Generate text with Gemini Live API

This sample demonstrates how to generate text using Gemini Live API

Explore further

For detailed documentation that includes this code sample, see the following:

• Live API reference

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Go API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"

	"google.golang.org/genai"
)

// generateLiveWithText demonstrates using a live Gemini model
// that performs live with text and handles responses.
func generateLiveWithText(w io.Writer) error {
	ctx := context.Background()

	client, err := genai.NewClient(ctx, &genai.ClientConfig{
		HTTPOptions: genai.HTTPOptions{APIVersion: "v1"},
	})
	if err != nil {
		return fmt.Errorf("failed to create genai client: %w", err)
	}

	modelName := "gemini-2.0-flash-live-preview-04-09"

	config := &genai.LiveConnectConfig{
		ResponseModalities: []genai.Modality{genai.ModalityText},
	}

	// Open a live session
	session, err := client.Live.Connect(ctx, modelName, config)
	if err != nil {
		return fmt.Errorf("failed to connect live: %w", err)
	}
	defer session.Close()

	// Prepare the input message
	inputText := "Hello? Gemini, are you there?"
	fmt.Fprintf(w, "> %s\n\n", inputText)

	// Send text content to the model
	err = session.SendClientContent(genai.LiveClientContentInput{
		Turns: []*genai.Content{
			{
				Role: genai.RoleUser,
				Parts: []*genai.Part{
					{Text: inputText},
				},
			},
		},
	})
	if err != nil {
		return fmt.Errorf("failed to send content: %w", err)
	}

	// Stream the response
	var response string
	for {
		chunk, err := session.Receive()
		if err != nil {
			if err == io.EOF {
				break
			}
			return fmt.Errorf("error receiving response: %w", err)
		}

		if chunk.ServerContent != nil && chunk.ServerContent.ModelTurn != nil {
			for _, part := range chunk.ServerContent.ModelTurn.Parts {
				if part.Text != "" {
					response += part.Text
				}
			}
		}
	}

	// Example output:
	//  >  Hello? Gemini are you there?
	//  Yes, I'm here. What would you like to talk about?
	fmt.Fprintln(w, response)
	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Java API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import static com.google.genai.types.Modality.Known.TEXT;

import com.google.genai.AsyncSession;
import com.google.genai.Client;
import com.google.genai.types.Content;
import com.google.genai.types.HttpOptions;
import com.google.genai.types.LiveConnectConfig;
import com.google.genai.types.LiveSendClientContentParameters;
import com.google.genai.types.LiveServerContent;
import com.google.genai.types.LiveServerMessage;
import com.google.genai.types.Part;
import java.util.concurrent.CompletableFuture;

public class LiveWithTxt {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String modelId = "gemini-2.0-flash-live-preview-04-09";
    generateContent(modelId);
  }

  // Shows how to send a text prompt and receive messages from the live session.
  public static String generateContent(String modelId) {
    // Client Initialization. Once created, it can be reused for multiple requests.
    try (Client client =
        Client.builder()
            .location("us-central1")
            .vertexAI(true)
            .httpOptions(HttpOptions.builder().apiVersion("v1beta1").build())
            .build()) {

      // Connects to the live server.
      CompletableFuture<AsyncSession> sessionFuture =
          client.async.live.connect(
              modelId, LiveConnectConfig.builder().responseModalities(TEXT).build());

      // Sends and receives messages from the live session.
      CompletableFuture<String> responseFuture =
          sessionFuture.thenCompose(
              session -> {
                // A future that completes when the model signals the end of its turn.
                CompletableFuture<Void> turnComplete = new CompletableFuture<>();
                // A variable to concatenate the text response from the model.
                StringBuilder modelResponse = new StringBuilder();
                // Starts receiving messages from the live session.
                session.receive(
                    message -> handleLiveServerMessage(message, turnComplete, modelResponse));
                // Sends content to the live session and waits for the turn to complete.
                return sendContent(session)
                    .thenCompose(unused -> turnComplete)
                    .thenCompose(
                        unused -> session.close().thenApply(result -> modelResponse.toString()));
              });

      String response = responseFuture.join();
      System.out.println(response);
      // Example output:
      // > Hello? Gemini, are you there?
      //
      // Yes, I am here. How can I help you today?
      return response;
    }
  }

  // Sends content to the live session.
  private static CompletableFuture<Void> sendContent(AsyncSession session) {
    String textInput = "Hello? Gemini, are you there?";
    System.out.printf("> %s\n", textInput);
    return session.sendClientContent(
        LiveSendClientContentParameters.builder()
            .turns(Content.builder().role("user").parts(Part.fromText(textInput)).build())
            .turnComplete(true)
            .build());
  }

  // Concatenates the output transcription from the model and signals
  // `turnComplete` when the model is done generating the response.
  private static void handleLiveServerMessage(
      LiveServerMessage message, CompletableFuture<Void> turnComplete, StringBuilder response) {
    message
        .serverContent()
        .flatMap(LiveServerContent::modelTurn)
        .flatMap(Content::parts)
        .ifPresent(parts -> parts.forEach(part -> part.text().ifPresent(response::append)));
    // Checks if the model's turn is over.
    if (message.serverContent().flatMap(LiveServerContent::turnComplete).orElse(false)) {
      turnComplete.complete(null);
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Node.js API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

'use strict';

const {GoogleGenAI, Modality} = require('@google/genai');

const GOOGLE_CLOUD_PROJECT = process.env.GOOGLE_CLOUD_PROJECT;
const GOOGLE_CLOUD_LOCATION = process.env.GOOGLE_CLOUD_LOCATION || 'global';

async function generateLiveConversation(
  projectId = GOOGLE_CLOUD_PROJECT,
  location = GOOGLE_CLOUD_LOCATION
) {
  const client = new GoogleGenAI({
    vertexai: true,
    project: projectId,
    location: location,
  });

  const modelId = 'gemini-2.0-flash-live-preview-04-09';
  const config = {responseModalities: [Modality.TEXT]};

  const responseQueue = [];

  async function waitMessage() {
    while (responseQueue.length === 0) {
      await new Promise(resolve => setTimeout(resolve, 100));
    }
    return responseQueue.shift();
  }

  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;
      }
    }
    return turns;
  }

  const session = await client.live.connect({
    model: modelId,
    config: config,
    callbacks: {
      onmessage: msg => responseQueue.push(msg),
      onerror: e => console.error('Error:', e.message),
    },
  });

  const textInput = 'Hello? Gemini, are you there?';
  console.log('> ', textInput, '\n');

  await session.sendClientContent({
    turns: [{role: 'user', parts: [{text: textInput}]}],
  });

  const turns = await handleTurn();
  for (const turn of turns) {
    if (turn.text) {
      console.log('Received text:', turn.text);
    }
  }
  // Example output:
  //> Hello? Gemini, are you there?
  // Received text: Yes
  // Received text: I'm here. How can I help you today?
  session.close();
  return turns;
}

Python

Before trying this sample, follow the Python setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Python API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

from google import genai
from google.genai.types import (Content, HttpOptions, LiveConnectConfig,
                                Modality, Part)

client = genai.Client(http_options=HttpOptions(api_version="v1beta1"))
model_id = "gemini-2.0-flash-live-preview-04-09"

async with client.aio.live.connect(
    model=model_id,
    config=LiveConnectConfig(response_modalities=[Modality.TEXT]),
) as session:
    text_input = "Hello? Gemini, are you there?"
    print("> ", text_input, "\n")
    await session.send_client_content(
        turns=Content(role="user", parts=[Part(text=text_input)])
    )

    response = []

    async for message in session.receive():
        if message.text:
            response.append(message.text)

    print("".join(response))
# Example output:
# >  Hello? Gemini, are you there?
# Yes, I'm here. What would you like to talk about?

What's next

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