Terms of Service
Last updated: August 27, 2026
These Terms govern your use of Zidna (the “Service”), which turns your questions into animated, narrated math lessons played in your browser, with an AI tutor you can ask about them. By creating an account or using the Service, you agree to these Terms.
The Service
Zidna generates lessons and tutor answers from the questions you provide, using third-party AI and speech services. Output is produced automatically and may contain errors; you are responsible for checking anything you rely on or pass on to others.
Accounts
You must provide accurate information and keep your credentials secure. You are responsible for activity under your account. You must be old enough to form a binding contract in your jurisdiction.
Subscriptions and billing
Zidna is a paid subscription offered in three tiers — Starter ($10/month, 45 lessons), Plus ($20/month, 100 lessons), Max ($50/month, 300 lessons)— billed in advance through our payment processor, Stripe. A tier's lessons are an allowance of usage measured in lessons: starting a lesson uses about one, and adding scenes, generating or expanding concept maps and asking the tutor use part of one. No more than 40% of a month's allowance can be used in any one week. Unused allowance does not carry over. New accounts may use 5lessons' worth free before subscribing. Your subscription renews automatically until cancelled. You can cancel anytime from the billing page; cancellation takes effect at the end of the current billing period. See our Refund Policy for details on refunds.
Acceptable use
Do not use the Service to generate unlawful, infringing, or abusive content, to attempt to overload or reverse-engineer the system, or to resell access without permission. We may suspend accounts that violate these Terms or create excessive load.
Your content
You retain ownership of the questions you submit and the lessons they produce. You grant us a limited license to process them solely to operate the Service (for example, to write a lesson, narrate it, and store your history so you can return to it).
Disclaimers and liability
The Service is provided “as is,” without warranties of any kind. To the maximum extent permitted by law, our aggregate liability is limited to the amount you paid in the three months before the claim.
Changes and contact
We may update these Terms; material changes will be posted here. Questions? Contact us at saqr@zidna.co.