# Stable Audio 3 Small SFX Base Audio Inpainting > Stable Audio 3 Small SFX Base audio inpainting is the foundational 459 million parameter checkpoint for editing or filling selected sound-effect segments guided by text prompts. ## Overview - **Endpoint**: `https://fal.run/fal-ai/stable-audio-3/small/sfx/base/audio-inpainting` - **Model ID**: `fal-ai/stable-audio-3/small/sfx/base/audio-inpainting` - **Category**: audio-to-audio - **Kind**: inference **Tags**: sfx, editing, restoration ## Pricing - **Price**: $0.0331 per audios For more details, see [fal.ai pricing](https://fal.ai/pricing). ## API Information This model can be used via our HTTP API or more conveniently via our client libraries. See the input and output schema below, as well as the usage examples. ### Input Schema The API accepts the following input parameters: - **`negative_prompt`** (`string`, _optional_): Text description of qualities to avoid in the output. Default value: `""` - Default: `""` - **`num_inference_steps`** (`integer`, _optional_): Number of sampling steps. Base (non-distilled) checkpoints typically need ~50 for good quality. Default value: `50` - Default: `50` - Range: `1` to `100` - **`guidance_scale`** (`float`, _optional_): Classifier-free guidance scale. Higher values follow the prompt more strictly; ~7.0 is a good starting point for base checkpoints. Default value: `7` - Default: `7` - Range: `0` to `25` - **`seed`** (`integer`, _optional_): Random seed for reproducible outputs. Omit for a random seed. - **`enable_prompt_expansion`** (`boolean`, _optional_): If True, the prompt will be expanded using an LLM for more detailed and higher quality results. - Default: `false` - **`enable_safety_checker`** (`boolean`, _optional_): Enable NSFW content safety checking. Default value: `true` - Default: `true` - **`sync_mode`** (`boolean`, _optional_): If True, the audio is returned inline as a data URI and the result is not saved to the request history. - Default: `false` - **`output_format`** (`OutputFormatEnum`, _optional_): Container format for the generated audio output. Default value: `"mp3"` - Default: `"mp3"` - Options: `"mp3"`, `"wav"`, `"flac"`, `"ogg"`, `"opus"`, `"m4a"`, `"aac"` - **`bitrate`** (`string`, _optional_): Audio bitrate for compressed output formats (e.g., mp3, aac, opus). Format e.g. '192k' or '320k'. Ignored for lossless formats (wav, flac). Default value: `"192k"` - Default: `"192k"` - **`prompt`** (`string`, _required_): Text description guiding how the masked region is regenerated. - Examples: "punchy kick drum fill" - **`audio_url`** (`string`, _required_): Source audio. Only the masked region is regenerated. - Examples: "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav" - **`mask_start_seconds`** (`float`, _required_): Start of the region to regenerate, in seconds. - Range: `0` to `120` - Examples: 4 - **`mask_end_seconds`** (`float`, _required_): End of the region to regenerate, in seconds. - Range: `0` to `120` - Examples: 8 **Required Parameters Example**: ```json { "prompt": "punchy kick drum fill", "audio_url": "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav", "mask_start_seconds": 4, "mask_end_seconds": 8 } ``` **Full Example**: ```json { "num_inference_steps": 50, "guidance_scale": 7, "enable_safety_checker": true, "output_format": "mp3", "bitrate": "192k", "prompt": "punchy kick drum fill", "audio_url": "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav", "mask_start_seconds": 4, "mask_end_seconds": 8 } ``` ### Output Schema The API returns the following output format: - **`audio`** (`File`, _required_): The generated audio clip. - **`seed`** (`integer`, _required_): The random seed used for generation. - **`prompt`** (`string`, _required_): The prompt used for generation. **Example Response**: ```json { "audio": { "url": "", "content_type": "image/png", "file_name": "z9RV14K95DvU.png", "file_size": 4404019 }, "prompt": "" } ``` ## Usage Examples ### cURL ```bash curl --request POST \ --url https://fal.run/fal-ai/stable-audio-3/small/sfx/base/audio-inpainting \ --header "Authorization: Key $FAL_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "punchy kick drum fill", "audio_url": "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav", "mask_start_seconds": 4, "mask_end_seconds": 8 }' ``` ### Python Ensure you have the Python client installed: ```bash pip install fal-client ``` Then use the API client to make requests: ```python import fal_client def on_queue_update(update): if isinstance(update, fal_client.InProgress): for log in update.logs: print(log["message"]) result = fal_client.subscribe( "fal-ai/stable-audio-3/small/sfx/base/audio-inpainting", arguments={ "prompt": "punchy kick drum fill", "audio_url": "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav", "mask_start_seconds": 4, "mask_end_seconds": 8 }, with_logs=True, on_queue_update=on_queue_update, ) print(result) ``` ### JavaScript Ensure you have the JavaScript client installed: ```bash npm install --save @fal-ai/client ``` Then use the API client to make requests: ```javascript import { fal } from "@fal-ai/client"; const result = await fal.subscribe("fal-ai/stable-audio-3/small/sfx/base/audio-inpainting", { input: { prompt: "punchy kick drum fill", audio_url: "https://storage.googleapis.com/falserverless/model_tests/diffrythm/rock_en.wav", mask_start_seconds: 4, mask_end_seconds: 8 }, logs: true, onQueueUpdate: (update) => { if (update.status === "IN_PROGRESS") { update.logs.map((log) => log.message).forEach(console.log); } }, }); console.log(result.data); console.log(result.requestId); ``` ## Additional Resources ### Documentation - [Model Playground](https://fal.ai/models/fal-ai/stable-audio-3/small/sfx/base/audio-inpainting) - [API Documentation](https://fal.ai/models/fal-ai/stable-audio-3/small/sfx/base/audio-inpainting/api) - [OpenAPI Schema](https://fal.ai/api/openapi/queue/openapi.json?endpoint_id=fal-ai/stable-audio-3/small/sfx/base/audio-inpainting) ### fal.ai Platform - [Platform Documentation](https://docs.fal.ai) - [Python Client](https://docs.fal.ai/clients/python) - [JavaScript Client](https://docs.fal.ai/clients/javascript)