# Download Bilibili Audio

> Download the highest available source-quality audio from one Bilibili link only when the user explicitly asks to 提取音频, 下载音频, extract audio, or download audio and the link belongs to bilibili.com or b23.tv. Do not activate for a bare Bilibili link that the user only wants opened, read, summarized, or discussed.

- Skill: `yuansays/download-bilibili-audio` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add yuansays/download-bilibili-audio`
- Raw SKILL.md: https://api.skillmd.com/api/skills/yuansays/download-bilibili-audio/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: yuansays (https://skillmd.com/u/yuansays)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/yuansays/download-bilibili-audio

---


# Download Bilibili Audio

Use this Skill's wrapper for the shared deterministic downloader. Accept exactly one published-video URL whose normalized hostname is `bilibili.com` or `b23.tv`, or one of their subdomains.

## Run

- Resolve the absolute path to this Skill directory. Encode the complete URL as UTF-8 Base64 in memory before composing the command. Never place the raw URL in a shell command or pass it as a positional argument.
- Run this Skill's `scripts/run.py`; the wrapper applies the fixed Bilibili platform guard:

```powershell
py -3 "<skill-dir>\scripts\run.py" --url-base64 "<UTF8_BASE64>"
```

On macOS or Linux, use `python3 "<skill-dir>/scripts/run.py" --url-base64 "<UTF8_BASE64>"`.

- If the user explicitly supplies another output directory, Base64-encode it outside the shell and append `--output-dir-base64 '<UTF8_BASE64>'`.
- The wrapper keeps `--expected-platform Bilibili` fixed. Reject a mismatched platform, multiple URLs, a playlist-only URL, or an active livestream.
- Preserve the best source audio codec exposed by Bilibili and yt-dlp. A container-only remux is acceptable; an unexpected codec change is a failure.

## Authentication and safety

- Always attempt the public download first, without browser cookies.
- Only if the JSON result is `authentication_required`, ask for permission to use Chrome cookies for this exact URL. After explicit permission, Base64-encode the allowed `chrome[:profile]` value outside the shell and add `--cookies-from-browser-base64 '<UTF8_BASE64>'`.
- Never export or persist cookies, request a password, or bypass DRM, paid access, account entitlement, or a region restriction. Process only content the user is authorized to download; platform terms still apply.
- Do not silently install or upgrade dependencies.

## Results

The downloader emits one JSON object. On `downloaded` or `already_exists`, report the final absolute path, title, codec/container, available bitrate/sample-rate/channel details, and codec-preservation status. On `authentication_required`, stop and request URL-specific cookie permission. If any result contains `recovery_path` or `previous_file_backup`, always report that absolute recovery path. For other failures, report only the safe `message` and `error_code`; do not expose subprocess stderr, signed media URLs, cookie data, or browser-profile paths.