Google Cloud Pub/Sub: Node.js Client

Cloud Pub/Sub is a fully-managed real-time messaging service that allows you to send and receive messages between independent applications.

This document contains links to an API reference, samples, and other resources useful to developing Node.js applications. For additional help developing Pub/Sub applications, in Node.js and other languages, see our Pub/Sub quickstart, publisher, and subscriber guides.

A comprehensive list of changes in each version may be found in the CHANGELOG.

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

Table of contents:

Quickstart

Before you begin

Installing the client library

npm install @google-cloud/pubsub

Using the client library

// Imports the Google Cloud client library
const {PubSub} = require('@google-cloud/pubsub');

async function quickstart(
  projectId = 'your-project-id', // Your Google Cloud Platform project ID
  topicName = 'my-topic', // Name for the new topic to create
  subscriptionName = 'my-sub' // Name for the new subscription to create
) {
  // Instantiates a client
  const pubsub = new PubSub({projectId});

  // Creates a new topic
  const [topic] = await pubsub.createTopic(topicName);
  console.log(`Topic ${topic.name} created.`);

  // Creates a subscription on that new topic
  const [subscription] = await topic.createSubscription(subscriptionName);

  // Receive callbacks for new messages on the subscription
  subscription.on('message', message => {
    console.log('Received message:', message.data.toString());
    process.exit(0);
  });

  // Receive callbacks for errors on the subscription
  subscription.on('error', error => {
    console.error('Received error:', error);
    process.exit(1);
  });

  // Send a message to the topic
  topic.publish(Buffer.from('Test message!'));
}

Running gRPC C++ bindings

For some workflows and environments it might make sense to use the C++ gRPC implementation, instead of the default one (see: #770):

To configure @google-cloud/pubsub to use an alternative grpc transport:

1. npm install grpc, adding grpc as a dependency.

2. instantiate @google-cloud/pubsub with grpc:

   const {PubSub} = require('@google-cloud/pubsub');
   const grpc = require('grpc');
   const pubsub = new PubSub({grpc});

Samples

Samples are in the samples/ directory. Each sample's README.md has instructions for running its sample.

Sample Source Code Try it Create an Avro based Schema source code

Create a Proto based Schema source code

Create Push Subscription source code

Create Subscription source code

Create Subscription With Dead Letter Policy source code

Create Subscription with ordering enabled source code

Create Topic source code

Create Topic With Schema source code

Delete a previously created schema source code

Delete Subscription source code

Delete Topic source code

Detach Subscription source code

Get a previously created schema source code

Get Subscription source code

Get Subscription Policy source code

Get Topic Policy source code

List All Topics source code

List schemas on a project source code

List Subscriptions source code

List Subscriptions On a Topic source code

Listen For Avro Records source code

Listen For Errors source code

Listen For Messages source code

Listen For Protobuf Messages source code

Listen For Messages With Custom Attributes source code

Modify Push Configuration source code

OpenTelemetry Tracing source code

Publish Avro Records to a Topic source code

Publish Batched Messages source code

Publish Message source code

Publish Message With Custom Attributes source code

Publish Ordered Message source code

Publish Protobuf Messages to a Topic source code

Publish With Retry Settings source code

Quickstart source code

Remove Dead Letter Policy source code

Resume Publish source code

Set Subscription IAM Policy source code

Set Topic IAM Policy source code

Subscribe With Flow Control Settings source code

Synchronous Pull source code

Synchronous Pull with delivery attempt. source code

Synchronous Pull With Lease Management source code

Test Subscription Permissions source code

Test Topic Permissions source code

Update Dead Letter Policy source code

The Google Cloud Pub/Sub Node.js Client API Reference documentation also contains samples.

Supported Node.js Versions

Our client libraries follow the Node.js release schedule. Libraries are compatible with all current active and maintenance versions of Node.js.

Client libraries targeting some end-of-life versions of Node.js are available, and can be installed via npm dist-tags. The dist-tags follow the naming convention legacy-(version).

Legacy Node.js versions are supported as a best effort:

• Legacy versions will not be tested in continuous integration.
• Some security patches may not be able to be backported.
• Dependencies will not be kept up-to-date, and features will not be backported.

Legacy tags available

• legacy-8: install client libraries from this dist-tag for versions compatible with Node.js 8.

Versioning

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

Contributing

Contributions welcome! See the Contributing Guide.

Please note that this README.md, the samples/README.md, and a variety of configuration files in this repository (including .nycrc and tsconfig.json) are generated from a central template. To edit one of these files, make an edit to its templates in directory.

License

Apache Version 2.0

See LICENSE