Privacy Policy

This Privacy Policy describes how Theory of π ("we", "us", "our") collects, uses, and protects information when you use our service at theoryofpi.com (the "Service"). Theory of π is operated as a Canadian business. Contact: [email protected].

Information you provide: account information (name, email address, hashed password), payment information (handled entirely by Stripe — we do not store card details), and communications (AI tutor messages, support requests, feedback).

Information collected automatically: usage data (lessons viewed, questions attempted, mastery progress), technical data (IP address, browser type, device), and cookies for authentication and session management.

From third parties: name, email, and profile picture from authentication providers (Clerk, Google OAuth); subscription status and payment confirmation from Stripe.

We use your information to: provide and improve the Service; process payments; authenticate you and secure your account; personalize your learning experience; provide AI tutor responses; send transactional emails; detect and prevent fraud; and comply with legal obligations.

We share information with the following providers solely to operate the Service:

Your AI tutor messages are sent to OpenAI through its API for processing. By default, OpenAI does not use API inputs or outputs to train its models.

Account data is retained while your account is active and deleted within 30 days of closure. Payment records are retained for 7 years for tax/legal purposes. AI tutor conversations are retained for up to 90 days then deleted. Server logs are retained for up to 90 days.

You may request access to, correction of, deletion of, or portability of your personal data. You may also withdraw consent for marketing communications or object to certain processing. To exercise these rights, email [email protected]. We will respond within 30 days.

If you are a resident of Quebec, you have additional rights under Quebec's Act respecting the protection of personal information in the private sector ("Law 25"), including the right to be informed of automated decision-making and to access your data in portable form. Contact: [email protected].

If you are in the EEA, UK, or Switzerland, you have rights under GDPR including those listed in Section 6, plus the right to lodge a complaint with your national data protection authority. Our legal bases for processing are: contract (to provide the Service), legitimate interest (to improve the Service and prevent fraud), consent (for marketing), and legal obligation.

If you are a California resident, you have rights under the California Consumer Privacy Act. We do not sell personal information.

Theory of π is for users aged 13 and older. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child under 13 has provided information to us, contact [email protected] and we will delete it promptly.

Your information may be transferred to and stored on servers outside your country, including in the United States where our service providers operate. We rely on standard contractual clauses and similar mechanisms to ensure adequate protection during transfers.

We use encryption in transit (HTTPS/TLS), encryption at rest, access controls, and regular security reviews of providers. However, no system is 100% secure. You are responsible for keeping your account credentials confidential.

We use cookies for authentication (keeping you signed in) and preferences (remembering your settings). You can disable cookies in your browser settings, but this may prevent the Service from functioning correctly.

Material changes will be communicated via email or notice in the Service at least 30 days before taking effect.

Theory of π
[email protected]
Mailing address provided upon request.