Apple's Custom Keyboard Extension API is deliberately narrow — narrower than most developers
expect coming from Android's InputConnection. Knowing the actual boundary up front saves you
from designing a feature the platform will simply never let you ship.
Can you actually build a production system keyboard — an Android IME, an iOS Custom Keyboard Extension — entirely in React Native? Not a demo, not a toy, but something you'd ship to real users on both platforms from one codebase?
Yes. This is the proof, and the library that makes it repeatable.
Every mobile app that wants a custom system keyboard has run into the same wall: Android IMEs and iOS Custom Keyboard Extensions are native surfaces. Building one has always meant writing (and maintaining) two separate native UIs in Kotlin and Swift — even if your app is otherwise 100% React Native. Most teams either give up on the idea or pay for a fully native rewrite of a single screen.
react-native-keyboard-bridge removes that wall. You write one component — plain View,
Text, TouchableOpacity, useState — and it runs live on both platforms, as a real, live React
Native surface hosted inside the IME process on Android and the Custom Keyboard Extension process
on iOS. Not a schema. Not a subset. Real React Native, running where conventional wisdom said it
couldn't.