Google Cloud Pub/Sub: Node.js Client

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

This document contains links to anAPI 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 ourPub/Sub quickstart,publisher, andsubscriberguides.

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

• Google Cloud Pub/Sub Node.js Client API Reference
• Google Cloud Pub/Sub Documentation
• github.com/googleapis/nodejs-pubsub

Read more about the client libraries for Cloud APIs, including the olderGoogle APIs Client Libraries, inClient Libraries Explained.

Table of contents:

• Quickstart
  • Before you begin
  • Installing the client library
  • Using the client library
• Samples
• Versioning
• Contributing
• License

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 theAPI from your local workstation.

Installing the client library

npm install @google-cloud/pubsub

Using the client library

// Imports the Google Cloud client libraryconst {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 = newPubSub({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 alternativegrpc transport:

1. npm install grpc, addinggrpc as a dependency.

2. instantiate@google-cloud/pubsub withgrpc:

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

Samples

Samples are in thesamples/ directory. Each sample'sREADME.md has instructions for running its sample.

Sample	Source Code	Try it
Create an Avro based Schema	source code
Create BigQuery Subscription	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 an exactly-once delivery subscription	source code
Create Subscription With Filtering	source code
Create Subscription with ordering enabled	source code
Create Subscription With Retry Policy	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 with exactly-once delivery	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 flow control	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
Validate a schema definition	source code

TheGoogle Cloud Pub/Sub Node.js Client API Reference documentationalso contains samples.

Supported Node.js Versions

Our client libraries follow theNode.js release schedule.Libraries are compatible with all currentactive andmaintenance versions ofNode.js.If you are using an end-of-life version of Node.js, we recommend that you updateas soon as possible to an actively supported LTS version.

Google's client libraries support legacy versions of Node.js runtimes on abest-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, andcan be installed through npmdist-tags.The dist-tags follow the naming conventionlegacy-(version).For example,npm install @google-cloud/pubsub@legacy-8 installs client librariesfor versions compatible with Node.js 8.

Versioning

This library followsSemantic Versioning.

This library is considered to bestable. The code surface will not change in backwards-incompatible waysunless absolutely necessary (e.g. because of critical security issues) or withan extensive deprecation period. Issues and requests againststable librariesare addressed with the highest priority.

More Information:Google Cloud Platform Launch Stages

Contributing

Contributions welcome! See theContributing Guide.

Please note that thisREADME.md, thesamples/README.md,and a variety of configuration files in this repository (including.nycrc andtsconfig.json)are generated from a central template. To edit one of these files, make an editto its templates indirectory.

License

Apache Version 2.0

SeeLICENSE