Google Assistant has always been able to read your SMS text messages sent via the native Messages app or Hangouts. However, the Assistant was not compatible with other third-party apps such as WhatsApp, Telegram, Slack, Discord, GroupMe, apps which are more popular than Google’s native ones.
Now things are about to change and you can see how by asking the Assistant: “read my messages”. If this is your first time doing it, you will first have to give it notification access.
After you do this, you will receive cards with your latest messages and you will be able to hear it out loud. The Assistant will tell you which app the message is coming from, who wrote it to you, and its contents.
After that, you will have the option to either dictate or write your reply. Once that is done, the message is marked as read and the answer is sent over to the recipient.
There’s one thing the Assistant can’t do however and that is access messages with pictures, video or audio; it will tell you that “the message just contains an audio attachment” but will not play it for you.
For now, this feature appears here and there – some users might have received it as a test while others can’t access it yet so Google is most likely still in the process of rolling it out. For now, you can only try it yourself and see if it works wherever you are in the world.