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

# Azure Voice Live

> Use the Azure Voice Live speech-to-speech model in a Zero Runtime pipeline. Setup and usage in Python.

Azure Voice Live is a **speech-to-speech** model. It unifies speech recognition, generative
AI, and text-to-speech into a single Microsoft Azure endpoint, so it goes in the pipeline's
`llm` slot with no separate STT or TTS. The `Pipeline` auto-detects
[Realtime mode](/build/configure-a-pipeline/modes) when you pass it.

## Setup

Set your Azure Voice Live API key in the worker environment. Generate a key from the [Azure AI Foundry portal](https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/create-resource?pivots=web-portal):

```bash theme={null}
export AZURE_VOICE_LIVE_API_KEY=<key>
```

<Note>
  Azure Voice Live also needs a service endpoint. Pass it explicitly as `endpoint` (or set it
  on `AzureVoiceLiveConfig`), or export it as `AZURE_VOICE_LIVE_ENDPOINT` and it will be picked
  up automatically.
</Note>

```bash theme={null}
export AZURE_VOICE_LIVE_ENDPOINT=<your-azure-ai-service-endpoint>
```

## Usage

Pass the realtime model to the pipeline's `llm` slot, no `stt` or `tts` needed.

```python theme={null}
from zrt import Pipeline
from zrt.plugins import AzureVoiceLive, AzureVoiceLiveConfig

llm = AzureVoiceLive(
    config=AzureVoiceLiveConfig(
        model="gpt-4o-realtime-preview",
        voice="en-US-AvaNeural",
        modalities=["text", "audio"],
    ),
)

pipeline = Pipeline(llm=llm)
```

## Parameters

*Constructor parameters for the Python SDK (`AzureVoiceLive`). Model behavior is configured
through the nested `AzureVoiceLiveConfig` object.*

| Parameter  | Type                   | Default | Description                                                                                                                                          |
| ---------- | ---------------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
| `api_key`  | `str`                  | `None`  | Azure Voice Live API key. Falls back to the `AZURE_VOICE_LIVE_API_KEY` environment variable when unset.                                              |
| `config`   | `AzureVoiceLiveConfig` | `None`  | Model behavior configuration (see below). When omitted, a default `AzureVoiceLiveConfig` is used.                                                    |
| `endpoint` | `str`                  | `None`  | Azure Voice Live service endpoint. Falls back to `config.endpoint`, then the `AZURE_VOICE_LIVE_ENDPOINT` environment variable, then an empty string. |

### `AzureVoiceLiveConfig`

| Field                        | Type                            | Default                     | Description                                                                                                                                                    |
| ---------------------------- | ------------------------------- | --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `model`                      | `str`                           | `"gpt-4o-realtime-preview"` | Voice Live model ID.                                                                                                                                           |
| `voice`                      | `str`                           | `"en-US-AvaNeural"`         | Output voice: an Azure neural voice (e.g. `"en-US-AvaNeural"`) or an OpenAI voice (e.g. `"alloy"`).                                                            |
| `endpoint`                   | `str`                           | `None`                      | Azure Voice Live service endpoint.                                                                                                                             |
| `modalities`                 | `list[str]`                     | `["text", "audio"]`         | Enabled response modalities. Drop `"audio"` for text-only.                                                                                                     |
| `temperature`                | `float`                         | `None`                      | Sampling randomness.                                                                                                                                           |
| `max_response_output_tokens` | `int \| str`                    | `None`                      | Caps the length of each response.                                                                                                                              |
| `turn_detection`             | `TurnDetectionConfig`           | server VAD                  | Turn detection (`server_vad`, threshold `0.5`, `prefix_padding_ms` `300`, `silence_duration_ms` `500`, `create_response` `True`, `interrupt_response` `True`). |
| `input_audio_transcription`  | `InputAudioTranscriptionConfig` | `gpt-4o-mini-transcribe`    | Transcription model for the caller's audio.                                                                                                                    |
| `tool_choice`                | `str`                           | `"auto"`                    | How the model decides when to call tools.                                                                                                                      |

To pair the realtime model with an external STT or TTS instead, see
[the plugins overview](/plugins/overview).