Google Cloud Pub/Sub: Node.js Client

release level npm version

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

  1. Select or create a Cloud Platform project.
  2. Enable billing for your project.
  3. Enable the Google Cloud Pub/Sub 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 @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
  topicNameOrId = '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(topicNameOrId);
  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.publishMessage({data: 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.

SampleSource CodeTry it
Create an Avro based Schemasource codeOpen in Cloud Shell
Create BigQuery Subscriptionsource codeOpen in Cloud Shell
Create a Proto based Schemasource codeOpen in Cloud Shell
Create Push Subscriptionsource codeOpen in Cloud Shell
Create Subscriptionsource codeOpen in Cloud Shell
Create Subscription With Dead Letter Policysource codeOpen in Cloud Shell
Create an exactly-once delivery subscriptionsource codeOpen in Cloud Shell
Create Subscription With Filteringsource codeOpen in Cloud Shell
Create Subscription with ordering enabledsource codeOpen in Cloud Shell
Create Subscription With Retry Policysource codeOpen in Cloud Shell
Create Topicsource codeOpen in Cloud Shell
Create Topic With Schemasource codeOpen in Cloud Shell
Delete a previously created schemasource codeOpen in Cloud Shell
Delete Subscriptionsource codeOpen in Cloud Shell
Delete Topicsource codeOpen in Cloud Shell
Detach Subscriptionsource codeOpen in Cloud Shell
Get a previously created schemasource codeOpen in Cloud Shell
Get Subscriptionsource codeOpen in Cloud Shell
Get Subscription Policysource codeOpen in Cloud Shell
Get Topic Policysource codeOpen in Cloud Shell
List All Topicssource codeOpen in Cloud Shell
List schemas on a projectsource codeOpen in Cloud Shell
List Subscriptionssource codeOpen in Cloud Shell
List Subscriptions On a Topicsource codeOpen in Cloud Shell
Listen For Avro Recordssource codeOpen in Cloud Shell
Listen For Errorssource codeOpen in Cloud Shell
Listen For Messagessource codeOpen in Cloud Shell
Listen with exactly-once deliverysource codeOpen in Cloud Shell
Listen For Protobuf Messagessource codeOpen in Cloud Shell
Listen For Messages With Custom Attributessource codeOpen in Cloud Shell
Modify Push Configurationsource codeOpen in Cloud Shell
OpenTelemetry Tracingsource codeOpen in Cloud Shell
Publish Avro Records to a Topicsource codeOpen in Cloud Shell
Publish Batched Messagessource codeOpen in Cloud Shell
Publish Messagesource codeOpen in Cloud Shell
Publish Message With Custom Attributessource codeOpen in Cloud Shell
Publish Ordered Messagesource codeOpen in Cloud Shell
Publish Protobuf Messages to a Topicsource codeOpen in Cloud Shell
Publish with flow controlsource codeOpen in Cloud Shell
Publish With Retry Settingssource codeOpen in Cloud Shell
Quickstartsource codeOpen in Cloud Shell
Remove Dead Letter Policysource codeOpen in Cloud Shell
Resume Publishsource codeOpen in Cloud Shell
Set Subscription IAM Policysource codeOpen in Cloud Shell
Set Topic IAM Policysource codeOpen in Cloud Shell
Subscribe With Flow Control Settingssource codeOpen in Cloud Shell
Synchronous Pullsource codeOpen in Cloud Shell
Synchronous Pull with delivery attempt.source codeOpen in Cloud Shell
Synchronous Pull With Lease Managementsource codeOpen in Cloud Shell
Test Subscription Permissionssource codeOpen in Cloud Shell
Test Topic Permissionssource codeOpen in Cloud Shell
Update Dead Letter Policysource codeOpen in Cloud Shell
Validate a schema definitionsource codeOpen in Cloud Shell

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. If you are using an end-of-life version of Node.js, we recommend that you update as soon as possible to an actively supported LTS version.

Google's client libraries support legacy versions of Node.js runtimes on a best-efforts basis with the following warnings:

  • Legacy versions are not tested in continuous integration.
  • Some security patches and features cannot be backported.
  • Dependencies cannot be kept up-to-date.

Client libraries targeting some end-of-life versions of Node.js are available, and can be installed through npm dist-tags. The dist-tags follow the naming convention legacy-(version). For example, npm install @google-cloud/pubsub@legacy-8 installs client libraries for versions compatible with Node.js 8.

Versioning

This library follows Semantic Versioning.

This library is considered to be 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 stable 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