# ACE-Step API on Opennan

> ACE-Step API on Opennan: $0.0156 per minute of audio.

- Maker: ACE Studio & StepFun
- Category: Music
- Model id: `ace-step`
- Endpoint: POST https://api.opennan.com/v1/music/generations
- MCP: https://api.opennan.com/v1/mcp (generate_music)
- Page: https://opennan.com/models/ace-step

## ACE-Step API prices

| Tier | Opennan | Official | Below official |
| --- | --- | --- | --- |
| Per minute of audio | $0.0156 | 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 ACE-Step from code

```bash
curl https://api.opennan.com/v1/music/generations \
  -H "Authorization: Bearer $OPENNAN_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"ace-step","prompt":"Warm lo-fi hip hop, soft piano, vinyl crackle, relaxed tempo","duration":30,"instrumental":true}'

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

## ACE-Step API questions

### How much does the ACE-Step API cost?

ACE-Step API on Opennan: $0.0156 per minute of audio. Prices are in US dollars per call, shown before you run, and every tier is in the price table.

### What inputs does ACE-Step take?

Text prompt.

### Which options can a call set?

Tracks from 10 to 240 seconds.

### How is it billed?

Per second of audio made, priced per minute.

### What happens if a generation fails?

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

### How do I call ACE-Step 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 generate_music tool with model "ace-step". Or send a POST to https://api.opennan.com/v1/music/generations.

## Similar models

- [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