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

# Create Infill Audio

> Create infill audio between two clips.

<Tabs>
  <Tab title="Python">
    ```python theme={null}
    def infill_create(client: Cartesia, *args: str) -> None:
        """Create infill audio between two clips."""
        from pathlib import Path

        if len(args) < 3:
            print("Usage: stt_transcribe <audio_file_before> <audio_file_after> <transcript>")
            sys.exit(1)

        left_file, right_file, *transcript_parts = args

        # Can pass file paths directly (as Path objects)
        response = client.tts.infill(
            model_id="sonic-3",
            language="en",
            transcript=" ".join(transcript_parts),
            left_audio=Path(left_file),
            right_audio=Path(right_file),
            voice_id="6ccbfb76-1fc6-48f7-b71d-91ac6298247b",
            output_format={"container": "wav", "encoding": "pcm_s16le", "sample_rate": 44100},
        )
        response.write_to_file("infill_output.wav")
        print(f"Saved audio to infill_output.wav")
        print(f"Play with: ffplay -f wav infill_output.wav")
    ```

    From [cartesia-python/examples/examples.py:578](https://github.com/cartesia-ai/cartesia-python/blob/v3.2.0/examples/examples.py#L578)
  </Tab>

  <Tab title="Python (Async)">
    ```python theme={null}
    async def infill_create_async(client: AsyncCartesia, *args: str) -> None:
        """Async infill creation."""
        import sys
        from pathlib import Path

        if len(args) < 3:
            print("Usage: infill_create_async <audio_file_before> <audio_file_after> <transcript>")
            sys.exit(1)

        left_file, right_file, *transcript_parts = args

        response = await client.tts.infill(
            model_id="sonic-3",
            language="en",
            transcript=" ".join(transcript_parts),
            left_audio=Path(left_file),
            right_audio=Path(right_file),
            voice_id="6ccbfb76-1fc6-48f7-b71d-91ac6298247b",
            output_format={"container": "wav", "encoding": "pcm_s16le", "sample_rate": 44100},
        )
        await response.write_to_file("infill_output_async.wav")
        print("Saved audio to infill_output_async.wav")
        print("Play with: ffplay -f wav infill_output_async.wav")
    ```

    From [cartesia-python/examples/async\_examples.py:690](https://github.com/cartesia-ai/cartesia-python/blob/v3.2.0/examples/async_examples.py#L690)
  </Tab>
</Tabs>

## Run this example

<Tabs>
  <Tab title="Python">
    ```sh theme={null}
    git clone --branch v3.2.0 https://github.com/cartesia-ai/cartesia-python
    cd cartesia-python
    uv sync
    CARTESIA_API_KEY=YOUR_KEY uv run examples/examples.py infill_create left.wav right.wav "transcript to infill"
    ```
  </Tab>

  <Tab title="Python (Async)">
    ```sh theme={null}
    git clone --branch v3.2.0 https://github.com/cartesia-ai/cartesia-python
    cd cartesia-python
    uv sync
    CARTESIA_API_KEY=YOUR_KEY uv run examples/async_examples.py infill_create_async left.wav right.wav "transcript to infill"
    ```
  </Tab>
</Tabs>