Terms of Service

Who you are contracting with

Lenz is operated by Lenz IO DPK, a company registered in Bulgaria, EU VAT Identification Number (VATIN) BG208892119. In these Terms, “Lenz”, “we” and “us” mean that company, and it is the party you contract with when you use the service.

Acceptance of Terms

By using Lenz at lenz.io, creating an account, creating an API key, connecting Lenz to an assistant or another application through OAuth, or making a request to the API, you agree to these Terms of Service and to the data practices described in our Privacy Policy. If you do not agree to these terms, do not use the service. The Covered Verification clause applies notwithstanding every other section of these Terms.

“You” means the person using the service, the holder of an API key or of an OAuth connection to Lenz, and any entity on whose behalf either is used. These Terms cover every endpoint under /api/v1/ and every other way of using Lenz described below.

Description of Service

Lenz checks factual claims against public sources, using multiple large language models. You can use it through the API and the SDKs; inside an assistant, through the MCP connector; through the integrations we publish, such as n8n and Zapier; through the website and the Workbench; and through WhatsApp. The results are generated automatically and, except where warranted under the Covered Verification clause, are intended for informational purposes only. They do not constitute professional, legal, medical, financial, or any other form of expert advice. You should always exercise your own critical thinking and consult qualified professionals where appropriate.

Accounts, API Keys & Connected Apps

To use certain features of the service you may need to create an account. You agree to provide accurate and complete information during registration and to keep your account credentials secure. You are responsible for all activity that occurs under your account. You must notify us immediately if you suspect any unauthorised use of your account. You must be at least 18 years old. If you use the service on behalf of a business, you confirm that you have authority to bind it, and “you” in these Terms includes that business.

Your API key authenticates requests as you. Keep it confidential: do not commit it to public source repositories, expose it in client-side code, or share it with third parties. You are responsible for all traffic and charges incurred through your key until you revoke it on the API credentials page or tell us, through the contact page, that it may be compromised. A revoked key is invalidated immediately and we do not charge you for subsequent traffic on it. Rotate keys when team members leave or when you suspect exposure. An application you connect to your account through OAuth acts as you in the same way, and disconnecting it ends its access.

We may suspend a key or a connection without notice if we detect abuse, fraud, or traffic that materially affects service stability for other users.

Acceptable Use

You agree not to:

• Use the service for any unlawful purpose or in violation of any applicable laws or regulations
• Access the service by automated means other than through the API, which includes our SDKs, MCP server and the integrations we publish, such as n8n and Zapier; or scrape data from it
• Resell raw API access, for example by offering a wrapper around /verify as a verification API of your own. You may sell products that embed results as part of a broader service, such as research reports, compliance findings or document review
• Attempt to interfere with, disrupt, or compromise the integrity or security of the service
• Circumvent any rate limits, access controls, or other technical measures we implement

Credits, Plans & Payments

Lenz is offered under four plans. Each includes a monthly allowance of credits, spent by every billable call: a claim verification costs 10 credits — or 5 at reduced depth — and a fast check or a follow-up question costs 1. Claim extraction costs no credits and is subject to a fair-use limit of 1,000 calls per account per day.

• Free — 100 credits per month at no charge (10 claim verifications, or 100 follow-up questions). Your monthly allowance resets on the first day of each calendar month.
• Plus — 500 credits per month (50 claim verifications, or 500 follow-up questions) for $7.99/month (billed monthly). Your allowance resets on each billing anniversary.
• Pro — 5,000 credits per month (500 claim verifications, or 5,000 follow-up questions) for $99/month (billed monthly) or $990/year (billed annually). Your allowance resets on each billing anniversary.
• Scale — 20,000 credits per month (2,000 claim verifications, or 20,000 follow-up questions) for $399/month (billed monthly) or $3,990/year (billed annually). Your allowance resets on each billing anniversary.

Top-ups are one-time purchases of credits that do not expire.

Credits are one pool per account, shared by every API key and every channel on it: an API call, a check on the website and a WhatsApp message all draw on the same allowance, and fair-use limits are per account too. Rate limits are soft-enforced: bursts above the limit may be served or may return 429 Too Many Requests depending on aggregate load. We provide no SLA on burst capacity. If you need higher or guaranteed throughput, contact us about Enterprise terms.

All payments are processed by Stripe. By subscribing, you agree to pay the applicable fees and authorise us to charge your chosen payment method. Paid subscriptions renew automatically on your billing cycle; you may cancel at any time through your account settings. Cancellation takes effect at the end of the current billing period, after which your account reverts to the Free plan. Upgrade and downgrade between paid plans is available at any time from the plans page.

Using Results in Your Product

The service, including its design, software and branding, is owned by Lenz and protected by applicable intellectual property laws. You retain ownership of the text you submit. By submitting it, you grant us a non-exclusive licence to process and analyse it and, where you make a claim public, to display it and its results. Rights in the third-party sources a result cites remain with their owners. Upload only documents you have the right to submit. When you download a checked document, Lenz adds comments and suggested edits, shown as tracked changes you can accept or reject; it does not change the document’s own text.

You may use the results Lenz returns for your text — the verdict, the score, the summary and the citation list — in reports and products you distribute. That permission survives the end of your subscription for results you already hold. You may say that Lenz checked a claim and what verdict it gave. Lenz returns evidence-based assessments, not authoritative truth, and you are responsible for how you present results to your own users. Where a verification is warranted, you may say so and reproduce or link to its certificate; the certificate states what is warranted and what is not.

Claim Visibility & Deletion

Every claim you submit is private by default, whichever way you submit it, except a claim you ask the Lenz bot to check on X, which it answers in public. You control the visibility of each claim and can change it at any time:

• Private — the claim is visible only to you. A warranty certificate for the claim can be read by anyone you give its link to.
• Public — you make the claim verification publicly accessible. It may also be included in the Library.

On the API, each customer sees their own verification id, never another customer’s, even when the result is served from a verification already run. On the website, in the Workbench, on WhatsApp and on X, a claim already checked may be answered with a link to that verification, which is either public or one you ran yourself.

You can permanently delete any claim you created at any time. Deletion is irreversible. It removes the claim text, the analysis, the evidence and any follow-up questions, and the text of each request that submitted the claim from your credit history and from our log of that API call (on a batch, that claim only). A record that each request was made remains, with its date, cost and outcome. Deletion does not reach our log of the messages you sent us on WhatsApp or our record of a post that asked us on X to check a claim. You can also delete a draft you checked on the website or in the Workbench, which removes its text, the statements found in it, its quick checks, its citation checks and its suggested edits, and the Word document it came from; deleting all your claims at once also deletes every draft you checked. A verification started from a draft is a claim of its own and stays until you delete it. Copies held in our caches expire within 24 hours, and deleted content leaves our backups within 60 days. One exception: where the verification was warranted, its certificate — including the statement checked, the verdict and the sources — is retained after the claim is deleted, on the basis set out in the Privacy Policy, and its warranty continues.

Published claims are not attributed to you by name. Notes you add to a claim are private to your account. If you ask us to check a claim publicly on X, that claim’s page credits the X handle you used.

Data We Process

Text you submit is processed by Lenz and by third-party large language model providers as described in our Privacy Policy. The current list of subprocessors is at lenz.io/subprocessors.

We log each API call, including the text you send and the response we return, to run and support the service. These logs are never exposed to another customer or to the public. Deleting a verification erases the text of the calls that submitted it, and deleting your account erases the text and responses they hold.

By default we keep the text you submit, the result and evidence of each verification, and these logs for as long as your account exists. An account on Pro or Scale can set a retention period on the API credentials page. It applies to everything the account submits, on every channel, and takes effect 24 hours after it is set. From then on, anything older than the period is removed within an hour: the text you sent, the result and evidence of each verification, each draft you checked with its statements, quick checks, citation checks, suggested edits and the Word document it came from (kept for at most 30 days in any case), the API-call log entries and your follow-up questions. A verification removed this way keeps its identifier, and requests for it answer that it is no longer available. A quick check of a single statement sent through the API or a connected AI assistant, and an extraction, create no record: their text and result are held in caches for up to 24 hours, and in your account’s API-call log, which the retention period also covers. Copies held in our caches expire within 24 hours, and backups within 60 days.

The shortest retention period is zero retention. With it, what the account submits is never written to our database: not the text you send, not the result or evidence of a verification, not a draft you check, its checks or its suggested edits, not a Word document you upload, not the bodies of your API calls. If we offer you a choice between claims on WhatsApp, that choice is held until you answer, or for at most an hour. A result stays readable from our cache for 24 hours, where you can also ask follow-up questions about it, and is then gone. Because nothing is written to our database, nothing reaches our backups. Warranty certificates are off while zero retention is set, because a certificate retains the checked statement. What it does not change: the task queue holds a check for the minutes it runs, request logs keep identifiers only, a note or follow-up question you add on the website to a public verification someone else ran is kept for up to an hour, and the model and search providers keep what their own terms say (see subprocessors).

A retention period does not remove warranty certificates. A certificate retains the checked statement, which can be identical to the text you submitted, the verdict, the summary and the sources, for as long as the warranty needs it.

Do not submit personal data, payment card data, health records, or other regulated data that you are not authorised to share with third-party LLM processors. You are the data controller for any text you submit; we are the processor, except for warranty certificates, which we retain as controller to establish or answer warranty claims.

Accuracy Disclaimer

All claim verifications are produced entirely by automated AI systems. Except where a verification is warranted under the Covered Verification clause, Lenz does not guarantee the accuracy, completeness, or reliability of any verification result and accepts no liability for any errors, omissions, or consequences arising from reliance on it.

Verdicts are produced by a multi-model pipeline and may be wrong. They are a research and verification aid, not authoritative truth. You are responsible for any decisions or actions taken on the basis of a verdict, including how you present verdicts to your end users. Where a verdict is warranted, the Covered Verification clause applies to it notwithstanding this section.

We may restrict access to, or remove, any claim that breaches these Terms, and may remove a public claim from the Library, for example where an automated screen finds it unsuitable for publication or a technical fault affected the analysis. Removing a claim does not by itself withdraw a warranted verdict; withdrawal follows the Covered Verification clause.

Verification reports show the sources consulted and the reasoning behind the verdict, so you can check any conclusion yourself; the detail varies by check type and channel.

Service Availability & Changes

Lenz is provided on a best-effort basis. We do not offer an uptime SLA on standard tiers. Outages, planned maintenance, and material API changes are reflected in the API documentation and, where applicable, communicated by email to the address on your account.

We may add new endpoints, parameters, response fields, or performance improvements at any time. We provide at least 30 days' notice before removing endpoints or making breaking changes to existing response shapes. Model versions used inside the verification pipeline may change without notice; the verdict shape remains stable.

Colleague invitations

Registered users can invite colleagues to Lenz, by email from the invite page or with a personal invite link, and both receive extra credits.

• Eligibility — requires a verified Lenz account. Invitations by email can be sent once the account has checked a claim or a draft, and are limited per day and per address.
• Credits — the invited colleague receives 200 extra credits (added on top of the monthly allowance) when they verify their email, and the inviter receives 200 when the colleague has checked a claim or a draft with Lenz. Both receive 2000 extra credits if the colleague purchases a paid subscription.
• Lifetime cap — an inviter is credited for at most 25 colleagues; subscription credits do not count towards it. Credits received as an invited colleague are not capped.
• No cash value — extra credits can only be spent on the service and cannot be transferred or redeemed for cash.
• One invitation per account — each account can join through one invitation; inviting yourself is not permitted.
• Abuse — we may revoke extra credits and suspend accounts for fraud, fake sign-ups, unwanted invitations or other manipulation of the programme.
• Changes — we may alter credit amounts or discontinue invitations at any time. Credits already granted remain valid unless forfeited under the abuse clause.

Disclaimer of Warranties

The service is provided on an “as is” and “as available” basis without warranties of any kind, whether express or implied, other than the Warranty given in the Covered Verification clause. Except as set out in the Covered Verification clause, we do not warrant that the AI-generated results are accurate, complete, reliable, or error-free. Verification analyses are produced by automated systems and may contain mistakes or omissions. You acknowledge that reliance on any results is at your own risk.

Indemnification

If you use the service on behalf of a business, or you distribute results to people outside your own organisation, you agree to indemnify and hold harmless Lenz, its operators, and its officers from any claim, loss, liability, or expense (including reasonable legal fees) arising from (a) how you present, distribute, or rely on Lenz results in your own product or publication, (b) your breach of these Terms, or (c) your violation of any applicable law in connection with your use of the service. It does not apply to a consumer using the service for purposes outside a trade, business or profession. This indemnity does not extend to any amount Lenz pays, or is liable to pay, under the Covered Verification clause.

Limitation of Liability

To the fullest extent permitted by law, Lenz and its operators shall not be liable for any indirect, incidental, special, consequential, or punitive damages arising out of or related to your use of the service. This includes, without limitation, damages resulting from decisions made based on AI-generated results, loss of data, or service interruptions. Our total liability, in aggregate across all claims, shall not exceed the amount you paid us in the twelve months preceding the event giving rise to the first of them. This section does not limit an amount payable under the Covered Verification clause.

Termination

We may suspend or terminate your account or your API access immediately for breach of these Terms, or for abuse, fraud, or activity that materially affects service stability or is harmful to other users, us, or third parties. Upon termination, your right to use the service ceases immediately. For a paying customer in good standing whose access we end for a reason other than breach, we give at least 30 days' written notice and a prorated refund of unused prepaid fees for the active billing period.

You may end these Terms at any time by cancelling your subscription in billing settings and revoking your keys on the API credentials page. We do not refund partial billing periods on customer-initiated cancellation.

Changes to These Terms

We may update these Terms from time to time. We will notify users of significant changes by posting a notice on the site; breaking changes to the API follow the notice period in Service Availability & Changes. Continued use of the service after changes are posted constitutes acceptance of the revised terms. A revision does not change the version that governs a certificate already issued.

Governing Law

These Terms shall be governed by and construed in accordance with the laws of Bulgaria. Any disputes arising from or relating to these terms or your use of the service shall be resolved in the courts of Sofia, Bulgaria. If you are a consumer, this does not remove the protection of the mandatory laws of the country where you live. If any provision of these Terms is held unenforceable, the remainder continues in effect.

Warranty Information in API Responses

Responses describing a verification may include a coverage object indicating whether that verification is warranted under the Covered Verification clause of these Terms, and if not, why not. The values are informational and describe the position as at the time of the response. The certificate, and the version of these Terms it records, govern in the event of any inconsistency.

The coverage object is absent where Lenz is not operating the Warranty, and on responses to unauthenticated requests. Its absence is not a statement about the verification: a verification that is not warranted carries the object with a status of uncovered and the reasons why.

An account on a paid Pro or Scale plan may turn certificates off for the verifications it submits from then on. Those verifications are not warranted, and their coverage object gives the reason account. A verification that already carries a certificate keeps it.

Covered Verification (the “Warranty”)

What is warranted. Where a verification meets the eligibility criteria published at lenz.io/warranty and is issued on a paid Pro or Scale plan, Lenz warrants to the holder of the Lenz account under which the certificate was issued, together with any entity on whose behalf that account is used (the “Customer”), that the verdict stated on the corresponding certificate is correct in respect of the exact statement reproduced on that certificate. The warnings listed on the certificate qualify that warranty: Lenz warrants the statement as so qualified, and a finding that turns on a matter a warning identified does not contradict the verdict. The Customer is not required to reproduce the warnings. The Warranty does not extend to the explanatory summary, the sources, the confidence score, or to any statement other than the one reproduced on the certificate.

Eligibility. A verification is warranted only if the certificate has been issued and its qualified timestamp has been applied. Verdicts other than “True” and “False” are not warranted. Lenz publishes the full eligibility criteria and may change them prospectively; a change does not affect a certificate already issued.

When Lenz pays. Lenz will pay the Customer where all of the following are satisfied:

• the Customer published the warranted statement, or delivered it to a person outside the Customer’s own organisation, in each case in the form reproduced on the certificate or in a form that asserts no more than it, and after the qualified timestamp on that certificate;
• a court or regulator of competent jurisdiction has made a finding on that statement which contradicts the warranted verdict, and either the time for appealing that finding has expired without an appeal being brought or all appeals have been determined;
• that finding forms part of the basis on which damages were awarded against the Customer in the same proceeding;
• at the time of the verification the Customer neither knew nor ought reasonably to have known of circumstances likely to give rise to such a proceeding;
• the proceeding was commenced within twelve (12) months of the publication or delivery referred to above; and
• the Customer notified Lenz in writing, by email to support@lenz.io quoting the certificate ID, within thirty (30) days of being served in that proceeding.

Amount. The amount payable is the lesser of the damages awarded against the Customer in that proceeding and the per-certificate cap. The caps are: €10,000 per certificate, €500,000 across all Lenz certificates in any rolling 12 months. Payments count against the aggregate on the date they are made, in the order Lenz decides the claims, and a claim that would exceed it is paid up to what remains. Lenz will make one payment per certificate and one payment per proceeding, irrespective of the number of certificates a proceeding concerns.

What is not covered. The Warranty does not cover: defence or legal costs; consequential, indirect or economic loss beyond the damages awarded against the Customer in that proceeding; fines or regulatory penalties; amounts payable under a settlement, compromise or consent order; any matter where the Customer acted fraudulently or misrepresented any fact to Lenz; and any publication or delivery made before the qualified timestamp on the certificate.

Withdrawal. Lenz may withdraw a verdict at any time by written notice to each Customer holding a certificate for it. The Warranty does not apply to any publication or delivery made after that notice. Publications and deliveries made before the notice are unaffected. Withdrawal does not invalidate the certificate as a record.

Precedence. This clause applies notwithstanding the Accuracy Disclaimer, the Disclaimer of Warranties and the Limitation of Liability in these Terms, and the Indemnification and Limitation of Liability sections of the API Terms of Service, each of which is subject to it. An amount payable under this clause is limited only by the caps stated in it: the exclusion of indirect and consequential loss elsewhere in these Terms does not apply to it, and the fact that the loss arose from reliance on a verification is not a ground for refusing it.

Nature of this clause. The Warranty is a contractual undertaking given by Lenz in respect of its own services. It is not a contract of insurance, and Lenz does not act as an insurer or as an insurance intermediary.

Survival. The Warranty continues in respect of certificates already issued notwithstanding the expiry or termination of the Customer’s subscription. It ends if the Customer deletes their account, except for a proceeding already notified to Lenz.

Version. Each certificate records the version of this clause under which it was issued. That version governs it, and remains available at lenz.io/terms/<version> indefinitely.

Contact Us

If you have questions about these Terms, please reach out through our contact page.