Monorepo

A monorepo is a single repository that holds several projects, for example a React Native app, a Next.js site and shared packages for UI, types and API clients. The package manager’s workspaces feature links them so the app can import @acme/ui as if it came from the registry.

Teams adopt it to share code between mobile and web, keep one version of TypeScript and lint config, and change an API client and its callers in one pull request.

React Native makes monorepos harder than the web does, for three reasons:

• Metro must see the whole repository. It needs to watch and resolve files outside the app folder. Expo’s Metro config detects workspaces automatically; bare projects usually set watchFolders themselves.
• Native dependencies must be visible to the app. Autolinking only links native libraries the app depends on, so a library used by a shared package must also be listed in the app’s own package.json.
• There must be exactly one copy of React and React Native. Two copies cause "Invalid hook call" errors or native crashes.

That last point is the classic failure. Different packages pin slightly different versions of react, the package manager installs both, and the app breaks in ways that look unrelated. Declare react and react-native as peer dependencies in shared packages, and keep a single version at the root.

Hoisting also matters. Some React Native tooling still assumes packages live in a flat node_modules, so pnpm’s isolated layout may need node-linker=hoisted, depending on your toolchain version. Tools such as Nx and Turborepo add caching and task orchestration on top, but the workspace rules above apply whichever you pick.