Ace Step Audio Outpaint

Ace Step Audio Outpaint

Playground

ACE-Step Audio Outpaint generates seamless start or end extensions that match the original, ideal for intros, outros and longer tracks. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

ACE-Step Audio Outpaint

Extend your audio tracks seamlessly with AI-powered music generation. Upload any audio clip and let the model generate new content before or after it — perfectly matching the style, rhythm, and mood of your original track.

Why It Sounds Great

• Style-aware generation: Uses tag-based guidance to match genres like lofi, hiphop, trap, drum and bass, and more.
• Seamless transitions: Generated audio blends naturally with your original track without abrupt cuts or mismatched beats.
• Bidirectional extension: Extend audio at the beginning, end, or both directions simultaneously.
• Lyrics support: Optionally provide lyrics to guide vocal generation in extended sections.
• Reproducible results: Use the seed parameter to recreate exact outputs or explore variations.

Parameters

How to Use

1. Upload your audio — drag and drop or paste a public URL.
2. Add style tags — describe the genre and mood (e.g., “lofi, hiphop, chill”).
3. Set extension duration:
   • Use extend_after_duration to add time at the end.
   • Use extend_before_duration to add time at the beginning.
4. Add lyrics (optional) — provide text if you want vocals in the extended section.
5. Set seed (optional) — use -1 for random, or a specific number for reproducible results.
6. Run — click the button and wait for generation.
7. Download — preview and save your extended audio.

Pricing

Per-second billing based on total output duration.

Billing Formula

Total cost = (original audio duration + extend_before_duration + extend_after_duration) × $0.0002

Examples

Best Use Cases

• Music Production — Extend loops, intros, or outros for full-length tracks.
• Content Creation — Generate longer background music for videos and podcasts.
• DJ & Remix Work — Create extended mixes or seamless transitions between tracks.
• Game & Media Audio — Produce adaptive music that can loop or extend dynamically.
• Songwriting — Explore new directions by extending existing ideas with AI assistance.

Pro Tips for Best Results

• Use descriptive, specific tags — “lofi, hiphop, jazzy, chill, piano” works better than just “music”.
• For consistent style, keep the original audio and extension durations balanced.
• Experiment with different seeds to find the perfect variation.
• When using lyrics, match the syllable count and rhythm to the expected musical phrasing.
• Start with shorter extensions (15-30s) to test the style match before generating longer segments.

Notes

• If using a URL, ensure it is publicly accessible. A preview player in the interface confirms successful loading.
• Processing time scales with total output duration.
• For best results, use clean source audio with consistent tempo and style.

# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/ace-step/audio-outpaint" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
    "extend_before_duration": 0,
    "extend_after_duration": 30,
    "lyrics": "",
    "seed": -1
}'

# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"