获取文本嵌入

重要提示：textembedding-gecko@001 和 textembedding-gecko@002 已弃用，2025 年 4 月 9 日起将无法再使用。请尽快迁移到更高版本。

本文档介绍如何使用 Vertex AI 文本嵌入 API 创建文本嵌入。

Vertex AI 文本嵌入 API 使用密集向量表示法：例如，text-embedding-gecko 使用 768 维向量。密集向量嵌入模型使用与大语言模型所用方法类似的深度学习方法。与倾向于将字词直接映射到数字的稀疏向量不同，密集向量旨在更好地表示一段文本的含义。在生成式 AI 中使用密集向量嵌入的优势在于，您可以更好地搜索与查询含义相符的段落，而不是搜索直接的字词或语法匹配项，即使段落不使用相同的语言也是如此。

• 如需详细了解嵌入，请参阅嵌入 API 概览。
• 如需了解文本嵌入模型，请参阅文本嵌入。
• 如需了解每个嵌入模型支持的语言，请参阅支持的文本语言。

如需查看获取文本嵌入的示例，请在以下其中一个环境中运行“文本嵌入新 API”Jupyter 笔记本：

在 Colab 中打开 | 在 Colab Enterprise 中打开 | 在 Vertex AI Workbench 用户管理的笔记本中打开 | 在 GitHub 上查看

准备工作

1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   Go to project selector

3. Enable the Vertex AI API.

   Enable the API

4. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   Go to project selector

5. Enable the Vertex AI API.

   Enable the API

6. 为嵌入作业选择任务类型。

支持的模型

您可以使用以下模型获取文本嵌入：

英语模型	多语言模型
textembedding-gecko@001	textembedding-gecko-multilingual@001
textembedding-gecko@003	text-multilingual-embedding-002
text-embedding-004
text-embedding-preview-0815

如果您刚开始接触这些模型，我们建议您使用最新版本。对于英语文本，请使用 text-embedding-004。对于多语言文本，请使用 text-multilingual-embedding-002。

注意：请仅使用支持的模型表中列出的模型。请勿将模型指定为 textembedding-gecko（不带 @version 后缀）或 textembedding-gecko@latest。这些模型名称被视为无效。

获取文本片段的文本嵌入

您可以使用 Vertex AI API 或 Python 版 Vertex AI SDK 获取文本片段的文本嵌入。对于每个请求，在 us-central1，输入文本上限为 250 个，而在其他区域，输入文本数上限为 5。 API 的输入词元数量上限为 20,000。超出此限制的输入将导致 500 错误。每个输入文本进一步限制为 2048 个词元；任何多余的内容都会以静默方式截断。您还可以通过将 autoTruncate 设置为 false 来停用静默截断。

默认情况下，所有模型都会生成具有 768 个维度的输出。不过，以下模型可让用户选择 1 到 768 之间的输出维数。通过选择较小的输出维度，用户可以节省内存和存储空间，从而实现更高效的计算。

• text-embedding-004
• text-multilingual-embedding-002
• text-embedding-preview-0815

以下示例使用 text-embedding-004 模型。

REST

如需获取文本嵌入，请通过指定发布者模型的 ID 来发送 POST 请求。

在使用任何请求数据之前，请先进行以下替换：

• PROJECT_ID：您的项目 ID。
• TEXT：您要为其生成嵌入的文本。限制：五个文本，除 textembedding-gecko@001 之外的所有模型的每个文本最多 2,048 个词元。textembedding-gecko@001 的输入词元长度上限为 3072。
• AUTO_TRUNCATE：如果设置为 false，则超出词元限制的文本会导致请求失败。默认值为 true。

HTTP 方法和网址：

POST https://us-central1-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/publishers/google/models/text-embedding-004:predict

请求 JSON 正文：

{
  "instances": [
    { "content": "TEXT"}
  ],
  "parameters": { 
    "autoTruncate": AUTO_TRUNCATE 
  }
}

如需发送请求，请选择以下方式之一：

curl

注意：以下命令假定您已使用您的用户账号通过运行 gcloud init 或 gcloud auth login 登录 gcloud CLI，或者使用了 Cloud Shell，这会使您自动登录 gcloud CLI。您可以运行 gcloud auth list 来检查当前活跃的账号。

将请求正文保存在名为 request.json 的文件中，然后执行以下命令：

curl -X POST \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: application/json; charset=utf-8" \
     -d @request.json \
     "https://us-central1-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/publishers/google/models/text-embedding-004:predict"

PowerShell

注意：以下命令假定您已使用您的用户账号通过运行 gcloud init 或 gcloud auth login 登录 gcloud CLI。您可以运行 gcloud auth list 来检查当前活跃的账号。

将请求正文保存在名为 request.json 的文件中，然后执行以下命令：

$cred = gcloud auth print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://us-central1-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/publishers/google/models/text-embedding-004:predict" | Select-Object -Expand Content

您应该收到类似以下内容的 JSON 响应。请注意，为节省空间，系统截断了 values。

响应

{
  "predictions": [
    {
      "embeddings": {
        "statistics": {
          "truncated": false,
          "token_count": 6
        },
        "values": [ ... ]
      }
    }
  ]
}

示例 curl 命令

MODEL_ID="text-embedding-004"
PROJECT_ID=PROJECT_ID

curl \
-X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Content-Type: application/json" \
https://us-central1-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/publishers/google/models/${MODEL_ID}:predict -d \
$'{
  "instances": [
    { "content": "What is life?"}
  ],
}'

Python

如需了解如何安装或更新 Vertex AI SDK for Python，请参阅安装 Vertex AI SDK for Python。 如需了解详情，请参阅 Python API 参考文档。

from typing import List, Optional

from vertexai.language_models import TextEmbeddingInput, TextEmbeddingModel


def embed_text(
    texts: list = None,
    task: str = "RETRIEVAL_DOCUMENT",
    dimensionality: Optional[int] = 256,
) -> List[List[float]]:
    """Embeds texts with a pre-trained, foundational model.
    Args:
        texts (List[str]): A list of texts to be embedded.
        task (str): The task type for embedding. Check the available tasks in the model's documentation.
        dimensionality (Optional[int]): The dimensionality of the output embeddings.
    Returns:
        List[List[float]]: A list of lists containing the embedding vectors for each input text
    """
    if texts is None:
        texts = ["banana muffins? ", "banana bread? banana muffins?"]
    model = TextEmbeddingModel.from_pretrained("text-embedding-004")
    inputs = [TextEmbeddingInput(text, task) for text in texts]
    kwargs = dict(output_dimensionality=dimensionality) if dimensionality else {}
    embeddings = model.get_embeddings(inputs, **kwargs)
    # Example response:
    # [[0.006135190837085247, -0.01462465338408947, 0.004978656303137541, ...],
    return [embedding.values for embedding in embeddings]

Go

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Go 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Go API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import (
	"context"
	"fmt"
	"io"

	aiplatform "cloud.google.com/go/aiplatform/apiv1"
	"cloud.google.com/go/aiplatform/apiv1/aiplatformpb"

	"google.golang.org/api/option"
	"google.golang.org/protobuf/types/known/structpb"
)

// embedTexts shows how embeddings are set for text-embedding-preview-0409 model
func embedTexts(w io.Writer, project, location string) error {
	// location := "us-central1"
	ctx := context.Background()

	apiEndpoint := fmt.Sprintf("%s-aiplatform.googleapis.com:443", location)
	dimensionality := 5
	model := "text-embedding-004"
	texts := []string{"banana muffins? ", "banana bread? banana muffins?"}

	client, err := aiplatform.NewPredictionClient(ctx, option.WithEndpoint(apiEndpoint))
	if err != nil {
		return err
	}
	defer client.Close()

	endpoint := fmt.Sprintf("projects/%s/locations/%s/publishers/google/models/%s", project, location, model)
	instances := make([]*structpb.Value, len(texts))
	for i, text := range texts {
		instances[i] = structpb.NewStructValue(&structpb.Struct{
			Fields: map[string]*structpb.Value{
				"content":   structpb.NewStringValue(text),
				"task_type": structpb.NewStringValue("QUESTION_ANSWERING"),
			},
		})
	}

	params := structpb.NewStructValue(&structpb.Struct{
		Fields: map[string]*structpb.Value{
			"outputDimensionality": structpb.NewNumberValue(float64(dimensionality)),
		},
	})

	req := &aiplatformpb.PredictRequest{
		Endpoint:   endpoint,
		Instances:  instances,
		Parameters: params,
	}
	resp, err := client.Predict(ctx, req)
	if err != nil {
		return err
	}
	embeddings := make([][]float32, len(resp.Predictions))
	for i, prediction := range resp.Predictions {
		values := prediction.GetStructValue().Fields["embeddings"].GetStructValue().Fields["values"].GetListValue().Values
		embeddings[i] = make([]float32, len(values))
		for j, value := range values {
			embeddings[i][j] = float32(value.GetNumberValue())
		}
	}

	fmt.Fprintf(w, "Dimensionality: %d. Embeddings length: %d", len(embeddings[0]), len(embeddings))
	return nil
}

Java

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Java 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Java API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import static java.util.stream.Collectors.toList;

import com.google.cloud.aiplatform.v1.EndpointName;
import com.google.cloud.aiplatform.v1.PredictRequest;
import com.google.cloud.aiplatform.v1.PredictResponse;
import com.google.cloud.aiplatform.v1.PredictionServiceClient;
import com.google.cloud.aiplatform.v1.PredictionServiceSettings;
import com.google.protobuf.Struct;
import com.google.protobuf.Value;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.OptionalInt;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PredictTextEmbeddingsSample {
  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    // Details about text embedding request structure and supported models are available in:
    // https://cloud.google.com/vertex-ai/docs/generative-ai/embeddings/get-text-embeddings
    String endpoint = "us-central1-aiplatform.googleapis.com:443";
    String project = "YOUR_PROJECT_ID";
    String model = "text-embedding-004";
    predictTextEmbeddings(
        endpoint,
        project,
        model,
        List.of("banana bread?", "banana muffins?"),
        "QUESTION_ANSWERING",
        OptionalInt.of(256));
  }

  // Gets text embeddings from a pretrained, foundational model.
  public static List<List<Float>> predictTextEmbeddings(
      String endpoint,
      String project,
      String model,
      List<String> texts,
      String task,
      OptionalInt outputDimensionality)
      throws IOException {
    PredictionServiceSettings settings =
        PredictionServiceSettings.newBuilder().setEndpoint(endpoint).build();
    Matcher matcher = Pattern.compile("^(?<Location>\\w+-\\w+)").matcher(endpoint);
    String location = matcher.matches() ? matcher.group("Location") : "us-central1";
    EndpointName endpointName =
        EndpointName.ofProjectLocationPublisherModelName(project, location, "google", model);

    // You can use this prediction service client for multiple requests.
    try (PredictionServiceClient client = PredictionServiceClient.create(settings)) {
      PredictRequest.Builder request =
          PredictRequest.newBuilder().setEndpoint(endpointName.toString());
      if (outputDimensionality.isPresent()) {
        request.setParameters(
            Value.newBuilder()
                .setStructValue(
                    Struct.newBuilder()
                        .putFields("outputDimensionality", valueOf(outputDimensionality.getAsInt()))
                        .build()));
      }
      for (int i = 0; i < texts.size(); i++) {
        request.addInstances(
            Value.newBuilder()
                .setStructValue(
                    Struct.newBuilder()
                        .putFields("content", valueOf(texts.get(i)))
                        .putFields("task_type", valueOf(task))
                        .build()));
      }
      PredictResponse response = client.predict(request.build());
      List<List<Float>> floats = new ArrayList<>();
      for (Value prediction : response.getPredictionsList()) {
        Value embeddings = prediction.getStructValue().getFieldsOrThrow("embeddings");
        Value values = embeddings.getStructValue().getFieldsOrThrow("values");
        floats.add(
            values.getListValue().getValuesList().stream()
                .map(Value::getNumberValue)
                .map(Double::floatValue)
                .collect(toList()));
      }
      return floats;
    }
  }

  private static Value valueOf(String s) {
    return Value.newBuilder().setStringValue(s).build();
  }

  private static Value valueOf(int n) {
    return Value.newBuilder().setNumberValue(n).build();
  }
}

Node.js

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Node.js 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Node.js API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

async function main(
  project,
  model = 'text-embedding-004',
  texts = 'banana bread?;banana muffins?',
  task = 'QUESTION_ANSWERING',
  dimensionality = 0,
  apiEndpoint = 'us-central1-aiplatform.googleapis.com'
) {
  const aiplatform = require('@google-cloud/aiplatform');
  const {PredictionServiceClient} = aiplatform.v1;
  const {helpers} = aiplatform; // helps construct protobuf.Value objects.
  const clientOptions = {apiEndpoint: apiEndpoint};
  const location = 'us-central1';
  const endpoint = `projects/${project}/locations/${location}/publishers/google/models/${model}`;

  async function callPredict() {
    const instances = texts
      .split(';')
      .map(e => helpers.toValue({content: e, task_type: task}));
    const parameters = helpers.toValue(
      dimensionality > 0 ? {outputDimensionality: parseInt(dimensionality)} : {}
    );
    const request = {endpoint, instances, parameters};
    const client = new PredictionServiceClient(clientOptions);
    const [response] = await client.predict(request);
    const predictions = response.predictions;
    const embeddings = predictions.map(p => {
      const embeddingsProto = p.structValue.fields.embeddings;
      const valuesProto = embeddingsProto.structValue.fields.values;
      return valuesProto.listValue.values.map(v => v.numberValue);
    });
    console.log('Got embeddings: \n' + JSON.stringify(embeddings));
  }

  callPredict();
}

最新模型

预览

本产品或功能须遵守服务专用条款的“通用服务条款”部分中的“非正式版产品条款”。 正式发布前产品和功能“按原样”提供，可能仅提供有限支持。 如需了解详情，请参阅发布阶段说明。

预览版中提供一个嵌入模型：

• text-embedding-preview-0815

此模型支持新的任务类型 CODE_RETRIEVAL_QUERY，可用于使用纯文本查询检索相关代码块。如需使用此功能，应使用 RETRIEVAL_DOCUMENT 任务类型嵌入代码块，并使用 CODE_RETRIEVAL_QUERY 嵌入文本查询。

如需了解所有任务类型，请参阅模型参考。

示例如下：

REST

PROJECT_ID=PROJECT_ID

curl \
-X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Content-Type: application/json" \
https://us-central1-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/publishers/google/models/text-embedding-preview-0815:predict -d \
$'{
  "instances": [
    {
      "task_type": "CODE_RETRIEVAL_QUERY",
      "content": "Function to add two numbers"
    }
  ],
}'

Python

如需了解如何安装或更新 Vertex AI SDK for Python，请参阅安装 Vertex AI SDK for Python。 如需了解详情，请参阅 Python API 参考文档。

from vertexai.language_models import TextEmbeddingInput, TextEmbeddingModel

MODEL_NAME = "text-embedding-preview-0815"
DIMENSIONALITY = 256


def embed_text(
    texts: list[str] = ["Retrieve a function that adds two numbers"],
    task: str = "CODE_RETRIEVAL_QUERY",
    model_name: str = "text-embedding-preview-0815",
    dimensionality: int | None = 256,
) -> list[list[float]]:
    """Embeds texts with a pre-trained, foundational model."""
    model = TextEmbeddingModel.from_pretrained(model_name)
    inputs = [TextEmbeddingInput(text, task) for text in texts]
    kwargs = dict(output_dimensionality=dimensionality) if dimensionality else {}
    embeddings = model.get_embeddings(inputs, **kwargs)
    # Example response:
    # [[0.025890009477734566, -0.05553026497364044, 0.006374752148985863,...],
    return [embedding.values for embedding in embeddings]


if __name__ == "__main__":
    # Embeds code block with a pre-trained, foundational model.
    # Using this function to calculate the embedding for corpus.
    texts = ["Retrieve a function that adds two numbers"]
    task = "CODE_RETRIEVAL_QUERY"
    code_block_embeddings = embed_text(
        texts=texts, task=task, model_name=MODEL_NAME, dimensionality=DIMENSIONALITY
    )

    # Embeds code retrieval with a pre-trained, foundational model.
    # Using this function to calculate the embedding for query.
    texts = [
        "def func(a, b): return a + b",
        "def func(a, b): return a - b",
        "def func(a, b): return (a ** 2 + b ** 2) ** 0.5",
    ]
    task = "RETRIEVAL_DOCUMENT"
    code_query_embeddings = embed_text(
        texts=texts, task=task, model_name=MODEL_NAME, dimensionality=DIMENSIONALITY
    )

Go

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Go 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Go API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import (
	"context"
	"fmt"
	"io"

	aiplatform "cloud.google.com/go/aiplatform/apiv1"
	"cloud.google.com/go/aiplatform/apiv1/aiplatformpb"

	"google.golang.org/api/option"
	"google.golang.org/protobuf/types/known/structpb"
)

// Embeds code query with a pre-trained, foundational model by specifying the task type as 'CODE_RETRIEVAL_QUERY'. e.g. 'Retrieve a function that adds two numbers'.
// Embeds code block with a pre-trained, foundational model by specifying the task type as 'RETRIEVAL_DOCUMENT'. e.g. 'texts := []string{"def func(a, b): return a + b", "def func(a, b): return a - b", "def func(a, b): return (a ** 2 + b ** 2) ** 0.5"}'.
// embedTextsPreview shows how embeddings are set for text-embedding-preview-0815 model
func embedTextsPreview(w io.Writer, projectID, location string) error {
	// location := "us-central1"
	ctx := context.Background()

	apiEndpoint := fmt.Sprintf("%s-aiplatform.googleapis.com:443", location)
	dimensionality := 5
	model := "text-embedding-preview-0815"
	texts := []string{"banana muffins? ", "banana bread? banana muffins?"}

	client, err := aiplatform.NewPredictionClient(ctx, option.WithEndpoint(apiEndpoint))
	if err != nil {
		return err
	}
	defer client.Close()

	endpoint := fmt.Sprintf("projects/%s/locations/%s/publishers/google/models/%s", projectID, location, model)
	instances := make([]*structpb.Value, len(texts))
	for i, text := range texts {
		instances[i] = structpb.NewStructValue(&structpb.Struct{
			Fields: map[string]*structpb.Value{
				"content":   structpb.NewStringValue(text),
				"task_type": structpb.NewStringValue("CODE_RETRIEVAL_QUERY"),
			},
		})
	}

	params := structpb.NewStructValue(&structpb.Struct{
		Fields: map[string]*structpb.Value{
			"outputDimensionality": structpb.NewNumberValue(float64(dimensionality)),
		},
	})

	req := &aiplatformpb.PredictRequest{
		Endpoint:   endpoint,
		Instances:  instances,
		Parameters: params,
	}
	resp, err := client.Predict(ctx, req)
	if err != nil {
		return err
	}
	embeddings := make([][]float32, len(resp.Predictions))
	for i, prediction := range resp.Predictions {
		values := prediction.GetStructValue().Fields["embeddings"].GetStructValue().Fields["values"].GetListValue().Values
		embeddings[i] = make([]float32, len(values))
		for j, value := range values {
			embeddings[i][j] = float32(value.GetNumberValue())
		}
	}

	fmt.Fprintf(w, "Dimensionality: %d. Embeddings length: %d", len(embeddings[0]), len(embeddings))
	return nil
}

Java

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Java 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Java API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import static java.util.stream.Collectors.toList;

import com.google.cloud.aiplatform.v1beta1.EndpointName;
import com.google.cloud.aiplatform.v1beta1.PredictRequest;
import com.google.cloud.aiplatform.v1beta1.PredictResponse;
import com.google.cloud.aiplatform.v1beta1.PredictionServiceClient;
import com.google.cloud.aiplatform.v1beta1.PredictionServiceSettings;
import com.google.protobuf.Struct;
import com.google.protobuf.Value;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.OptionalInt;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PredictTextEmbeddingsSamplePreview {
  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    // Details about text embedding request structure and supported models are
    // available in:
    // https://cloud.google.com/vertex-ai/docs/generative-ai/embeddings/get-text-embeddings
    String endpoint = "us-central1-aiplatform.googleapis.com";
    String project = "YOUR_PROJECT_ID";
    String model = "text-embedding-preview-0815";
    // Calculate the embedding for a code retrieval query. Using 'CODE_RETRIEVAL_QUERY' for query.
    predictTextEmbeddings(
        endpoint,
        project,
        model,
        List.of("Retrieve a function that adds two numbers"),
        "CODE_RETRIEVAL_QUERY",
        OptionalInt.of(256));

    // Calculate the embedding for code blocks. Using 'RETRIEVAL_DOCUMENT' for corpus.
    predictTextEmbeddings(
        endpoint,
        project,
        model,
        List.of(
            "def func(a, b): return a + b",
            "def func(a, b): return a - b",
            "def func(a, b): return (a ** 2 + b ** 2) ** 0.5"),
        "RETRIEVAL_DOCUMENT",
        OptionalInt.of(256));
  }

  // Gets text embeddings from a pretrained, foundational model.
  public static List<List<Float>> predictTextEmbeddings(
      String endpoint,
      String project,
      String model,
      List<String> texts,
      String task,
      OptionalInt outputDimensionality)
      throws IOException {
    PredictionServiceSettings settings =
        PredictionServiceSettings.newBuilder().setEndpoint(endpoint).build();
    Matcher matcher = Pattern.compile("^(?<Location>\\w+-\\w+)").matcher(endpoint);
    String location = matcher.matches() ? matcher.group("Location") : "us-central1";
    EndpointName endpointName =
        EndpointName.ofProjectLocationPublisherModelName(project, location, "google", model);

    // You can use this prediction service client for multiple requests.
    try (PredictionServiceClient client = PredictionServiceClient.create(settings)) {
      PredictRequest.Builder request =
          PredictRequest.newBuilder().setEndpoint(endpointName.toString());
      if (outputDimensionality.isPresent()) {
        request.setParameters(
            Value.newBuilder()
                .setStructValue(
                    Struct.newBuilder()
                        .putFields("outputDimensionality", valueOf(outputDimensionality.getAsInt()))
                        .build()));
      }
      for (int i = 0; i < texts.size(); i++) {
        request.addInstances(
            Value.newBuilder()
                .setStructValue(
                    Struct.newBuilder()
                        .putFields("content", valueOf(texts.get(i)))
                        .putFields("task_type", valueOf(task))
                        .build()));
      }
      PredictResponse response = client.predict(request.build());
      List<List<Float>> floats = new ArrayList<>();
      for (Value prediction : response.getPredictionsList()) {
        Value embeddings = prediction.getStructValue().getFieldsOrThrow("embeddings");
        Value values = embeddings.getStructValue().getFieldsOrThrow("values");
        floats.add(
            values.getListValue().getValuesList().stream()
                .map(Value::getNumberValue)
                .map(Double::floatValue)
                .collect(toList()));
      }
      return floats;
    }
  }

  private static Value valueOf(String s) {
    return Value.newBuilder().setStringValue(s).build();
  }

  private static Value valueOf(int n) {
    return Value.newBuilder().setNumberValue(n).build();
  }
}

Node.js

在尝试此示例之前，请按照《Vertex AI 快速入门：使用客户端库》中的 Node.js 设置说明执行操作。 如需了解详情，请参阅 Vertex AI Node.js API 参考文档。

如需向 Vertex AI 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

// TODO(developer): Update the following for your own use case.
const project = 'long-door-651';
const model = 'text-embedding-preview-0815';
const location = 'us-central1';
// Calculate the embedding for code blocks. Using 'RETRIEVAL_DOCUMENT' for corpus.
// Specify the task type as 'CODE_RETRIEVAL_QUERY' for query, e.g. 'Retrieve a function that adds two numbers'.
const texts =
  'def func(a, b): return a + b;def func(a, b): return a - b;def func(a, b): return (a ** 2 + b ** 2) ** 0.5';
const task = 'RETRIEVAL_DOCUMENT';
const dimensionality = 3;
const apiEndpoint = 'us-central1-aiplatform.googleapis.com';

const aiplatform = require('@google-cloud/aiplatform');
const {PredictionServiceClient} = aiplatform.v1;
const {helpers} = aiplatform; // helps construct protobuf.Value objects.
const clientOptions = {apiEndpoint: apiEndpoint};
const endpoint = `projects/${project}/locations/${location}/publishers/google/models/${model}`;
const parameters = helpers.toValue({
  outputDimensionality: parseInt(dimensionality),
});

async function callPredict() {
  const instances = texts
    .split(';')
    .map(e => helpers.toValue({content: e, task_type: task}));
  const request = {endpoint, instances, parameters};
  const client = new PredictionServiceClient(clientOptions);
  const [response] = await client.predict(request);
  const predictions = response.predictions;
  const embeddings = predictions.map(p => {
    const embeddingsProto = p.structValue.fields.embeddings;
    const valuesProto = embeddingsProto.structValue.fields.values;
    return valuesProto.listValue.values.map(v => v.numberValue);
  });
  console.log('Got embeddings: \n' + JSON.stringify(embeddings));
}
await callPredict();

使用这些模型时，存在以下限制：

• 请勿在任务关键型系统或生产系统中使用这些预览版模型。
• 这些模型仅在 us-central1 中提供。
• 不支持批量预测。
• 不支持自定义。

将嵌入添加到向量数据库

生成嵌入后，您可以将嵌入添加到向量数据库，例如 Vector Search。这样可以实现低延迟检索，并且随着数据规模扩大，这一点至关重要。

如需详细了解 Vector Search，请参阅 Vector Search 概览。

后续步骤

• 如需详细了解速率限制，请参阅 Vertex AI 上的生成式 AI 速率限制。
• 如需获取嵌入的批量预测结果，请参阅获取批量文本嵌入预测结果
• 如需详细了解多模态嵌入，请参阅获取多模态嵌入
• 如需对嵌入调优，请参阅对文本嵌入调优
• 如需详细了解 text-embedding-004 和 text-multilingual-embedding-002 背后的研究，请参阅研究论文 Gecko：从大语言模型中提炼的多功能文本嵌入。