ACE-Step
Live on the APIace-step$0.0156/min of audio
- Input → output
- Text promptAudio
- Lengths
- 10–240 s
ACE-Step
ACE Studio & StepFun
Input
promptStyle, mood, instruments and tempo.instrumentalSung vocals, with your lyrics or lyrics written for you.No extra chargelyricsSung as written; leave it empty and lyrics are written for you.duration30 s30 s30 s
ACE-Step API prices
Every tier we sell, next to the model maker's official price.
| Tier | Opennan | 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 your code
Everything for your first call is on this page: the endpoint, a key, the request and every parameter.
https:/Get an API key
Create a key in the console. It uses the same balance as the playground.
Create a keySend your first request
The same request the playground sends. Set OPENNAN_KEY to your key.
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"Poll the task
The call answers right away with a task id. Ask for the task until it finishes:
GEThttps:// api.opennan.com/ v1/ tasks/ {id} - queued
- Waiting for a worker
- running
- Being made
- succeeded
- Done: outputs[].url holds the files
- failed
- Failed: you are not charged
Parameters
Built from the live catalog: every value listed here is one the API accepts.
Errors and how to fix them
401Missing or wrong key
Send the header Authorization: Bearer with a key from the console.
402Balance too low
Add credit in Billing, then send the same call again.
400A value is not accepted
Read error.message: it names the field. Use a value from the parameter table.
429Too many requests
Wait a few seconds and try again, waiting longer after each 429.
Add Opennan to your AI app
One install gives your AI every Opennan tool: video, images, chat, voice, music, sound effects, 3D, captions and dubbing. Pick your app and follow the steps.
https:/Works in the Codex CLI, the Codex app and the Codex IDE extension: they share ~/.codex/config.toml. If the app or IDE does not see OPENNAN_KEY, use the config.toml option with your key in it. Codex asks before each tool call: approve it to go on.
Get an API key
Create a key in the console. It starts with sk- and uses the same balance as the website.
Create a keySave your key as OPENNAN_KEY
# macOS / Linux (zsh shown; bash: ~/.bashrc) echo 'export OPENNAN_KEY="sk-..."' >> ~/.zshrc source ~/.zshrc # Windows (PowerShell), then open a new terminal setx OPENNAN_KEY "sk-..."Install the Opennan plugin: the server plus a skill that teaches your AI to pick models, confirm prices and wait for results
codex plugin marketplace add Opennan/opennan-ai-plugin codex plugin add opennan@opennanOr add only the server
codex mcp add opennan --url https://api.opennan.com/v1/mcp --bearer-token-env-var OPENNAN_KEYOr add this to ~/.codex/config.toml
[mcp_servers.opennan] url = "https://api.opennan.com/v1/mcp" http_headers = { Authorization = "Bearer sk-..." }Check that opennan is listed
codex mcp listRestart Codex, then ask for anything
“Make a 5 second video of rain on a neon street, a song to go with it and a poster image.”
Replace sk-... with your own key and keep it private: anyone who has it can spend your balance. Your app can list the tools before you add a key; making anything needs one.
This tool from your AI
Once Opennan is added, your AI calls this tool with arguments like these.
- Tool
- generate_music
- Example arguments
{ "model": "ace-step", "prompt": "Warm lo-fi hip hop, soft piano, vinyl crackle, relaxed tempo", "duration": 30 }
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
Music models you can call with the same key.