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

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

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.

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.

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 "

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 browser UI automation to extract subtitles.

Check Tool Availability:

Check if chrome-devtools-mcp tools (specifically mcp__plugin_claude-code-settings_chrome__new_page) are available. CRITICAL CHECK: If chrome-devtools-mcp 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 configure chrome-devtools-mcp (for browser automation)."

Initialize Browser Session (If tools are available):

Call mcp__plugin_claude-code-settings_chrome__new_page to open the video URL.

3.2 Analyze Page State

Call mcp__plugin_claude-code-settings_chrome__take_snapshot to read the page accessibility tree.

3.3 Expand Video Description

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

Search the snapshot for a button labeled "...more", "...更多", or "Show more" (usually located in the description block below the video title). Call mcp__plugin_claude-code-settings_chrome__click to click that button. 3.4 Open Transcript Panel Call mcp__plugin_claude-code-settings_chrome__take_snapshot to get the updated UI snapshot. Search for a button labeled "Show transcript", "显示转录稿", or "内容转文字". Call mcp__plugin_claude-code-settings_chrome__click to click that button. 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.

Call mcp__plugin_claude-code-settings_chrome__evaluate_script to execute the following JavaScript:

() => { // Select all transcript segment containers const segments = document.querySelectorAll("ytd-transcript-segment-renderer"); if (!segments.length) return "BUFFERING"; // Retry if empty

// Iterate and format as "timestamp text" 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 a few seconds and retry.

3.6 Save and Cleanup Use the Write tool to save the extracted text as a local file (e.g.,