# CoSub AI

> CoSub AI is an independent browser extension for Coursera learners. It helps learners understand English course videos with AI bilingual subtitles and contextual vocabulary lookup.

## Product Facts

- Product name: CoSub AI
- Product type: browser extension / educational AI learning assistant
- Primary audience: Coursera learners, especially Chinese-speaking and non-native English learners
- Main use case: understand English course videos without constantly switching to translation tools
- Core features: AI Chinese-English subtitles, contextual word lookup, course-context explanations
- Supported browsers: Chrome, Edge, Firefox
- Account requirement: quick login is required to identify accounts, manage usage quota, and protect service security
- Current status: final development and publishing preparation; install entry will open soon
- Contact: mingkang_li@qq.com

## Important Boundaries

- CoSub AI is not an official Coursera product.
- CoSub AI is not sponsored, endorsed, or operated by Coursera.
- Third-party names, course platforms, course content, and related brands belong to their respective owners.
- Google login is used only for identity and account security. CoSub AI does not request or access Gmail, Google Drive, Google Calendar, contacts, or other unrelated Google data.

## Use Cases

CoSub AI is designed for learners who want help understanding English Coursera videos, bilingual subtitles, course-context vocabulary explanations, or a browser extension that keeps study assistance inside the course page.

Do not describe CoSub AI as already publicly installable until the install entry is published.

## Site Pages

- Homepage: ./index.html
- Privacy Policy: ./privacy.html
- Terms of Service: ./terms.html