youtube-transcribe-skill

name	youtube-transcribe-skill
description	Extract subtitles/transcripts from YouTube videos. Triggers: "youtube transcript", "extract subtitles", "video captions", "视频字幕", "字幕提取", "YouTube转文字", "提取字幕".

YouTube Transcript Extraction

Extract subtitles/transcripts from a YouTube video URL and save them as a local file.

Input YouTube URL: $ARGUMENTS

Step 1: Verify URL and Get Video Information

1. Verify URL Format: Confirm the input is a valid YouTube URL (supports youtube.com/watch?v= or youtu.be/ formats).

2. Get Video Information: Use WebFetch or firecrawl to fetch the page and extract the video title for subsequent file naming.

Step 2: CLI Quick Extraction (Priority Attempt)

Use command-line tools to quickly extract subtitles.

1. Check Tool Availability: Execute which yt-dlp.

   • If yt-dlp is found, proceed to subtitle download.
   • If yt-dlp is NOT found, skip immediately to Step 3.

2. Execute Subtitle Download (Only if yt-dlp is found):

   • Tip: Always add --cookies-from-browser to avoid sign-in restrictions. Default to chrome.
   • Retry Logic: If yt-dlp fails with a browser error (e.g., "Could not open Chrome"), ask the user to specify their available browser (e.g., firefox, safari, edge) and retry.

   # Get the title first (try chrome first)
   yt-dlp --cookies-from-browser=chrome --get-title "[VIDEO_URL]"
   
   # Download subtitles
   yt-dlp --cookies-from-browser=chrome --write-auto-sub --write-sub --sub-lang zh-Hans,zh-Hant,en --skip-download --output "<Video Title>.%(ext)s" "[VIDEO_URL]"
   

3. Verify Results:

   • Check the command exit code.
   • Exit code 0 (Success): Subtitles have been saved locally, task complete.
   • Exit code non-0 (Failure):
     • If error is related to browser/cookies, ask user for correct browser and retry Step 2.
     • If other errors (e.g., video unavailable), proceed to Step 3.

Step 3: Browser Automation (Fallback)

When the CLI method fails or yt-dlp is missing, use superpowers-chrome browser automation to extract subtitles.

3.1 Check Tool Availability

• Check if use_browser MCP tool is available (mcp__plugin_superpowers-chrome_chrome__use_browser).
• CRITICAL CHECK: If use_browser is NOT available AND yt-dlp was NOT found in Step 2:
  • STOP execution.
  • Notify the User: "Unable to proceed. Please either install yt-dlp (for fast CLI extraction) OR enable superpowers-chrome plugin (for browser automation)."

3.2 Navigate to Video Page

Use use_browser with navigate action to open the video URL:

{
  "action": "navigate",
  "payload": "[VIDEO_URL]"
}

Then wait for page to load:

{
  "action": "await_element",
  "selector": "#description",
  "timeout": 10000
}

3.3 Expand Video Description

Reason: The "Show transcript" button is usually hidden within the collapsed description area.

1. Click the "...more" / "...更多" / "Show more" button to expand description:

{
  "action": "click",
  "selector": "tp-yt-paper-button#expand"
}

Or use the alternative selector:

{
  "action": "click",
  "selector": "#description-inline-expander #expand"
}

2. Wait for expansion:

{
  "action": "await_element",
  "selector": "ytd-video-description-transcript-section-renderer",
  "timeout": 5000
}

3.4 Open Transcript Panel

1. Click the "Show transcript" / "显示转录稿" / "内容转文字" button:

{
  "action": "click",
  "selector": "ytd-video-description-transcript-section-renderer button"
}

2. Wait for transcript panel to load:

{
  "action": "await_element",
  "selector": "ytd-transcript-segment-renderer",
  "timeout": 10000
}

3.5 Extract Content via DOM

Reason: Directly reading the accessibility tree for long lists is slow and consumes many tokens; DOM injection is more efficient.

Use eval action to execute JavaScript and extract transcript:

{
  "action": "eval",
  "payload": "(() => { const segments = document.querySelectorAll('ytd-transcript-segment-renderer'); if (!segments.length) return 'BUFFERING'; return Array.from(segments).map(seg => { const time = seg.querySelector('.segment-timestamp')?.innerText.trim(); const text = seg.querySelector('.segment-text')?.innerText.trim(); return `${time} ${text}`; }).join('\\n'); })()"
}

If it returns "BUFFERING", wait 2-3 seconds and retry.

3.6 Save and Cleanup

1. Use the Write tool to save the extracted text as a local file (e.g., <Video Title>.txt).

2. Close the browser tab to release resources:

{
  "action": "close_tab"
}

Output Requirements

• Save the subtitle file to the current working directory.
• Filename format: <Video Title>.txt
• File content format: Each line should be Timestamp Subtitle Text.
• Report upon completion: File path, subtitle language, total number of lines.