Expo Brownfield
Integrate Expo and React Native into an existing native iOS or Android app.
Install
npx skills add expo/skills --skill expo-brownfield -g -a claude-code -y- Repository
- expo/skills4k
- Category
- Design
- Updated
- 3d ago
- License
- MIT
- Context cost
- Lightabout 1,373 tokens
- Runs scripts
- No, instructions only
What it does
Integrate Expo and React Native into an existing native iOS or Android app. Use for brownfield, embedding a React Native screen in SwiftUI/UIKit or Kotlin, or AAR/XCFramework packaging. Covers isolated and integrated approaches. For building or distributing a purely native app with EAS, use eas-app-stores.
Expo Brownfield
A brownfield app is an existing native iOS or Android app that adopts React Native incrementally, as opposed to a greenfield app that is React Native from day one.
Inspect the host first
Identify the existing app entry point, navigation owner, native build system, deployment targets, and any React Native runtime already linked. Record the installed Expo, React Native, and brownfield package versions from the lockfile. Adding EAS Build or Submit to a Swift app alone does not require React Native; route that task to eas-app-stores.
Preserve the host's SwiftUI App / UIKit window and native screens when embedding a feature. Do not run prebuild in a manually maintained native host, including during troubleshooting. An isolated Expo producer may use CNG; keep its generated ios/ and android/ separate from the consuming app.
Expo supports two distinct ways to add React Native to a brownfield project:
| Approach | What ships to the native app | When to choose |
|---|---|---|
| Isolated | Prebuilt AAR / XCFramework | Native team doesn't need Node or RN tooling; RN code can live in a separate repo |
| Integrated | React Native sources added to the existing Gradle / CocoaPods build | One team owns everything; comfortable with RN tooling; wants a single build |
For the full decision matrix, see ./references/comparison.md.
Pick an approach
Use these quick rules, fall through to comparison.md for anything ambiguous.
