Subclip Enhance Audio API

Authentication

Pass your API key in either header:

Authorization: Bearer YOUR_SUBCLIP_API_KEY
x-api-key: YOUR_SUBCLIP_API_KEY

Before you start

Check API key setup, storage quota, and AI credit status on the API overview.

1. Create an upload URL

This creates a Subclip project id. The same projectId is used for upload, job creation, status, and download.

Audio and video inputs are supported. Use the real contentType and fileSize for the file you will upload.

curl -X POST https://www.subclip.app/api/v1/enhance-video/uploads \
  -H "Authorization: Bearer $SUBCLIP_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "fileName": "interview.mp4",
    "contentType": "video/mp4",
    "fileSize": 52428800,
    "projectName": "Interview cleanup"
  }'

{
  "projectId": "veproj_...",
  "uploadUrl": "https://...",
  "objectKey": "user/voice-enhance/...",
  "expiresIn": 900
}

2. Upload the file

Content-Length must match the actual file size. curl --data-binary usually sets it automatically, but Node.js streamed uploads need it explicitly.

curl -X PUT "$UPLOAD_URL" \
  -H "Content-Type: video/mp4" \
  -H "Content-Length: 52428800" \
  --data-binary "@interview.mp4"

3. Start enhancement

durationSeconds is optional. Subclip always detects the uploaded media duration server-side with ffprobe and uses the detected duration for the credit check. If you provide durationSeconds, Subclip verifies it against the uploaded file and rejects mismatches before processing starts.

provider is optional and defaults to cleanvoice. Use cleanvoice when you want an enhanced video output for video input. Use resemble for Resemble AI voice enhancement. For video inputs, Subclip muxes the enhanced Resemble audio back onto the original video and returns final video. For audio inputs, the result is enhanced audio.

Background music separation is disabled for API jobs right now.

curl -X POST https://www.subclip.app/api/v1/enhance-video/jobs \
  -H "Authorization: Bearer $SUBCLIP_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "projectId": "veproj_...",
    "durationSeconds": 180,
    "provider": "cleanvoice"
  }'

4. Poll status

Poll every 5 seconds for normal videos. For longer videos, poll every 15 seconds. Do not poll in a tight loop; if you receive 429 rate_limited, wait until X-RateLimit-Reset before trying again.

curl https://www.subclip.app/api/v1/enhance-video/jobs/veproj_... \
  -H "Authorization: Bearer $SUBCLIP_API_KEY"

{
  "projectId": "veproj_...",
  "status": "completed",
  "provider": "cleanvoice",
  "progress": 100,
  "outputReady": true,
  "outputMediaType": "video",
  "creditsUsed": 20
}

5. Download result

The Subclip API returns JSON with a short-lived signed download URL. Download that URL to get the enhanced bytes. Cleanvoice can return video for video inputs. Resemble returns final video for video inputs and enhanced audio for audio inputs.

DOWNLOAD_JSON=$(curl -s https://www.subclip.app/api/v1/enhance-video/jobs/veproj_.../download \
  -H "Authorization: Bearer $SUBCLIP_API_KEY")

DOWNLOAD_URL=$(echo "$DOWNLOAD_JSON" | jq -r '.downloadUrl')

curl -L "$DOWNLOAD_URL" -o enhanced.mp4

{
  "projectId": "veproj_...",
  "downloadUrl": "https://...",
  "expiresIn": 180,
  "mediaType": "video",
  "contentType": "video/mp4"
}

Errors and limits