# Demucs API on Opennan

> Demucs API on Opennan: $0.01794 per 1-min song, +$0.00299 per extra minute.

- Maker: Meta
- Category: Stems
- Model id: `demucs`
- Endpoint: POST https://api.opennan.com/v1/audio/separations
- MCP: https://api.opennan.com/v1/mcp (separate_audio)
- Page: https://opennan.com/models/demucs

## Demucs API prices

| Tier | Opennan | Official | Below official |
| --- | --- | --- | --- |
| 1-min song, +$0.00299 per extra minute | $0.01794 | No official price | - |

The maker doesn't sell this exact model on its own API (open weights, or retired there), so there is no official price to compare.

## Call Demucs from code

```bash
curl https://api.opennan.com/v1/audio/separations \
  -H "Authorization: Bearer $OPENNAN_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"demucs","audio_url":"https://example.com/song.mp3","stems":"vocals"}'

# Then poll until "status" is "succeeded" or "failed":
curl https://api.opennan.com/v1/tasks/<task id> -H "Authorization: Bearer $OPENNAN_KEY"
```

## Demucs API questions

### How much does the Demucs API cost?

Demucs API on Opennan: $0.01794 per 1-min song, +$0.00299 per extra minute. Prices are in US dollars per call, shown before you run, and every tier is in the price table.

### What inputs does Demucs take?

Audio.

### Which options can a call set?

Stems: vocals, all. Songs up to 15 minutes long.

### How is it billed?

$0.01794 for a 1-minute song, plus $0.00299 for each extra minute of input audio.

### What happens if a generation fails?

A failed task is refunded in full. You pay only for results.

### How do I call Demucs from an AI agent?

Add the MCP server https://api.opennan.com/v1/mcp with your API key as a bearer token, then call the separate_audio tool with model "demucs". Or send a POST to https://api.opennan.com/v1/audio/separations.

## Similar models

- [ACE-Step](https://opennan.com/models/ace-step): from $0.0156 per minute of audio
- [CassetteAI Sound Effects](https://opennan.com/models/cassette-sfx): from $0.013 per track
- [CassetteAI Music](https://opennan.com/models/cassette-music): from $0.026 per minute of audio (billed per started minute)
- [Stable Audio 3 Small SFX](https://opennan.com/models/stable-audio-3-sfx): from $0.02678 per track
- [Stable Audio 3 Small](https://opennan.com/models/stable-audio-3-small): from $0.02821 per track
- [Stable Audio 3](https://opennan.com/models/stable-audio-3): from $0.04888 per track