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Use Lenz inside Claude or ChatGPT.

Connect Lenz once, then ask the chat to check a claim.

Connect Lenz to Claude Using ChatGPT? Beta steps below

Then type: Check the claims in this draft with Lenz.

Claude

Desktop · web · mobile

One sign-in. No key to paste.

  1. Open the Lenz connector page and click Connect to Claude.

  2. Complete Sign in with Lenz.

Claude Desktop, claude.ai and the Claude mobile apps share one account, so connecting once covers all three.

Settings → Extensions → Browse extensions, search for Lenz and click +, then complete the sign-in prompt. Same connection, same account.

ChatGPT Beta

chatgpt.com · Custom app (beta)

One sign-in. No key to paste.

  1. In ChatGPT, open Plugins, click Add, and choose Add custom MCP server.

  2. Name it Lenz, paste https://lenz.io/mcp as the server URL, leave OAuth under Authentication, tick I understand and want to continue, and click Create as a plugin. ChatGPT warns that a custom app carries risk; that applies to any custom app, and Lenz checks claims and changes nothing.

  3. Click Continue to Lenz, sign in with Lenz if asked, then click Connect and return to ChatGPT and Allow access.

Once, by an owner or admin. Workspace settings → Plugins opens OpenAI's Admin Console. Click Add → Create MCP plugin and fill in the same form, with OAuth under Authentication. Sign in with Lenz when asked, then open Lenz, click Review app, confirm the two risk notices and click Publish.

Then, each person. Open Plugins, pick Lenz, click Connect and sign in with Lenz.

OpenAI’s guide ↗

Connected? Ask either one. In ChatGPT, tick Lenz under + in the chat first.

Check with Lenz whether indeed 90% of startups fail within their first year.

You get a quick verdict and how confident Lenz is, usually with a short reasoning, in about fifteen seconds. Ask for a deep check to see the sources. Naming Lenz is what makes the assistant reach for it rather than answer from memory.

  • ClaudeOne click
  • ChatGPTA few steps, in beta
  • KeyNone for either
  • First answerQuick verdict and confidence

The answer comes back in the thread: a quick verdict, how confident Lenz is, and usually a short reasoning, in about fifteen seconds. Ask for a deep check and Lenz investigates the claim against independent public sources and shows its main sources. No key for either. Claude takes one click; ChatGPT takes a few more steps, and that route is in beta.

01What to ask

What you can ask it.

Name Lenz in the question. That is what makes the assistant reach for it rather than answer from its own knowledge. In ChatGPT, tick Lenz under + in the chat first.

  • “Check with Lenz whether indeed 90% of startups fail within their first year.”
  • “Check the claims in this draft with Lenz before I send it.”
  • “Is that last answer right? Check it with Lenz.”
  • “Run a deep check on the second one.”

Start with a quick check: a quick verdict on each claim and how confident Lenz is, usually with a short reasoning, in about fifteen seconds. When it matters, or a claim comes back uncertain, the deep check investigates the claim against independent public sources and shows its main sources with a summary of the reasoning. It takes about a minute or two. The deep check can change the quick verdict. When it does, rely on the deep check: it is the one that shows its sources and its reasoning.

02Cost

What it costs.

Free to start, no card required: 100 credits a month, which is 100 quick checks or 10 deep checks. Checks from the chat draw on the same credits as everything else on your account.

See the plans

03Questions

No, for either. You sign in with your Lenz account and the connection is authorized against it — on Claude through Connect to Claude, on ChatGPT through the Lenz sign-in that follows when you add the app. If you do not have a Lenz account yet, the sign-in creates one.

Yes. One Lenz account, one balance. A check you run from Claude draws on the same credits as one you run on the site or through the API.

Lenz is not in the ChatGPT app directory yet, so you add it by its address. In a Business, Enterprise or Edu workspace an owner or admin adds it once. ChatGPT shows a risk warning for any custom app, and Lenz checks claims and changes nothing. Once it is added, Lenz is an app you pick under + in each new chat.

Yes. A claim submitted through the connector is private to your account, as is every claim you check on the Lenz website or through the API. You can make any claim public from its own page.

04Other ways to connect

The same verdicts, wherever you work.

Check a claim without leaving the chat.

Connect Lenz to Claude ChatGPT steps (beta)

Then type: Check the claims in this draft with Lenz.

Free tier, no card required