Create React Native Library

title: Create a React Native Library impact: HIGH tags: react-native, library, create-react-native-library, expo, builder-bob, scaffolding

Skill: Create a React Native Library

Scaffold a new library with create-react-native-library.

When to Use

• Starting a new React Native library that may be published to npm

• Working on an existing React Native library scaffolded with create-react-native-library

Prerequisites

• Node.js version should match one of the following:

  • 20.19.0 or higher (LTS)

  • 22.12.0 or higher (LTS)

  • 23.4.0 or higher

Step-by-Step Instructions

Progress checklist:
- [ ] Scaffold library with CLI
- [ ] Read generated CONTRIBUTING.md for next steps
- [ ] Run yarn install to set up dependencies
- [ ] Run post install tasks (e.g. prebuild, pod-install, nitrogen)
- [ ] Run example app to test the library

• Run npx create-react-native-library@latest --help to check the latest available options.

• Choose the appropriate --type based on user's requirements:

  • Use turbo-module or nitro-module for exposing native APIs.

  • Use fabric-view or nitro-view for rendering native UI components.

  • Use library for a JS-only package.

• Choose the appropriate --languages based on the --type:

  • Use kotlin-objc for Turbo Modules or Fabric Components.

  • Use kotlin-swift for Nitro Modules or Nitro Views.

  • Use js for a JS-only library.

• Choose the appropriate --example:

  • Use expo for a managed Expo example app. This is recommended for smoother upgrades unless the user explicitly requests a different example.

  • Use vanilla for an app with React Native Community CLI.

  • Use test-app for a Microsoft's React Native Test App example.

• Run the npx create-react-native-library@latest command with the appropriate flags to scaffold the library:

  Copy

  # Scaffold a library with turbo modules and the Expo example app
  npx create-react-native-library@latest awesome-library \
    --no-interactive \
    --yes \
    --description "A brief description of the library" \
    --type turbo-module \
    --languages kotlin-objc \
    --example expo

• Read the generated CONTRIBUTING.md for project-specific install, build, lint, test, and release instructions.

• Run yarn install after scaffolding to set up dependencies.

• When using expo example for native modules and views, run yarn example expo prebuild to generate native code for the example app.

• For native modules and views, run cd example && npx pod-install to install CocoaPod dependencies.

• For nitro modules and views, run yarn nitrogen to generate required native code before building the example app.

• Use yarn example start to start the metro bundler for the example app.

• Use yarn example ios or yarn example android to run the example app on a simulator or device.

• Use yarn example web to run the example app in a web browser if the library should work on web.

Generated Project Structure

Typical generated layout:

awesome-library/
  src/              TypeScript entry points
  example/          Example app to test the library during development
  android/          Android native implementation when applicable
  ios/              iOS native implementation when applicable
  package.json      Package metadata, scripts and config
  CONTRIBUTING.md   Development workflow for the generated project

The exact files vary by --type, --languages, and selected tools.

Common Pitfalls

• Not using Yarn: The generated project uses a monorepo based on Yarn workspaces. Only use yarn and do not use other package managers.

• Using incompatible Node.js version: Ensure the Node.js version matches the required versions mentioned in the prerequisites.

• Incorrectly adding native dependencies: Any React Native libraries that contain native code and are used in the library must be added as peerDependencies and devDependencies in the library's root package.json, then dependencies of the example app's package.json.

Canonical Docs

• Scaffold a React Native library

• React Native Turbo Modules

• React Native Fabric Native Components

• Nitro Modules - Getting Started