Creare conversazioni con più turni (chat) utilizzando l'API Gemini

Utilizzando Gemini API, puoi creare conversazioni in formato libero in più turni. L'SDK Firebase AI Logic semplifica la procedura gestendo lo stato della conversazione, quindi, a differenza di generateContent() (o generateContentStream()), non devi memorizzare la cronologia della conversazione in autonomia.

Prima di iniziare

Fai clic sul tuo fornitore Gemini API per visualizzare i contenuti e il codice specifici del fornitore in questa pagina.

Se non l'hai ancora fatto, completa la guida introduttiva, che descrive come configurare il progetto Firebase, connettere l'app a Firebase, aggiungere l'SDK, inizializzare il servizio di backend per il provider Gemini API scelto e creare un'istanza GenerativeModel.

Per testare e perfezionare i prompt e persino ottenere uno snippet di codice generato, ti consigliamo di utilizzare Google AI Studio.

Creare un'esperienza di chat solo testuale

Prima di provare questo esempio, completa la sezione Prima di iniziare di questa guida per configurare il progetto e l'app.
In questa sezione, fai clic anche su un pulsante per il provider Gemini API che hai scelto, in modo da visualizzare i contenuti specifici del provider in questa pagina.

Per creare una conversazione in più turni (come una chat), inizia inizializzando la chat chiamando startChat(). Poi utilizza sendMessage() per inviare un nuovo messaggio all'utente, che aggiungerà anche il messaggio e la risposta alla cronologia della chat.

Esistono due possibili opzioni per role associato ai contenuti di una conversazione:

  • user: il ruolo che fornisce i prompt. Questo valore è il valore predefinito per le chiamate a sendMessage() e la funzione genera un'eccezione se viene passato un ruolo diverso.

  • model: il ruolo che fornisce le risposte. Questo ruolo può essere utilizzato quando si chiama startChat() con history esistente.

Swift

Puoi chiamare startChat() e sendMessage() per inviare un messaggio a un nuovo utente:


import FirebaseAI

// Initialize the Gemini Developer API backend service
let ai = FirebaseAI.firebaseAI(backend: .googleAI())

// Create a `GenerativeModel` instance with a model that supports your use case
let model = ai.generativeModel(modelName: "gemini-2.5-flash")


// Optionally specify existing chat history
let history = [
  ModelContent(role: "user", parts: "Hello, I have 2 dogs in my house."),
  ModelContent(role: "model", parts: "Great to meet you. What would you like to know?"),
]

// Initialize the chat with optional chat history
let chat = model.startChat(history: history)

// To generate text output, call sendMessage and pass in the message
let response = try await chat.sendMessage("How many paws are in my house?")
print(response.text ?? "No text in response.")

Kotlin

Puoi chiamare startChat() e sendMessage() per inviare un messaggio a un nuovo utente:

Per Kotlin, i metodi in questo SDK sono funzioni di sospensione e devono essere chiamati da un ambito di coroutine. 

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
val model = Firebase.ai(backend = GenerativeBackend.googleAI())
                        .generativeModel("gemini-2.5-flash")


// Initialize the chat
val chat = generativeModel.startChat(
  history = listOf(
    content(role = "user") { text("Hello, I have 2 dogs in my house.") },
    content(role = "model") { text("Great to meet you. What would you like to know?") }
  )
)

val response = chat.sendMessage("How many paws are in my house?")
print(response.text)

Java

Puoi chiamare startChat() e sendMessage() per inviare un messaggio a un nuovo utente:

Per Java, i metodi in questo SDK restituiscono un ListenableFuture. 

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI())
        .generativeModel("gemini-2.5-flash");

// Use the GenerativeModelFutures Java compatibility layer which offers
// support for ListenableFuture and Publisher APIs
GenerativeModelFutures model = GenerativeModelFutures.from(ai);


// (optional) Create previous chat history for context
Content.Builder userContentBuilder = new Content.Builder();
userContentBuilder.setRole("user");
userContentBuilder.addText("Hello, I have 2 dogs in my house.");
Content userContent = userContentBuilder.build();

Content.Builder modelContentBuilder = new Content.Builder();
modelContentBuilder.setRole("model");
modelContentBuilder.addText("Great to meet you. What would you like to know?");
Content modelContent = userContentBuilder.build();

List<Content> history = Arrays.asList(userContent, modelContent);

// Initialize the chat
ChatFutures chat = model.startChat(history);

// Create a new user message
Content.Builder messageBuilder = new Content.Builder();
messageBuilder.setRole("user");
messageBuilder.addText("How many paws are in my house?");

Content message = messageBuilder.build();

// Send the message
ListenableFuture<GenerateContentResponse> response = chat.sendMessage(message);
Futures.addCallback(response, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        String resultText = result.getText();
        System.out.println(resultText);
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web

Puoi chiamare startChat() e sendMessage() per inviare un messaggio a un nuovo utente:


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend } from "firebase/ai";

// TODO(developer) Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, { model: "gemini-2.5-flash" });


async function run() {
  const chat = model.startChat({
    history: [
      {
        role: "user",
        parts: [{ text: "Hello, I have 2 dogs in my house." }],
      },
      {
        role: "model",
        parts: [{ text: "Great to meet you. What would you like to know?" }],
      },
    ],
    generationConfig: {
      maxOutputTokens: 100,
    },
  });

  const msg = "How many paws are in my house?";

  const result = await chat.sendMessage(msg);

  const response = await result.response;
  const text = response.text();
  console.log(text);
}

run();

Dart

Puoi chiamare startChat() e sendMessage() per inviare un messaggio a un nuovo utente:


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

// Initialize FirebaseApp
await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a model that supports your use case
final model =
      FirebaseAI.googleAI().generativeModel(model: 'gemini-2.5-flash');


final chat = model.startChat();
// Provide a prompt that contains text
final prompt = [Content.text('Write a story about a magic backpack.')];

final response = await chat.sendMessage(prompt);
print(response.text);

Unity

Puoi chiamare StartChat() e SendMessageAsync() per inviare un messaggio a un nuovo utente:


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service
var ai = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI());

// Create a `GenerativeModel` instance with a model that supports your use case
var model = ai.GetGenerativeModel(modelName: "gemini-2.5-flash");


// Optionally specify existing chat history
var history = new [] {
  ModelContent.Text("Hello, I have 2 dogs in my house."),
  new ModelContent("model", new ModelContent.TextPart("Great to meet you. What would you like to know?")),
};

// Initialize the chat with optional chat history
var chat = model.StartChat(history);

// To generate text output, call SendMessageAsync and pass in the message
var response = await chat.SendMessageAsync("How many paws are in my house?");
UnityEngine.Debug.Log(response.Text ?? "No text in response.");

Scopri come scegliere un modello adatta al tuo caso d'uso e alla tua app.

Iterare e modificare le immagini utilizzando la chat multi-turno

Prima di provare questo esempio, completa la sezione Prima di iniziare di questa guida per configurare il progetto e l'app.
In questa sezione, fai clic anche su un pulsante per il provider Gemini API che hai scelto, in modo da visualizzare i contenuti specifici del provider in questa pagina.

Utilizzando la chat multi-turn, puoi interagire con un modello Gemini sulle immagini che genera o che fornisci.

Assicurati di creare un'istanza GenerativeModel, includi responseModalities: ["TEXT", "IMAGE"] nella configurazione del modello e chiama startChat() e sendMessage() per inviare nuovi messaggi agli utenti.

Swift 


import FirebaseAI

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a Gemini model that supports image output
let generativeModel = FirebaseAI.firebaseAI(backend: .googleAI()).generativeModel(
  modelName: "gemini-2.0-flash-preview-image-generation",
  // Configure the model to respond with text and images
  generationConfig: GenerationConfig(responseModalities: [.text, .image])
)

// Initialize the chat
let chat = model.startChat()

guard let image = UIImage(named: "scones") else { fatalError("Image file not found.") }

// Provide an initial text prompt instructing the model to edit the image
let prompt = "Edit this image to make it look like a cartoon"

// To generate an initial response, send a user message with the image and text prompt
let response = try await chat.sendMessage(image, prompt)

// Inspect the generated image
guard let inlineDataPart = response.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let uiImage = UIImage(data: inlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

// Follow up requests do not need to specify the image again
let followUpResponse = try await chat.sendMessage("But make it old-school line drawing style")

// Inspect the edited image after the follow up request
guard let followUpInlineDataPart = followUpResponse.inlineDataParts.first else {
  fatalError("No image data in response.")
}
guard let followUpUIImage = UIImage(data: followUpInlineDataPart.data) else {
  fatalError("Failed to convert data to UIImage.")
}

Kotlin 


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a Gemini model that supports image output
val model = Firebase.ai(backend = GenerativeBackend.googleAI()).generativeModel(
    modelName = "gemini-2.0-flash-preview-image-generation",
    // Configure the model to respond with text and images
    generationConfig = generationConfig {
responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE) }
)

// Provide an image for the model to edit
val bitmap = BitmapFactory.decodeResource(context.resources, R.drawable.scones)

// Create the initial prompt instructing the model to edit the image
val prompt = content {
    image(bitmap)
    text("Edit this image to make it look like a cartoon")
}

// Initialize the chat
val chat = model.startChat()

// To generate an initial response, send a user message with the image and text prompt
var response = chat.sendMessage(prompt)
// Inspect the returned image
var generatedImageAsBitmap = response
    .candidates.first().content.parts.firstNotNullOf { it.asImageOrNull() }

// Follow up requests do not need to specify the image again
response = chat.sendMessage("But make it old-school line drawing style")
generatedImageAsBitmap = response
    .candidates.first().content.parts.firstNotNullOf { it.asImageOrNull() }

Java 


// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a Gemini model that supports image output
GenerativeModel ai = FirebaseAI.getInstance(GenerativeBackend.googleAI()).generativeModel(
    "gemini-2.0-flash-preview-image-generation",
    // Configure the model to respond with text and images
    new GenerationConfig.Builder()
        .setResponseModalities(Arrays.asList(ResponseModality.TEXT, ResponseModality.IMAGE))
        .build()
);

GenerativeModelFutures model = GenerativeModelFutures.from(ai);

// Provide an image for the model to edit
Bitmap bitmap = BitmapFactory.decodeResource(resources, R.drawable.scones);

// Initialize the chat
ChatFutures chat = model.startChat();

// Create the initial prompt instructing the model to edit the image
Content prompt = new Content.Builder()
        .setRole("user")
        .addImage(bitmap)
        .addText("Edit this image to make it look like a cartoon")
        .build();

// To generate an initial response, send a user message with the image and text prompt
ListenableFuture<GenerateContentResponse> response = chat.sendMessage(prompt);
// Extract the image from the initial response
ListenableFuture<@Nullable Bitmap> initialRequest = Futures.transform(response, result -> {
    for (Part part : result.getCandidates().get(0).getContent().getParts()) {
        if (part instanceof ImagePart) {
            ImagePart imagePart = (ImagePart) part;
            return imagePart.getImage();
        }
    }
    return null;
}, executor);

// Follow up requests do not need to specify the image again
ListenableFuture<GenerateContentResponse> modelResponseFuture = Futures.transformAsync(
        initialRequest,
        generatedImage -> {
            Content followUpPrompt = new Content.Builder()
                    .addText("But make it old-school line drawing style")
                    .build();
            return chat.sendMessage(followUpPrompt);
        },
        executor);

// Add a final callback to check the reworked image
Futures.addCallback(modelResponseFuture, new FutureCallback<GenerateContentResponse>() {
    @Override
    public void onSuccess(GenerateContentResponse result) {
        for (Part part : result.getCandidates().get(0).getContent().getParts()) {
            if (part instanceof ImagePart) {
                ImagePart imagePart = (ImagePart) part;
                Bitmap generatedImageAsBitmap = imagePart.getImage();
                break;
            }
        }
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
}, executor);

Web 


import { initializeApp } from "firebase/app";
import { getAI, getGenerativeModel, GoogleAIBackend, ResponseModality } from "firebase/ai";

// TODO(developer) Replace the following with your app's Firebase configuration
// See: https://firebase.google.com/docs/web/learn-more#config-object
const firebaseConfig = {
  // ...
};

// Initialize FirebaseApp
const firebaseApp = initializeApp(firebaseConfig);

// Initialize the Gemini Developer API backend service
const ai = getAI(firebaseApp, { backend: new GoogleAIBackend() });

// Create a `GenerativeModel` instance with a model that supports your use case
const model = getGenerativeModel(ai, {
  model: "gemini-2.0-flash-preview-image-generation",
  // Configure the model to respond with text and images
  generationConfig: {
    responseModalities: [ResponseModality.TEXT, ResponseModality.IMAGE],
  },
});

// Prepare an image for the model to edit
async function fileToGenerativePart(file) {
  const base64EncodedDataPromise = new Promise((resolve) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.readAsDataURL(file);
  });
  return {
    inlineData: { data: await base64EncodedDataPromise, mimeType: file.type },
  };
}

const fileInputEl = document.querySelector("input[type=file]");
const imagePart = await fileToGenerativePart(fileInputEl.files[0]);

// Provide an initial text prompt instructing the model to edit the image
const prompt = "Edit this image to make it look like a cartoon";

// Initialize the chat
const chat = model.startChat();

// To generate an initial response, send a user message with the image and text prompt
const result = await chat.sendMessage([prompt, imagePart]);

// Request and inspect the generated image
try {
  const inlineDataParts = result.response.inlineDataParts();
  if (inlineDataParts?.[0]) {
    // Inspect the generated image
    const image = inlineDataParts[0].inlineData;
    console.log(image.mimeType, image.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

// Follow up requests do not need to specify the image again
const followUpResult = await chat.sendMessage("But make it old-school line drawing style");

// Request and inspect the returned image
try {
  const followUpInlineDataParts = followUpResult.response.inlineDataParts();
  if (followUpInlineDataParts?.[0]) {
    // Inspect the generated image
    const followUpImage = followUpInlineDataParts[0].inlineData;
    console.log(followUpImage.mimeType, followUpImage.data);
  }
} catch (err) {
  console.error('Prompt or candidate was blocked:', err);
}

Dart 


import 'package:firebase_ai/firebase_ai.dart';
import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a Gemini model that supports image output
final model = FirebaseAI.googleAI().generativeModel(
  model: 'gemini-2.0-flash-preview-image-generation',
  // Configure the model to respond with text and images
  generationConfig: GenerationConfig(responseModalities: [ResponseModality.text, ResponseModality.image]),
);

// Prepare an image for the model to edit
final image = await File('scones.jpg').readAsBytes();
final imagePart = InlineDataPart('image/jpeg', image);

// Provide an initial text prompt instructing the model to edit the image
final prompt = TextPart("Edit this image to make it look like a cartoon");

// Initialize the chat
final chat = model.startChat();

// To generate an initial response, send a user message with the image and text prompt
final response = await chat.sendMessage([
  Content.multi([prompt,imagePart])
]);

// Inspect the returned image
if (response.inlineDataParts.isNotEmpty) {
  final imageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

// Follow up requests do not need to specify the image again
final followUpResponse = await chat.sendMessage([
  Content.text("But make it old-school line drawing style")
]);

// Inspect the returned image
if (followUpResponse.inlineDataParts.isNotEmpty) {
  final followUpImageBytes = response.inlineDataParts[0].bytes;
  // Process the image
} else {
  // Handle the case where no images were generated
  print('Error: No images were generated.');
}

Unity 


using Firebase;
using Firebase.AI;

// Initialize the Gemini Developer API backend service
// Create a `GenerativeModel` instance with a Gemini model that supports image output
var model = FirebaseAI.GetInstance(FirebaseAI.Backend.GoogleAI()).GetGenerativeModel(
  modelName: "gemini-2.0-flash-preview-image-generation",
  // Configure the model to respond with text and images
  generationConfig: new GenerationConfig(
    responseModalities: new[] { ResponseModality.Text, ResponseModality.Image })
);

// Prepare an image for the model to edit
var imageFile = System.IO.File.ReadAllBytes(System.IO.Path.Combine(
  UnityEngine.Application.streamingAssetsPath, "scones.jpg"));
var image = ModelContent.InlineData("image/jpeg", imageFile);

// Provide an initial text prompt instructing the model to edit the image
var prompt = ModelContent.Text("Edit this image to make it look like a cartoon.");

// Initialize the chat
var chat = model.StartChat();

// To generate an initial response, send a user message with the image and text prompt
var response = await chat.SendMessageAsync(new [] { prompt, image });

// Inspect the returned image
var imageParts = response.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
// Load the image into a Unity Texture2D object
UnityEngine.Texture2D texture2D = new(2, 2);
if (texture2D.LoadImage(imageParts.First().Data.ToArray())) {
  // Do something with the image
}

// Follow up requests do not need to specify the image again
var followUpResponse = await chat.SendMessageAsync("But make it old-school line drawing style");

// Inspect the returned image
var followUpImageParts = followUpResponse.Candidates.First().Content.Parts
                         .OfType<ModelContent.InlineDataPart>()
                         .Where(part => part.MimeType == "image/png");
// Load the image into a Unity Texture2D object
UnityEngine.Texture2D followUpTexture2D = new(2, 2);
if (followUpTexture2D.LoadImage(followUpImageParts.First().Data.ToArray())) {
  // Do something with the image
}

Visualizzare in streaming la risposta

Prima di provare questo esempio, completa la sezione Prima di iniziare di questa guida per configurare il progetto e l'app.
In questa sezione, fai clic anche su un pulsante per il provider Gemini API che hai scelto, in modo da visualizzare i contenuti specifici del provider in questa pagina.

Puoi ottenere interazioni più rapide senza attendere l'intero risultato della generazione del modello e utilizzare invece lo streaming per gestire i risultati parziali. Per riprodurre in streaming la risposta, chiama il numero sendMessageStream().


Cos'altro puoi fare?

Prova altre funzionalità

Scopri come controllare la generazione di contenuti

Puoi anche sperimentare prompt e configurazioni del modello e persino ottenere uno snippet di codice generato utilizzando Google AI Studio.

Scopri di più sui modelli supportati

Scopri di più sui modelli disponibili per vari casi d'uso e sulle relative quote e prezzi.


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