@google-cloud/pubsub

Examples

Install the client library with <a href="https://www.npmjs.com/">npm</a>:
```
npm install @google-cloud/pubsub

```

Import the client library
```
const {PubSub} = require('@google-cloud/pubsub');

```

Create a client that uses <a href="https://cloud.google.com/docs/authentication/production#providing_credentials_to_your_application">Application Default Credentials (ADC)</a>:
```
const pubsub = new PubSub();

```

Create a client with <a href="https://cloud.google.com/docs/authentication/production#obtaining_and_providing_service_account_credentials_manually">explicit credentials</a>:
```
const pubsub = new PubSub({
  projectId: 'your-project-id',
  keyFilename: '/path/to/keyfile.json'
});

```

Full quickstart example:

// Imports the Google Cloud client library
import {PubSub} from '@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!')});
}