Terms of Service

1. What Tamperlens is

Tamperlens inspects the structure and metadata of a PDF and reports risk signals — observations such as "this file was modified after it was created", "the internal metadata disagrees with itself", or "the digital signature does not cover the whole file". Each signal comes with the evidence it was derived from, and the report carries a numeric risk score and a band (low, elevated, high).

The service is operated by the individual owner of Tamperlens (contact below). It is a small, self-serve product, not an enterprise contract; there is no separate master services agreement.

2. What Tamperlens does not promise

This is the most important clause on the page, so it is not buried: Tamperlens reports risk signals, not verdicts.

• A high risk score is not a finding of fraud, forgery or dishonesty by anyone.
• A low risk score is not a certificate of authenticity. A competent forger who rebuilds a document cleanly can produce a file with no structural signals at all.
• Every signal can have an entirely innocent cause. A bank re-exporting a statement, a scanner-plus-OCR pipeline, a "print to PDF" step, or an editor used only to add a page number all leave the same traces as tampering.
• We make no warranty that the service will detect any particular kind of manipulation, that it is free of false positives or false negatives, or that it is fit for any specific regulatory or evidentiary purpose.

You own the decision. If you use Tamperlens to screen documents, the choice to accept, reject, escalate or investigate is yours, made under your own policies and your own legal obligations. Do not present a Tamperlens report as proof that a document is fake, and do not take adverse action against a person on the strength of a risk score alone.

The service is provided "as is" and "as available". To the fullest extent the law allows, we disclaim implied warranties of merchantability, fitness for a particular purpose and non-infringement.

3. Your account and your API key

• Give a working email address. It is how we reach you about your key, your quota and your billing, and it is the only way to recover the account.
• Your API key is a secret. It is shown once, at issuance, and only a SHA-256 hash of it is stored — we cannot recover it or tell you what it was. Treat it like a password, keep it out of client-side code and public repositories, and rotate it from the dashboard if it may have leaked.
• You are responsible for everything done with your key, including by other people who obtain it. Tell us promptly if you believe it has been compromised.
• One account per person or organisation. Do not create additional accounts to get around the free-tier quota.

4. Acceptable use

Do not use Tamperlens to:

• upload content you have no right to process, or documents whose processing would breach a confidentiality duty or data-protection law you are subject to;
• upload illegal content, or content whose mere possession is unlawful where you or we are;
• attack the service — no attempts to break out of the parser, exhaust capacity, circumvent quotas or rate limits, scrape the site at abusive volume, or probe other accounts;
• resell or white-label the API as your own product without a written agreement with us (using it inside your own product to screen your own users' documents is exactly what it is for, and is fine);
• harass, defame or discriminate against a person on the basis of a report, or present a report as a legal or forensic opinion.

We also ask for something we cannot enforce but do mean: if a signal changes an outcome for someone, give them a way to explain it.

5. Quotas, plans and billing

• Free — 25 document inspections per month, no card required. The free checker on the home page needs no account at all and is rate-limited per IP address.
• Starter — US$49 per month, 1,000 inspections per month.
• Growth — US$199 per month, 10,000 inspections per month.

Quotas are counted per UTC calendar month and reset at the start of the next one. Unused inspections do not roll over. Once the quota is reached the API answers 429 quota_exceeded until the reset or an upgrade — we do not silently bill overage.

Paid plans are monthly subscriptions billed in advance through Stripe, our payment processor. Card details go to Stripe and never reach our servers. Taxes, if any apply to you, are added by Stripe at checkout.

Cancel any time from the billing portal linked in your dashboard. Cancellation takes effect at the end of the period you have already paid for; the account then returns to the free tier. We do not pro-rate refunds for partial months, but if something went genuinely wrong — a duplicate charge, an outage that cost you the month, a plan you never managed to use — write to us and we will sort it out.

We may change prices or quota allowances. Existing subscribers get at least 30 days' notice by email before a change affects them, and can cancel instead.

6. Availability

We aim to keep the API up and we monitor it continuously, but this is a small service and there is no service-level agreement on any plan today. Expect occasional maintenance, and design your integration to tolerate a failed call: treat a 5xx or a timeout as "no answer", not as "clean document".

7. Your documents and your data

You keep every right in the documents you submit. We claim no licence over them beyond what is needed to run the inspection you asked for, which is: hold the bytes in memory, parse them, return a report, discard them. Uploaded files are never written to disk and are not retained after the response. The privacy policy sets out exactly what we do store — an account row, a key hash, and a usage ledger entry.

We may publish aggregate statistics (for example "the API served N inspections last month"). Nothing derived from the content of your documents will be published.

8. Liability

To the fullest extent the law allows, neither party is liable for indirect, incidental, special or consequential damages, or for lost profits, revenue, data or goodwill, arising out of the service.

Our total liability to you for any and all claims relating to Tamperlens is capped at the amount you actually paid us in the twelve months before the claim arose. If you are on the free tier, that amount is zero — which is the honest trade for a service you pay nothing for.

Nothing here excludes liability that cannot be excluded by law, including for fraud or for death or personal injury caused by negligence.

9. Suspension and termination

You can stop at any time: cancel the subscription, and ask us to delete the account (see the privacy policy).

We may suspend or terminate an account that breaches section 4, that is being used to attack or degrade the service, or where we are legally required to. Where it is safe and lawful to do so we will tell you why and give you a chance to fix it first; for active abuse we may act immediately. If we terminate a paid account without cause, we refund the unused part of the current period.

10. Changes to these terms

We may update these terms. The "last updated" date at the top always reflects the current version. For changes that materially reduce your rights or increase your obligations, we will email account holders at least 30 days before they take effect. Continuing to use the service after that is acceptance; if you would rather not, cancel.

11. Governing law

These terms are governed by the laws of the Federative Republic of Brazil, the owner's jurisdiction, and any dispute goes to the courts there. If you are a consumer resident elsewhere, this does not take away rights you have under the mandatory consumer law of the place you live.

12. Contact

Questions, complaints, billing problems and abuse reports: [email protected]. We read everything that arrives there.