BiliMind Privacy Policy

Last updated: June 3, 2026

BiliMind ("we", "our", or "the extension") is a Chrome browser extension that generates mind maps from Bilibili video subtitles. This policy explains what data we collect, how we use it, and your rights.

1. Data We Collect

Google account information – when you sign in with Google, we receive your email address, display name, and profile picture URL via Google OAuth 2.0. We store these in our database to identify your account.
Video subtitles – subtitles are fetched directly from Bilibili's public API inside your browser and sent to our server solely to generate a mind map. We store the subtitle text alongside the resulting mind map so you can reload it on future visits.
Mind map content – the generated Markdown mind map is stored on our server linked to your user ID and the Bilibili video ID.
Token usage – we record how many AI tokens each mind-map generation consumed (prompt tokens, completion tokens, generation time) for your personal usage statistics.
SiliconFlow API Key – your API Key is stored only in your browser (chrome.storage.local) and is never sent to or stored on our servers. It is transmitted to SiliconFlow's API directly per request and is not logged.

2. Data We Do NOT Collect

Browsing history or any activity outside of bilibili.com/video/* pages.
Passwords or payment information.
Any data from pages where the extension is not active.

3. How We Use Your Data

To authenticate you and maintain your session.
To generate, cache, and display mind maps for videos you visit.
To show you your personal token usage statistics.

We do not sell, rent, or share your personal data with third parties for advertising or marketing purposes.

4. Third-Party Services

Google OAuth 2.0 – used for sign-in. Governed by Google's Privacy Policy.
SiliconFlow API – used to run the AI model that generates mind maps. Your subtitle text is sent to SiliconFlow per your request using your own API Key. Governed by SiliconFlow's Privacy Policy.
Bilibili API – subtitle data is fetched from Bilibili's public API. Governed by Bilibili's Privacy Policy.
Vercel – our backend is hosted on Vercel. Request logs may be retained per Vercel's standard logging policy.

5. Data Retention

Your account data and mind maps are retained as long as your account exists. You may delete your account and all associated data at any time by contacting us. After deletion, data is permanently removed within 30 days.

6. Security

All data is transmitted over HTTPS. Your Google credentials are never stored — only the verified user identity (email, name, avatar) returned by Google's servers is saved. Your SiliconFlow API Key never leaves your browser.

7. Children's Privacy

BiliMind is not directed at children under 13. We do not knowingly collect personal information from children.

8. Changes to This Policy

We may update this policy from time to time. The "Last updated" date at the top will reflect any changes. Continued use of the extension after changes constitutes acceptance of the updated policy.

9. Contact

If you have questions or requests regarding your data, please contact us at: xman4vip@gmail.com