Terms of Service

Last updated: May 28, 2026

1. Acceptance of Terms

By accessing or using PhysTrail ("the Service"), you agree to be bound by these Terms of Service. If you do not agree, please do not use the Service.

2. Description of Service

PhysTrail provides educational physics content (general relativity, quantum mechanics, quantum field theory, and quantum gravity) in multiple languages. Some content is available for free; additional content requires a one-time purchase.

3. Account Registration

• You must provide a valid email address to create an account.
• You are responsible for maintaining the confidentiality of your account credentials.
• One account per person. Account sharing is prohibited.

4. Purchases and Payments

• Purchases are one-time payments processed through Stripe.
• Each purchase grants lifetime access to the specified content in all available languages.
• Prices are displayed in USD. Local currency equivalents may vary.

5. Refund Policy

Since approximately one-third of each content is available for free preview before purchase, refunds are generally not provided. If you experience a technical issue preventing access to purchased content, please contact us within 14 days of purchase.

6. Permitted Use

• Purchased content is for your personal, non-commercial use only.
• You may access the content from up to 2 devices simultaneously.
• You may not redistribute, reproduce, or publicly display the content.
• You may not use automated tools to scrape or bulk-download content.

7. Intellectual Property

All content, including text, equations, figures, and code, is the intellectual property of the Service operator. Purchase grants a personal license to access, not ownership of the content.

8. AI-Assisted Content Disclosure

Content on PhysTrail is created with the assistance of AI (Claude by Anthropic). The author reviews, edits, and verifies all content. If you find errors, please report them — verified corrections may qualify for a cashback reward during the beta period.

9. Limitation of Liability

The Service is provided "as is." We do not guarantee that the content is free of errors. The Service shall not be liable for any damages arising from use of the content, including but not limited to academic or professional decisions made based on the content.

10. Termination

We reserve the right to suspend or terminate accounts that violate these terms, particularly those engaged in content redistribution or automated scraping.

11. Changes to Terms

We may update these terms from time to time. Continued use of the Service after changes constitutes acceptance of the new terms.

12. Governing Law and Jurisdiction

These Terms shall be governed by the laws of Japan. Any disputes arising in connection with the Service shall be subject to the exclusive jurisdiction of the Tokyo District Court as the court of first instance.

13. Contact

For questions about these terms, please contact: support@phystrail.com