Privacy Policy

Last updated: 2026-06.

This policy explains what data Twinbook collects, how we use and protect it, and the controls you have. It is written to match how the system actually behaves; for the technical detail, see our Trust & Security center.

What we collect

  • Account data — your email, profile, and account/tier status. Passwords are managed by our authentication provider, never stored by Twinbook.
  • Content you upload — books, slides, images, notes, problem sets, PDFs, and video references you add, plus the structure we extract from them.
  • Generated study material — summaries, questions, flashcards, and notebooks built from your content.
  • Learning memory — the concepts you've encountered, mastery estimates, and study sessions, scoped privately to you.
  • Usage data — authentication events, API activity, and AI-usage accounting used to run the service securely.
  • Billing records — purchase and subscription history (card data is handled by our payment processor; we don't store raw card numbers).

How we use it

We process your content to provide the service — extracting structure, generating study materials, answering questions, and building your learning memory — and for nothing else. We do not sell your data, share it with advertisers, or use it to build products for third parties.

We do not train AI on your content

We do not train or fine-tune models on user-uploaded content, learning data, private notes, conversations, learning memory, or institutional education records. When we use AI providers, we send only the content needed for the task, under terms where your content is not used to train their models. See Trust & Security §2.

How it's protected

Data is encrypted in transit and at rest, scoped per user and workspace, and reachable only through authenticated, access-checked requests. Our Subprocessors page lists the third parties that help us operate.

Your choices and control

  • Export all of your notes — including the drawings and images inside them — at any time, from within the app. Your work is portable; there's no lock-in.
  • Delete your content, a space, or your account from within the app; this removes the associated data from our databases, document store, and file storage.
  • Request a copy or deletion of your data by emailing us.
  • See Data retention & deletion for the full schedule of what's kept and for how long.

Children and education records

When an institution adopts Twinbook for coursework, education records may be involved; we are prepared to operate under FERPA-aligned terms. See FERPA posture.

Changes & contact

We'll update this page as the product evolves and note the date above. Questions about privacy? Contact us.

This is a plain-language summary of our practices, not legal advice. We're finalizing our full legal privacy terms; reach out if you need them for a procurement review.