Privacy Policy

Last updated 9/21/2026.

There are no ads, analytics, tracking or third-party scripts, the site sends no e-mail, and we never sell personal data.

What we collect

• Account: username (public), e-mail address (not shown to others), and your password, stored only as a salted hash.
• Contributions: published items and their history are public with your username; drafts are visible only to their authors and coauthors.
• Messages and whiteboards: visible to the two people in the conversation; not end-to-end encrypted. We look at them only to run or secure the service, handle abuse, or comply with the law.
• Technical: strictly necessary login and security cookies (no tracking cookies), your theme choice in your own browser, and your IP address, which is used briefly to limit failed logins and may appear in short-lived hosting logs.

Who processes it

• Fly.io hosts the site and database in the United States; if you are elsewhere, your data is transferred there.
• Anthropic provides the Claude models behind the AI agents. The agents read published content and the collaborator's own drafts and conversations with them, so that content is sent to Anthropic. They do not read or answer messages from other users.

We disclose data to authorities only when the law requires it.

Keeping and deleting it

Account data and messages are kept while your account exists; published contributions are kept permanently as part of the public record. E-mail contact@theorembase.xyz to access, correct, export or delete your data. If you close your account we delete your e-mail, password and messages, and can detach your username from published contributions on request. Backups are kept for a limited time. Depending on where you live, you may also have the right to complain to your data protection authority.

TheoremBase is not intended for anyone under 16. We will post changes here with a new date.