> ## 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.

# Gemini Live

> Use the Google Gemini Live speech-to-speech model in a Zero Runtime pipeline. Setup, options, and usage in Python, JavaScript, and Go.

Gemini Live is a **speech-to-speech** model. It handles transcription, reasoning, and voice
synthesis end-to-end, 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 Google API key in the worker environment. Generate a key from the [Google AI Studio](https://aistudio.google.com/apikey):

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

<Note>
  To run Gemini Live through **Vertex AI**, set `vertexai=True` and authenticate with a
  service account (`GOOGLE_APPLICATION_CREDENTIALS`), as with the [Gemini LLM](/plugins/llm/google#vertex-ai)
  plugin.
</Note>

## Usage

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

<CodeGroup>
  ```python Python theme={null}
  from zrt import Pipeline
  from zrt.plugins import GeminiRealtime, GeminiLiveConfig

  model = GeminiRealtime(
      config=GeminiLiveConfig(
          model="gemini-3.1-flash-live-preview",
          voice="Puck",
          response_modalities=["AUDIO"],
      ),
  )

  pipeline = Pipeline(llm=model)
  ```
</CodeGroup>

<Note>
  The default model is `gemini-3.1-flash-live-preview` in every SDK. Pass `model` explicitly for
  consistency.
</Note>

## Configuration

*`GeminiRealtime` constructor and `GeminiLiveConfig` fields for the Python SDK. The JavaScript SDK passes the same settings via the flat `config` object; the Go SDK via `RealtimeOptions`.*

### Constructor

| Parameter | Type               | Default | Description                                                                         |
| --------- | ------------------ | ------- | ----------------------------------------------------------------------------------- |
| `api_key` | `str`              | `None`  | Gemini API key. Falls back to the `GOOGLE_API_KEY` environment variable when unset. |
| `config`  | `GeminiLiveConfig` | `None`  | Model behavior configuration (see below).                                           |

### `GeminiLiveConfig`

| Field                                | Type            | Default                           | Description                                                                                              |
| ------------------------------------ | --------------- | --------------------------------- | -------------------------------------------------------------------------------------------------------- |
| `model`                              | `str`           | `"gemini-3.1-flash-live-preview"` | Gemini Live model ID.                                                                                    |
| `voice`                              | `str`           | `"Puck"`                          | Output voice: `Puck`, `Charon`, `Kore`, `Fenrir`, or `Aoede`.                                            |
| `language_code`                      | `str`           | `None`                            | Language for speech synthesis.                                                                           |
| `response_modalities`                | `list`          | `["AUDIO"]`                       | Enabled response types (`"TEXT"`, `"AUDIO"`).                                                            |
| `top_p`                              | `float`         | `None`                            | Nucleus-sampling cutoff.                                                                                 |
| `top_k`                              | `int`           | `None`                            | Top-k sampling cutoff.                                                                                   |
| `max_output_tokens`                  | `int`           | `None`                            | Caps the length of each response.                                                                        |
| `thinking_budget`                    | `int`           | `None`                            | Thinking budget; `0` disables it for low-latency voice (native-audio models only).                       |
| `include_thoughts`                   | `bool`          | `False`                           | Include the model's thought summaries in the response.                                                   |
| `vad_start_sensitivity`              | `str`           | `None`                            | Start-of-speech sensitivity for automatic activity detection.                                            |
| `vad_end_sensitivity`                | `str`           | `None`                            | End-of-speech sensitivity for automatic activity detection.                                              |
| `vad_prefix_padding_ms`              | `int`           | `None`                            | Audio padding retained before detected speech, in milliseconds.                                          |
| `vad_silence_duration_ms`            | `int`           | `None`                            | Silence duration that ends a turn, in milliseconds.                                                      |
| `context_compression_trigger_tokens` | `int`           | `None`                            | Token count that triggers context-window compression to extend sessions past the connection cap.         |
| `session_resumption_handle`          | `str`           | `None`                            | Handle used to resume a previous session on reconnect.                                                   |
| `vertexai`                           | `bool`          | `False`                           | Route through Vertex AI instead of the Gemini API.                                                       |
| `vertex_project_id`                  | `str`           | `None`                            | Google Cloud project ID for Vertex AI (required when `vertexai=True`).                                   |
| `vertex_location`                    | `str`           | `"us-central1"`                   | Vertex AI region.                                                                                        |
| `vertex_service_account_json`        | `str` or `dict` | `None`                            | Inline service-account credentials for Vertex AI.                                                        |
| `vertex_service_account_path`        | `str`           | `None`                            | Path to a service-account JSON for Vertex AI. Falls back to `GOOGLE_APPLICATION_CREDENTIALS` when unset. |

## Import paths

| SDK        | Import                                                     | Constructor                                                         |
| ---------- | ---------------------------------------------------------- | ------------------------------------------------------------------- |
| Python     | `from zrt.plugins import GeminiRealtime, GeminiLiveConfig` | `GeminiRealtime(config=GeminiLiveConfig(...))`                      |
| JavaScript | `from '@zrt/js-sdk/plugins/gemini_realtime'`               | `GeminiRealtime({ config: { ... } })`                               |
| Go         | `.../zrt-golang-sdk/plugins/gemini_realtime`               | `gemini_realtime.NewRealtime(gemini_realtime.RealtimeOptions{...})` |

To pair the realtime model with an external STT or TTS, see
[Hybrid mode](/build/configure-a-pipeline/modes#hybrid).