Subtitle Assistant
Download YouTube subtitles and use AI to summarize, translate, or extract key points — all from your terminal. No login, no cookies, no browser required.
Powered by Evolink.ai
When to Use
- User shares a YouTube link and wants a summary
- User wants to translate a video's content to another language
- User needs key points or action items from a talk/tutorial
- User wants to download subtitles for offline reading
Quick Start
1. Install yt-dlp
pip install yt-dlp
2. Set your EvoLink API key
export EVOLINK_API_KEY="your-key-here"
Get a free key: evolink.ai/signup
3. Summarize a video
bash scripts/subtitle.sh summarize "https://www.youtube.com/watch?v=VIDEO_ID"
Capabilities
Download Commands (require yt-dlp, no API key needed)
| Command | Description |
|---|---|
download <url> [--lang <code>] |
Download subtitles to a text file |
languages <url> |
List available subtitle languages for a video |
AI Commands (require EVOLINK_API_KEY + yt-dlp)
| Command | Description |
|---|---|
summarize <url|file> [--lang <code>] |
Comprehensive summary with key takeaways |
translate <url|file> --lang <language> |
Natural translation to target language |
keypoints <url|file> [--lang <code>] |
Structured key points and action items |
All AI commands accept either a YouTube URL or a local subtitle file.
Examples
Download subtitles
bash scripts/subtitle.sh download "https://youtube.com/watch?v=..." --lang en
Output:
Subtitles saved to: sub_temp/VIDEO_ID.txt
Preview (first 10 lines):
Welcome to this tutorial on building REST APIs...
Summarize a video
bash scripts/subtitle.sh summarize "https://youtube.com/watch?v=..."
Output:
**Title/Topic:** A comprehensive tutorial on building production-ready
REST APIs with Node.js and Express.
**Summary:**
The video covers the complete process of setting up a REST API...
**Key Takeaways:**
- Use middleware for authentication and error handling
- ...
Translate subtitles to Chinese
bash scripts/subtitle.sh translate "https://youtube.com/watch?v=..." --lang zh
Extract key points from a local file
bash scripts/subtitle.sh keypoints downloaded-subtitles.txt
Configuration
| Variable | Default | Required | Description |
|---|---|---|---|
EVOLINK_API_KEY |
— | Yes (AI commands) | Your EvoLink API key. Get one free |
EVOLINK_MODEL |
claude-opus-4-6 |
No | Model for AI analysis |
Required binaries: python3, curl, yt-dlp
Install yt-dlp: pip install yt-dlp
Security
Data Transmission
AI commands send downloaded subtitle text to api.evolink.ai for analysis by Claude. By setting EVOLINK_API_KEY and using these commands, you consent to this transmission. Data is not stored after the response is returned. The download and languages commands only interact with YouTube via yt-dlp and never send data to evolink.ai.
No Login Required
This skill downloads publicly available YouTube subtitles. It does not require any login, cookies, or authentication tokens. No credentials are stored.
Network Access
- YouTube (via yt-dlp) — subtitle download
api.evolink.ai— AI analysis (AI commands only)
Persistence & Privilege
Downloaded subtitles are saved to a sub_temp/ directory in the current working directory. Temporary files for API payloads are cleaned up automatically. No system-level changes are made.