ace-step

ace-step is a skill for Claude Code, Codex from calesthio/generative-media-skills. It costs 76 tokens per session (4,792 once invoked), scanned A, original, MIT.

An open-source AI music tool for creating or editing songs, instrumental tracks, covers, stems, and soundtrack ideas from text, lyrics, or reference audio.

In plain words
What is it for?
Use it for songs, background music, vocal tracks, covers, remixes, layered tracks, stem extraction, and video, advertising, game, or social soundtracks.
Why use it?
It gives teams a local or hosted option for developing music and making targeted changes to generated tracks.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it for songs, background music, vocal tracks, covers, remixes, layered tracks, stem extraction, and video, advertising, game, or social soundtracks.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/calesthio/generative-media-skills/ace-step
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add calesthio/generative-media-skills --skill ace-step
Clone the repo
git clone --depth 1 https://github.com/calesthio/generative-media-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ace-step

README.md
[![agentmods](https://agentmods.dev/badge/skills/calesthio/generative-media-skills/ace-step/github.svg)](https://agentmods.dev/skills/calesthio/generative-media-skills/ace-step)
Your own site
<a href="https://agentmods.dev/skills/calesthio/generative-media-skills/ace-step"><img src="https://agentmods.dev/badge/skills/calesthio/generative-media-skills/ace-step/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ace-step

Your own site · 80×15
<a href="https://agentmods.dev/skills/calesthio/generative-media-skills/ace-step"><img src="https://agentmods.dev/badge/skills/calesthio/generative-media-skills/ace-step.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,792 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00076 $0.04792
Opus 5 $0.00038 $0.02396
Sonnet 5 $0.00015 $0.00958
Haiku 4.5 $0.00008 $0.00479

Measured 9d ago against content hash afe36c3f2021, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

ace-step scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/providers/music-generation/ace-step/SKILL.md · 354 lines

How it starts

The opening of the file, as written. The whole thing — 354 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ACE-Step music production

Use this skill when a task calls for ACE-Step or ACE-Step 1.5 as the music engine, or when choosing an open-weight/local music-generation path for songs, background music, vocal tracks, covers, remixes, stems, or video soundtrack assets.

Treat ACE-Step as a fast generative music workstation, not a deterministic MIDI sequencer. It can follow style, lyric, structure, tempo, key, and reference-audio guidance, but outputs still need listening, selection, edits, mastering, rights checks, and delivery-format prep.

Current facts to anchor on

Documented facts below were verified on 2026-07-10 from official ACE-Step GitHub, Hugging Face model cards, official docs, and arXiv reports.

  • ACE-Step 1.5 is an open-source music foundation model co-led by ACE Studio and StepFun. It combines a planning language model with a diffusion transformer acoustic renderer.
  • Main generation modes include text-to-music, lyrics-to-song, instrumental generation, cover/style transfer, repainting, LEGO/layered track generation, extraction, and completion. Some editing modes are documented as base-model-only.
  • The official ACE-Step 1.5 Hugging Face card lists license MIT, model type Text2Music, 50+ languages, and consumer-hardware/local operation claims. The GitHub repository is MIT-licensed.
  • The official API is asynchronous: submit with POST /release_task, poll POST /query_result, then download files via /v1/audio?path=....
  • Duration control exists through audio_duration / duration / target_duration; the official API docs list range 10-600 seconds. The technical report describes v1.5 as scaling from short loops to 10-minute compositions.
  • Output format options documented in the API include flac, mp3, opus, aac, wav, and wav32.
  • Official model-zoo guidance distinguishes DiT model families:
    • acestep-v15-turbo: fast, SFT, 8-step, high quality, medium diversity, medium fine-tunability; good first default for production iteration.
    • acestep-v15-base: 50-step, CFG-enabled, medium quality, high diversity, easy fine-tuning; use when you need base-only tasks, CFG, higher exploration, extraction/LEGO/complete support, or training/fine-tuning workflows.
    • acestep-v15-sft: 50-step, high quality, medium diversity, easy fine-tuning; use when you prefer SFT quality over turbo speed and do not need base-only capabilities.
    • XL models use a larger 4B DiT decoder; official docs say they target higher quality and require more VRAM, with >=12GB VRAM using offload/quantization or >=20GB without offload.
    • LM options include acestep-5Hz-lm-0.6B, 1.7B, and 4B; larger LMs are documented as stronger at composition and melody copying.
  • Official docs state launch scripts exist for Windows CUDA, Windows ROCm, Linux CUDA, and macOS Apple Silicon MLX. Custom launch settings can be kept in .env using variables such as ACESTEP_CONFIG_PATH, ACESTEP_LM_MODEL_PATH, PORT, and LANGUAGE.
  • ACE-Step DAW is a separate AGPL-3.0-or-later project and has different distribution obligations than the MIT model repository; do not assume MIT terms apply to a bundled DAW deployment.

Read the full file on GitHub · 354 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 354 lines · 76 tokens per session scan A afe36c3f2021

Subscribe to this mod's changes

ace-step is a skill published in the GitHub repository calesthio/generative-media-skills (170 stars, last pushed 2mo ago), licensed MIT. It adds 76 tokens to every session and 4,792 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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