YouTube Audio Download

Download video audio file (best available format, no conversion).

Quick Start

/mk-youtube-get-audio <URL> [output_dir] [browser] [--force]

Parameters

Parameter	Required	Default	Description
URL	Yes	-	YouTube video URL
output_dir	No	/tmp/monkey_knowledge/youtube/audio	Output directory for audio file
browser	No	auto	Browser for cookies (chrome, firefox, safari, edge, brave)
--force	No	false	Force re-download even if cached file exists

Examples

/mk-youtube-get-audio https://youtube.com/watch?v=xxx - Download with auto cookie fallback
/mk-youtube-get-audio https://youtube.com/watch?v=xxx ~/Music - Save to custom directory
/mk-youtube-get-audio https://youtube.com/watch?v=xxx /tmp chrome - Use Chrome cookies

How it Works

Execute: {baseDir}/scripts/audio.sh "<URL>" "<output_dir>" "<browser>"
First attempt: download without authentication
If failed: retry with browser cookies (auto-detect or specified)
Parse JSON output to get file path

┌─────────────────────────────┐
│   First attempt (no auth)   │
└──────────────┬──────────────┘
               │
       ┌───────┴───────┐
       │               │
    Success         Failed
       │               │
       ▼               ▼
   [Return]    ┌─────────────────────┐
               │ Retry with cookies  │
               │ chrome → firefox →  │
               │ safari → edge →     │
               │ brave               │
               └──────────┬──────────┘
                          │
                  ┌───────┴───────┐
                  │               │
               Success         Failed
                  │               │
                  ▼               ▼
              [Return]        [Error]

Output Format

Success:

{
  "status": "success",
  "file_path": "/tmp/monkey_knowledge/youtube/audio/20091025__VIDEO_ID.m4a",
  "file_size": "5.2M",
  "cached": false,
  "video_id": "dQw4w9WgXcQ",
  "title": "Video Title",
  "channel": "Channel Name",
  "url": "https://www.youtube.com/watch?v=dQw4w9WgXcQ",
  "duration_string": "3:32"
}

Cache hit (returns existing file):

{
  "status": "success",
  "file_path": "/tmp/monkey_knowledge/youtube/audio/20091025__VIDEO_ID.m4a",
  "file_size": "5.2M",
  "cached": true,
  ...
}

Error:

{
  "status": "error",
  "message": "Download failed (tried with and without cookies)"
}

Filename Format

Files use unified naming with date prefix: {YYYYMMDD}__{video_id}.{ext}

Example: 20091025__dQw4w9WgXcQ.m4a

Browser Cookie Fallback

When download fails (e.g., member-only or age-restricted content), the script automatically:

Tries each browser: chrome → firefox → safari → edge → brave
For Chrome: tries all profiles (Default, Profile 1, Profile 2, ...)
Uses first successful browser/profile combination

Supported browsers:

Browser	Parameter	Chrome Profile Support
Chrome	`chrome`	Yes (auto-detect all profiles)
Firefox	`firefox`	Default profile only
Safari	`safari`	Default profile only
Edge	`edge`	Default profile only
Brave	`brave`	Default profile only

Use Cases

Download audio for speech-to-text when video has no subtitles
Podcast or music download
Member-only or age-restricted content (with browser cookies)

Notes

File caching: If audio file already exists for this video, it will be reused (returns cached: true)
Force refresh: Use --force flag to re-download even if cached file exists
Uses system yt-dlp/jq if available, otherwise auto-downloads on first run
No ffmpeg required (uses best available format without conversion)
Output format depends on source (typically m4a, webm, or opus)
Cookie fallback only activates when initial download fails
Using cookies may risk YouTube account suspension - use secondary account if needed

Next Step

After downloading the audio, invoke /mk-youtube-audio-transcribe with the file_path from the output:

/mk-youtube-audio-transcribe <file_path> [model] [language]

Tip: If you know the video's language from /mk-youtube-get-info, pass it as the language parameter for better model auto-selection (e.g., zh → belle-zh, ja → kotoba-ja).