id, claim, verdict, confidence, lenz_score, key_finding, executive_summary, created_at.
Verify a Claim~90 sThe full pipeline: framing, research, debate, panel review, conclusion. Fields detailed below. Needs a webhook secret on the key (see above).
Assess (Fast)~15 sstatus (ok | no_claim) and claims[], one entry per claim found in the text, each with claim, verdict, confidence, passed, verification_url. No score, summary, or sources.
Extract ClaimsfreePulls the verifiable claims out of a block of text and checks nothing: claim (the primary one), identified_claims, domain, key_entities, presumed_intent. Text can also be a single public web page URL (http or https, nothing else in the field): Lenz reads the page, or a YouTube video's transcript, up to its first 50,000 characters. Pages behind a login can't be read. A page read can take longer than a Zap step's 30 seconds; if the step times out, paste the page's text instead.
Ask Follow-Up—answer: a reply grounded in the research behind a completed Verify a Claim result. Pick a recent verification from the dropdown, or map a verification_id from an earlier step.

Clicking Test in the Zap editor returns example output so you can map fields without spending credits on a claim you don’t care about. A turned-on Zap checks the input you actually give it.

04Verify a Claim output

Branch on status. Then on passed.

  1. Check status firstOnly completed carries a verdict. needs_input means the text held several claims and arrives with a reason and a message; failed arrives with an error.
  2. Use passed to approve or escalateThe ready-made boolean. Add verdict or lenz_score for a finer threshold.
  3. Send key_finding to peopleOne sentence, the short form for Slack or email. executive_summary is the longer write-up; sources is an array, each with a title and a url.
  4. Keep verification_idAsk Follow-Up needs it, and it pulls the full reasoning trace from the API later.

Verify a Claim output · JSON

{
  "status": "completed",  // completed | needs_input | failed
  "passed": true,  // true for True and Mostly True
  "verdict": "True",  // five labels, True to False
  "lenz_score": 9,  // integer 1–10
  "confidence": "high",  // high | medium | low
  "key_finding": "...",  // one sentence, for Slack or email
  "executive_summary": "...",  // the longer write-up
  "sources": [...],  // each with title and url
  "verification_id": "ab12cd34",  // look it up later via the API
  "task_id": "2f8b2e2b..."  // the pipeline run
}

05Getting started

Three steps to a working fact-check step.

Get a free API key

No credit card required.

Get a key

Generate a webhook secret

On that key, once, if you plan to use Verify a Claim.

Add a Lenz step to a Zap

Paste the lenz_… key.

The app lives in Zapier’s app directory, so there is no manual install. View the Lenz app on Zapier ↗

The same key works across every surface: Zapier, n8n, the MCP server, the SDKs, and the REST API. Credits come from your account balance, not from each integration.

06Other ways to connect

The same verdicts, wherever you work.

Verify AI output before your Zap sends it.

Try free View on Zapier ↗

Self-serve from day one · free tier, no card