Agent skill

Acestep

by calesthio in calesthio/OpenMontage

AI music generation with ACE-Step 1.5 — background music, vocal tracks, covers, stem extraction for video production.

AGPL-3.0Auto-check: notesMedia & Creative

Install Acestep

skills CLI
$ npx skills add calesthio/OpenMontage --skill acestep -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install calesthio/OpenMontage acestep --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/calesthio/OpenMontage.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/acestep .claude/skills/acestep && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
acestep
GitHub stars
66k
Token cost
~2.3k tokens
SKILL.md length
737 words
Files
1
Skills in repo
41
Repo updated
First seen
Licence
AGPL-3.0

At a glance

AI music generation with ACE-Step 1.5 — background music, vocal tracks, covers, stem extraction for video production.

  • Works in 3 steps: Instrumental background track (simplest) → Song with vocals and lyrics → Using a preset for video background
  • Generating music
  • SKILL.md covers Quick Reference, Creating a Song (Step by Step), Scene Presets and Task Types, plus 3 more sections
  • Calls python; needs RUNPOD_API_KEY

What it does

Acestep is an agent skill from calesthio/OpenMontage. AI music generation with ACE-Step 1.5 — background music, vocal tracks, covers, stem extraction for video production. Use when generating music, soundtracks, jingles, or working with audio stems. Triggers include background music, soundtrack, jingle, music generation, stem extraction, cover, style transfer, or musical composition tasks.

Its SKILL.md is about 2.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Media & Creative, covering Music and audio generation and Video production. The repository describes itself as: World's first open-source, agentic video production system. 12 production pipelines, 100+ tools, 700+ agent skill and production-knowledge files. Turn your AI coding assistant… The licence is AGPL-3.0.

When your agent uses it

  • Generating music
  • Working with audio stems
  • Include background music
  • Music generation

Example prompts

  • “/acestep”

Requirements

  • Python 3
  • A credential in RUNPOD_API_KEY

Workflow steps

3 steps, taken from the step headings in SKILL.md.

  1. Instrumental background track (simplest)
  2. Song with vocals and lyrics
  3. Using a preset for video background

What it can do on your machine

Read from SKILL.md and the folder at commit 9327439. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • python

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names these keys or tokens, usually read from environment variables:

    • RUNPOD_API_KEY

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Acestep loads about 2.3k tokens when it runs. Until then it costs about 87 tokens; SKILL.md has 737 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~87
When it runs · the whole SKILL.md, loaded when a task matches
~2.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

  • NoteMentions a .env fileSKILL.md:9
    EY` and `RUNPOD_ACESTEP_ENDPOINT_ID` in `.env` (run `--setup` to create endpoint).

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from calesthio/OpenMontage at commit 9327439, republished under its AGPL-3.0 licence (© calesthio). 737 words, ~2,300 tokens.

Download SKILL.mdSave it as .claude/skills/acestep/SKILL.md (or your agent's skills folder).
name
acestep
description
AI music generation with ACE-Step 1.5 — background music, vocal tracks, covers, stem extraction for video production. Use when generating music, soundtracks, jingles, or working with audio stems. Triggers include background music, soundtrack, jingle, music generation, stem extraction, cover, style transfer, or musical composition tasks.

ACE-Step 1.5 Music Generation

Open-source music generation (MIT license) via tools/music_gen.py. Runs on RunPod serverless. Requires RUNPOD_API_KEY and RUNPOD_ACESTEP_ENDPOINT_ID in .env (run --setup to create endpoint).

Quick Reference

bash
# Basic generation
python tools/music_gen.py --prompt "Upbeat tech corporate" --duration 60 --output bg.mp3

# With musical control
python tools/music_gen.py --prompt "Calm ambient piano" --duration 30 --bpm 72 --key "D Major" --output ambient.mp3

# Scene presets (video production)
python tools/music_gen.py --preset corporate-bg --duration 60 --output bg.mp3
python tools/music_gen.py --preset tension --duration 20 --output problem.mp3
python tools/music_gen.py --preset cta --brand digital-samba --duration 15 --output cta.mp3

# Vocals with lyrics
python tools/music_gen.py --prompt "Indie pop jingle" --lyrics "[verse]\nBuild it better\nShip it faster" --duration 30 --output jingle.mp3

# Cover / style transfer
python tools/music_gen.py --cover --reference theme.mp3 --prompt "Jazz piano version" --duration 60 --output jazz_cover.mp3

# Stem extraction
python tools/music_gen.py --extract vocals --input mixed.mp3 --output vocals.mp3

# List presets
python tools/music_gen.py --list-presets

Creating a Song (Step by Step)

1. Instrumental background track (simplest)
bash
python tools/music_gen.py --prompt "Upbeat indie rock, driving drums, jangly guitar" --duration 60 --bpm 120 --key "G Major" --output track.mp3
2. Song with vocals and lyrics

Write lyrics in a temp file or pass inline. Use structure tags to control song sections.

bash
# Write lyrics to a file first (recommended for longer songs)
cat > /tmp/lyrics.txt << 'LYRICS'
[Verse 1]
Walking through the morning light
Coffee in my hand feels right
Another day to build and dream
Nothing's ever what it seems

[Chorus - anthemic]
WE KEEP MOVING FORWARD
Through the noise and doubt
We keep moving forward
That's what it's about

[Verse 2]
Screens are glowing late at night
Shipping code until it's right
The deadline's close but so are we
Almost there, just wait and see

[Chorus - bigger]
WE KEEP MOVING FORWARD
Through the noise and doubt
We keep moving forward
That's what it's about

[Outro - fade]
(Moving forward...)
LYRICS

# Generate the song
python tools/music_gen.py \
  --prompt "Upbeat indie rock anthem, male vocal, driving drums, electric guitar, studio polish" \
  --lyrics "$(cat /tmp/lyrics.txt)" \
  --duration 60 \
  --bpm 128 \
  --key "G Major" \
  --output my_song.mp3
3. Using a preset for video background
bash
python tools/music_gen.py --preset tension --duration 20 --output problem_scene.mp3
Key tips for good results
  • Caption = overall style (genre, instruments, mood, production quality)
  • Lyrics = temporal structure (verse/chorus flow, vocal delivery)
  • UPPERCASE in lyrics = high vocal intensity
  • Parentheses = background vocals: "We rise (together)"
  • Keep 6-10 syllables per line for natural rhythm
  • Don't describe the melody in the caption — describe the sound and feeling
  • Use --seed to lock randomness when iterating on prompt/lyrics

Scene Presets

PresetBPMKeyUse Case
corporate-bg110C MajorProfessional background, presentations
upbeat-tech128G MajorProduct launches, tech demos
ambient72D MajorOverview slides, reflective content
dramatic90D MinorReveals, announcements
tension85A MinorProblem statements, challenges
hopeful120C MajorSolution reveals, resolutions
cta135E MajorCall to action, closing energy
lofi85F MajorScreen recordings, coding demos

Task Types

text2music (default)

Generate music from text prompt + optional lyrics.

cover

Style transfer from reference audio. Control blend with --cover-strength (0.0-1.0):

  • 0.2 — Loose style inspiration (more creative freedom)
  • 0.5 — Balanced style transfer
  • 0.7 — Close to original structure (default)
  • 1.0 — Maximum fidelity to source
extract

Stem separation — isolate individual tracks from mixed audio. Tracks: vocals, drums, bass, guitar, piano, keyboard, strings, brass, woodwinds, other

repaint (future)

Regenerate a specific time segment within existing audio while preserving the rest.

lego (future, requires base model)

Generate individual instrument tracks within an existing audio context.

complete (future, requires base model)

Extend partial compositions by adding specified instruments.

Prompt Engineering

Caption Writing — Layer Dimensions

Write captions by layering multiple descriptive dimensions rather than single-word descriptions.

Dimensions to include:

  • Genre/Style: pop, rock, jazz, electronic, lo-fi, synthwave, orchestral
  • Emotion/Mood: melancholic, euphoric, dreamy, nostalgic, intimate, tense
  • Instruments: acoustic guitar, synth pads, 808 drums, strings, brass, piano
  • Timbre: warm, crisp, airy, punchy, lush, polished, raw
  • Era: "80s synth-pop", "modern indie", "classical romantic"
  • Production: lo-fi, studio-polished, live recording, cinematic
  • Vocal: breathy, powerful, falsetto, raspy, spoken word (or "instrumental")

Good: "Slow melancholic piano ballad with intimate female vocal, warm strings building to powerful chorus, studio-polished production" Bad: "Sad song"

Key Principles
  1. Specificity over vagueness — describe instruments, mood, production style
  2. Avoid contradictions — don't request "classical strings" and "hardcore metal" simultaneously
  3. Repetition reinforces priority — repeat important elements for emphasis
  4. Sparse captions = more creative freedom — detailed captions constrain the model
  5. Use metadata params for BPM/key — don't write "120 BPM" in the caption, use --bpm 120
Show full SKILL.md (284 more words)Show less
Lyrics Formatting

Structure tags (use in lyrics, not caption):

[Intro]
[Verse]
[Chorus]
[Bridge]
[Outro]
[Instrumental]
[Guitar Solo]
[Build]
[Drop]
[Breakdown]

Vocal control (prefix lines or sections):

[raspy vocal]
[whispered]
[falsetto]
[powerful belting]
[harmonies]
[ad-lib]

Energy indicators:

  • UPPERCASE = high intensity ("WE RISE ABOVE")
  • Parentheses = background vocals ("We rise (together)")
  • Keep 6-10 syllables per line within sections for natural rhythm

Example — Tech Product Jingle:

[Verse]
Build it better, ship it faster
Every feature tells a story

[Chorus - anthemic]
THIS IS YOUR PLATFORM
Your vision, your stage
Digital Samba, every page

[Outro - fade]
(Build it better...)

Video Production Integration

Music for Scene Types
ScenePresetDurationNotes
Titledramatic or ambient3-5sShort, mood-setting
Problemtension10-15sDark, unsettling
Solutionhopeful10-15sRelief, optimism
Demolofi or corporate-bg30-120sNon-distracting, matches demo length
Statsupbeat-tech8-12sBuilding credibility
CTActa5-10sMaximum energy, punchy
Creditsambient5-10sGentle fade-out
Timing Workflow
  1. Plan scene durations first (from voiceover script)
  2. Generate music to match: --duration <scene_seconds>
  3. Music duration is precise (within 0.1s of requested)
  4. For background music spanning multiple scenes: generate one long track
Combining with Voiceover

Background music should be mixed at 10-20% volume in Remotion:

tsx
<Audio src={staticFile('voiceover.mp3')} volume={1} />
<Audio src={staticFile('bg-music.mp3')} volume={0.15} />

For music under narration: use instrumental presets (corporate-bg, ambient, lofi). For music-forward scenes (title, CTA): can use higher volume or vocal tracks.

Brand Consistency

Use --brand <name> to load hints from brands/<name>/brand.json. Use --cover --reference brand_theme.mp3 to create variations of a brand's sonic identity. For consistent sound across a project: fix the seed (--seed 42) and vary only duration/prompt.

Technical Details

  • Output: 48kHz MP3/WAV/FLAC
  • Duration range: 10-600 seconds
  • BPM range: 30-300
  • Inference: ~2-3s on GPU (turbo, 8 steps), ~40-60s on Mac MPS
  • Turbo model: 8 steps, no CFG needed, fast and good quality
  • Shift parameter: 3.0 recommended for turbo (improves quality)
When NOT to use ACE-Step
  • Voice cloning — use Qwen3-TTS or ElevenLabs instead
  • Sound effects — use ElevenLabs SFX (tools/sfx.py)
  • Speech/narration — use voiceover tools, not music gen
  • Stem extraction from video — extract audio first with FFmpeg, then use --extract

© calesthio, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .agents/skills/acestep of calesthio/OpenMontage.

Open the folder on GitHubat commit 9327439

Compare with similar skills

Acestep next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Acestep compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Acestep this skillcalesthio/OpenMontage66k—~2.3kAutomated safety check: NotesAGPL-3.0
Music to Videoheygen-com/hyperframes59k3 repos~4.7kAutomated safety check: NotesApache-2.0
Paper Collage Explainer Generatortl2012tl/comfyUI-llama-TE2414 repos~5.2kAutomated safety check: PassNone
Short Form Editnateherkai/hyperframes-student-kit1.2k—~5.3kAutomated safety check: PassCustom licence
Tesseract Videomirage-hq/Tesseract128—~1.9kAutomated safety check: PassCustom licence
Make VideoBintzGavin/helios118—~2kAutomated safety check: PassApache-2.0

Similar skills

  • Music to Video

    heygen-com/hyperframes

    Turns a music track into a beat-synced HyperFrames video such as a lyric video, slideshow or kinetic promo, with any supplied images or clips cut onto the beat grid.

    59k GitHub starsUsed in 3 repos~4.7k tokens
    Media & CreativeAuto-check: notes
  • Paper Collage Explainer Generator

    tl2012tl/comfyUI-llama-TE

    For creators, educators, and social-video editors who need a tactile paper-collage language for narration, knowledge points, opinions, or abstract topics.

    241 GitHub starsUsed in 4 repos~5.2k tokens
    Media & CreativeAuto-check passed
  • Short Form Edit

    nateherkai/hyperframes-student-kit

    Turn talking-head footage into a finished reel, YouTube Short, or short advertisement with curiosity-led openings, earned payoffs, story-driven cuts, transcript-synced motion graphics, moving…

    1.2k GitHub stars~5.3k tokensUpdated 11 days ago
    Media & CreativeAuto-check passed
  • Tesseract Video

    mirage-hq/Tesseract

    Edit existing footage into finished videos locally with Tesseract.

    128 GitHub stars~1.9k tokensUpdated 8 days ago
    Media & CreativeAuto-check passed
  • Make Video

    BintzGavin/helios

    Make videos drawn with code: motion graphics, launch and explainer videos, animated shorts, animated charts and data, logo reveals, social clips, music visualizers, UI demos and GIF loops.

    118 GitHub stars~2k tokensUpdated yesterday
    Media & CreativeAuto-check passed
  • Audio And Video

    glifxyz/glif-mcp-server

    Make or edit audio and video with Glif, from a text brief or from a reference image, video or audio file.

    212 GitHub stars~1.6k tokensUpdated yesterday
    Media & CreativeAuto-check passed

More from calesthio/OpenMontage

All 41 skills in this repo
  • Video Understand

    calesthio/OpenMontage

    Understand video content locally using ffmpeg frame extraction and Whisper transcription.

    66k GitHub stars~841 tokensUpdated 6 days ago
    Auto-check passed
  • Avatar Video

    calesthio/OpenMontage

    Create AI avatar videos with precise control over avatars, voices, scripts, scenes, and backgrounds using HeyGen's v2 API.

    66k GitHub stars~1.6k tokensUpdated 6 days ago
    Auto-check passed
  • D3 Viz

    calesthio/OpenMontage

    Creating interactive data visualisations using d3.js. An agent skill from calesthio/OpenMontage.

    66k GitHub starsUsed in 3 repos~5.4k tokens
    Auto-check passed
  • Create Video

    calesthio/OpenMontage

    Create videos from a text prompt using HeyGen's Video Agent.

    66k GitHub stars~1.3k tokensUpdated 6 days ago
    Auto-check passed
  • Threejs World Generation

    calesthio/OpenMontage

    Build deterministic, editable, free-viewpoint Three.js worlds from text or structured briefs.

    66k GitHub stars~2k tokensUpdated 6 days ago
    Auto-check passed
  • Video Edit

    calesthio/OpenMontage

    Edit videos locally using ffmpeg. An agent skill from calesthio/OpenMontage.

    66k GitHub stars~855 tokensUpdated 6 days ago
    Auto-check: notes

Questions about Acestep

What does Acestep do?

AI music generation with ACE-Step 1.5 — background music, vocal tracks, covers, stem extraction for video production. Acestep is an agent skill from calesthio/OpenMontage.5 — background music, vocal tracks, covers, stem extraction for video production.

When should I use Acestep?

Acestep fits situations like: generating music; working with audio stems; include background music; music generation.

How do I install Acestep in Claude Code?

Run `npx skills add calesthio/OpenMontage --skill acestep -a claude-code`. Or copy the skill folder (.agents/skills/acestep in calesthio/OpenMontage) into .claude/skills/acestep in your project. Claude Code loads it when a task matches its description.

How do I install Acestep in Codex?

Run `npx skills add calesthio/OpenMontage --skill acestep -a codex`. Or copy the skill folder (.agents/skills/acestep in calesthio/OpenMontage) into .agents/skills/acestep in your project. Codex loads it when a task matches its description.

Can I use Acestep in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add calesthio/OpenMontage --skill acestep -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/acestep, .gemini/skills/acestep, .github/skills/acestep and .opencode/skills/acestep in your project.

What does Acestep need to run?

Going by SKILL.md and its folder, Acestep needs the command-line tools its instructions call (python) and credentials named RUNPOD_API_KEY. Our summary lists: Python 3; A credential in RUNPOD_API_KEY.

Does Acestep access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Acestep safe to install?

Our automated static check of SKILL.md found notes only (mentions a .env file), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.

What licence does Acestep use?

Acestep is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Acestep use?

About 2.3k tokens (SKILL.md is roughly 9.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Acestep?

Skills that share tags, products or a category with Acestep: Music to Video (heygen-com/hyperframes, 59k stars), Paper Collage Explainer Generator (tl2012tl/comfyUI-llama-TE, 241 stars), Short Form Edit (nateherkai/hyperframes-student-kit, 1.2k stars) and Tesseract Video (mirage-hq/Tesseract, 128 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Acestep?

calesthio (a GitHub user) maintains it in calesthio/OpenMontage, which has 65,614 GitHub stars. The repository holds 41 skills in this directory. The repository was last updated on October 3, 2026.

Source: calesthio/OpenMontage on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.