Terms of Service

Last updated October 5, 2026

Terms version 2026-10. When this version changes, the app asks you to agree again.

1. Agreement

These terms are an agreement between you and the maker of Tentaku (“Tentaku”, “we”, “us”). You accept them when you check the box or click to agree in the app or at checkout, or by installing or using Tentaku or this website. If you don’t agree, don’t use Tentaku. Our Privacy Policy, Acceptable use policy, Recording & consent notice and Refund policy are part of these terms.

2. Who can use Tentaku

You must be at least 18 years old, or the age of majority where you live if that’s higher. Tentaku connects to AI services whose own terms require users to be adults. You may not use Tentaku where the law or your school forbids it.

3. Your license

We give you a personal, non-exclusive, non-transferable, revocable license to use Tentaku for your own study. A Pro key activates on up to 2 computers at a time; release a seat with Settings → License → Apply with an empty box. We own Tentaku and its software, design, mascot and brand; you get no rights in them beyond this license.

4. Free, trial and paid plans

Free covers one class with every feature and 3 recordings per rolling 7 days, live or imported. If you have more than one class — for example from the trial — you choose one Free class that keeps every feature. Your other classes become read-only: you can open, search and read them, review their flashcards, edit what’s already there, export them, move documents out or delete them, but you can’t record, import a recording, add documents or run new AI builds there until you go Pro or make one of them your Free class. Your first choice can be changed right away; after that you can switch once every 30 days. Nothing is ever deleted. Creating another class needs Pro.
14-day Pro trial. Granted automatically on first launch, once per computer. No card, no automatic charge. When it ends you drop to Free and keep every file. Each computer gets one trial.
Pro — Semester is a single payment for Pro for 150 days from purchase. It never renews and never charges you again. If the app is offline when a Semester key reaches its end date, Pro may continue for up to 3 more days.
License checks. The app checks a Pro key at every launch while online and every 24 hours while it’s open. Offline, Pro keeps working for up to 7 days or 20 launches, whichever comes first; after that Pro pauses (you’re on Free) until the next successful check, when it comes back by itself. Keys are checked by plan, never by the amount paid.
Pro — Year and Founding student are yearly subscriptions — see section 5.
When a key is refunded, disabled, reaches its end date or is cleared on another computer, Pro ends at the app’s next check — never in the middle of a recording; it switches when the recording stops — and Settings → License says why. You drop to Free and keep every file.
Prices are in US dollars; tax is added at checkout where required. We may change prices for future purchases. A price change never applies to a period you’ve already paid for, and we’ll tell you before it applies to a renewal. The Founding student price of $39 a year holds for as long as your subscription stays active without a lapse.

5. Automatic renewal and cancellation

Pro — Year ($49/yr) and Founding student ($39/yr after a $29 first year) renew automatically every year, at the then-current price shown to you, charged to your payment method on file, until you cancel. You can cancel anytime online in the Lemon Squeezy customer portal (linked on the pricing page and in every receipt and renewal email), or by emailing help@tentaku.app. Cancellation takes effect at the end of the year you’ve paid for; Pro stays on until then, after which Tentaku returns to Free and you keep every file. After you subscribe we email you these terms and how to cancel, and we email you a notice 15 to 45 days before each yearly renewal.

6. Payments

Lemon Squeezy is the merchant of record for every purchase: it processes the payment, collects any tax, and issues receipts and refunds under its own terms. We never see your full card details. Refunds follow our refund policy. If you dispute a charge with your bank instead of contacting us, we may suspend the related key while the dispute is open.

Founder promo codes and student discount codes are promotional, time-limited and non-transferable, may be limited in how many times they can be used, have no cash value, and can’t be combined unless we say so. We may revoke a code that has been leaked, resold or shared publicly, used more times than it allows, or obtained by misrepresenting eligibility. Revoking a code ends only the Pro that code granted — paid keys and your files are never affected.

8. Recording is your responsibility

Tentaku records only when you press ● Record. You alone decide what to record, and you are solely responsible for getting any permission or consent that your school, your instructors, the people being recorded or the law requires, and for how you use and share recordings and transcripts. We don’t know what you record and can’t check whether you have consent. See Recording & consent.

9. AI output and your studies

Notes, summaries, answers, flashcards, practice tests, plans and visuals are generated by AI models and can be incomplete, outdated or wrong. Check anything important against your course materials and instructors.
Tentaku is a study aid. It doesn’t replace attending class, and it isn’t educational, medical, legal, financial or professional advice. We make no promise about grades or exam results.
You’re responsible for following your school’s academic-integrity rules, including any limits on using AI tools for coursework or assessments.

10. Your AI account and other services

Tentaku connects to services you choose — an AI provider (Anthropic, OpenAI, Google, OpenRouter or a local model), your school’s calendar feed, public course websites, Lemon Squeezy, AI apps you connect Tentaku to (such as the Claude desktop app), and AI services you hand notes off to yourself. Those services are run by others under their own terms and privacy policies; we don’t control them and aren’t responsible for their availability, accuracy, charges or data handling. You’re responsible for your AI provider account, its costs and its terms. Tentaku doesn’t sell AI access, and you may not use Tentaku to resell AI access or keys.

11. Your content and backups

Your recordings, notes and files are yours. They live on your computer; we claim no rights to them and don’t receive them. Because your data stays with you, keeping backups is your responsibility — we can’t recover anything you lose.

12. Rules

Don’t copy, modify, resell or redistribute the app, or interfere with how it’s licensed.
Use the free plan, the trial and student discounts as described.
Follow the Acceptable use policy.

13. Beta versions and disclaimer of warranties

Builds labelled “Beta” — including the current Windows version and, while it carries the label, the Apple silicon Mac build — are pre-release software that may contain bugs and may change without notice.

TO THE FULLEST EXTENT PERMITTED BY LAW, TENTAKU AND THIS WEBSITE ARE PROVIDED “AS IS” AND “AS AVAILABLE”, WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, NON-INFRINGEMENT AND ACCURACY. WE DON’T WARRANT THAT TENTAKU WILL BE UNINTERRUPTED, ERROR-FREE OR SECURE, THAT IT WILL CAPTURE OR TRANSCRIBE EVERY RECORDING CORRECTLY, OR THAT AI OUTPUT WILL BE ACCURATE.

14. Limitation of liability

TO THE FULLEST EXTENT PERMITTED BY LAW: (A) WE WON’T BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY OR PUNITIVE DAMAGES, OR FOR LOST DATA, LOST PROFITS, OR ACADEMIC OUTCOMES SUCH AS GRADES, EVEN IF WE WERE TOLD THEY WERE POSSIBLE; AND (B) OUR TOTAL LIABILITY FOR ALL CLAIMS RELATING TO TENTAKU OR THESE TERMS IS LIMITED TO THE GREATER OF THE AMOUNT YOU PAID US IN THE 12 MONTHS BEFORE THE CLAIM AROSE OR US $50.

Some places don’t allow these exclusions or limits, so some of them may not apply to you; in that case they apply to the fullest extent the law allows.

15. Indemnity

You agree to defend, indemnify and hold us harmless from claims, losses and costs (including reasonable attorneys’ fees) arising from your recordings, your use or sharing of recordings, transcripts or class packs, your breach of these terms, or your violation of any law or anyone else’s rights.

16. Disputes: informal resolution, arbitration and class-action waiver

Please read this section carefully; it affects how disputes are resolved.

Talk to us first. Before filing any claim, email help@tentaku.app with a description of the problem. We’ll try in good faith to resolve it within 60 days.
Arbitration. If we can’t resolve it, you and we agree that any dispute relating to Tentaku or these terms will be resolved by final, binding arbitration on an individual basis under the Consumer Arbitration Rules of the American Arbitration Association, rather than in court. The Federal Arbitration Act governs this section.
Small claims. Either of us may instead bring an individual claim in small-claims court if it qualifies.
No class actions. Claims may be brought only individually, not as a plaintiff or class member in any class, collective or representative proceeding, and the arbitrator may not combine claims of more than one person.
Opt out. You may opt out of this arbitration agreement by emailing help@tentaku.app with the subject “Arbitration opt-out” within 30 days of first accepting these terms.
If the class-action waiver is found unenforceable for a claim, that claim must proceed in court, not in arbitration.

17. Governing law and venue

These terms are governed by the laws of the State of New York and applicable U.S. federal law, without regard to conflict-of-law rules. Any claim not subject to arbitration will be brought in the state or federal courts located in New York, and you and we consent to their jurisdiction. This doesn’t take away mandatory consumer protections of the place where you live.

18. Termination

You can stop using Tentaku anytime. We may suspend or end your license if you break these terms, with a refund of any unused prepaid time where the law requires it. Sections 8–17 and 19 survive.

19. Changes and general terms

We may update these terms; we’ll post the new version here with a new date, and material changes apply from your next purchase, renewal or acceptance in the app. Other product, school and company names belong to their owners; Tentaku isn’t affiliated with or endorsed by them. These terms are the entire agreement between you and us about Tentaku. If a provision is unenforceable, the rest stays in effect. Our not enforcing a provision isn’t a waiver. You may not transfer these terms; we may transfer them to a successor. We aren’t liable for delays caused by events beyond our reasonable control.

20. Support payments

Payments made on the Support Tentaku page are voluntary payments to us, a for-profit business, used for running and improving Tentaku. They aren’t charitable gifts, aren’t tax-deductible, and don’t buy any product, service, perk, Pro time or license right.
Support payments are processed by Stripe under its own terms. We refund any support payment in full if you ask within 14 days; after that they aren’t refundable except where the law requires.
If a checkout lets you pay more than a plan’s listed price, the extra is optional, buys nothing more, and is refunded together with the order under our refund policy.

21. Who we are and contact

Tentaku is made and run by Robert Smalls, a sole proprietor in New York. Email: help@tentaku.app.