> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mosaic.so/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Audio Upload URL

> Create a signed upload URL for an audio asset.

**Limits:** 500 MB, 5 hour duration

## Request

```bash theme={null}
curl -X POST "https://api.mosaic.so/uploads/audio/get_upload_url" \
  -H "Authorization: Bearer mk_your_api_key"
```

## Response

```json theme={null}
{
  "audio_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "upload_url": "https://storage.googleapis.com/...",
  "upload_fields": {
    "key": "...",
    "policy": "...",
    "x-goog-signature": "..."
  },
  "max_file_size_bytes": 524288000
}
```

Use `audio_id` in `update_params` after [finalizing the upload](/api/asset-management/post-uploads-audio-finalize-upload).