download-youtube-audio

name	download-youtube-audio
description	Use when the user wants to download audio from a YouTube URL (or YouTube playlist). Triggers on phrases like "download audio from youtube", "grab the audio from this yt link", "yt-dlp this", or any YouTube URL paired with a request to save audio. Saves to ~/audio/yt-raw using yt-dlp.

Download YouTube Audio

Download the audio track from a YouTube URL using yt-dlp and save it to ~/audio/yt-raw/.

Steps

1. Ensure the output directory exists:

   mkdir -p ~/audio/yt-raw
   

2. Run yt-dlp with audio extraction. Default to m4a (no re-encode when source is already AAC, otherwise best available). As of yt-dlp 2026.03.17, YouTube requires a JS runtime + remote EJS challenge solver or extraction fails with This video is not available:

   yt-dlp -x --audio-format m4a --audio-quality 0 \
     --js-runtimes "node:$(which node)" \
     --remote-components ejs:github \
     -o "$HOME/audio/yt-raw/%(title)s.%(ext)s" \
     "<URL>"
   

   • -x extracts audio only
   • --audio-format m4a — default; if the user asks for mp3, swap to mp3
   • --audio-quality 0 — best available
   • --js-runtimes node:<path> — point at Node (deno is the only default; not always available). Resolve via which node.
   • --remote-components ejs:github — pulls the signature/n challenge solver from yt-dlp's EJS release. Without this, formats resolve to nothing.
   • Filename is the video title

3. Report the final saved file path to the user. Use ls -lt ~/audio/yt-raw/ | head -3 if you need to confirm.

Notes

• If the URL is a playlist, yt-dlp will download every entry into the same folder — confirm with the user first if the URL looks like a playlist (list= param) and they only wanted one track.
• If yt-dlp is missing, install via pipx install yt-dlp or pip install --user -U yt-dlp.
• Do not re-encode unnecessarily; -x --audio-format m4a is fast when the source is already AAC.
• For mp3 requests, add --embed-thumbnail --add-metadata so tags and cover art carry over.