Tool use with Live API

Tool use allows Live API to go beyond just conversation by enabling it to perform actions in the real-world and pull in external context while maintaining a real time connection. You can define tools such as Function calling and Google Search with the Live API.

Overview of supported tools

Here's a brief overview of the available tools for Live API models:

Tool Gemini 3.1 Flash Live Preview Gemini 2.5 Flash Live Preview
Search Supported Supported
Function calling Supported (synchronous only) Supported (synchronous and asynchronous)
Google Maps Not supported Not supported
Code execution Not supported Not supported
URL context Not supported Not supported

Function calling

Live API supports function calling, just like regular content generation requests. Function calling lets the Live API interact with external data and programs, greatly increasing what your applications can accomplish.

You can define function declarations as part of the session configuration. After receiving tool calls, the client should respond with a list of FunctionResponse objects using the session.send_tool_response method.

See the Function calling tutorial to learn more.

Python

import asyncio
import wave
from google import genai
from google.genai import types

client = genai.Client()

model = "gemini-3.8-live"

# Simple function definitions
turn_on_the_lights = {"name": "turn_on_the_lights"}
turn_off_the_lights = {"name": "turn_off_the_lights"}

tools = [{"function_declarations": [turn_on_the_lights, turn_off_the_lights]}]
config = {"response_modalities": ["AUDIO"], "tools": tools}

async def main():
    async with client.aio.live.connect(model=model, config=config) as session:
        prompt = "Turn on the lights please"
        await session.send_client_content(turns={"parts": [{"text": prompt}]})

        wf = wave.open("audio.wav", "wb")
        wf.setnchannels(1)
        wf.setsampwidth(2)
        wf.setframerate(24000)  # Output is 24kHz

        async for response in session.receive():
            if response.data is not None:
                wf.writeframes(response.data)
            elif response.tool_call:
                print("The tool was called")
                function_responses = []
                for fc in response.tool_call.function_calls:
                    function_response = types.FunctionResponse(
                        id=fc.id,
                        name=fc.name,
                        response={ "result": "ok" } # simple, hard-coded function response
                    )
                    function_responses.append(function_response)

                await session.send_tool_response(function_responses=function_responses)

        wf.close()

if __name__ == "__main__":
    asyncio.run(main())

JavaScript

import { GoogleGenAI, Modality } from '@google/genai';
import * as fs from "node:fs";
import pkg from 'wavefile';  // npm install wavefile
const { WaveFile } = pkg;

const ai = new GoogleGenAI({});
const model = 'gemini-3.8-live';

// Simple function definitions
const turn_on_the_lights = { name: "turn_on_the_lights" } // , description: '...', parameters: { ... }
const turn_off_the_lights = { name: "turn_off_the_lights" }

const tools = [{ functionDeclarations: [turn_on_the_lights, turn_off_the_lights] }]

const config = {
  responseModalities: [Modality.AUDIO],
  tools: tools
}

async function live() {
  const responseQueue = [];

  async function waitMessage() {
    let done = false;
    let message = undefined;
    while (!done) {
      message = responseQueue.shift();
      if (message) {
        done = true;
      } else {
        await new Promise((resolve) => setTimeout(resolve, 100));
      }
    }
    return message;
  }

  async function handleTurn() {
    const turns = [];
    let done = false;
    while (!done) {
      const message = await waitMessage();
      turns.push(message);
      if (message.serverContent && message.serverContent.turnComplete) {
        done = true;
      } else if (message.toolCall) {
        done = true;
      }
    }
    return turns;
  }

  const session = await ai.live.connect({
    model: model,
    callbacks: {
      onopen: function () {
        console.debug('Opened');
      },
      onmessage: function (message) {
        responseQueue.push(message);
      },
      onerror: function (e) {
        console.debug('Error:', e.message);
      },
      onclose: function (e) {
        console.debug('Close:', e.reason);
      },
    },
    config: config,
  });

  const inputTurns = 'Turn on the lights please';
  session.sendClientContent({ turns: inputTurns });

  let turns = await handleTurn();

  for (const turn of turns) {
    if (turn.toolCall) {
      console.debug('A tool was called');
      const functionResponses = [];
      for (const fc of turn.toolCall.functionCalls) {
        functionResponses.push({
          id: fc.id,