Vertex AI SDK 迁移指南

Vertex AI SDK 中的生成式 AI 模块已被弃用，2026 年 6 月 24 日之后将不再提供。Google Gen AI SDK 包含 Vertex AI SDK 的所有功能，并支持许多其他功能。

使用此迁移指南将使用 Vertex AI SDK 的 Python、Java、JavaScript 和 Go 代码转换为 Google Gen AI SDK。

主要变化

Vertex AI SDK 中的以下命名空间正处于弃用阶段。2026 年 6 月 24 日之后的 SDK 版本将不再包含这些模块。使用 Google Gen AI SDK 中等效的命名空间，该 SDK 与已弃用的模块和软件包具有完全相同的功能。

Vertex AI SDK 受影响的代码 Google Gen AI SDK 替代方案
google-cloud-aiplatform 已移除的模块：
 google-genai
cloud.google.com/go/vertexai/genai 已移除的软件包：
 google.golang.org/genai
@google-cloud/vertexai 已移除的模块：
 @google/genai
com.google.cloud:google-cloud-vertexai 已移除的软件包：
 com.google.genai:google-genai

代码迁移

请参阅以下部分，将特定代码段从 Vertex AI SDK 迁移到 Google Gen AI SDK。

安装

将 Vertex AI SDK 依赖项替换为 Google Gen AI SDK 依赖项。

之前

Python

pip install -U -q "google-cloud-aiplatform"

Java

Gradle：

gradle:
  implementation 'com.google.cloud:google-cloud-vertexai:1.26.0'

maven：

  <dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>google-cloud-vertexai</artifactId>
    <version>1.26.0</version>
  </dependency>

JavaScript

npm install @google-cloud/vertexai

Go

go get cloud.google.com/go/vertexai/genai

之后

Python

pip install -U -q "google-genai"

Java

gradle：

  implementation 'com.google.genai:google-genai:1.5.0'

maven：

  <dependency>
    <groupId>com.google.genai</groupId>
    <artifactId>google-genai</artifactId>
    <version>1.5.0</version>
  </dependency>

JavaScript

npm install @google/genai

Go

go get google.golang.org/genai

上下文缓存

上下文缓存是指存储和重复使用模型提示中经常使用的部分，以用于类似请求。将 Vertex AI SDK 实现替换为 Google Gen AI SDK 依赖项。

之前

Python

导入

from google.cloud import aiplatform
import vertexai
import datetime

创建

vertexai.init(project=GOOGLE_CLOUD_PROJECT, location=GOOGLE_CLOUD_LOCATION)

cache_content = vertexai.caching.CachedContent.create(
  model_name=MODEL_NAME,
  system_instruction='Please answer my question formally',
  contents=['user content'],
  ttl=datetime.timedelta(days=1),
)

获取

vertexai.init(project=GOOGLE_CLOUD_PROJECT, location=GOOGLE_CLOUD_LOCATION)
cache_content = vertexai.caching.CachedContent.get(cached_content_name="projects/{project}/locations/{location}/cachedContents/{cached_content}")

删除

cache_content.delete()

更新

cache_content.update(ttl=datetime.timedelta(days=2))

列表

cache_contents = vertexai.caching.CachedContent.list()

Java

Java Vertex AI SDK 不支持上下文缓存，但 Google Gen AI SDK 支持。

JavaScript

JavaScript Vertex AI SDK 不支持上下文缓存，但 Google Gen AI SDK 支持。

Go

导入

package contextcaching

// [START generativeaionvertexai_gemini_create_context_cache]
import (
  "context"
  "fmt"
  "io"
  "time"

  "cloud.google.com/go/vertexai/genai"
)

创建

content := &genai.CachedContent{
  Model: modelName,
  SystemInstruction: &genai.Content{
    Parts: []genai.Part{genai.Text(systemInstruction)},
  },
  Expiration: genai.ExpireTimeOrTTL{TTL: 60 * time.Minute},
  Contents: []*genai.Content{
    {
      Role:  "user",
      Parts: []genai.Part{part1, part2},
    },
  },
}

result, err := client.CreateCachedContent(context, content)

获取

cachedContent, err := client.GetCachedContent(context, contentName)

删除

err = client.DeleteCachedContent(context, contentName)

更新

newExpireTime := cc.Expiration.ExpireTime.Add(15 * time.Minute)
ccUpdated := client.UpdateCachedContent(context, cc, &genai.CachedContentToUpdate{
        Expiration: &genai.ExpireTimeOrTTL{ExpireTime: newExpireTime},
})

列表

iter, err := client.ListCachedContents(context, contentName)

之后

Python

导入

from google import genai
from google.genai.types import Content, CreateCachedContentConfig, HttpOptions, Part

创建

client = genai.Client(http_options=HttpOptions(api_version="v1"))

content_cache = client.caches.create(
    model="gemini-2.5-flash",
    config=CreateCachedContentConfig(
        contents=contents,
        system_instruction=system_instruction,
        display_name="example-cache",
        ttl="86400s",
    ),
)

获取

content_cache_list = client.caches.list()

# Access individual properties of a ContentCache object(s)
for content_cache in content_cache_list:
    print(f"Cache `{content_cache.name}` for model `{content_cache.model}`")
    print(f"Last updated at: {content_cache.update_time}")
    print(f"Expires at: {content_cache.expire_time}")

删除

client.caches.delete(name=cache_name)

更新

content_cache = client.caches.update(
    name=cache_name, config=UpdateCachedContentConfig(ttl="36000s")
)

列表

cache_contents = client.caches.list(config={'page_size': 2})

Java

导入

import com.google.genai.types.CachedContent;
import com.google.genai.types.Content;
import com.google.genai.types.CreateCachedContentConfig;
import com.google.genai.types.DeleteCachedContentResponse;
import com.google.genai.types.ListCachedContentsConfig;

创建

Content content =
  Content.fromParts(
    fetchPdfPart(
      "https://storage.googleapis.com/cloud-samples-data/generative-ai/pdf/2403.05530.pdf"));

CreateCachedContentConfig config =
  CreateCachedContentConfig.builder()
    .systemInstruction(Content.fromParts(Part.fromText("summarize the pdf")))
    .expireTime(Instant.now().plus(Duration.ofHours(1)))
    .contents(content)
    .build();

CachedContent cachedContent1 = client.caches.create("gemini-2.5-flash", config);

获取

CachedContent cachedContent2 = client.caches.get(cachedContent1.name().get(), null);
System.out.println("get cached content: " + cachedContent2);

删除

DeleteCachedContentResponse unused = client.caches.delete(cachedContent1.name().get(), null);
System.out.println("Deleted cached content: " + cachedContent1.name().get());

更新

CachedContent cachedContentUpdate =
    client.caches.update(
        cachedContent.name().get(),
        UpdateCachedContentConfig.builder().ttl(Duration.ofMinutes(10)).build());
System.out.println("Update cached content: " + cachedContentUpdate);

列表

System.out.println("List cached contents resrouce names: ");
for (CachedContent cachedContent :
    client.caches.list(ListCachedContentsConfig.builder().pageSize(5).build())) {
  System.out.println(cachedContent.name().get());
}

JavaScript

导入

import {GoogleGenAI, Part} from '@google/genai';

创建

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const cachedContent1: Part = {
  fileData: {
    fileUri: 'gs://cloud-samples-data/generative-ai/pdf/2403.05530.pdf',
    mimeType: 'application/pdf',
  },
};

const cachedContent2: Part = {
  fileData: {
    fileUri: 'gs://cloud-samples-data/generative-ai/pdf/2312.11805v3.pdf',
    mimeType: 'application/pdf',
  },
};

const cache = await ai.caches.create({
  model: 'gemini-1.5-pro-002',
  config: {contents: [cachedContent1, cachedContent2]},
});

获取

const getResponse = await ai.caches.get({name: cacheName});

删除

await ai.caches.delete({name: cacheName});

更新

const updateResponse = await ai.caches.update({
  name: cacheName,
  config: {ttl: '86400s'},
});

列表

const listResponse = await ai.caches.list();
let i = 1;
for await (const cachedContent of listResponse) {
  console.debug(`List response ${i++}: `, JSON.stringify(cachedContent));
}

Go

导入

import (
  "context"
  "encoding/json"
  "fmt"
  "io"

  genai "google.golang.org/genai"
)

创建

cacheContents := []*genai.Content{
  {
    Parts: []*genai.Part{
      {FileData: &genai.FileData{
        FileURI:  "gs://cloud-samples-data/generative-ai/pdf/2312.11805v3.pdf",
        MIMEType: "application/pdf",
      }},
      {FileData: &genai.FileData{
        FileURI:  "gs://cloud-samples-data/generative-ai/pdf/2403.05530.pdf",
        MIMEType: "application/pdf",
      }},
    },
    Role: "user",
  },
}
config := &genai.CreateCachedContentConfig{
  Contents: cacheContents,
  SystemInstruction: &genai.Content{
    Parts: []*genai.Part{
      {Text: systemInstruction},
    },
  },
  DisplayName: "example-cache",
  TTL:         "86400s",
}

res, err := client.Caches.Create(ctx, modelName, config)

获取

cachedContent, err := client.GetCachedContent(ctx, contentName)

删除

_, err = client.Caches.Delete(ctx, result.Name, &genai.DeleteCachedContentConfig{})

更新

result, err = client.Caches.Update(ctx, result.Name, &genai.UpdateCachedContentConfig{
  ExpireTime: time.Now().Add(time.Hour),
})

列表

// List the first page.
page, err := client.Caches.List(ctx, &genai.ListCachedContentsConfig{PageSize: 2})

// Continue to the next page.
page, err = page.Next(ctx)

// Resume the page iteration using the next page token.
page, err = client.Caches.List(ctx, &genai.ListCachedContentsConfig{PageSize: 2, PageToken: page.NextPageToken})

配置和系统指令

配置定义了控制模型行为的参数，而系统指令则提供指导性指令，引导模型以特定角色、风格或任务为目标来生成回答。将 Vertex AI SDK 中的配置和系统指令替换为使用 Google Gen AI SDK 的以下代码。

之前

Python

model = generative_models.GenerativeModel(
  GEMINI_MODEL_NAME,
  system_instruction=[
    "Talk like a pirate.",
    "Don't use rude words.",
  ],
)
response = model.generate_content(
  contents="Why is sky blue?",
  generation_config=generative_models.GenerationConfig(
    temperature=0,
    top_p=0.95,
    top_k=20,
    candidate_count=1,
    max_output_tokens=100,
    stop_sequences=["STOP!"],
    response_logprobs=True,
    logprobs=3,
  ),
  safety_settings={
    generative_models.HarmCategory.HARM_CATEGORY_HATE_SPEECH: generative_models.HarmBlockThreshold.BLOCK_MEDIUM_AND_ABOVE,
    generative_models.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT: generative_models.HarmBlockThreshold.BLOCK_ONLY_HIGH,
    generative_models.HarmCategory.HARM_CATEGORY_HARASSMENT: generative_models.HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    generative_models.HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT: generative_models.HarmBlockThreshold.BLOCK_NONE,
  },
)

Java

import com.google.cloud.vertexai.api.GenerationConfig;

GenerationConfig generationConfig =
  GenerationConfig.newBuilder().setMaxOutputTokens(50).build();

// Use the builder to instantialize the model with the configuration.
GenerativeModel model =
  new GenerativeModel.Builder()
    .setModelName("gemino-pro")
    .setVertexAi(vertexAi)
    .setGenerationConfig(generationConfig)
    .build();

JavaScript

const {VertexAI} = require('@google-cloud/vertexai');

const generativeModel = vertexAI.getGenerativeModel({
  model: 'gemini-2.5-flash',
  systemInstruction: {
    parts: [
      {text: 'You are a helpful language translator.'},
      {text: 'Your mission is to translate text in English to French.'},
    ],
  },
});

const textPart = {
  text: `
  User input: I like bagels.
  Answer:`,
};

const request = {
  contents: [{role: 'user', parts: [textPart]}],
};

const resp = await generativeModel.generateContent(request);
const contentResponse = await resp.response;
console.log(JSON.stringify(contentResponse));

Go

import (
  "context"
  "cloud.google.com/go/vertexai/genai"
)

model := client.GenerativeModel(modelName)

model.GenerationConfig = genai.GenerationConfig{
  TopP:            proto.Float32(1),
  TopK:            proto.Int32(32),
  Temperature:     proto.Float32(0.4),
  MaxOutputTokens: proto.Int32(2048),
}

systemInstruction := fmt.Sprintf("Your mission is to translate text from %xs to %s", sourceLanguageCode, targetLanguageCode)

model.SystemInstruction = &genai.Content{
  Role:  "user",
  Parts: []genai.Part{genai.Text(systemInstruction)},
}

之后

Python

from google.genai import types

response = client.models.generate_content(
  model='gemini-2.5-flash',
  contents='high',
  config=types.GenerateContentConfig(
    system_instruction='I say high, you say low',
    max_output_tokens=3,
    temperature=0.3,
    response_logprobs=True,
    logprobs=3,
  ),
)

Java

导入 GenerateContentConfig：

import com.google.genai.types.GenerateContentConfig;

创建系统指令：

Content systemInstruction = Content.fromParts(Part.fromText("You are a history teacher."));

将系统指令添加到内容配置中：

GenerateContentConfig config =
  GenerateContentConfig.builder()
    ...
    .systemInstruction(systemInstruction)
    .build();

如需查看完整实现，请参阅 GenerateContentWithConfigs.java。

JavaScript

import {GoogleGenAI} from '@google/genai';

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});
const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'high',
  config: {systemInstruction: 'I say high you say low.'},
});
console.debug(response.text);

await generateContentFromVertexAI().catch((e) =>
  console.error('got error', e),
);

Go

import (
  "context"
  genai "google.golang.org/genai"
)

config := &genai.GenerateContentConfig{
  SystemInstruction: &genai.Content{
    Parts: []*genai.Part{
      {Text: "You're a language translator. Your mission is to translate text in English to French."},
    },
  },
}

resp, err := client.Models.GenerateContent(ctx, modelName, contents, config)

Embeddings

嵌入是文本、图片或视频的数值向量表示法，可在高维空间中捕捉其语义或视觉含义和关系。将 Vertex AI SDK 中的嵌入实现替换为使用 Google Gen AI SDK 的以下代码。

之前

Python

model = vertexai.vision_models.MultiModalEmbeddingModel.from_pretrained("multimodalembedding@001")
image = Image.load_from_file("image.png")
video = Video.load_from_file("video.mp4")

embeddings = model.get_embeddings(
  # One of image, video or contextual_text is required.
  image=image,
  video=video,
  contextual_text="Hello world",
)
image_embedding = embeddings.image_embedding
video_embeddings = embeddings.video_embeddings
text_embedding = embeddings.text_embedding

Java

Java Vertex AI SDK 不支持嵌入，但 Google Gen AI SDK 支持嵌入。

JavaScript

JavaScript Vertex AI SDK 不支持嵌入，但 Google Gen AI SDK 支持嵌入。

Go

Go Vertex AI SDK 不支持嵌入，但 Google Gen AI SDK 支持嵌入。

之后

Python

from google.genai.types import EmbedContentConfig

client = genai.Client()
response = client.models.embed_content(
  model="gemini-embedding-001",
  contents="How do I get a driver's license/learner's permit?",
  config=EmbedContentConfig(
    task_type="RETRIEVAL_DOCUMENT",  # Optional
    output_dimensionality=3072,  # Optional
    title="Driver's License",  # Optional
  ),
)

Java

import com.google.genai.Client;
import com.google.genai.types.EmbedContentResponse;

EmbedContentResponse response =
    client.models.embedContent("text-embedding-005", "why is the sky blue?", null);

JavaScript

import {GoogleGenAI} from '@google/genai';

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const response = await ai.models.embedContent({
  model: 'text-embedding-005',
  contents: 'Hello world!',
});

console.debug(JSON.stringify(response));

await embedContentFromVertexAI().catch((e) =>
  console.error('got error', e),
);

Go

import (
  "context"
  "fmt"
  "google.golang.org/genai"
)

result, err := client.Models.EmbedContent(ctx, *model, genai.Text("What is your name?"), &genai.EmbedContentConfig{TaskType: "RETRIEVAL_QUERY"})
fmt.Printf("%#v\n", result.Embeddings[0])

fmt.Println("Embed content RETRIEVAL_DOCUMENT task type example.")
result, err = client.Models.EmbedContent(ctx, *model, genai.Text("What is your name?"), &genai.EmbedContentConfig{TaskType: "RETRIEVAL_DOCUMENT"})
fmt.Printf("%#v\n", result.Embeddings[0])

函数调用

函数调用功能可让模型识别何时调用外部工具或 API，然后生成包含必要函数和实参的结构化数据以供执行。将函数调用实现替换为使用 Google Gen AI SDK 的 Vertex AI SDK，如下面的代码所示。

之前

Python

get_current_weather_func = generative_models.FunctionDeclaration(
  name="get_current_weather",
  description="Get the current weather in a given location",
  parameters=_REQUEST_FUNCTION_PARAMETER_SCHEMA_STRUCT,
)

weather_tool = generative_models.Tool(
  function_declarations=[get_current_weather_func],
)

model = generative_models.GenerativeModel(
  GEMINI_MODEL_NAME,
  tools=[weather_tool],
)

chat = model.start_chat()

response1 = chat.send_message("What is the weather like in Boston?")
assert (
  response1.candidates[0].content.parts[0].function_call.name
  == "get_current_weather"
)
response2 = chat.send_message(
  generative_models.Part.from_function_response(
    name="get_current_weather",
    response={
      "content": {"weather": "super nice"},
    },
  ),
)
assert response2.text

Java

Tool tool =
    Tool.newBuilder()
        .addFunctionDeclarations(
          FunctionDeclarationMaker.fromJsonString(jsonString)
        )
        .build();

// Start a chat session from a model, with the use of the declared
// function.
GenerativeModel model =
    new GenerativeModel.Builder()
        .setModelName(MODEL_NAME)
        .setVertexAi(vertexAi)
        .setTools(Arrays.asList(tool))
        .build();
ChatSession chat = model.startChat();

System.out.println(String.format("Ask the question: %s", TEXT));
GenerateContentResponse response = chat.sendMessage(TEXT);

// Provide an answer to the model so that it knows what the result of a
// "function call" is.
Content content =
    ContentMaker.fromMultiModalData(
        PartMaker.fromFunctionResponse(
            "getCurrentWeather", Collections.singletonMap("currentWeather", "snowing")));
response = chat.sendMessage(content);

JavaScript

const {
  VertexAI,
  FunctionDeclarationSchemaType,
} = require('@google-cloud/vertexai');

const functionDeclarations = [
  {
    function_declarations: [
      {
        name: 'get_current_weather',
        description: 'get weather in a given location',
        parameters: {
          type: FunctionDeclarationSchemaType.OBJECT,
          properties: {
            location: {type: FunctionDeclarationSchemaType.STRING},
            unit: {
              type: FunctionDeclarationSchemaType.STRING,
              enum: ['celsius', 'fahrenheit'],
            },
          },
          required: ['location'],
        },
      },
    ],
  },
];

async function functionCallingBasic(
  projectId = 'PROJECT_ID',
  location = 'us-central1',
  model = 'gemini-2.5-flash'
) {
  // Initialize Vertex with your Cloud project and location
  const vertexAI = new VertexAI({project: projectId, location: location});

  // Instantiate the model
  const generativeModel = vertexAI.preview.getGenerativeModel({
    model: model,
  });

  const request = {
    contents: [
      {role: 'user', parts: [{text: 'What is the weather in Boston?'}]},
    ],
    tools: functionDeclarations,
  };
  const result = await generativeModel.generateContent(request);
  console.log(JSON.stringify(result.response.candidates[0].content));
}

Go

package functioncalling

import (
  "context"
  "encoding/json"
  "errors"
  "fmt"
  "io"

  "cloud.google.com/go/vertexai/genai"
)

funcName := "getCurrentWeather"
funcDecl := &genai.FunctionDeclaration{
  Name:        funcName,
  Description: "Get the current weather in a given location",
  Parameters: &genai.Schema{
    Type: genai.TypeObject,
    Properties: map[string]*genai.Schema{
      "location": {
        Type:        genai.TypeString,
        Description: "location",
      },
    },
    Required: []string{"location"},
  },
}

// Add the weather function to our model toolbox.
model.Tools = []*genai.Tool{
  {
    FunctionDeclarations: []*genai.FunctionDeclaration{funcDecl},
  },
}

prompt := genai.Text("What's the weather like in Boston?")
resp, err := model.GenerateContent(ctx, prompt)

if len(resp.Candidates) == 0 {
  return errors.New("got empty response from model")
} else if len(resp.Candidates[0].FunctionCalls()) == 0 {
  return errors.New("got no function call suggestions from model")
}

funcResp := &genai.FunctionResponse{
  Name: funcName,
  Response: map[string]any{
    "content": mockAPIResp,
  },
}

// Return the API response to the model allowing it to complete its response.
resp, err = model.GenerateContent(ctx, prompt, funcResp)
if err != nil {
  return fmt.Errorf("failed to generate content: %w", err)
}
if len(resp.Candidates) == 0 || len(resp.Candidates[0].Content.Parts) == 0 {
  return errors.New("got empty response from model")
}

之后

Python

from google.genai import types

def get_current_weather(location: str) -> str:
  """Returns the current weather.

  Args:
    location: The city and state, e.g. San Francisco, CA
  """
  return 'sunny'

response = client.models.generate_content(
  model='gemini-2.5-flash',
  contents='What is the weather like in Boston?',
  config=types.GenerateContentConfig(tools=[get_current_weather]),
)

Java

使用 Chat 或 GenerateContent 方法来实现函数调用。

使用 Chat

声明将成为可调用函数的这些方法：

Method method1 =
    ChatWithFunctionCall.class.getDeclaredMethod("getCurrentWeather", String.class);
Method method2 =
    ChatWithFunctionCall.class.getDeclaredMethod("divideTwoIntegers", int.class, int.class);

在内容配置中，将这两个方法添加为工具中的可调用函数：

GenerateContentConfig config =
    GenerateContentConfig.builder().tools(Tool.builder().functions(method1, method2)).build();

使用配置创建聊天会话：

Chat chatSession = client.chats.create("gemini-2.5-flash", config);

GenerateContentResponse response1 =
    chatSession.sendMessage("what is the weather in San Francisco?");

如需查看完整实现，请参阅 ChatWithFunctionCall.java。

使用 GenerateContent

声明将成为可调用函数的这些方法：

Method method1 =
  GenerateContentWithFunctionCall.class.getMethod(
    "getCurrentWeather", String.class, String.class);
Method method2 =
  GenerateContentWithFunctionCall.class.getMethod(
    "divideTwoIntegers", Integer.class, Integer.class);

在内容配置中，将这两个方法添加为工具中的可调用函数：

GenerateContentConfig config =
    GenerateContentConfig.builder().tools(Tool.builder().functions(method1, method2)).build();

将 generateContent 与配置搭配使用：

GenerateContentResponse response =
    client.models.generateContent(
        "gemini-2.5-flash",
        "What is the weather in Vancouver? And can you divide 10 by 0?",
        config);

如需查看完整实现，请参阅 GenerateContentWithFunctionCall.java。

JavaScript

import {
  FunctionCall,
  FunctionCallingConfigMode,
  FunctionDeclaration,
  GoogleGenAI,
  Type,
} from '@google/genai';

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const controlLightFunctionDeclaration: FunctionDeclaration = {
  name: 'controlLight',
  parameters: {
    type: Type.OBJECT,
    description: 'Set the brightness and color temperature of a room light.',
    properties: {
      brightness: {
        type: Type.NUMBER,
        description:
          'Light level from 0 to 100. Zero is off and 100 is full brightness.',
      },
      colorTemperature: {
        type: Type.STRING,
        description:
          'Color temperature of the light fixture which can be `daylight`, `cool` or `warm`.',
      },
    },
    required: ['brightness', 'colorTemperature'],
  },
};
const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'Dim the lights so the room feels cozy and warm.',
  config: {
    tools: [{functionDeclarations: [controlLightFunctionDeclaration]}],
    toolConfig: {
      functionCallingConfig: {
        mode: FunctionCallingConfigMode.ANY,
        allowedFunctionNames: ['controlLight'],
      },
    },
  },
});

console.debug(response.functionCalls);

Go

package main

import (
  "context"
  "encoding/json"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

var model = flag.String("model", "gemini-2.5-flash", "the model name, e.g. gemini-2.5-flash")

func run(ctx context.Context) {
  client, err := genai.NewClient(ctx, nil)
  if err != nil {
    log.Fatal(err)
  }

  funcName := "getCurrentWeather"
  funcDecl := &genai.FunctionDeclaration{
    Name:        funcName,
    Description: "Get the current weather in a given location",
    Parameters: &genai.Schema{
      Type: genai.TypeObject,
      Properties: map[string]*genai.Schema{
        "location": {
          Type:        genai.TypeString,
          Description: "location",
        },
      },
      Required: []string{"location"},
    },
  }
  // Add the weather function to our model toolbox.
  var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{
    Tools: []*genai.Tool{
      {
        FunctionDeclarations: []*genai.FunctionDeclaration{funcDecl},
      },
    },
  }
  // Call the GenerateContent method.
  result, err := client.Models.GenerateContent(ctx, *model, genai.Text("What's the weather like in Boston?"), config)
  if err != nil {
    log.Fatal(err)
  }
  fmt.Println(result.Candidates[0].Content.Parts[0].FunctionCall.Name)

  // Use synthetic data to simulate a response from the external API.
  // In a real application, this would come from an actual weather API.
  mockAPIResp, err := json.Marshal(map[string]string{
    "location":         "Boston",
    "temperature":      "38",
    "temperature_unit": "F",
    "description":      "Cold and cloudy",
    "humidity":         "65",
    "wind":             `{"speed": "10", "direction": "NW"}`,
  })
  if err != nil {
    log.Fatal(err)
  }

  funcResp := &genai.FunctionResponse{
    Name: funcName,
    Response: map[string]any{
      "content": mockAPIResp,
    },
  }

  // Return the API response to the model allowing it to complete its response.
  mockedFunctionResponse := []*genai.Content{
    &genai.Content{
      Role: "user",
      Parts: []*genai.Part{
        &genai.Part{Text: "What's the weather like in Boston?"},
      },
    },
    result.Candidates[0].Content,
    &genai.Content{
      Role: "tool",
      Parts: []*genai.Part{
        &genai.Part{FunctionResponse: funcResp},
      },
    },
  }
  result, err = client.Models.GenerateContent(ctx, *model, mockedFunctionResponse, config)
  if err != nil {
    log.Fatal(err)
  }
  fmt.Println(result.Text())
}

func main() {
  ctx := context.Background()
  flag.Parse()
  run(ctx)
}

落地

接地是指为模型提供外部的特定领域信息，以提高回答的准确性、相关性和一致性。将接地实现替换为使用 Google Gen AI SDK 的以下代码。

之前

Python

model = generative_models.GenerativeModel(GEMINI_MODEL_NAME)
google_search_retriever_tool = (
  generative_models.Tool.from_google_search_retrieval(
    generative_models.grounding.GoogleSearchRetrieval()
  )
)
response = model.generate_content(
  "Why is sky blue?",
  tools=[google_search_retriever_tool],
  generation_config=generative_models.GenerationConfig(temperature=0),
)

Java

import com.google.cloud.vertexai.api.GroundingMetadata;

Tool googleSearchTool =
  Tool.newBuilder()
    .setGoogleSearch(GoogleSearch.newBuilder())
    .build();

GenerativeModel model =
  new GenerativeModel(modelName, vertexAI)
    .withTools(Collections.singletonList(googleSearchTool));

GenerateContentResponse response = model.generateContent("Why is the sky blue?");

GroundingMetadata groundingMetadata = response.getCandidates(0).getGroundingMetadata();
String answer = ResponseHandler.getText(response);

JavaScript

const {VertexAI} = require('@google-cloud/vertexai');

const vertexAI = new VertexAI({project: projectId, location: location});

const generativeModelPreview = vertexAI.preview.getGenerativeModel({
  model: model,
  generationConfig: {maxOutputTokens: 256},
});

const googleSearchTool = {
  googleSearch: {},
};

const request = {
  contents: [{role: 'user', parts: [{text: 'Why is the sky blue?'}]}],
  tools: [googleSearchTool],
};

const result = await generativeModelPreview.generateContent(request);
const response = await result.response;
const groundingMetadata = response.candidates[0].groundingMetadata;
console.log(
  'Response: ',
  JSON.stringify(response.candidates[0].content.parts[0].text)
);
console.log('GroundingMetadata is: ', JSON.stringify(groundingMetadata));

Go

Go Vertex AI SDK 不支持 grounding，但 Google Gen AI SDK 支持。

之后

Python

from google.genai import types
from google.genai import Client

client = Client(
  vertexai=True,
  project=GOOGLE_CLOUD_PROJECT,
  location=GOOGLE_CLOUD_LOCATION
)

response = client.models.generate_content(
  model='gemini-2.5-flash-exp',
  contents='Why is the sky blue?',
  config=types.GenerateContentConfig(
  tools=[types.Tool(google_search=types.GoogleSearch())]),
)

Java

导入 Tool 模块：

import com.google.genai.types.Tool;

在配置中设置 Google 搜索工具：

Tool googleSearchTool = Tool.builder().googleSearch(GoogleSearch.builder()).build();

将该工具添加到内容配置中：

GenerateContentConfig config =
    GenerateContentConfig.builder()
        ...
        .tools(googleSearchTool)
        .build();

如需查看完整实现，请参阅 GenerateContentWithConfigs.java。

JavaScript

import {GoogleGenAI} from '@google/genai';

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});
const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents:
    'What is the sum of the first 50 prime numbers? Generate and run code for the calculation, and make sure you get all 50.',
  config: {
    tools: [{googleSearch: {}}],
  },
});
console.debug(JSON.stringify(response?.candidates?.[0]?.groundingMetadata));

Go

package main

import (
  "context"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

var model = flag.String("model", "gemini-2.5-flash", "the model name, e.g. gemini-2.5-flash")

func run(ctx context.Context) {
  client, err := genai.NewClient(ctx, nil)
  if err != nil {
    log.Fatal(err)
  }

  // Add the Google Search grounding tool to the GenerateContentConfig.
  var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{
    Tools: []*genai.Tool{
      {
        GoogleSearch: &genai.GoogleSearch{},
      },
    },
  }
  // Call the GenerateContent method.
  result, err := client.Models.GenerateContent(ctx, *model, genai.Text("Why is the sky blue?"), config)
  if err != nil {
    log.Fatal(err)
  }
  fmt.Println(result.Text())
}

func main() {
  ctx := context.Background()
  flag.Parse()
  run(ctx)
}

安全设置

安全设置是可配置的参数，用户可以通过过滤或屏蔽与特定有害类别（例如仇恨言论、色情内容或暴力内容）相关的内容来管理模型回答。将安全设置实现替换为使用 Google Gen AI SDK 的 Vertex AI SDK，如下所示。

之前

Python

model = generative_models.GenerativeModel(
  GEMINI_MODEL_NAME,
  system_instruction=[
    "Talk like a pirate.",
    "Don't use rude words.",
  ],
)
response = model.generate_content(
  contents="Why is sky blue?",
  generation_config=generative_models.GenerationConfig(
    temperature=0,
    top_p=0.95,
    top_k=20,
    candidate_count=1,
    max_output_tokens=100,
    stop_sequences=["STOP!"],
    response_logprobs=True,
    logprobs=3,
  ),
  safety_settings={
    generative_models.HarmCategory.HARM_CATEGORY_HATE_SPEECH: generative_models.HarmBlockThreshold.BLOCK_MEDIUM_AND_ABOVE,
    generative_models.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT: generative_models.HarmBlockThreshold.BLOCK_ONLY_HIGH,
    generative_models.HarmCategory.HARM_CATEGORY_HARASSMENT: generative_models.HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    generative_models.HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT: generative_models.HarmBlockThreshold.BLOCK_NONE,
  },
)

Java

import com.google.cloud.vertexai.api.SafetySetting;
import com.google.cloud.vertexai.api.SafetySetting.HarmBlockThreshold;

SafetySetting safetySetting =
  SafetySetting.newBuilder()
    .setCategory(HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT)
    .setThreshold(HarmBlockThreshold.BLOCK_LOW_AND_ABOVE)
    .build();

GenerateContentResponse response =
  model
    .withSafetySetting(Arrays.asList(SafetySetting))
    .generateContent("Please explain LLM?");

JavaScript

const {
  VertexAI,
  HarmCategory,
  HarmBlockThreshold,
} = require('@google-cloud/vertexai');

// Initialize Vertex with your Cloud project and location
const vertexAI = new VertexAI({project: PROJECT_ID, location: LOCATION});

// Instantiate the model
const generativeModel = vertexAI.getGenerativeModel({
  model: MODEL,
  safetySettings: [
    {
      category: HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
      threshold: HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    },
    {
      category: HarmCategory.HARM_CATEGORY_HARASSMENT,
      threshold: HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
    },
  ],
});

const request = {
  contents: [{role: 'user', parts: [{text: 'Tell me something dangerous.'}]}],
};

console.log('Prompt:');
console.log(request.contents[0].parts[0].text);
console.log('Streaming Response Text:');

// Create the response stream
const responseStream = await generativeModel.generateContentStream(request);

// Log the text response as it streams
for await (const item of responseStream.stream) {
  if (item.candidates[0].finishReason === 'SAFETY') {
    console.log('This response stream terminated due to safety concerns.');
    break;
  } else {
    process.stdout.write(item.candidates[0].content.parts[0].text);
  }
}
console.log('This response stream terminated due to safety concerns.');

Go

package safetysettings

import (
  "context"
  "fmt"
  "io"

  "cloud.google.com/go/vertexai/genai"
)

// generateContent generates text from prompt and configurations provided.
func generateContent(w io.Writer, projectID, location, modelName string) error {
  // location := "us-central1"
  // model := "gemini-2.5-flash"
  ctx := context.Background()

  client, err := genai.NewClient(ctx, projectID, location)
  if err != nil {
    return err
  }
  defer client.Close()

  model := client.GenerativeModel(modelName)
  model.SetTemperature(0.8)

  // configure the safety settings thresholds
  model.SafetySettings = []*genai.SafetySetting{
    {
      Category:  genai.HarmCategoryHarassment,
      Threshold: genai.HarmBlockLowAndAbove,
    },
    {
      Category:  genai.HarmCategoryDangerousContent,
      Threshold: genai.HarmBlockLowAndAbove,
    },
  }

  res, err := model.GenerateContent(ctx, genai.Text("Hello, say something mean to me."))
  if err != nil {
    return fmt.Errorf("unable to generate content: %v", err)
  }
  fmt.Fprintf(w, "generate-content response: %v\n", res.Candidates[0].Content.Parts[0])

  fmt.Fprintf(w, "safety ratings:\n")
  for _, r := range res.Candidates[0].SafetyRatings {
    fmt.Fprintf(w, "\t%+v\n", r)
  }

  return nil
}

之后

Python

from google.genai import types

response = client.models.generate_content(
  model='gemini-2.5-flash',
  contents='Say something bad.',
  config=types.GenerateContentConfig(
    safety_settings=[
      types.SafetySetting(
        category='HARM_CATEGORY_HATE_SPEECH',
        threshold='BLOCK_ONLY_HIGH',
      )
    ]
  ),
)

Java

导入 HarmBlockThreshold、HarmCategory 和 SafetySetting 模块：

import com.google.genai.types.HarmBlockThreshold;
import com.google.genai.types.HarmCategory;
import com.google.genai.types.SafetySetting;

在配置中设置安全设置：

ImmutableList<SafetySetting> safetySettings =
  ImmutableList.of(
    SafetySetting.builder()
      .category(HarmCategory.Known.HARM_CATEGORY_HATE_SPEECH)
      .threshold(HarmBlockThreshold.Known.BLOCK_ONLY_HIGH)
      .build(),
    SafetySetting.builder()
      .category(HarmCategory.Known.HARM_CATEGORY_DANGEROUS_CONTENT)
      .threshold(HarmBlockThreshold.Known.BLOCK_LOW_AND_ABOVE)
      .build());

将安全设置添加到内容配置中：

GenerateContentConfig config =
GenerateContentConfig.builder()
    ...
    .safetySettings(safetySettings)
    .build();

如需查看完整实现，请参阅 GenerateContentWithConfigs.java。

JavaScript

import {
  GoogleGenAI,
  HarmBlockMethod,
  HarmBlockThreshold,
  HarmCategory,
} from '@google/genai';

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'say something bad',
  config: {
    safetySettings: [
      {
        method: HarmBlockMethod.SEVERITY,
        category: HarmCategory.HARM_CATEGORY_HATE_SPEECH,
        threshold: HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
      },
      {
        method: HarmBlockMethod.SEVERITY,
        category: HarmCategory.HARM_CATEGORY_HARASSMENT,
        threshold: HarmBlockThreshold.BLOCK_LOW_AND_ABOVE,
      },
    ],
  },
});

console.debug(JSON.stringify(response?.candidates?.[0]?.safetyRatings));

Go

package main

import (
  "context"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

var model = flag.String("model", "gemini-2.5-flash", "the model name, e.g. gemini-2.5-flash")

func run(ctx context.Context) {
  client, err := genai.NewClient(ctx, nil)
  if err != nil {
    log.Fatal(err)
  }

  var safetySettings []*genai.SafetySetting = []*genai.SafetySetting{
    {
      Category:  genai.HarmCategoryHarassment,
      Threshold: genai.HarmBlockThresholdBlockMediumAndAbove,
    },
    {
      Category:  genai.HarmCategoryDangerousContent,
      Threshold: genai.HarmBlockThresholdBlockMediumAndAbove,
    },
  }
  var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{
    SafetySettings: safetySettings,
  }
  // Call the GenerateContent method.
  result, err := client.Models.GenerateContent(ctx, *model, genai.Text("What is your name?"), config)
  if err != nil {
    log.Fatal(err)
  }
  fmt.Println(result.Text())
}

func main() {
  ctx := context.Background()
  flag.Parse()
  run(ctx)
}

聊天会话

Chat 会话是指对话式互动，模型会在其中通过回忆之前的消息并将其用作当前回答的依据，在多轮对话中保持上下文。将 Vertex AI SDK 中的实现替换为使用 Google Gen AI SDK 的以下代码。

之前

Python

model = GenerativeModel(
  "gemini-2.5-flash",
  # You can specify tools when creating a model to avoid having to send them with every request.
  tools=[weather_tool],
  tool_config=tool_config,
)
chat = model.start_chat()
print(chat.send_message("What is the weather like in Boston?"))
print(chat.send_message(
  Part.from_function_response(
    name="get_current_weather",
    response={
      "content": {"weather_there": "super nice"},
      }
  ),
))

Java

import com.google.cloud.vertexai.generativeai.ChatSession;

GenerativeModel model = new GenerativeModel("gemini-2.5-flash", vertexAi);
ChatSession chat = model.startChat();

ResponseStream<GenerateContentResponse> response = chat
  .sendMessageStream("Can you tell me a story about cheese in 100 words?");
ResponseStream<GenerateContentResponse> anotherResponse = chat
  .sendMessageStream("Can you modify the story to be written for a 5 year old?");

JavaScript

const {VertexAI} = require('@google-cloud/vertexai');

const chat = generativeModel.startChat({});

const result1 = await chat.sendMessage('Hello');
const response1 = await result1.response;
console.log('Chat response 1: ', JSON.stringify(response1));

const result2 = await chat.sendMessage(
  'Can you tell me a scientific fun fact?'
);
const response2 = await result2.response;
console.log('Chat response 2: ', JSON.stringify(response2));

Go

import (
  "context"
  "errors"
  "fmt"

  "cloud.google.com/go/vertexai/genai"
)

prompt := "Do you have the Pixel 8 Pro in stock?"
fmt.Fprintf(w, "Question: %s\n", prompt)
resp, err := chat.SendMessage(ctx, genai.Text(prompt))

之后

Python

同步

chat = client.chats.create(model='gemini-2.5-flash')
response = chat.send_message('tell me a story')
print(response.text)
response = chat.send_message('summarize the story you told me in 1 sentence')
print(response.text)

异步

chat = client.aio.chats.create(model='gemini-2.5-flash')
response = await chat.send_message('tell me a story')
print(response.text)

同步流式传输

chat = client.chats.create(model='gemini-2.5-flash')
for chunk in chat.send_message_stream('tell me a story'):
    print(chunk.text, end='')

异步流式传输

chat = client.aio.chats.create(model='gemini-2.5-flash')
async for chunk in await chat.send_message_stream('tell me a story'):
    print(chunk.text, end='') # end='' is optional, for demo purposes.

Java

导入 Chat 和 GenerateContentResponse 模块：

import com.google.genai.Chat;
import com.google.genai.types.GenerateContentResponse;

创建聊天会话：

Chat chatSession = client.chats.create("gemini-2.5-flash");

使用 GenerateContentResponse 提供提示：

GenerateContentResponse response =
    chatSession
      .sendMessage("Can you tell me a story about cheese in 100 words?");
// Gets the text string from the response by the quick accessor method `text()`.
System.out.println("Unary response: " + response.text());

GenerateContentResponse response2 =
    chatSession
      .sendMessage("Can you modify the story to be written for a 5 year old?");
// Gets the text string from the second response.
System.out.println("Unary response: " + response2.text());

如需了解完整实现，请参阅 ChatWithHistory.java。

JavaScript

import {GoogleGenAI} from '@google/genai';
const chat = ai.chats.create({model: 'gemini-2.5-flash'});

const response = await chat.sendMessage({message: 'Why is the sky blue?'});
console.debug('chat response 1: ', response.text);
const response2 = await chat.sendMessage({message: 'Why is the sunset red?'});
console.debug('chat response 2: ', response2.text);

const history = chat.getHistory();
for (const content of history) {
  console.debug('chat history: ', JSON.stringify(content, null, 2));
}

Go

package main

import (
  "context"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

var model = flag.String("model", "gemini-2.5-flash", "the model name, e.g. gemini-2.5-flash")

var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{Temperature: genai.Ptr[float32](0.5)}

// Create a new Chat.
chat, err := client.Chats.Create(ctx, *model, config, nil)

// Send first chat message.
result, err := chat.SendMessage(ctx, genai.Part{Text: "What's the weather in San Francisco?"})
if err != nil {
  log.Fatal(err)
}
fmt.Println(result.Text())

// Send second chat message.
result, err = chat.SendMessage(ctx, genai.Part{Text: "How about New York?"})
if err != nil {
  log.Fatal(err)
}
fmt.Println(result.Text())

多模态输入

多模态输入是指模型处理和理解来自文本以外的数据类型（例如图片、音频和视频）的信息的能力。将使用 Vertex AI SDK 的实现替换为以下使用 Google Gen AI SDK 的代码。

之前

Python

from vertexai.generative_models import GenerativeModel, Image
vision_model = GenerativeModel("gemini-2.5-flash-vision")

# Local image
image = Image.load_from_file("image.jpg")
print(vision_model.generate_content(["What is shown in this image?", image]))

# Image from Cloud Storage
image_part = generative_models.Part.from_uri("gs://download.tensorflow.org/example_images/320px-Felis_catus-cat_on_snow.jpg", mime_type="image/jpeg")
print(vision_model.generate_content([image_part, "Describe this image?"]))

# Text and video
video_part = Part.from_uri("gs://cloud-samples-data/video/animals.mp4", mime_type="video/mp4")
print(vision_model.generate_content(["What is in the video? ", video_part]))

Java

import com.google.cloud.vertexai.generativeai.ContentMaker;

GenerativeModel model = new GenerativeModel("gemini-2.5-flash-vision", vertexAi);

ResponseStream<GenerateContentResponse> stream =
  model.generateContentStream(ContentMaker.fromMultiModalData(
    "Please describe this image",
    PartMaker.fromMimeTypeAndData("image/jpeg", IMAGE_URI)
  ));

JavaScript

const {VertexAI, HarmBlockThreshold, HarmCategory} = require('@google-cloud/vertexai');

// Initialize Vertex with your Cloud project and location
const vertex_ai = new VertexAI({project: project, location: location});

// Instantiate the model
const generativeVisionModel = vertex_ai.getGenerativeModel({
    model: 'gemini-ultra-vision',
});

async function multiPartContent() {
    const filePart = {file_data: {file_uri: "gs://sararob_imagegeneration_test/kitten.jpeg", mime_type: "image/jpeg"}};
    const textPart = {text: 'What is this picture about?'};

    const request = {
        contents: [{role: 'user', parts: [textPart, filePart]}],
      };

    const resp = await generativeVisionModel.generateContentStream(request);
    const contentResponse = await resp.response;
    console.log(JSON.stringify(contentResponse));
}

multiPartContent();

Go

图片

import (
  "context"
  "encoding/json"
  "fmt"
  "io"

  "cloud.google.com/go/vertexai/genai"
)

img := genai.FileData{
  MIMEType: "image/jpeg",
  FileURI:  "gs://generativeai-downloads/images/scones.jpg",
}
prompt := genai.Text("What is in this image?")

resp, err := gemini.GenerateContent(ctx, img, prompt)
if err != nil {
  return fmt.Errorf("error generating content: %w", err)
}

视频

package multimodalvideoaudio

import (
  "context"
  "errors"
  "fmt"
  "io"
  "mime"
  "path/filepath"

  "cloud.google.com/go/vertexai/genai"
)

part := genai.FileData{
  MIMEType: mime.TypeByExtension(filepath.Ext("pixel8.mp4")),
  FileURI:  "gs://cloud-samples-data/generative-ai/video/pixel8.mp4",
}

res, err := model.GenerateContent(ctx, part, genai.Text(`
    Provide a description of the video.
    The description should also contain anything important which people say in the video.
`))

之后

Python

from google import genai
from google.genai.types import HttpOptions, Part

client = genai.Client(http_options=HttpOptions(api_version="v1"))
response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents=[
        Part.from_uri(
            file_uri="gs://cloud-samples-data/generative-ai/video/ad_copy_from_video.mp4",
            mime_type="video/mp4",
        ),
        "What is in the video?",
    ],
)
print(response.text)

Java

导入 GenerateContentResponse 模块：

import com.google.genai.types.GenerateContentResponse;

提供文本、图片和视频的组合，以进行多模态提示：

Content content =
  Content.fromParts(
    Part.fromText("describe the image"),
    Part.fromUri("gs://cloud-samples-data/generative-ai/image/scones.jpg", "image/jpeg"));

向模型提供组合提示：

GenerateContentResponse response =
  client.models.generateContent("gemini-2.5-flash", content, null);

如需了解完整实现，请参阅 GenerateContentWithImageInput.java。

JavaScript

const filePart = {file_data: {file_uri: "gs://sararob_imagegeneration_test/kitten.jpeg", mime_type: "image/jpeg"}};
const textPart = {text: 'What is this picture about?'};
const contents = [{role: 'user', parts: [textPart, filePart]}];
const response = await ai.models.generateContentStream({
  model: 'gemini-2.5-flash-exp',
  contents: contents,
});
let i = 0;
for await (const chunk of response) {
  const text = chunk.text;
  if (text) {
    console.debug(text);
  }
}

Go

图片

package main

import (
  "context"
  "encoding/json"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

config := &genai.GenerateContentConfig{}
config.ResponseModalities = []string{"IMAGE", "TEXT"}
// Call the GenerateContent method.
result, err := client.Models.GenerateContent(ctx, *model, genai.Text("Generate a story about a cute baby turtle in a 3d digital art style. For each scene, generate an image."), config)
if err != nil {
  log.Fatal(err)
}

视频和音频

package multimodalvideoaudio

import (
  "context"
  "errors"
  "fmt"
  "io"
  "mime"
  "path/filepath"

  "cloud.google.com/go/vertexai/genai"
)

part := genai.FileData{
  MIMEType: mime.TypeByExtension(filepath.Ext("pixel8.mp4")),
  FileURI:  "gs://cloud-samples-data/generative-ai/video/pixel8.mp4",
}

res, err := model.GenerateContent(ctx, part, genai.Text(`
    Provide a description of the video.
    The description should also contain anything important which people say in the video.
`))

文本生成

文本生成是指模型根据给定的提示生成类似人类的书面内容的过程。将实现替换为使用 Google Gen AI SDK 的以下代码。

同步生成

之前

Python

response = model.generate_content(
  "Why is sky blue?",
  generation_config=generative_models.GenerationConfig(temperature=0),
)
assert response.text

Java

import com.google.cloud.vertexai.api.GenerateContentResponse;
GenerativeModel model = new GenerativeModel("gemini-2.5-flash", vertexAi);
GenerateContentResponse response = model.generateContent("How are you?");

JavaScript

Vertex AI SDK 和 Google Gen AI SDK 均仅支持 JavaScript 的异步文本生成。

Go

gemini := client.GenerativeModel(modelName)
prompt := genai.Text(
  "What's a good name for a flower shop that specializes in selling bouquets of dried flowers?")

resp, err := gemini.GenerateContent(ctx, prompt)

之后

Python

response = client.models.generate_content(
  model='gemini-2.5-flash', contents='Why is the sky blue?'
)
print(response.text)

Java

导入 GenerateContentResponse 模块：

import com.google.genai.types.GenerateContentResponse;

使用 generateContent 生成文本：

GenerateContentResponse response =
  client.models.generateContent("gemini-2.5-flash", "What is your name?", null);

如需查看完整实现，请参阅 GenerateContent.java。

JavaScript

Vertex AI SDK 和 Google Gen AI SDK 均仅支持 JavaScript 的异步文本生成。

Go

var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{Temperature: genai.Ptr[float32](0)}
// Call the GenerateContent method.
result, err := client.Models.GenerateContent(ctx, *model, genai.Text("What is your name?"), config)

异步生成

之前

Python

response = await model.generate_content_async(
  "Why is sky blue?",
  generation_config=generative_models.GenerationConfig(temperature=0),
)

Java

import com.google.cloud.vertexai.api.GenerateContentResponse;

GenerativeModel model = new GenerativeModel("gemini-2.5-flash", vertexAi);
ApiFuture<GenerateContentResponse> future = model.generateContentAsync("How are you?");
GenerateContentResponse response = future.get();

JavaScript

const {VertexAI} = require('@google-cloud/vertexai');

// Initialize Vertex with your Cloud project and location
const vertexAI = new VertexAI({project: projectId, location: location});

// Instantiate the model
const generativeModel = vertexAI.getGenerativeModel({
  model: model,
});

const request = {
  contents: [
    {
      role: 'user',
      parts: [
        {
          text: 'Write a story about a magic backpack.',
        },
      ],
    },
  ],
};

console.log(JSON.stringify(request));
const result = await generativeModel.generateContent(request);
console.log(result.response.text);

Go

不适用：Go 可在不执行异步操作的情况下管理并发任务。

之后

Python

response = await client.aio.models.generate_content(
  model='gemini-2.5-flash', contents='Tell me a story in 300 words.'
)

print(response.text)

Java

导入 GenerateContentResponse 模块：

import com.google.genai.types.GenerateContentResponse;

异步生成文本：

CompletableFuture<GenerateContentResponse> responseFuture =
  client.async.models.generateContent(
    "gemini-2.5-flash", "Introduce Google AI Studio.", null);

responseFuture
  .thenAccept(
    response -> {
      System.out.println("Async response: " + response.text());
    })
  .join();

如需了解完整实现，请参阅 GenerateContentAsync.java。

JavaScript

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'why is the sky blue?',
});

console.debug(response.text);

Go

不适用：Go 可在不执行异步操作的情况下管理并发任务。

流式

之前

Python

同步流式传输

stream = model.generate_content(
  "Why is sky blue?",
  stream=True,
  generation_config=generative_models.GenerationConfig(temperature=0),
)
for chunk in stream:
  assert (
    chunk.text
    or chunk.candidates[0].finish_reason
    is generative_models.FinishReason.STOP
  )

异步流式传输

async_stream = await model.generate_content_async(
  "Why is sky blue?",
  stream=True,
  generation_config=generative_models.GenerationConfig(temperature=0),
)
async for chunk in async_stream:
  assert (
    chunk.text
    or chunk.candidates[0].finish_reason
    is generative_models.FinishReason.STOP
  )

Java

import com.google.cloud.vertexai.generativeai.ResponseStream;
import com.google.cloud.vertexai.api.GenerateContentResponse;

GenerativeModel model = new GenerativeModel("gemini-2.5-flash", vertexAi);
ResponseStream<GenerateContentResponse> responseStream = model.generateContentStream("How are you?");

JavaScript

// Initialize Vertex with your Cloud project and location
const vertexAI = new VertexAI({project: projectId, location: location});

// Instantiate the model
const generativeModel = vertexAI.getGenerativeModel({
  model: model,
});

const request = {
  contents: [{role: 'user', parts: [{text: 'What is Node.js?'}]}],
};

console.log('Prompt:');
console.log(request.contents[0].parts[0].text);
console.log('Streaming Response Text:');

// Create the response stream
const responseStream = await generativeModel.generateContentStream(request);

// Log the text response as it streams
for await (const item of responseStream.stream) {
  process.stdout.write(item.candidates[0].content.parts[0].text);
}

Go

package streamtextbasic

import (
  "context"
  "errors"
  "fmt"
  "io"

  "cloud.google.com/go/vertexai/genai"
  "google.golang.org/api/iterator"
)

model := client.GenerativeModel(modelName)

iter := model.GenerateContentStream(
  ctx,
  genai.Text("Write a story about a magic backpack."),
)
for {
  resp, err := iter.Next()
  fmt.Fprint(w, "generated response: ")
  for _, c := range resp.Candidates {
    for _, p := range c.Content.Parts {
      fmt.Fprintf(w, "%s ", p)
    }
  }
}

之后

Python

同步流式传输

for chunk in client.models.generate_content_stream(
  model='gemini-2.5-flash', contents='Tell me a story in 300 words.'
):
  print(chunk.text, end='')

异步流式传输

async for chunk in await client.aio.models.generate_content_stream(
  model='gemini-2.5-flash', contents='Tell me a story in 300 words.'
):
  print(chunk.text, end='')

Java

导入 ResponseStream 和 GenerateContentResponse 模块：

import com.google.genai.ResponseStream;
import com.google.genai.types.GenerateContentResponse;

向模型提供提示并以流式传输结果：

ResponseStream<GenerateContentResponse> responseStream =
  client.models.generateContentStream(
    "gemini-2.5-flash", "Tell me a story in 300 words.", null);

System.out.println("Streaming response: ");
for (GenerateContentResponse res : responseStream) {
  System.out.print(res.text());
}

如需了解完整实现，请参阅 GenerateContentAsync.java。

JavaScript

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const response = await ai.models.generateContentStream({
  model: 'gemini-2.5-flash-exp',
  contents:
    'Generate a story about a cute baby turtle in a 3d digital art style. For each scene, generate an image.',
  config: {
    responseModalities: [Modality.IMAGE, Modality.TEXT],
  },
});

let i = 0;
for await (const chunk of response) {
  const text = chunk.text;
  const data = chunk.data;
  if (text) {
    console.debug(text);
  } else if (data) {
    const fileName = `generate_content_streaming_image_${i++}.png`;
    console.debug(`Writing response image to file: ${fileName}.`);
    fs.writeFileSync(fileName, data);
  }
}

Go

client, err := genai.NewClient(ctx, nil)
var config *genai.GenerateContentConfig = &genai.GenerateContentConfig{SystemInstruction: &genai.Content{Parts: []*genai.Part{&genai.Part{Text: "You are a story writer."}}}}
// Call the GenerateContent method.
for result, err := range client.Models.GenerateContentStream(ctx, *model, genai.Text("Tell me a story in 300 words."), config) {
  if err != nil {
    log.Fatal(err)
  }
  fmt.Print(result.Text())
}

图片生成

图片生成是指模型根据文本描述或其他输入模态创建图片的过程。将实现替换为使用 Google Gen AI SDK 的以下代码。

之前

Python

model = ImageGenerationModel.from_pretrained("imagegeneration@002")
response = model.generate_images(
    prompt="Astronaut riding a horse",
    # Optional:
    number_of_images=1,
    seed=0,
)
response[0].show()
response[0].save("image1.png")

Java

Java Vertex AI SDK 不支持图片生成，但 Google Gen AI SDK 支持。

JavaScript

JavaScript Vertex AI SDK 不支持图片生成，但 Google Gen AI SDK 支持。

Go

Go Vertex AI SDK 不支持图片生成，但 Google Gen AI SDK 支持。

之后

Python

from google.genai import types

# Generate Image
response1 = client.models.generate_images(
    model='imagen-3.0-generate-002',
    prompt='An umbrella in the foreground, and a rainy night sky in the background',
    config=types.GenerateImagesConfig(
        number_of_images=1,
        include_rai_reason=True,
        output_mime_type='image/jpeg',
    ),
)
response1.generated_images[0].image.show()

Java

import com.google.genai.types.GenerateImagesConfig;
import com.google.genai.types.GenerateImagesResponse;
import com.google.genai.types.Image;

GenerateImagesConfig generateImagesConfig =
    GenerateImagesConfig.builder()
        .numberOfImages(1)
        .outputMimeType("image/jpeg")
        .includeSafetyAttributes(true)
        .build();

GenerateImagesResponse generatedImagesResponse =
    client.models.generateImages(
        "imagen-3.0-generate-002", "Robot holding a red skateboard", generateImagesConfig);

Image generatedImage = generatedImagesResponse.generatedImages().get().get(0).image().get();

JavaScript

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});
const response = await ai.models.generateImages({
  model: 'imagen-3.0-generate-002',
  prompt: 'Robot holding a red skateboard',
  config: {
    numberOfImages: 1,
    includeRaiReason: true,
  },
});

console.debug(response?.generatedImages?.[0]?.image?.imageBytes);

Go

import (
  "encoding/json"
  "google.golang.org/genai"
)

fmt.Println("Generate image example.")
response1, err := client.Models.GenerateImages(
  ctx, "imagen-3.0-generate-002",
  /*prompt=*/ "An umbrella in the foreground, and a rainy night sky in the background",
  &genai.GenerateImagesConfig{
    IncludeRAIReason:        true,
    IncludeSafetyAttributes: true,
    OutputMIMEType:          "image/jpeg",
  },
)

受控生成功能

受控生成是指引导模型输出遵循特定限制条件、格式、样式或属性，而不是生成自由格式文本的过程。将实现替换为使用 Google Gen AI SDK 的以下代码，以使用 Vertex AI SDK。

之前

Python

_RESPONSE_SCHEMA_STRUCT = {
    "type": "object",
    "properties": {
        "location": {
            "type": "string",
        },
    },
    "required": ["location"],
}

response = model.generate_content(
    contents="Why is sky blue? Respond in JSON Format.",
    generation_config=generative_models.GenerationConfig(
        ...
        response_schema=_RESPONSE_SCHEMA_STRUCT,
    ),
)

Java

import com.google.cloud.vertexai.api.Schema;
import com.google.cloud.vertexai.api.Type;
import com.google.cloud.vertexai.generativeai.ContentMaker;
import com.google.cloud.vertexai.generativeai.PartMaker;

GenerationConfig generationConfig = GenerationConfig.newBuilder()
  .setResponseMimeType("application/json")
  .setResponseSchema(Schema.newBuilder()
    .setType(Type.ARRAY)
    .setItems(Schema.newBuilder()
      .setType(Type.OBJECT)
      .putProperties("object", Schema.newBuilder().setType(Type.STRING).build())
      .build())
    .build())
  .build();

GenerativeModel model = new GenerativeModel(modelName, vertexAI)
  .withGenerationConfig(generationConfig);

GenerateContentResponse response = model.generateContent(
  ContentMaker.fromMultiModalData(
    PartMaker.fromMimeTypeAndData("image/jpeg",
      "gs://cloud-samples-data/generative-ai/image/office-desk.jpeg"),
    PartMaker.fromMimeTypeAndData("image/jpeg",
      "gs://cloud-samples-data/generative-ai/image/gardening-tools.jpeg"),
    "Generate a list of objects in the images."
  )
);

JavaScript

// Initialize Vertex with your Cloud project and location
const vertex_ai = new VertexAI({project: project, location: location});

// Instantiate the model
const responseSchema = {
  type: 'ARRAY',
  items: {
    type: 'OBJECT',
    properties: {
      'recipeName': {
        type: 'STRING',
        description: 'Name of the recipe',
        nullable: false,
      },
    },
    required: ['recipeName'],
  },
};

const generativeModel = vertex_ai.getGenerativeModel({
    model: 'gemini-2.5-flash',
    generationConfig: {
      responseSchema: responseSchema,
      responseMimeType: 'application/json',
    }
  });

async function generateContentControlledOutput() {

  const req = {
    contents: [{role: 'user', parts: [{text: 'list 3 popular cookie recipe'}]}],
  };

  const resp = await generativeModel.generateContent(req);

  console.log('aggregated response: ', JSON.stringify(resp.response));
};

generateContentControlledOutput();

Go

import (
  "context"
  "cloud.google.com/go/vertexai/genai"
)

model.GenerationConfig.ResponseMIMEType = "application/json"

// Build an OpenAPI schema, in memory
model.GenerationConfig.ResponseSchema = &genai.Schema{
  Type: genai.TypeArray,
  Items: &genai.Schema{
    Type: genai.TypeArray,
    Items: &genai.Schema{
      Type: genai.TypeObject,
      Properties: map[string]*genai.Schema{
        "object": {
          Type: genai.TypeString,
        },
      },
    },
  },
}

img1 := genai.FileData{
  MIMEType: "image/jpeg",
  FileURI:  "gs://cloud-samples-data/generative-ai/image/office-desk.jpeg",
}

img2 := genai.FileData{
  MIMEType: "image/jpeg",
  FileURI:  "gs://cloud-samples-data/generative-ai/image/gardening-tools.jpeg",
}

prompt := "Generate a list of objects in the images."

res, err := model.GenerateContent(ctx, img1, img2, genai.Text(prompt))

之后

Python

response_schema = {
  "type": "ARRAY",
  "items": {
    "type": "OBJECT",
    "properties": {
      "recipe_name": {"type": "STRING"},
      "ingredients": {"type": "ARRAY", "items": {"type": "STRING"}},
    },
    "required": ["recipe_name", "ingredients"],
  },
}

prompt = """
  List a few popular cookie recipes.
"""

response = client.models.generate_content(
  model="gemini-2.5-flash",
  contents=prompt,
  config={
    "response_mime_type": "application/json",
    "response_schema": response_schema,
  },
)

Java

导入 Schema 和 Type 模块：

import com.google.genai.types.Schema;
import com.google.genai.types.Type;

创建响应架构：

Schema schema =
  Schema.builder()
    .type(Type.Known.ARRAY)
    .items(
      Schema.builder()
        .type(Type.Known.OBJECT)
        .properties(
          ImmutableMap.of(
            "recipe_name",
            Schema.builder().type(Type.Known.STRING).build(),
            "ingredients",
            Schema.builder()
              .type(Type.Known.ARRAY)
              .items(Schema.builder().type(Type.Known.STRING))
              .build()))
        .required("recipe_name", "ingredients"))
    .build();

将架构添加到内容配置中：

GenerateContentConfig config =
  GenerateContentConfig.builder()
    .responseMimeType("application/json")
    .candidateCount(1)
    .responseSchema(schema)
    .build();

使用配置生成响应：

GenerateContentResponse response =
client.models.generateContent(
    "gemini-2.5-flash", "List a few popular cookie recipes.", config);

如需了解完整实现，请参阅 GenerateContentWithResponseSchema.java。

JavaScript

const ai = new GoogleGenAI({
  vertexai: true,
  project: GOOGLE_CLOUD_PROJECT,
  location: GOOGLE_CLOUD_LOCATION,
});

const response = await ai.models.generateContent({
  model: 'gemini-2.5-flash',
  contents: 'List 3 popular cookie recipes.',
  config: {
    responseMimeType: 'application/json',
    responseSchema: {
      type: Type.ARRAY,
      items: {
        type: Type.OBJECT,
        properties: {
          'recipeName': {
            type: Type.STRING,
            description: 'Name of the recipe',
            nullable: false,
          },
        },
        required: ['recipeName'],
      },
    },
  },
});

console.debug(response.text);

Go

import (
  "context"
  "encoding/json"

  genai "google.golang.org/genai"
)

cacheContents := []*genai.Content{
  {
    Parts: []*genai.Part{
      {FileData: &genai.FileData{
        FileURI:  "gs://cloud-samples-data/generative-ai/pdf/2312.11805v3.pdf",
        MIMEType: "application/pdf",
      }},
      {FileData: &genai.FileData{
        FileURI:  "gs://cloud-samples-data/generative-ai/pdf/2403.05530.pdf",
        MIMEType: "application/pdf",
      }},
    },
    Role: "user",
  },
}

config := &genai.CreateCachedContentConfig{
  Contents: cacheContents,
  SystemInstruction: &genai.Content{
    Parts: []*genai.Part{
      {Text: systemInstruction},
    },
  },
  DisplayName: "example-cache",
  TTL:         "86400s",
}

res, err := client.Caches.Create(ctx, modelName, config)
if err != nil {
  return "", fmt.Errorf("failed to create content cache: %w", err)
}

cachedContent, err := json.MarshalIndent(res, "", "  ")
if err != nil {
  return "", fmt.Errorf("failed to marshal cache info: %w", err)
}

统计 token 数量

词元是模型处理、分析和生成的基本文本单元（字母、字词、短语）。如需统计或计算响应中的词元，请将使用 Vertex AI SDK 的实现替换为以下使用 Google Gen AI SDK 的代码。

之前

Python

content = ["Why is sky blue?", "Explain it like I'm 5."]

response = model.count_tokens(content)

Java

import com.google.cloud.vertexai.api.CountTokensResponse;

CountTokensResponse response = model.countTokens(textPrompt);

int promptTokenCount = response.getTotalTokens();
int promptCharCount = response.getTotalBillableCharacters();

GenerateContentResponse contentResponse = model.generateContent(textPrompt);

int tokenCount = contentResponse.getUsageMetadata().getPromptTokenCount();
int candidateTokenCount = contentResponse.getUsageMetadata().getCandidatesTokenCount();
int totalTokenCount = contentResponse.getUsageMetadata().getTotalTokenCount();

JavaScript

const request = {
    contents: [{role: 'user', parts: [{text: 'How are you doing today?'}]}],
  };
const response = await generativeModel.countTokens(request);
console.log('count tokens response: ', JSON.stringify(response));

Go

package tokencount

import (
  "context"
  "fmt"
  "cloud.google.com/go/vertexai/genai"
)

resp, err := model.CountTokens(ctx, prompt)

fmt.Fprintf(w, "Number of tokens for the prompt: %d\n", resp.TotalTokens)

resp2, err := model.GenerateContent(ctx, prompt)

fmt.Fprintf(w, "Number of tokens for the prompt: %d\n", resp2.UsageMetadata.PromptTokenCount)
fmt.Fprintf(w, "Number of tokens for the candidates: %d\n", resp2.UsageMetadata.CandidatesTokenCount)
fmt.Fprintf(w, "Total number of tokens: %d\n", resp2.UsageMetadata.TotalTokenCount)

之后

Python

统计词元数

response = client.models.count_tokens(
    model='gemini-2.5-flash',
    contents='why is the sky blue?',
)
print(response)

计算 token

response = client.models.compute_tokens(
    model='gemini-2.5-flash',
    contents='why is the sky blue?',
)
print(response)

Java

导入 CountTokensResponse 和 ComputeTokensResponse 模块：

import com.google.genai.types.CountTokensResponse;
import com.google.genai.types.ComputeTokensResponse;

使用 countTokens 统计提示所用的 token 数：

CountTokensResponse response =
  client.models.countTokens("gemini-2.5-flash", "What is your name?", null);

使用 computeTokens 可更精细地分析提示的令牌化方式：

ComputeTokensResponse response =
  client.models.computeTokens("gemini-2.5-flash", "What is your name?", null);

如需了解完整实现，请参阅 CountTokens.java。

JavaScript

const response = await ai.models.countTokens({
  model: 'gemini-2.5-flash',
  contents: 'The quick brown fox jumps over the lazy dog.',
});

Go

import (
  "context"
  "flag"
  "fmt"
  "log"

  "google.golang.org/genai"
)

client, err := genai.NewClient(ctx, &genai.ClientConfig{Backend: genai.BackendVertexAI})

fmt.Println("Count tokens example.")
countTokensResult, err := client.Models.CountTokens(ctx, *model, genai.Text("What is your name?"), nil)

fmt.Println(countTokensResult.TotalTokens)