Using Google+ Hangouts API

If someone adds [email protected] to his Google Hangout contacts and sends it a Google+ Hangout Chat message, I want to set up an automatic reply to his chat from my server. Is there a way to do that??

I think Its possible using the Google+ Hangouts API but I cannot figure out how.

(mydomain.com uses Google Apps for Business)

Does Google Hangouts have an API?

Hangouts Meet now available in the Google Calendar API.

Is Hangouts app being discontinued?

Share All sharing options for: Google Hangouts is shutting down in November. After sunsetting Google Hangouts for Workspace users in February, Google's now beginning the process of migrating free, personal Hangouts users to Chat.

Here's what you're looking: https://developers.google.com/+/hangouts/api/gapi.hangout.data

Here's the event for message recieved: (callback) https://developers.google.com/+/hangouts/api/gapi.hangout.data#gapi.hangout.data.onMessageReceived

And here's the event for sending the message: https://developers.google.com/+/hangouts/api/gapi.hangout.data#gapi.hangout.data.sendMessage