YouTube Video Downloader

Download YouTube videos with customizable quality and format options. Use this skill when the user asks to download, save, or grab YouTube videos. Supports v...

Security Scan

The skill's files and runtime instructions match its stated purpose (downloading YouTube videos); the main risk is that it automatically installs yt-dlp via pip at runtime without pinning and uses a flag that can alter system packages.

Purpose & Capability

Name, description, SKILL.md, and the included Python script all align: downloading single YouTube videos with selectable quality/format. Required binary (python3) is appropriate and no unrelated credentials or config paths are requested.

Instruction Scope

SKILL.md and the script stay within the downloader's scope (fetch video info, select formats, download to /mnt/user-data/outputs). The script does call out to external tool yt-dlp and will perform network I/O to fetch video data; it does not read unrelated files or environment variables.

Install Mechanism

There is no formal install spec, but the script auto-installs yt-dlp at runtime via pip (sys.executable -m pip install --break-system-packages yt-dlp). Using pip at runtime and the --break-system-packages flag can modify the host Python environment and is higher-risk than relying on an already-installed, pinned binary. The package install is unpinned (no fixed version), which increases supply-chain risk.

Credentials

No environment variables or external credentials are requested (appropriate). The script writes files to /mnt/user-data/outputs by default and will modify the Python environment by installing yt-dlp; consider whether that filesystem and Python environment are acceptable for the user.

Persistence & Privilege

Skill is not always-enabled and does not request elevated platform privileges or modify other skills' configs. Autonomous invocation is allowed by default but not combined with other concerning privileges here.

Assessment

This skill appears to do what it says: it runs yt-dlp to download single YouTube videos and includes a Python script to do that. Before installing/using it, consider: (1) the script will try to install yt-dlp via pip at runtime and uses --break-system-packages — run it in an isolated environment (virtualenv, container) to avoid altering system Python packages; (2) the pip install is not pinned to a specific yt-dlp version, which is a supply‑chain risk — you may prefer to pre-install a known-good yt-dlp version; (3) downloads default to /mnt/user-data/outputs — verify disk space and that this location is acceptable; (4) ensure downloading content complies with YouTube's terms and applicable laws; (5) if you need extra assurance, review or run the script in a sandboxed environment before granting it to an agent with network access.

Download YouTube videos with full control over quality and format settings.

Quick Start

The simplest way to download a video:

python scripts/download_video.py "https://www.youtube.com/watch?v=VIDEO_ID"

This downloads the video in best available quality as MP4 to /mnt/user-data/outputs/.

Options

Quality Settings

Use -q or --quality to specify video quality:

• best (default): Highest quality available
• 1080p: Full HD
• 720p: HD
• 480p: Standard definition
• 360p: Lower quality
• worst: Lowest quality available

Example:

python scripts/download_video.py "URL" -q 720p

Format Options

Use -f or --format to specify output format (video downloads only):

• mp4 (default): Most compatible
• webm: Modern format
• mkv: Matroska container

Example:

python scripts/download_video.py "URL" -f webm

Audio Only

Use -a or --audio-only to download only audio as MP3:

python scripts/download_video.py "URL" -a

Custom Output Directory

Use -o or --output to specify a different output directory:

python scripts/download_video.py "URL" -o /path/to/directory

Complete Examples

1. Download video in 1080p as MP4:

python scripts/download_video.py "https://www.youtube.com/watch?v=dQw4w9WgXcQ" -q 1080p

2. Download audio only as MP3:

python scripts/download_video.py "https://www.youtube.com/watch?v=dQw4w9WgXcQ" -a

3. Download in 720p as WebM to custom directory:

python scripts/download_video.py "https://www.youtube.com/watch?v=dQw4w9WgXcQ" -q 720p -f webm -o /custom/path

How It Works

The skill uses yt-dlp, a robust YouTube downloader that:

• Automatically installs itself if not present
• Fetches video information before downloading
• Selects the best available streams matching your criteria
• Merges video and audio streams when needed
• Supports a wide range of YouTube video formats

Important Notes

• Downloads are saved to /mnt/user-data/outputs/ by default
• Video filename is automatically generated from the video title
• The script handles installation of yt-dlp automatically
• Only single videos are downloaded (playlists are skipped by default)
• Higher quality videos may take longer to download and use more disk space