The Pixel 4 is the first Android phone to feature a proper secure face unlock mechanism that can't be easily fooled by pictures or similar looking people. To enable authentication in banking apps or password managers, this technology requires Android 10's new biometrics API. Since it's different from the previous fingerprint API, there are only a handful of applications that already support it. A new Xposed module provides a workaround for unsupported apps that aren't yet compatible with the Pixel 4's face unlock. The only caveat: it requires root access.

The module comes courtesy of XDA Developer forum member SemonCat and proxies the old fingerprint API to the biometrics API. You'll still receive apps' fingerprint prompts, but you should see the face unlock overlay with the 'Confirm' button on top of them.

Instead of waiting for devs to update apps to add Face Unlock support on Pixel 4, this guy took matters into his own hands by "proxying" the fingerprint API to the new biometrics API. Requires root, though. XDA thread: https://t.co/6MxTNg8b02 GitHub: https://t.co/IRhoWOFglc — Mishaal Rahman (@MishaalRahman) October 29, 2019

The module should be secure since it doesn't have any network permissions, so it can't send out any information. Both fingerprint and biometrics API only process data locally anyway and merely relay to apps whether an authentication was successful or not. Still, there's always a remaining risk when tampering with root and APIs, so you should assess carefully whether you really want this added convenience over security.

Fingerprint prompts will be accompanied by the new FaceID overlay when you use the module.

You can download the Xposed module from the Play Store for $1 to support the developer, but it's also available on Github if you'd rather build the APK yourself.