acestep

name: acestep

description: Use ACE-Step API to generate music, edit songs, and remix music. Supports text-to-music, lyrics generation, audio continuation, and audio repainting. Use this skill when users mention generating music, creating songs, music production, remix, or audio continuation.

allowed-tools: Read, Write, Bash, Skill

ACE-Step Music Generation Skill

Use ACE-Step V1.5 API for music generation. Always use scripts/acestep.sh script — do NOT call API endpoints directly.

Quick Start


# 1. cd to this skill's directory

cd {project_root}/{.claude or .codex}/skills/acestep/



# 2. Check API service health

./scripts/acestep.sh health



# 3. Generate with lyrics (recommended)

./scripts/acestep.sh generate -c "pop, female vocal, piano" -l "[Verse] Your lyrics here..." --duration 120 --language zh



# 4. Output saved to: {project_root}/acestep_output/

Workflow

For user requests requiring vocals:

Use the acestep-songwriting skill for lyrics writing, caption creation, duration/BPM/key selection
Write complete, well-structured lyrics yourself based on the songwriting guide
Generate using Caption mode with -c and -l parameters

Only use Simple/Random mode (-d or random) for quick inspiration or instrumental exploration.

If the user needs a simple music video, use the acestep-simplemv skill to render one with waveform visualization and synced lyrics.

MV Production Requirements: Making a simple MV requires three additional skills to be installed:

acestep-songwriting — for writing lyrics and planning song structure
acestep-lyrics-transcription — for transcribing audio to timestamped lyrics (LRC)
acestep-simplemv — for rendering the final music video

Script Commands

CRITICAL - Complete Lyrics Input: When providing lyrics via the -l parameter, you MUST pass ALL lyrics content WITHOUT any omission:

If user provides lyrics, pass the ENTIRE text they give you
If you generate lyrics yourself, pass the COMPLETE lyrics you created
NEVER truncate, shorten, or pass only partial lyrics
Missing lyrics will result in incomplete or incoherent songs

Music Parameters: Use the acestep-songwriting skill for guidance on duration, BPM, key scale, and time signature.


# need to cd to this skill's directory first

cd {project_root}/{.claude or .codex}/skills/acestep/



# Caption mode - RECOMMENDED: Write lyrics first, then generate

./scripts/acestep.sh generate -c "Electronic pop, energetic synths" -l "[Verse] Your complete lyrics

[Chorus] Full chorus here..." --duration 120 --bpm 128



# Instrumental only

./scripts/acestep.sh generate "Jazz with saxophone"



# Quick exploration (Simple/Random mode)

./scripts/acestep.sh generate -d "A cheerful song about spring"

./scripts/acestep.sh random



# Options

./scripts/acestep.sh generate "Rock" --duration 60 --batch 2

./scripts/acestep.sh generate "EDM" --no-thinking    # Faster



# Other commands

./scripts/acestep.sh status <job_id>

./scripts/acestep.sh health

./scripts/acestep.sh models

Output Files

After generation, the script automatically saves results to the acestep_output folder in the project root (same level as .claude):


project_root/

├── .claude/

│   └── skills/acestep/...

├── acestep_output/          # Output directory

│   ├── <job_id>.json         # Complete task result (JSON)

│   ├── <job_id>_1.mp3        # First audio file

│   ├── <job_id>_2.mp3        # Second audio file (if batch_size > 1)

│   └── ...

└── ...

JSON Result Structure

Important: When LM enhancement is enabled (use_format=true), the final synthesized content may differ from your input. Check the JSON file for actual values:

| Field | Description |

|-------|-------------|

| prompt | Actual caption used for synthesis (may be LM-enhanced) |

| lyrics | Actual lyrics used for synthesis (may be LM-enhanced) |

| metas.prompt | Original input caption |

| metas.lyrics | Original input lyrics |

| metas.bpm | BPM used |

| metas.keyscale | Key scale used |

| metas.duration | Duration in seconds |

| generation_info | Detailed timing and model info |

| seed_value | Seeds used (for reproducibility) |

| lm_model | LM model name |

| dit_model | DiT model name |

To get the actual synthesized lyrics, parse the JSON and read the top-level lyrics field, not metas.lyrics.

Configuration

Important: Configuration follows this priority (high to low):

Command line arguments > config.json defaults
User-specified parameters temporarily override defaults but do not modify config.json
Only config --set command permanently modifies config.json

Default Config File (`scripts/config.json`)


{

  "api_url": "http://127.0.0.1:8001",

  "api_key": "",

  "api_mode": "completion",

  "generation": {

    "thinking": true,

    "use_format": false,

    "use_cot_caption": true,

    "use_cot_language": false,

    "batch_size": 1,

    "audio_format": "mp3",

    "vocal_language": "en"

  }

}

| Option | Default | Description |

|--------|---------|-------------|

| api_url | http://127.0.0.1:8001 | API server address |

| api_key | "" | API authentication key (optional) |

| api_mode | completion | API mode: completion (OpenRouter, default) or native (polling) |

| generation.thinking | true | Enable 5Hz LM (higher quality, slower) |

| generation.audio_format | mp3 | Output format (mp3/wav/flac) |

| generation.vocal_language | en | Vocal language |

Prerequisites - ACE-Step API Service

IMPORTANT: This skill requires the ACE-Step API server to be running.

Required Dependencies

The scripts/acestep.sh script requires: curl and jq.


# Check dependencies

curl --version

jq --version

If jq is not installed, the script will attempt to install it automatically. If automatic installation fails:

Windows: choco install jq or download from https://jqlang.github.io/jq/download/
macOS: brew install jq
Linux: sudo apt-get install jq (Debian/Ubuntu) or sudo dnf install jq (Fedora)

Before First Use

You MUST check the API key and URL status before proceeding. Run:


cd "{project_root}/{.claude or .codex}/skills/acestep/" && bash ./scripts/acestep.sh config --check-key

cd "{project_root}/{.claude or .codex}/skills/acestep/" && bash ./scripts/acestep.sh config --get api_url

Case 1: Using Official Cloud API (`https://api.acemusic.ai`) without API key

If api_url is https://api.acemusic.ai and api_key is empty, you MUST stop and guide the user to configure their key:

Tell the user: "You're using the ACE-Step official cloud API, but no API key is configured. An API key is required to use this service."
Explain how to get a key: API keys are currently available through acemusic.ai for free.
Use AskUserQuestion to ask the user to provide their API key.

Once provided, configure it:


cd "{project_root}/{.claude or .codex}/skills/acestep/" && bash ./scripts/acestep.sh config --set api_key <KEY>

Additionally, inform the user: "If you also want to render music videos (MV), it's recommended to configure a lyrics transcription API key as well (OpenAI Whisper or ElevenLabs Scribe), so that lyrics can be automatically transcribed with accurate timestamps. You can configure it later via the acestep-lyrics-transcription skill."

Case 2: API key is configured

Verify the API endpoint: ./scripts/acestep.sh health and proceed with music generation.

Case 3: Using local/custom API without key

Local services (http://127.0.0.1:*) typically don't require a key. Verify with ./scripts/acestep.sh health and proceed.

If health check fails:

Ask: "Do you have ACE-Step installed?"
If installed but not running: Use the acestep-docs skill to help them start the service
If not installed: Use acestep-docs skill to guide through installation

Service Configuration

Official Cloud API: ACE-Step provides an official API endpoint at https://api.acemusic.ai. To use it:


./scripts/acestep.sh config --set api_url "https://api.acemusic.ai"

./scripts/acestep.sh config --set api_key "your-key"

./scripts/acestep.sh config --set api_mode completion

API keys are currently available through acemusic.ai for free.

Local Service (Default): No configuration needed — connects to http://127.0.0.1:8001.

Custom Remote Service: Update scripts/config.json or use:


./scripts/acestep.sh config --set api_url "http://remote-server:8001"

./scripts/acestep.sh config --set api_key "your-key"

API Key Handling: When checking whether an API key is configured, use config --check-key which only reports configured or empty without printing the actual key. NEVER use config --get api_key or read config.json directly — these would expose the user's API key. The config --list command is safe — it automatically masks API keys as *** in output.

API Mode

The skill supports two API modes. Switch via api_mode in scripts/config.json:

| Mode | Endpoint | Description |

|------|----------|-------------|

| completion (default) | /v1/chat/completions | OpenRouter-compatible, sync request, audio returned as base64 |

| native | /release_task + /query_result | Async polling mode, supports all parameters |

Switch mode:


./scripts/acestep.sh config --set api_mode completion

./scripts/acestep.sh config --set api_mode native

Completion mode notes:

No polling needed — single request returns result directly
Audio is base64-encoded inline in the response (auto-decoded and saved)
inference_steps, infer_method, shift are not configurable (server defaults)
--no-wait and status commands are not applicable in completion mode
Requires model field — auto-detected from /v1/models if not specified

Using acestep-docs Skill for Setup Help

IMPORTANT: For installation and startup, always use the acestep-docs skill to get complete and accurate guidance.

DO NOT provide simplified startup commands - each user's environment may be different. Always guide them to use acestep-docs for proper setup.

For API debugging, see API Reference.