This code sample creates a simple Google Chat app that listens for messages via Cloud Pub/Sub.

For more information on how to build with Pub/Sub, please read the guide.

Before you can run the sample, do the following:

1. Follow the directions for setting up a topic and subscription as described in Build a Google Chat app behind a firewall with Pub/Sub.
2. Run the sample, substituting your subscription id and service account JSON file from step 1.

   PROJECT_ID=your-project-id SUBSCRIPTION_ID=your-subscription-id GOOGLE_APPLICATION_CREDENTIALS=your-service-account.json mvn compile exec:java \
   -Dexec.mainClass=Main
   

Either add and @mention the app in a space or in a direct mention to engage with the app.

When added to a space or messaged, the app will respond with a simple reply.