Proof

@callstack/react-native-brownfield

published ReactNativeBrownfield.js runs unchanged against a ReactNativeBrownfield seam that mirrors the hostless regime: silent methods, subscribed but never-emitted messages
50%
API coverage
No visual proof cases have been published for this package yet. The registry summary below describes what the compat layer implements.
Working (3)
module presence; ios popToNativesetNativeBackGestureAndButtonEnabledpostMessage all silent; onMessage subscribe and remove with zero events on both platforms; android back-button flag write
Missing (3)
host integration paths: android postMessage dispatchandroid popToNative back pressnative-to-js message emission