StepAudio 3 Gen API

About StepAudio 3 Gen

Generates dialogue, sound effects, ambience, and background music together in one clip from a written scene.

Character counting follows StepFun pricing: one Chinese character counts as one character, two English letters count as one character, and two punctuation marks count as one character.

Also known as StepFun StepAudio 3 Gen

StepAudio 3 Gen specs

Model ID

stepaudio-3-gen

Author

StepFun

Category

Audio Generation

Released

Sep 9, 2026

Input

Text

Output

Audio

Region

International

Endpoints

POST/v1/audio/generations

Alternate model IDs

stepaudio-3-gen-previewstepfun/stepaudio-3-gen

StepAudio 3 Gen API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

How to call the StepAudio 3 Gen API

StepAudio 3 Gen runs through POST /v1/audio/generations. The request returns a job_id right away; poll GET /v1/jobs/{job_id} until the job completes and read the output URLs from the result. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/audio/generations \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "stepaudio-3-gen",
    "prompt": "Describe what you want StepAudio 3 Gen to generate."
  }'

curl https://api.empiriolabs.ai/v1/jobs/JOB_ID \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY"

import requests

response = requests.post(
    "https://api.empiriolabs.ai/v1/audio/generations",
    headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    json={
        "model": "stepaudio-3-gen",
        "prompt": "Describe what you want StepAudio 3 Gen to generate.",
    },
)
job = response.json()

# Generation runs as an async job. Poll until it completes.
import time
while True:
    status = requests.get(
        f"https://api.empiriolabs.ai/v1/jobs/{job['job_id']}",
        headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    ).json()
    if status.get("status") in ("completed", "failed"):
        print(status)
        break
    time.sleep(5)

StepAudio 3 Gen API parameters

Request parameters supported by the StepAudio 3 Gen API on EmpirioLabs. Defaults apply when a field is omitted.

Good to know

Describe a scene and the model performs it as one finished clip: spoken lines, sound effects, ambience, and background music together. Send a prompt, or use roles and scripts for multi-speaker control. Wrap a sound effect or music cue in square brackets and a delivery direction in parentheses. Roles and instruction are capped at 500 characters each and scripts at 1,000. Output formats are mp3, wav, flac, opus, and pcm. Reference voices and voice cloning are not available on this model. This model is in preview and its capabilities may change.

StepAudio 3 Gen API: common questions

How much does the StepAudio 3 Gen API cost?

On EmpirioLabs, StepAudio 3 Gen is billed pay as you go: Generation $0.36 per 10,000 characters. The live rate card on this page always matches what the API charges.

Which endpoint does StepAudio 3 Gen use?

StepAudio 3 Gen is served through POST /v1/audio/generations on api.empiriolabs.ai with standard bearer-token authentication.

Can I try StepAudio 3 Gen in the browser before integrating?

Yes. The EmpirioLabs playground runs StepAudio 3 Gen in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a StepAudio 3 Gen API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.