So, You have rooted your OnePlus 3T and now want to use the "Google Assistant" that everyone is talking about. This article will help you enable the google assistant on your phone.
Requirements : Rooted OnePlus 3T running Android 6+(Marshmallow or higher)
2. Update Google Play Services & Google Now : Make sure your Google App is updated to the latest version. If not, just go to Google Play Store and update the Google App. Update Google Play Services to the latest version(if you don't find the option to update google play services, just continue with the next step)
3. Install Get Assistant - root : Install this helper app which will automatically edit the "build.prop" and set it up for google assistant. Open the app and choose the "New Method" button and continue to click on "Get Assistant" in the end.
4. Clear App Data and Cache : Now you need to manually wipe Google's app data and its cache.
6. Long Press Home Button : Just hold down the home button/fingerprint scanner and google assistant should pop up instantly.