Link: https://www.uploadvr.com/vrchat-gets-native-face-tracking-support-in-open-beta/

VRChat has technically supported Eye and Face Tracking for years over OSC (Open Sound Control) and the community-made VRCFaceTracking (VRCFT) app. However, avatars did not natively support full facial tracking, and instead needed to be configured with add-ons. Without them, avatars could only natively use Eye Tracking data for basic gaze and eyelid movement.

Now, VRChat's latest Open Beta client on Steam and Avatars SDK Version 3.10.6-beta.1 and higher bring support for SDK-level authoring of Face Tracking. Initially described as "High Fidelity Face Tracking," the feature allows creators to set up facial expressions for an avatar via a new dedicated section in the Avatar Descriptor component.