ace-step

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: ace-step
displayName: "ACE Step — Pro Pack on RunComfy"
allowed-tools: Bash(runcomfy *)
description: >
  Generate, inpaint, and outpaint music with ACE Step on RunComfy via
  the `runcomfy` CLI. ACE Step is StepFun-AI's open-weights music
  foundation model — tag-driven composition (genre, mood, instruments),
  multilingual lyrics with section markers, 5 s to 4 min stereo output,
  $0.0002–0.0003 per second (≈ 27× cheaper than ElevenLabs Music).
  Four endpoints: ACE Step text-to-audio (the default), ACE Step 1.5
  text-to-audio (50+ language lyrics, refined structured-lyric
  handling), ACE Step audio-inpaint (regenerate a time range inside an
  existing track), ACE Step audio-outpaint (extend an existing track
  before or after). Triggers on "ace step", "ace-step", "acestep",
  "ACE music", "open music model", "cheap AI music", "inpaint audio",
  "audio inpaint", "extend music", "audio outpaint", "lengthen
  track", "music with tags", or any explicit ask to generate or edit
  music with ACE Step.
homepage: https://www.runcomfy.com
license: MIT
---

# ACE Step — Pro Pack on RunComfy

Tag-driven music generation, inpainting, and outpainting with StepFun-AI's **ACE Step** open-weights model. Four CLI-reachable endpoints, $0.0002–0.0003 per second of audio, up to 4 minutes per call.

[runcomfy.com](https://www.runcomfy.com/?utm_source=skills.sh&utm_medium=skill&utm_campaign=ace-step) · [ACE Step base](https://www.runcomfy.com/models/acestep-ai/ace-step/text-to-audio?utm_source=skills.sh&utm_medium=skill&utm_campaign=ace-step) · [ACE Step 1.5](https://www.runcomfy.com/models/acestep-ai/ace-step-1.5/text-to-audio?utm_source=skills.sh&utm_medium=skill&utm_campaign=ace-step) · [CLI docs](https://docs.runcomfy.com/cli/introduction?utm_source=skills.sh&utm_medium=skill&utm_campaign=ace-step)

## Install this skill

```bash
npx skills add agentspace-so/runcomfy-agent-skills --skill ace-step -g
```

## Powered by the RunComfy CLI

**Step 1 — install** (one of, see the `runcomfy-cli` skill for details):

```bash
npm i -g @runcomfy/cli         # global install
npx -y @runcomfy/cli --version # zero-install
```

**Step 2 — sign in** (or set `RUNCOMFY_TOKEN` env var in CI / containers):

```bash
runcomfy login
```

**Step 3 — generate**:

```bash
runcomfy run acestep-ai/ace-step/text-to-audio \
  --input '{"tags": "..."}' \
  --output-dir ./out
```

CLI deep dive: [`runcomfy-cli`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/runcomfy-cli) skill.

---

## Pick the right endpoint

Listed newest first.

**ACE Step 1.5 (text-to-audio)** — `acestep-ai/ace-step-1.5/text-to-audio`
> Latest ACE Step generation. **50+ language vocal support**, refined structured-lyric handling, otherwise same shape as base. Slightly higher cost ($0.0003/s vs $0.0002/s).
> Pick for: multilingual lyrics, hero-quality vocal tracks, vocal songs that need clean section structure.
> Avoid for: cost-sensitive batches where the base model is good enough.

**ACE Step (text-to-audio)** — `acestep-ai/ace-step/text-to-audio` *(default — cheap & fast)*
> Original ACE Step. Tag-driven composition, optional lyrics, 5–240 s stereo. $0.0002/s — ~27× cheaper than ElevenLabs Music.
> Pick for: high-volume drafts, background music, jingles, game loops, cost-sensitive iteration.
> Avoid for: maximally polished commercial vocal hooks — try **ACE Step 1.5** or **ElevenLabs Music** for those.

**ACE Step (audio-inpaint)** — `acestep-ai/ace-step/audio-inpaint`
> Regenerate a **time range** inside an existing track (not mask-based; uses `start_time` / `end_time` in seconds, each anchored to track start or end).
> Pick for: fix a bad chorus in the middle, swap the bridge, replace a 20 s section without re-rendering the whole song.
> Avoid for: edits that aren't time-bounded — those don't fit the schema.

**ACE Step (audio-outpaint)** — `acestep-ai/ace-step/audio-outpaint`
> Extend an existing track **bidirectionally** — add intro before, outro after, or both.
> Pick for: