Google Assistant started reading messages from non-Google apps like WhatsApp, Slack and Telegram.
How it works
Google Assistant could always read SMS messages sent through the Messaging app or Hangouts. But many use other services for everyday communication and these applications were not available in Assistant (some could send but not read). Now it has changed.
To test a new feature, you need to tell the assistant “read my messages.” You will have to provide access to notifications, after which the Assistant will show the latest text messages, the application from which it comes and the name of the sender. Then you can print or dictate the answer. Upon completion, the response will be sent immediately and the notification will disappear.
This can be done with the last few chats, while the Assistant displays a carousel of received messages and views them one by one. Images, video and audio are not available, the assistant will simply say: “the message contains an audio attachment” and will not play it.
Most likely, the function is not yet available to everyone, but in the near future should appear for most users.