Gemini 3.8 Live is the default option for most low-latency voice agent experiences and real-time dialogue without reasoning-induced delays. It supports interleaved reasoning, asynchronous function calling, full session client content updates, and built-in audio streaming.
Documentation
Visit the Live API guide for full coverage of features and capabilities.
gemini-3.8-live
Migrating from Gemini 3.1 Flash Live
Gemini 3.8 Live delivers ultra-low latency audio-to-audio interactions
and expands support for asynchronous workflows. When migrating from
gemini-3.1-flash-live-preview, review the following updates:
- Model string: Update your model string from
gemini-3.1-flash-live-previewtogemini-3.8-live.
- Thinking level: thinking_levelis not supported forgemini-3.8-live. Omitthinking_level(orthinking_config) from your session setup.
- Asynchronous function calling: Async execution (behavior: NON_BLOCKING) is now the default function calling mode. You can still use synchronous blocking mode for backwards compatibility by settingbehavior: BLOCKINGon your tool declarations. Function scheduling (SILENT,WHEN_IDLE,INTERRUPTED) is supported.
- Client content updates: send_client_contentis supported throughout the entire session lifecycle with explicit roles (userormodel). Settingturn_complete=trueunconditionally interrupts active model generation. If you send content withoutturn_complete, the server waits for subsequent messages before responding.
- Proactive audio: Proactive audio is now permanently enabled. Setting
proactive_audio: falsereturns an error.
- Affective dialogue: Affective dialogue is removed from the API. Remove
any enable_affective_dialogconfigurations from your code.
- Turn coverage: Defaults to
TURN_INCLUDES_AUDIO_ACTIVITY_AND_ALL_VIDEO. Video frames are sent to the model by default, so only send frames when needed to manage context and cost.
- Response modalities: Audio is the supported response modality. Enable output audio transcription if your application requires a text transcript.
For a feature comparison across all Live API models, see the Model comparison table.