expo-module

Run npx create-expo-module with an explicit slug, choosing --local for app-internal modules or a standalone package for reuse. Pass --platform and --features to control generated platforms and example code, then replace the scaffold with your real implementation.

Use npx create-expo-module add-platform-support with --platform apple, android, or web from the module root. It only adds platforms missing from expo-module.config.json and refuses to overwrite existing android or ios directories.

Local modules live inside one app, use the app's tooling, and skip dependency installation and example apps. Standalone modules have their own package.json, install dependencies, build TypeScript, and usually include an example app for testing.

Yes, AsyncFunction on Android supports Kotlin coroutines using the Coroutine block, letting you call suspending functions like withContext(Dispatchers.IO) directly inside the module definition.

Declare events with Events("onChange") in the module definition, then call sendEvent from Swift or Kotlin. In JavaScript, subscribe with the useEvent hook or addListener, and use OnStartObserving to begin producing events.

Do not use it to migrate an existing Swift module from the definition DSL to the Expo Modules API 2.0 macros like @ExpoModule and @JS. For that migration, use the expo-migrate-module skill from the expo-experiments plugin instead.