react-native-brownfield-migration

SKILL.md

Migrating to React Native

Overview

Prescriptive workflow for incremental adoption of React Native in existing native apps using @callstack/react-native-brownfield, from initial setup through phased host integration.

Expo track

Bare React Native track

Use one track per task unless the user explicitly asks for migration or comparison.

Migration Strategy

Use this strategy for brownfield migration planning and execution:

Assess app state and select Expo or bare path.

Perform initial setup with @callstack/react-native-brownfield.

Package RN artifacts (XCFramework/AAR) from the RN source app.

Integrate one RN surface into the host app and validate startup/runtime.

Repeat integration by feature/screen for incremental rollout.

Agent Guardrails (Global)

Apply these rules across all reference files:

Select one path first (Expo or bare) and do not mix steps.

Use placeholders from the docs (<framework_target_name>, <android_module_name>, <registered_module_name>) and resolve from project files.

Validate each packaging command before moving to host integration.

Prefer official docs for long platform snippets and CLI option details.

Keep host apps isolated from direct React Native APIs when possible (facade approach).

For startup/runtime verification, use agent-device to open the host app, navigate to the RN surface, capture snapshots/screenshots, and collect device evidence. If it is missing and verification needs it, install it through the environment's approved/trusted path or ask the user to install or enable it.

Canonical Docs

Quick Start

Expo Integration

iOS Integration

Android Integration

Brownfield CLI

Guidelines

Troubleshooting

Path Selection Gate (Must Run First)

Before selecting any reference file, classify the project:

If no React Native app exists yet, use Expo creation path:

expo-create-app.md -> expo-quick-start.md

If React Native app exists, inspect package.json and app.json:

Expo if expo is present or Expo plugin workflow is requested.

Bare RN if native folders and direct RN CLI workflow are used without Expo path requirements.

If still unclear, ask one disambiguation question.

Continue with exactly one path.

When to Apply

Reference this package when:

Planning incremental migration from native-only apps to React Native or Expo

Creating brownfield integration flows for Expo or bare React Native projects

Performing initial setup with @callstack/react-native-brownfield

Generating iOS XCFramework artifacts from a React Native app

Generating and publishing Android AAR artifacts from a React Native app

Integrating generated artifacts into host iOS/Android apps

Quick Reference

File
Description

quick-start.md
Shared preflight and mandatory path-selection gate

expo-create-app.md
Scaffold a new Expo app before Expo brownfield setup

expo-quick-start.md
Expo plugin setup and packaging readiness

expo-ios-integration.md
Expo iOS packaging and host startup integration

expo-android-integration.md
Expo Android packaging, publish, and host integration

bare-quick-start.md
Bare React Native baseline setup

bare-ios-xcframework-generation.md
Bare iOS XCFramework generation

bare-android-aar-generation.md
Bare Android AAR generation and publish

bare-ios-native-integration.md
Bare iOS host integration

bare-android-native-integration.md
Bare Android host integration

Problem -> Skill Mapping

Problem
Start With

Need path decision first
quick-start.md

Need to create a new Expo app for brownfield
expo-create-app.md

Need Expo brownfield setup and plugin wiring
expo-quick-start.md

Need Expo iOS brownfield integration
expo-ios-integration.md

Need Expo Android brownfield integration
expo-android-integration.md

Need bare RN baseline setup
bare-quick-start.md

Need bare RN iOS XCFramework generation
bare-ios-xcframework-generation.md

Need bare RN Android AAR generation/publish
bare-android-aar-generation.md

Need bare RN iOS host integration
bare-ios-native-integration.md

Need bare RN Android host integration
bare-android-native-integration.md