Model reference · open weights
acestep-captioner is an open-weight audio or speech model from ACE-Step. AxForge deploys and operates it for you on dedicated EU-owned hardware — with the licence handled where one is required.
Available as managed deployment — configured and operated for you on dedicated EU hardware, quoted per deployment.
What it is
| Maker | ACE-Step |
|---|---|
| Type | Audio & music |
| Task | Music / audio |
| Parameters (lead) | 10.7B |
| Runs with | transformers |
| Released | 2026-01-23 |
| Popularity | 1k downloads / month |
| Licence | Open weights |
About
ACE-Step Captioner is the annotation model used by ACE-Step v1.5 for training data labeling. It is a professional-grade music captioning model that generates detailed, structured descriptions of audio content.
🏆 Accuracy surpasses Gemini Pro 2.5 in music description tasks
The usage is the same as Qwen2.5 Omni-7B.
Use the following prompt to caption audio:
*Task* Describe this audio in detail
The model generates natural language descriptions covering multiple aspects of the music.
A melancholic indie folk track featuring fingerpicked acoustic guitar
as the primary instrument. The song opens with a sparse, contemplative
intro before the vocals enter with a breathy, intimate delivery.
The arrangement gradually builds through the verse, adding subtle
string pads and a gentle kick drum. The chorus lifts with layered
harmonies and a warmer, fuller texture. The bridge introduces a
key change and emotional climax before returning to the stripped-down
acoustic arrangement for the outro.
| Category | Styles |
|---|---|
| Electronic | Ambient, Techno, House, Drum & Bass, Synthwave, IDM, Downtempo |
| Rock | Alternative, Indie, Post-Rock, Progressive, Psychedelic, Grunge |
| Pop | Synth-pop, Electropop, Dream Pop, Art Pop, Indie Pop |
| Classical | Orchestral, Chamber, Minimalist, Neo-Classical, Cinematic |
| World | Latin, African, Middle Eastern, Asian Traditional, Celtic |
| Jazz | Fusion, Smooth, Bebop, Modal, Free Jazz |
| Hip-Hop | Trap, Boom Bap, Lo-fi, Instrumental, Cloud Rap |
| Category | Examples |
|---|---|
| Strings | Acoustic Guitar, Electric Guitar, Violin, Cello, Bass, Harp, Mandolin |
| Keys | Piano, Synthesizer, Organ, Rhodes, Wurlitzer, Mellotron |
| Percussion | Drums, Electronic Drums, Congas, Bongos, Timpani, Vibraphone |
| Wind | Saxophone, Trumpet, Flute, Clarinet, Oboe, French Horn |
| Electronic | Synth Bass, Pad, Lead, Arpeggiator, Sampler, 808, 303 |
| Dimension | Descriptors |
|---|---|
| Texture | Warm, Bright, Dark, Crisp, Muddy, Clean, Distorted, Saturated |
| Space | Reverberant, Dry, Spacious, Intimate, Cavernous, Tight |
| Dynamics | Punchy, Soft, Aggressive, Gentle, Compressed, Dynamic |
| Character | Ethereal, Gritty, Smooth, Raw, Polished, Organic, Synthetic |
From the published model card. Full card on the HuggingFace links in the sidebar.
Using it via the API
Once AxForge deploys acestep-captioner for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (acestep-captioner below is illustrative; you get the exact model name on deployment.)
$ curl -sS https://api.axforge.ai/v1/audio/transcriptions \ -H "Authorization: Bearer $AXFORGE_API_KEY" \ -F model="acestep-captioner" -F file=@audio.mp3
Create an account — your API key is available in the console. 5M tokens/month currently included with every new account at launch.