# audio-ducking

Lowers a background music bed under voice audio or video via Sonilo. Useful for mixing podcasts, voiceovers, and clips without manual volume automation.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 1200 installs · ★ 117
- Author: sonilo-ai
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/sonilo-ai/skills/tree/HEAD/audio-ducking/SKILL.md
- Updated: 2026-10-20
- HTML: https://affpapa.org/en/nevibecode/skills/audio-ducking

## What it does

The skill sends an existing voice track and background music to Sonilo. Music volume drops automatically while someone speaks and comes back up during pauses. If you supply a video such as `mp4` or `mov` for the voice input, the tool extracts dialogue and muxes the finished mix back into a fresh video file.

The music parameter accepts audio files only, so supplying video there will fail upfront. Each input track cannot exceed 360 seconds (6 minutes), and the default upload limit is usually 300 MB.

You need either the Sonilo MCP server or the `sonilo` CLI configured with `SONILO_API_KEY`. Keep in mind that requests consume API credits, so run the tool only when you need it.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add sonilo-ai/skills --skill audio-ducking -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/audio-ducking/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/audio-ducking/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add sonilo-ai/skills --skill audio-ducking -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/audio-ducking/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add sonilo-ai/skills --skill audio-ducking -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/audio-ducking/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install sonilo-ai/skills audio-ducking
```

2. **Manually: put the files in place**
- File: `.github/skills/audio-ducking/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add sonilo-ai/skills --skill audio-ducking -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/sonilo-ai/skills --path audio-ducking
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/audio-ducking/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add sonilo-ai/skills --skill audio-ducking -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/sonilo-ai/skills/tree/HEAD/audio-ducking/SKILL.md

## When to use it
- lower background music volume automatically while voice speaks
- mix dialogue into video without drawing volume automation curves
- combine narration and audio tracks under 6 minutes long
- export a re-muxed video containing ducked background audio

## Example prompts
- Duck background.wav under speech in interview.mp4 using Sonilo
- Mix narration from voice.wav with bed.mp3 using the audio_ducking tool
- Run audio ducking on recording.mp4 with background music soundtrack.wav

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 16951169bb037128.

BEGIN THIRD-PARTY FILE 16951169bb037128
````text
---
name: audio-ducking
description: Duck a music bed under a voice track using Sonilo — automatically lowers the music wherever the voice speaks and lifts it back in the gaps. Use when mixing a separately-generated or existing music track under narration, dialogue, or a video's own voice track, without manual volume automation.
license: MIT
compatibility: "Requires Sonilo through either transport — the MCP server connected, or the `sonilo` CLI installed and signed in — plus credentials: a `sonilo login` sign-in, the hosted OAuth plugin, or SONILO_API_KEY. See the setup-api-key skill."
allowed-tools: Bash, Read, Write, mcp__sonilo__*
---

# Sonilo Audio Ducking

Automatically duck a music bed under a voice track: Sonilo lowers the music wherever the voice is speaking and lifts it back in the gaps, then returns the mixed result. The voice input may be a video — its audio track is used as the voice, and the ducked mix is muxed back into a new video.

> **Setup:** See the [setup-api-key](../setup-api-key) skill.

> ⚠️ **Cost:** makes an API call that may incur charges. Only call when explicitly requested.

## Transport: MCP or CLI

Pick one at the start of the session and stay on it. Do not mix the two inside
a single job, and do not announce the choice.

1. **Sonilo MCP tools visible in this session** (`audio_ducking` and friends) — use them. This is the preferred path: it needs no shell, and it is the only one that survives a very long generation. If a call fails to authenticate — rather than failing on its inputs — this transport is not usable in this session: go to 2 instead of retrying it.
2. **No usable Sonilo MCP tools, but `sonilo account` exits 0** — use the CLI commands below. Same API, same account, same credential file. Probe with `sonilo account`, not `sonilo whoami`: whoami exits 0 even when signed out, so it cannot tell the two states apart.
3. **Neither** — stop and run the [setup-api-key](../setup-api-key) skill. Do not call `api.sonilo.com` with curl to work around it; both transports handle uploads, polling and retries that a bare request does not.

## Quick Start

### MCP tool call (recommended)

```
audio_ducking(
    voice_path="~/Desktop/interview.mp4",
    music_path="~/Desktop/background-track.wav"
)
```

### Python (`pip install "sonilo>=0.13"`)

```python
from sonilo import Sonilo

client = Sonilo()  # reads SONILO_API_KEY

result = client.audio_ducking.generate(
    voice="interview.mp4",  # audio or video; also voice_url=
    music="background-track.wav",  # audio only; also music_url=
)
result.save("ducked.mp4" if result.output_type == "video" else "ducked.wav")
```

### JavaScript / TypeScript (`npm install sonilo@>=0.14`)

```ts
import { SoniloClient, download } from "sonilo";
import { writeFile } from "node:fs/promises";

const client = new SoniloClient(); // reads SONILO_API_KEY

const result = await client.audioDucking.generate({
  voice: "./interview.mp4", // audio or video; also voiceUrl
  musicUrl: "https://example.com/background-track.wav", // audio only; also music
});
await writeFile(
````
END THIRD-PARTY FILE 16951169bb037128

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