ACE Step Audio Inpaint | AI Voice Conversion API

ACE-Step Audio Inpaint

ACE-Step Audio Inpaint is a powerful music and audio editing model developed by WaveSpeedAI. It enables precise, intelligent modification of selected time ranges within an existing audio clip — perfect for fixing, remixing, or creatively reimagining tracks without re-generating the whole piece.

Key Features

Precise Segment Editing: Modify only the section you want — define start and end times to edit exactly the range you need.
Seamless Audio Blending: New content merges naturally with surrounding audio for smooth, undetectable transitions.
Flexible Timing Control: Choose whether your start or end times are relative to the beginning or end of the track.
Style & Lyric Adaptability: Add new instrumentation, effects, or lyrics while preserving the overall flow and tone.
Controlled Variation: Adjust how much the regenerated section diverges from the original using seed and creative parameters.

Parameters

Parameter	Description
audio*	Upload or link to an existing audio file (MP3 / WAV).
tags*	Define the target style or mood (e.g., lofi, hiphop, trap, chill).
start_time / end_time	Select the time range (in seconds) to edit.
start_time_relative_to / end_time_relative_to	Choose whether the range is relative to the start or end of the audio.
lyrics	(Optional) Add or replace lyrics for the edited section.
seed	Fix for reproducible results; -1 for randomized variation.

Use Cases

Repair or refine — Fix errors or off-beat moments in specific sections.
Rewrite lyrics — Try new vocal phrasing or emotional tone.
Remix segments — Replace or restyle a part of a song without altering the rest.
Audio storytelling — Modify voiceovers or sound effects within a fixed-length clip.

Pricing

Metric	Price
Per second of source audio	$0.0002 / s

Total cost = duration of uploaded audio (in seconds) × $0.0002

Examples

30s audio → 30 × $0.0002 = $0.006
60s audio → 60 × $0.0002 = $0.012
3 min (180s) audio → 180 × $0.0002 = $0.036

Notes

Pricing is based on the total duration of the source audio file, not the edited segment length.
Ensure uploaded audio URLs are publicly accessible.
Please ensure your content complies with usage guidelines.

Ace Step Audio Inpaint API — Quick start

Grab a WaveSpeedAI API key, then call POST https://api.wavespeed.ai/api/v3/wavespeed-ai/ace-step/audio-inpaint with your input as JSON. The endpoint returns a prediction id; poll the prediction endpoint until status flips to completed, then read the output URL from data.outputs[0]. Examples for Ace Step Audio Inpaint below.

HTTP example

# Submit the prediction
curl -X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/ace-step/audio-inpaint" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $WAVESPEED_API_KEY" \
  -d '{
    "audio": "https://example.com/your-audio.mp3",
    "start_time_relative_to": "start",
    "start_time": 0,
    "end_time_relative_to": "start",
    "end_time": 30,
    "seed": -1
}'

# Response includes a prediction id. Poll for the result:
curl -X GET "https://api.wavespeed.ai/api/v3/predictions/{request_id}/result" \
  -H "Authorization: Bearer $WAVESPEED_API_KEY"

# When status is "completed", read the output from data.outputs[0].

Node.js example

// npm install wavespeed
const WaveSpeed = require('wavespeed');

const client = new WaveSpeed(); // reads WAVESPEED_API_KEY from env

const result = await client.run("wavespeed-ai/ace-step/audio-inpaint", {
        "audio": "https://example.com/your-audio.mp3",
        "start_time_relative_to": "start",
        "start_time": 0,
        "end_time_relative_to": "start",
        "end_time": 30,
        "seed": -1
});

console.log(result.outputs[0]); // → URL of the generated output

Python example

# pip install wavespeed
import wavespeed

output = wavespeed.run(
    "wavespeed-ai/ace-step/audio-inpaint",
    {
    "audio": "https://example.com/your-audio.mp3",
    "start_time_relative_to": "start",
    "start_time": 0,
    "end_time_relative_to": "start",
    "end_time": 30,
    "seed": -1
}
)

print(output["outputs"][0])  # → URL of the generated output

Ace Step Audio Inpaint API — Frequently asked questions

What is the Ace Step Audio Inpaint API?

Ace Step Audio Inpaint is a WaveSpeedAI model for AI inference, exposed as a REST API on WaveSpeedAI. ACE-Step Audio Inpaint edits a specific audio segment to change lyrics or style while preserving the surrounding audio. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing. You can call it programmatically or try it from the playground above.

How do I call the Ace Step Audio Inpaint API?

POST your input parameters to the model's REST endpoint (shown in the API tab of this playground) with your WaveSpeedAI API key in the Authorization header. Submission returns a prediction ID; poll the prediction endpoint until status flips to "completed", then read the output URL from the result. The playground generates a ready-to-paste code sample in Python, JavaScript, or cURL for whatever inputs you've set. Full request/response shape is documented at https://wavespeed.ai/docs/docs-api/wavespeed-ai/ace-step-audio-inpaint.

How much does Ace Step Audio Inpaint cost per run?

Ace Step Audio Inpaint starts at $0.000 per run. That figure is the base price — the final charge scales with the parameters you set in the form (output size, length, count, references, or whatever knobs this model exposes), so a higher-quality or larger output costs more than a minimal one. The exact cost for your current input is shown live next to the Generate button before you submit, and the actual per-call charge is recorded on the prediction afterwards.

What inputs does Ace Step Audio Inpaint accept?

Key inputs: `audio`, `seed`, `end_time`, `end_time_relative_to`, `lyrics`, `start_time`. The full JSON schema (types, defaults, allowed values) is rendered above the Generate button and mirrored in the API reference at https://wavespeed.ai/docs/docs-api/wavespeed-ai/ace-step-audio-inpaint.

How long does Ace Step Audio Inpaint take to generate?

Average end-to-end generation time on WaveSpeedAI is around 82 seconds per request — measured across recent runs. Queue time scales with global demand; live status is visible in the prediction record.

Can I use Ace Step Audio Inpaint outputs commercially?

Commercial usage rights depend on the model's license, set by its provider (WaveSpeedAI). The license summary appears on the model card above; see WaveSpeedAI's Terms of Service for platform-level conditions.

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