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Google Cloud Natural Language API: Node.js Client

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Node.js idiomatic client for Natural Language API.

Cloud Natural Language API provides natural language understanding technologies to developers, including sentiment analysis, entity analysis, and syntax analysis. This API is part of the larger Cloud Machine Learning API family.

Read more about the client libraries for Cloud APIs, including the older Google APIs Client Libraries, in Client Libraries Explained.

Table of contents:


Before you begin

  1. Select or create a Cloud Platform project.

    Go to the projects page

  2. Enable billing for your project.

    Enable billing

  3. Enable the Google Cloud Natural Language API API.

    Enable the API

  4. Set up authentication with a service account so you can access the API from your local workstation.

Installing the client library

npm install --save @google-cloud/language

Using the client library

// Imports the Google Cloud client library
const language = require('@google-cloud/language');

// Instantiates a client
const client = new language.LanguageServiceClient();

// The text to analyze
const text = 'Hello, world!';

const document = {
  content: text,
  type: 'PLAIN_TEXT',

// Detects the sentiment of the text
  .analyzeSentiment({document: document})
  .then(results => {
    const sentiment = results[0].documentSentiment;

    console.log(`Text: ${text}`);
    console.log(`Sentiment score: ${sentiment.score}`);
    console.log(`Sentiment magnitude: ${sentiment.magnitude}`);
  .catch(err => {
    console.error('ERROR:', err);


Samples are in the samples/ directory. The samples' has instructions for running the samples.

Sample Source Code Try it
Analyze v1 source code Open in Cloud Shell
Analyze v1beta2 source code Open in Cloud Shell

The Natural Language API Node.js Client API Reference documentation also contains samples.


This library follows Semantic Versioning.

This library is considered to be General Availability (GA). This means it is stable; the code surface will not change in backwards-incompatible ways unless absolutely necessary (e.g. because of critical security issues) or with an extensive deprecation period. Issues and requests against GA libraries are addressed with the highest priority.

More Information: Google Cloud Platform Launch Stages


Contributions welcome! See the Contributing Guide.


Apache Version 2.0