The React Native technical documentation describes how React Native works internally, the subsystems it is composed of, how they work and how they interact with each other.

The intended audience is people who want to learn about the internals of React Native and contribute to it. End users of React Native are meant to use the public website instead (its code can be found here).

For details on how we approach technical documentation in this repository, see GUIDELINES.md.

This repository is not meant to be consumed directly by end users. Instead, it creates several packages that are published to the NPM registry for direct consumption by end users and frameworks.

This repository uses a monorepo approach, and public packages can be found in the packages directory (the ones that do not contain "private": true in their package.json file).

The most important package is the react-native package, located in packages/react-native, which contains the public JavaScript API.

This repository provides the Android and iOS versions of React Native. Versions for other platforms are maintained in their own repositories.

TODO: Explain the different components of React Native at a high level.

• Runtime
  • Cross-platform
    • Feature Flags
    • Host / Instance / Bridgeless
    • UI / Fabric
      • Events
      • Shadow Tree Lifecycle
        • Runtime Shadow Node Reference Update
        • passChildrenWhenCloningPersistedNodes
      • Layout
      • Mounting
    • Native Modules / TurboModules
    • JS Runtime
      • Event Loop
      • Globals and environment setup
      • Error handling
    • Developer Tools
      • React DevTools
      • LogBox
    • Misc
      • Web APIs
        • DOM Traversal & Layout APIs
        • IntersectionObserver
        • MutationObserver
        • Performance & PerformanceObserver
        • Timers
  • Platform-specific
    • Host Platform Interface
  • Android
    • UI
      • Events
      • Mounting
  • iOS
    • UI
      • Events
      • Mounting
• Build system
  • Android
  • iOS
  • C++
  • JavaScript
    • Metro
• Testing
  • Android
  • iOS
  • C++
  • JavaScript
    • Flow
    • TypeScript
    • Jest
    • ESLint
  • Integration / E2E
    • Fantom
• Tooling
  • React Native DevTools

This repository has many different types of dependencies: build systems, external packages to be used during development, external packages used at runtime, etc.

The main use cases for this repository are:

1. Developing React Native itself.
2. Testing and releasing React Native.
3. Synchronizing forks like react-native-windows and react-native-macos.