expo-module

# Writing Expo Modules Complete reference for building native modules and views using the Expo Modules API. Covers Swift (iOS), Kotlin (Android), and TypeScript. ## When to Use - Creating a new Expo native module or native view - Adding native functionality (camera, sensors, system APIs) to an Expo app - Wrapping platform SDKs for React Native consumption - Building config plugins that modify native project files - Adding Android, Apple, or web support to an existing Expo module - Editing `expo-module.config.json`, config plugins, or lifecycle hooks To migrate an existing Swift module from the definition DSL to the Expo Modules API 2.0 macros (`@ExpoModule`, `@JS`, `@Event`), use the `expo-migrate-module` skill (from the `expo-experiments` plugin) instead. ## References Consult these resources as needed: ``` references/ create-expo-module.md Scaffolding and add-platform-support workflow, defaults, and quirks native-module.md Module definition DSL: Name, Function, AsyncFunction, Property, Constant, Events, type system, shared objects native-view.md Native view components: View, Prop, EventDispatcher, view lifecycle, ref-based functions lifecycle.md Lifecycle hooks: module, iOS app/AppDelegate, Android activity/application listeners config-plugin.md Config plugins: modifying Info.plist, AndroidManifest.xml, reading values in native code module-config.md expo-module.config.json fields, file placement...