feat(developer-knowledge): add Developer Knowledge API samples

CODEOWNERS

@@ -54,3 +54,5 @@ media @GoogleCloudPlatform/cloud-media-team @GoogleCloudPlatform/nodejs-samples-
 healthcare @GoogleCloudPlatform/healthcare-life-sciences @GoogleCloudPlatform/nodejs-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 routeoptimization @GoogleCloudPlatform/geo-routeoptimization @GoogleCloudPlatform/nodejs-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
 translate @GoogleCloudPlatform/nodejs-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers @GoogleCloudPlatform/cloud-ml-translate-dev
+developer-knowledge @GoogleCloudPlatform/nodejs-samples-reviewers @GoogleCloudPlatform/cloud-samples-reviewers
+

developer-knowledge/.eslintrc.yml

@@ -0,0 +1,19 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+rules:
+  no-console: off
+  node/no-unsupported-features/node-builtins: off
+

developer-knowledge/README.md

@@ -0,0 +1,29 @@
+# Google Developer Knowledge API Node.js Samples
+
+This directory contains Node.js code samples demonstrating how to use the [Google Developer Knowledge API](https://developers.google.com/knowledge) client library (`@google/developer-knowledge`).
+
+## Setup
+
+1. Enable the Developer Knowledge API on your Google Cloud project:
+
+   ```bash
+   gcloud services enable developerknowledge.googleapis.com
+   ```
+
+2. Install dependencies:
+   ```bash
+   npm install
+   ```
+
+## Samples
+
+- **[Answer Query](answerQuery.js)**: Get a grounded, cited answer to a technical question (`developerknowledge_answer_query`).
+- **[Get Document](getDocument.js)**: Retrieve a single documentation page with full markdown content (`developerknowledge_get_document`).
+- **[Batch Get Documents](batchGetDocuments.js)**: Fetch multiple documentation pages in one call (`developerknowledge_batch_get_documents`).
+- **[Search Document Chunks](searchDocumentChunks.js)**: Search public developer documentation chunks by query (`developerknowledge_search_document_chunks`).
+
+## Running Tests
+
+```bash
+npm test
+```

developer-knowledge/answerQuery.js

@@ -0,0 +1,57 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+// [START developerknowledge_answer_query]
+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;
+}
+// [END developerknowledge_answer_query]
+
+module.exports = {answerQuery};
+
+if (require.main === module) {
+  answerQuery(...process.argv.slice(2)).catch(err => {
+    console.error(err);
+    process.exitCode = 1;
+  });
+}

developer-knowledge/batchGetDocuments.js

@@ -0,0 +1,58 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+// [START developerknowledge_batch_get_documents]
+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;
+}
+// [END developerknowledge_batch_get_documents]
+
+module.exports = {batchGetDocuments};
+
+if (require.main === module) {
+  batchGetDocuments().catch(err => {
+    console.error(err);
+    process.exitCode = 1;
+  });
+}

developer-knowledge/getDocument.js

@@ -0,0 +1,53 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+// [START developerknowledge_get_document]
+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;
+}
+// [END developerknowledge_get_document]
+
+module.exports = {getDocument};
+
+if (require.main === module) {
+  getDocument(...process.argv.slice(2)).catch(err => {
+    console.error(err);
+    process.exitCode = 1;
+  });
+}

developer-knowledge/package.json

@@ -0,0 +1,28 @@
+{
+  "name": "nodejs-developer-knowledge-samples",
+  "description": "Node.js samples for Google Developer Knowledge API",
+  "version": "0.0.1",
+  "private": true,
+  "license": "Apache-2.0",
+  "author": "Google LLC",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git",
+    "directory": "developer-knowledge"
+  },
+  "engines": {
+    "node": ">=18.0.0"
+  },
+  "files": [
+    "*.js"
+  ],
+  "scripts": {
+    "test": "mocha test/*.test.js --timeout 60000"
+  },
+  "dependencies": {
+    "@google/developer-knowledge": "^0.5.0"
+  },
+  "devDependencies": {
+    "mocha": "^10.0.0"
+  }
+}

developer-knowledge/searchDocumentChunks.js

@@ -0,0 +1,61 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+// [START developerknowledge_search_document_chunks]
+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;
+}
+// [END developerknowledge_search_document_chunks]
+
+module.exports = {searchDocumentChunks};
+
+if (require.main === module) {
+  searchDocumentChunks(...process.argv.slice(2)).catch(err => {
+    console.error(err);
+    process.exitCode = 1;
+  });
+}