Quickstart: Use client libraries with the Developer Knowledge API

This guide shows you how to get started with the Developer Knowledge API using official client libraries. You'll learn how to set up your environment, install the client library for your preferred language, and make API calls to search for and retrieve developer documentation.

Before you begin

Before you start using the Developer Knowledge API client libraries, complete the following sections.

Enable the API

Open the Developer Knowledge API page in the Google APIs library.
Check that you have the correct project selected in which you intend to use the API.
Click Enable. No specific IAM roles are required to enable or use the API.

Set up authentication

The Developer Knowledge API client libraries use Application Default Credentials (ADC) to authenticate requests.

To set up local authentication credentials, run the following command:

gcloud auth application-default login

To learn more about credential options like service accounts, refer to the Application Default Credentials documentation.

Install the client library

To install the official Developer Knowledge API client library, select your programming language:

Python

pip install google-developer-knowledge

Node.js and TypeScript

npm install @google/developer-knowledge

Go

go get cloud.google.com/go/developerknowledge/apiv1

Java

<!-- Maven dependency -->
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>google-cloud-developer-knowledge</artifactId>
  <version>0.3.0</version>
</dependency>

Answer a query with grounded generation

The AnswerQuery endpoint answers complex, natural-language questions, such as those involving code setup, troubleshooting procedures, and product capabilities, by synthesizing information across multiple official documentation sources.

Select a language tab to view an example of how to call AnswerQuery:

Python

from google.cloud import developer_knowledge_v1


def answer_query(
    query: str = "How do I create a Google Cloud Storage bucket?",
) -> developer_knowledge_v1.AnswerQueryResponse:
    """Answers a developer question grounded in Google developer documentation.

    Args:
        query: The technical question to answer.

    Returns:
        The AnswerQueryResponse containing the grounded answer,
        citations, and references.
    """
    client = developer_knowledge_v1.DeveloperKnowledgeClient()

    request = developer_knowledge_v1.AnswerQueryRequest(
        query=query,
    )

    response = client.answer_query(request=request)

    print(f"Answer:\n{response.answer.answer_text}\n")
    print(f"Citations count: {len(response.answer.citations)}")
    print(f"References count: {len(response.answer.references)}")

    return response

Node.js and TypeScript

const {DeveloperKnowledgeClient} = require('@google/developer-knowledge');

/**
 * Answers a developer question grounded in Google developer documentation.
 *
 * @param {string} query The technical question to answer.
 */
async function answerQuery(
  query = 'How do I create a Google Cloud Storage bucket?'
) {
  const client = new DeveloperKnowledgeClient();

  const request = {
    query,
  };

  const [response] = await client.answerQuery(request);

  console.log(`Answer:\n${response.answer.answerText}\n`);
  const citationsCount = response.answer.citations
    ? response.answer.citations.length
    : 0;
  const referencesCount = response.answer.references
    ? response.answer.references.length
    : 0;
  console.log(`Citations count: ${citationsCount}`);
  console.log(`References count: ${referencesCount}`);

  return response;
}

Go

import (
	"context"
	"fmt"
	"io"

	developerknowledge "cloud.google.com/go/developerknowledge/apiv1"
	developerknowledgepb "cloud.google.com/go/developerknowledge/apiv1/developerknowledgepb"
)

// answerQuery answers a developer question grounded in Google developer documentation.
func answerQuery(w io.Writer, query string) (*developerknowledgepb.AnswerQueryResponse, error) {
	ctx := context.Background()

	client, err := developerknowledge.NewDeveloperKnowledgeClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("developerknowledge.NewDeveloperKnowledgeClient: %w", err)
	}
	defer client.Close()

	req := &developerknowledgepb.AnswerQueryRequest{
		Query: query,
	}

	resp, err := client.AnswerQuery(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("AnswerQuery: %w", err)
	}

	if resp.GetAnswer() != nil {
		fmt.Fprintf(w, "Answer:\n%s\n\n", resp.GetAnswer().GetAnswerText())
		fmt.Fprintf(w, "Citations count: %d\n", len(resp.GetAnswer().GetCitations()))
		fmt.Fprintf(w, "References count: %d\n", len(resp.GetAnswer().GetReferences()))
	}

	return resp, nil
}

Java

import com.google.developers.knowledge.v1.AnswerQueryRequest;
import com.google.developers.knowledge.v1.AnswerQueryResponse;
import com.google.developers.knowledge.v1.DeveloperKnowledgeClient;
import java.io.IOException;

public class AnswerQuery {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String query = "How do I create a Google Cloud Storage bucket?";
    answerQuery(query);
  }

  // Answers a developer question grounded in Google developer documentation.
  public static AnswerQueryResponse answerQuery(String query) throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (DeveloperKnowledgeClient client = DeveloperKnowledgeClient.create()) {
      AnswerQueryRequest request =
          AnswerQueryRequest.newBuilder().setQuery(query).build();

      AnswerQueryResponse response = client.answerQuery(request);

      System.out.println("Answer:\n" + response.getAnswer().getAnswerText() + "\n");
      System.out.println("Citations count: " + response.getAnswer().getCitationsCount());
      System.out.println("References count: " + response.getAnswer().getReferencesCount());

      return response;
    }
  }
}

Search for document chunks

To find precise, localized text segments within the documentation rather than a synthesized answer, use the SearchDocumentChunks endpoint. This method scans the corpus and returns individual content snippets (chunks) alongside parent document identifiers, which you can use to retrieve the full document content.

Select a language tab to view an example of how to search document chunks:

Python

from google.cloud import developer_knowledge_v1


def search_document_chunks(
    query: str = "How to create a Cloud Storage bucket",
    page_size: int = 5,
) -> (
    developer_knowledge_v1.services.developer_knowledge.pagers.SearchDocumentChunksPager
):
    """Searches developer documentation chunks for a given query.

    Args:
        query: The natural language search query.
        page_size: The maximum number of document chunks to return.

    Returns:
        The SearchDocumentChunksPager containing relevant document chunks.
    """
    client = developer_knowledge_v1.DeveloperKnowledgeClient()

    request = developer_knowledge_v1.SearchDocumentChunksRequest(
        query=query,
        page_size=page_size,
    )

    response = client.search_document_chunks(request=request)

    count = 0
    for chunk in response:
        print(f"Parent Document: {chunk.parent}")
        print(f"Chunk ID: {chunk.id}")
        print(f"Content: {chunk.content[:100]}...\n")
        count += 1
        if page_size > 0 and count >= page_size:
            break

    return response

Node.js and TypeScript

const {DeveloperKnowledgeClient} = require('@google/developer-knowledge');

/**
 * Searches developer documentation chunks for a given query.
 *
 * @param {string} query The search query string.
 * @param {number} pageSize The maximum number of document chunks to return.
 */
async function searchDocumentChunks(
  query = 'How to create a Cloud Storage bucket',
  pageSize = 5
) {
  const client = new DeveloperKnowledgeClient();

  const request = {
    query,
    pageSize,
  };

  // Warning: Should always disable autoPaginate to avoid iterating through all pages.
  // By default NodeJS SDK returns an iterable where you can iterate through all
  // search results instead of only the limited number of results requested on pageSize.
  const [chunks] = await client.searchDocumentChunks(request, {
    autoPaginate: false,
  });

  for (const chunk of chunks) {
    console.log(`Parent Document: ${chunk.parent}`);
    console.log(`Chunk ID: ${chunk.id}`);
    console.log(`Content Preview: ${chunk.content.substring(0, 100)}...\n`);
  }

  return chunks;
}

Go

import (
	"context"
	"fmt"
	"io"

	developerknowledge "cloud.google.com/go/developerknowledge/apiv1"
	developerknowledgepb "cloud.google.com/go/developerknowledge/apiv1/developerknowledgepb"
	"google.golang.org/api/iterator"
)

// searchDocumentChunks searches developer documentation chunks for a given query.
func searchDocumentChunks(w io.Writer, query string, pageSize int32) ([]*developerknowledgepb.DocumentChunk, error) {
	ctx := context.Background()

	client, err := developerknowledge.NewDeveloperKnowledgeClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("developerknowledge.NewDeveloperKnowledgeClient: %w", err)
	}
	defer client.Close()

	req := &developerknowledgepb.SearchDocumentChunksRequest{
		Query:    query,
		PageSize: pageSize,
	}

	var results []*developerknowledgepb.DocumentChunk
	it := client.SearchDocumentChunks(ctx, req)
	for {
		chunk, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return nil, fmt.Errorf("SearchDocumentChunks: %w", err)
		}
		results = append(results, chunk)
		fmt.Fprintf(w, "Parent Document: %s\n", chunk.GetParent())
		fmt.Fprintf(w, "Chunk ID: %s\n", chunk.GetId())
		fmt.Fprintf(w, "Content: %s\n\n", chunk.GetContent())

		if pageSize > 0 && len(results) >= int(pageSize) {
			break
		}
	}

	return results, nil
}

Java

import com.google.developers.knowledge.v1.DeveloperKnowledgeClient;
import com.google.developers.knowledge.v1.DeveloperKnowledgeClient.SearchDocumentChunksPagedResponse;
import com.google.developers.knowledge.v1.DocumentChunk;
import com.google.developers.knowledge.v1.SearchDocumentChunksRequest;
import java.io.IOException;

public class SearchDocumentChunks {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String query = "How to create a Cloud Storage bucket";
    int pageSize = 5;
    searchDocumentChunks(query, pageSize);
  }

  // Searches developer documentation chunks for a given query.
  public static SearchDocumentChunksPagedResponse searchDocumentChunks(
      String query, int pageSize) throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (DeveloperKnowledgeClient client = DeveloperKnowledgeClient.create()) {
      SearchDocumentChunksRequest request =
          SearchDocumentChunksRequest.newBuilder()
              .setQuery(query)
              .setPageSize(pageSize)
              .build();

      SearchDocumentChunksPagedResponse response = client.searchDocumentChunks(request);

      for (DocumentChunk chunk : response.getPage().getValues()) {
        System.out.println("Parent Document: " + chunk.getParent());
        System.out.println("Chunk ID: " + chunk.getId());
        String preview = chunk.getContent();
        if (preview.length() > 100) {
          preview = preview.substring(0, 100) + "...";
        }
        System.out.println("Content: " + preview + "\n");
      }

      return response;
    }
  }
}

Retrieve a document

Each document chunk contains a parent field with the resource name of its parent document. Use GetDocument with that resource name to retrieve the full document.

The following samples retrieve a sample document. You can replace the sample document name with any parent resource name returned from your search results.

Select a language tab to view an example of how to call GetDocument:

Python

from google.cloud import developer_knowledge_v1


def get_document(
    name: str = "documents/docs.cloud.google.com/storage/docs/creating-buckets",
) -> developer_knowledge_v1.Document:
    """Retrieves a single developer documentation page by its resource name.

    Args:
        name: The resource name of the document in format
            'documents/{uri_without_scheme}'.

    Returns:
        The Document containing the full Markdown content and metadata.
    """
    client = developer_knowledge_v1.DeveloperKnowledgeClient()

    request = developer_knowledge_v1.GetDocumentRequest(
        name=name,
    )

    document = client.get_document(request=request)

    print(f"Title: {document.title}")
    print(f"URI: {document.uri}")
    print(f"Data Source: {document.data_source}")
    print(f"Content Length: {document.content_length_bytes} bytes")
    print(f"Content Preview: {document.content[:150]}...\n")

    return document

Node.js and TypeScript

const {DeveloperKnowledgeClient} = require('@google/developer-knowledge');

/**
 * Retrieves a single developer documentation page by its resource name.
 *
 * @param {string} name The resource name in format 'documents/{uri_without_scheme}'.
 */
async function getDocument(
  name = 'documents/docs.cloud.google.com/storage/docs/creating-buckets'
) {
  const client = new DeveloperKnowledgeClient();

  const request = {
    name,
  };

  const [document] = await client.getDocument(request);

  console.log(`Title: ${document.title}`);
  console.log(`URI: ${document.uri}`);
  console.log(`Data Source: ${document.dataSource}`);
  console.log(`Content Length: ${document.contentLengthBytes} bytes`);
  console.log(`Content Preview: ${document.content.substring(0, 150)}...\n`);

  return document;
}

Go

import (
	"context"
	"fmt"
	"io"

	developerknowledge "cloud.google.com/go/developerknowledge/apiv1"
	developerknowledgepb "cloud.google.com/go/developerknowledge/apiv1/developerknowledgepb"
)

// getDocument retrieves a single developer documentation page by its resource name.
func getDocument(w io.Writer, name string) (*developerknowledgepb.Document, error) {
	ctx := context.Background()

	client, err := developerknowledge.NewDeveloperKnowledgeClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("developerknowledge.NewDeveloperKnowledgeClient: %w", err)
	}
	defer client.Close()

	req := &developerknowledgepb.GetDocumentRequest{
		Name: name,
	}

	doc, err := client.GetDocument(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("GetDocument: %w", err)
	}

	fmt.Fprintf(w, "Title: %s\n", doc.GetTitle())
	fmt.Fprintf(w, "URI: %s\n", doc.GetUri())
	fmt.Fprintf(w, "Data Source: %s\n", doc.GetDataSource())
	fmt.Fprintf(w, "Content Length: %d bytes\n\n", doc.GetContentLengthBytes())

	return doc, nil
}

Java

import com.google.developers.knowledge.v1.DeveloperKnowledgeClient;
import com.google.developers.knowledge.v1.Document;
import com.google.developers.knowledge.v1.GetDocumentRequest;
import java.io.IOException;

public class GetDocument {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String name = "documents/docs.cloud.google.com/storage/docs/creating-buckets";
    getDocument(name);
  }

  // Retrieves a single developer documentation page by its resource name.
  public static Document getDocument(String name) throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (DeveloperKnowledgeClient client = DeveloperKnowledgeClient.create()) {
      GetDocumentRequest request = GetDocumentRequest.newBuilder().setName(name).build();

      Document document = client.getDocument(request);

      System.out.println("Title: " + document.getTitle());
      System.out.println("URI: " + document.getUri());
      System.out.println("Data Source: " + document.getDataSource());
      System.out.println("Content Length: " + document.getContentLengthBytes() + " bytes");
      String preview = document.getContent();
      if (preview.length() > 150) {
        preview = preview.substring(0, 150) + "...";
      }
      System.out.println("Content Preview: " + preview + "\n");

      return document;
    }
  }
}

Retrieve multiple documents

Use BatchGetDocuments to retrieve up to 20 documents by resource name in a single API call.

Select a language tab to view an example of how to call BatchGetDocuments:

Python

from typing import List, Optional

from google.cloud import developer_knowledge_v1


def batch_get_documents(
    names: Optional[List[str]] = None,
) -> developer_knowledge_v1.BatchGetDocumentsResponse:
    """Retrieves multiple developer documentation pages in a single request.

    Args:
        names: A list of resource names in format 'documents/{uri_without_scheme}'.

    Returns:
        The BatchGetDocumentsResponse containing the retrieved documents.
    """
    if names is None:
        names = [
            "documents/docs.cloud.google.com/storage/docs/creating-buckets",
            "documents/docs.cloud.google.com/storage/docs/deleting-buckets",
        ]

    client = developer_knowledge_v1.DeveloperKnowledgeClient()

    request = developer_knowledge_v1.BatchGetDocumentsRequest(
        names=names,
    )

    response = client.batch_get_documents(request=request)

    for doc in response.documents:
        print(f"Title: {doc.title}")
        print(f"URI: {doc.uri}")
        print(f"Content Length: {doc.content_length_bytes} bytes\n")

    return response

Node.js and TypeScript

const {DeveloperKnowledgeClient} = require('@google/developer-knowledge');

/**
 * Retrieves multiple developer documentation pages in a single request.
 *
 * @param {string[]} names Array of resource names in format 'documents/{uri_without_scheme}'.
 */
async function batchGetDocuments(
  names = [
    'documents/docs.cloud.google.com/storage/docs/creating-buckets',
    'documents/docs.cloud.google.com/storage/docs/deleting-buckets',
  ]
) {
  const client = new DeveloperKnowledgeClient();

  const request = {
    names,
  };

  const [response] = await client.batchGetDocuments(request);

  if (response.documents) {
    for (const doc of response.documents) {
      console.log(`Title: ${doc.title}`);
      console.log(`URI: ${doc.uri}`);
      console.log(`Content Length: ${doc.contentLengthBytes} bytes\n`);
    }
  }

  return response;
}

Go

import (
	"context"
	"fmt"
	"io"

	developerknowledge "cloud.google.com/go/developerknowledge/apiv1"
	developerknowledgepb "cloud.google.com/go/developerknowledge/apiv1/developerknowledgepb"
)

// batchGetDocuments retrieves multiple developer documentation pages in a single request.
func batchGetDocuments(w io.Writer, names []string) (*developerknowledgepb.BatchGetDocumentsResponse, error) {
	ctx := context.Background()

	client, err := developerknowledge.NewDeveloperKnowledgeClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("developerknowledge.NewDeveloperKnowledgeClient: %w", err)
	}
	defer client.Close()

	req := &developerknowledgepb.BatchGetDocumentsRequest{
		Names: names,
	}

	resp, err := client.BatchGetDocuments(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("BatchGetDocuments: %w", err)
	}

	for _, doc := range resp.GetDocuments() {
		fmt.Fprintf(w, "Title: %s\n", doc.GetTitle())
		fmt.Fprintf(w, "\tURI: %s\n", doc.GetUri())
		fmt.Fprintf(w, "\tContent Length: %d bytes\n\n", doc.GetContentLengthBytes())
	}

	return resp, nil
}

Java

import com.google.developers.knowledge.v1.BatchGetDocumentsRequest;
import com.google.developers.knowledge.v1.BatchGetDocumentsResponse;
import com.google.developers.knowledge.v1.DeveloperKnowledgeClient;
import com.google.developers.knowledge.v1.Document;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class BatchGetDocuments {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    List<String> names =
        Arrays.asList(
            "documents/docs.cloud.google.com/storage/docs/creating-buckets",
            "documents/docs.cloud.google.com/storage/docs/deleting-buckets");
    batchGetDocuments(names);
  }

  // Retrieves multiple developer documentation pages in a single request.
  public static BatchGetDocumentsResponse batchGetDocuments(List<String> names) throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (DeveloperKnowledgeClient client = DeveloperKnowledgeClient.create()) {
      BatchGetDocumentsRequest request =
          BatchGetDocumentsRequest.newBuilder().addAllNames(names).build();

      BatchGetDocumentsResponse response = client.batchGetDocuments(request);

      for (Document doc : response.getDocumentsList()) {
        System.out.println("Title: " + doc.getTitle());
        System.out.println("URI: " + doc.getUri());
        System.out.println("Content Length: " + doc.getContentLengthBytes() + " bytes\n");
      }

      return response;
    }
  }
}

What's next

Explore the Corpus reference to view the full list of included documentation.
Refer to the API reference documentation for details on API methods and parameters.
Learn how to set up the MCP server in Google Antigravity.

Quickstart: Use client libraries with the Developer Knowledge API Stay organized with collections Save and categorize content based on your preferences.

Before you begin

Enable the API

Set up authentication

Install the client library

Python

Node.js and TypeScript

Go

Java

Answer a query with grounded generation

Python

Node.js and TypeScript

Go

Java

Search for document chunks

Python

Node.js and TypeScript

Go

Java

Retrieve a document

Python

Node.js and TypeScript

Go

Java

Retrieve multiple documents

Python

Node.js and TypeScript

Go

Java

What's next

Quickstart: Use client libraries with the Developer Knowledge API