Natural Language client libraries

This page shows how to get started with the Cloud Client Libraries for the Cloud Natural Language API. Read more about the client libraries for Cloud APIs, including the older Google API Client Libraries, in Client Libraries Explained.

Installing the client library

C#

For more information, see Setting Up a C# Development Environment.

If you are using Visual Studio 2017 or higher, open nuget package manager window and type the following:

Install-Package Google.Apis

If you are using .NET Core command-line interface tools to install your dependencies, run the following command:

dotnet add package Google.Apis

Go

For more information, see Setting Up a Go Development Environment.

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

Java

For more information, see Setting Up a Java Development Environment.

If you are using Maven, add the following to your pom.xml file. For more information about BOMs, see The Google Cloud Platform Libraries BOM.

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>libraries-bom</artifactId>
      <version>25.4.0</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

<dependencies>
  <dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>google-cloud-language</artifactId>
  </dependency>

If you are using Gradle, add the following to your dependencies:

implementation platform('com.google.cloud:libraries-bom:25.4.0')

implementation 'com.google.cloud:google-cloud-language'

If you are using sbt, add the following to your dependencies:

libraryDependencies += "com.google.cloud" % "google-cloud-language" % "2.2.0"

If you're using Visual Studio Code, IntelliJ, or Eclipse, you can add client libraries to your project using the following IDE plugins:

The plugins provide additional functionality, such as key management for service accounts. Refer to each plugin's documentation for details.

Node.js

For more information, see Setting Up a Node.js Development Environment.

npm install --save @google-cloud/language

PHP

For more information, see Using PHP on Google Cloud.

composer require google/apiclient

Python

For more information, see Setting Up a Python Development Environment.

pip install --upgrade google-cloud-language

Ruby

For more information, see Setting Up a Ruby Development Environment.

gem install google-api-client

Setting up authentication

To run the client library, you must first set up authentication. One way to do that is to create a service account and set an environment variable, as shown in the following steps. For other ways to authenticate, see Authenticating as a service account.

Console

Create a service account:

  1. In the Google Cloud console, go to the Create service account page.

    Go to Create service account
  2. Select your project.
  3. In the Service account name field, enter a name. The Google Cloud console fills in the Service account ID field based on this name.

    In the Service account description field, enter a description. For example, Service account for quickstart.

  4. Click Create and continue.
  5. To provide access to your project, grant the following role(s) to your service account: Project > Owner.

    In the Select a role list, select a role.

    For additional roles, click Add another role and add each additional role.

  6. Click Continue.
  7. Click Done to finish creating the service account.

    Do not close your browser window. You will use it in the next step.

Create a service account key:

  1. In the Google Cloud console, click the email address for the service account that you created.
  2. Click Keys.
  3. Click Add key, and then click Create new key.
  4. Click Create. A JSON key file is downloaded to your computer.
  5. Click Close.

gcloud

Set up authentication:

  1. Create the service account:

    gcloud iam service-accounts create NAME

    Replace NAME with a name for the service account.

  2. Grant roles to the service account. Run the following command once for each of the following IAM roles: roles/owner:

    gcloud projects add-iam-policy-binding PROJECT_ID --member="serviceAccount:SERVICE_ACCOUNT_NAME@PROJECT_ID.iam.gserviceaccount.com" --role=ROLE

    Replace the following:

    • SERVICE_ACCOUNT_NAME: the name of the service account
    • PROJECT_ID: the project ID where you created the service account
    • ROLE: the role to grant
  3. Generate the key file:

    gcloud iam service-accounts keys create FILE_NAME.json --iam-account=SERVICE_ACCOUNT_NAME@PROJECT_ID.iam.gserviceaccount.com

    Replace the following:

    • FILE_NAME: a name for the key file
    • SERVICE_ACCOUNT_NAME: the name of the service account
    • PROJECT_ID: the project ID where you created the service account

Provide authentication credentials to your application code by setting the environment variable GOOGLE_APPLICATION_CREDENTIALS. This variable applies only to your current shell session. If you want the variable to apply to future shell sessions, set the variable in your shell startup file, for example in the ~/.bashrc or ~/.profile file.

Linux or macOS

export GOOGLE_APPLICATION_CREDENTIALS="KEY_PATH"

Replace KEY_PATH with the path of the JSON file that contains your service account key.

For example:

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/service-account-file.json"

Windows

For PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="KEY_PATH"

Replace KEY_PATH with the path of the JSON file that contains your service account key.

For example:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\service-account-file.json"

For command prompt:

set GOOGLE_APPLICATION_CREDENTIALS=KEY_PATH

Replace KEY_PATH with the path of the JSON file that contains your service account key.

Using the client library

The following example shows how to use the client library.

Go


// Sample language-quickstart uses the Google Cloud Natural API to analyze the
// sentiment of "Hello, world!".
package main

import (
	"context"
	"fmt"
	"log"

	language "cloud.google.com/go/language/apiv1"
	languagepb "google.golang.org/genproto/googleapis/cloud/language/v1"
)

func main() {
	ctx := context.Background()

	// Creates a client.
	client, err := language.NewClient(ctx)
	if err != nil {
		log.Fatalf("Failed to create client: %v", err)
	}
	defer client.Close()

	// Sets the text to analyze.
	text := "Hello, world!"

	// Detects the sentiment of the text.
	sentiment, err := client.AnalyzeSentiment(ctx, &languagepb.AnalyzeSentimentRequest{
		Document: &languagepb.Document{
			Source: &languagepb.Document_Content{
				Content: text,
			},
			Type: languagepb.Document_PLAIN_TEXT,
		},
		EncodingType: languagepb.EncodingType_UTF8,
	})
	if err != nil {
		log.Fatalf("Failed to analyze text: %v", err)
	}

	fmt.Printf("Text: %v\n", text)
	if sentiment.DocumentSentiment.Score >= 0 {
		fmt.Println("Sentiment: positive")
	} else {
		fmt.Println("Sentiment: negative")
	}
}

Java

// Imports the Google Cloud client library
import com.google.cloud.language.v1.Document;
import com.google.cloud.language.v1.Document.Type;
import com.google.cloud.language.v1.LanguageServiceClient;
import com.google.cloud.language.v1.Sentiment;

public class QuickstartSample {
  public static void main(String... args) throws Exception {
    // Instantiates a client
    try (LanguageServiceClient language = LanguageServiceClient.create()) {

      // The text to analyze
      String text = "Hello, world!";
      Document doc = Document.newBuilder().setContent(text).setType(Type.PLAIN_TEXT).build();

      // Detects the sentiment of the text
      Sentiment sentiment = language.analyzeSentiment(doc).getDocumentSentiment();

      System.out.printf("Text: %s%n", text);
      System.out.printf("Sentiment: %s, %s%n", sentiment.getScore(), sentiment.getMagnitude());
    }
  }
}

Node.js

async function quickstart() {
  // 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
  const [result] = await client.analyzeSentiment({document: document});
  const sentiment = result.documentSentiment;

  console.log(`Text: ${text}`);
  console.log(`Sentiment score: ${sentiment.score}`);
  console.log(`Sentiment magnitude: ${sentiment.magnitude}`);
}

Python

# Imports the Google Cloud client library
from google.cloud import language_v1

# Instantiates a client
client = language_v1.LanguageServiceClient()

# The text to analyze
text = "Hello, world!"
document = language_v1.Document(
    content=text, type_=language_v1.Document.Type.PLAIN_TEXT
)

# Detects the sentiment of the text
sentiment = client.analyze_sentiment(
    request={"document": document}
).document_sentiment

print("Text: {}".format(text))
print("Sentiment: {}, {}".format(sentiment.score, sentiment.magnitude))

Additional resources