Kematra

Subscription Terms

How paying for Kematra works: what you get, when you are charged, and how to stop.

In effect from 2026-08-01.

Kematra has a free plan and a paid plan. These terms cover the paid plan and sit alongside the Terms of Use.

The free plan is a complete way to study, not a trial. The planning engine, method selection, the stages, the memory model, adaptation and the calendar are all included and stay included. Paying adds convenience and personalisation on top — it does not unlock the method.

What the paid plan adds

The free plan gives you complete method templates rather than tailored ones, resource suggestions from what has already been found and stored rather than a fresh search, stored curriculum maps where one exists for your course, and pasting instead of uploading.

Price and tax

The plans are US$11.99 per month or US$119.00 per year. Prices are shown before tax; any GST or sales tax is calculated and added by Stripe at checkout, based on where you are.

The yearly plan costs roughly two months less than paying monthly for a year. The exact prices are always the ones shown on the upgrade page and at checkout — those come directly from Stripe, so what you are quoted is what you are charged.

Billing and renewal

You are charged when you subscribe, and again at the start of each period until you cancel. The renewal date is shown on your Billing page.

Payment is handled entirely by Stripe. Your card details go from your browser to Stripe and never reach Kematra — we cannot see them, store them, or show them back to you. Changing your card, viewing invoices, switching plan and cancelling all happen on Stripe's pages, behind their own identity checks.

If a payment does not go through

Nothing is taken away immediately. Your account keeps everything it had while your bank is asked again, and the Billing page tells you what happened and how to fix it.

Your card is retried up to 8 times over about 2 weeks. You keep the paid features for the whole of that time — the retries are the grace period, and there is no separate one.

If none of those attempts succeeds, the subscription is marked unpaid and the paid extras stop. Nothing is deleted: your subjects, topics, plan, results and history all stay exactly as they are, and the account continues on the free plan. The unpaid invoice is written off rather than pursued — we will not send it to a debt collector.

The subscription is not cancelled at that point, only unpaid, so updating your card on the Billing page restores the paid features without any loss and without having to subscribe again.

Changing or cancelling

You can cancel at any time from the Billing page. Cancelling stops the next charge; it does not cut off the period you have already paid for. You keep the paid features until that period ends, and then the account continues on the free plan.

If you are within 14 days of subscribing or renewing, you can have a full refund instead — see the Refund Policy.

Switching between monthly and yearly takes effect immediately. Stripe works out the difference for the time you have already paid for and applies it to the change — so moving to yearly part-way through a month credits what is left of that month, and moving to monthly does the same in reverse.

If you delete your account while you still have paid time left, that time is honoured — see the Privacy Policy on staged deletion.

Price changes

If we change the price, we will email you at least 30 days before it applies to you, and it will not apply until your next renewal. If you do not want to pay the new price, cancel before then and you will not be charged it.

Fair use

The paid plan has caps — on uploads, on searches, and on AI-generated content per day — set high enough that ordinary heavy studying never meets them. They exist so one account cannot exhaust a shared resource. If you hit one, Kematra says so plainly and the deterministic version of the feature keeps working.