--- title: 'Step-by-Step Guide to Creating an Expo Monorepo with Nx' slug: 'step-by-step-guide-to-creating-an-expo-monorepo-with-nx' authors: ['Emily Xiong'] cover_image: '/blog/images/2023-08-24/IpM0kZdUNXoDWV4r8J5xXQ.png' tags: [nx, tutorial] description: A comprehensive tutorial on building a multi-app Expo monorepo using Nx, featuring shared UI components, navigation setup, and deployment configurations, demonstrated through the creation of two mobile apps. --- This blog will show you how to create an Expo monorepo with Nx. In this example, you will be creating two Expo apps in a monorepo with `@nx/expo`: one shows random facts about cats, and the other shows random facts about dogs. ![](/blog/images/2023-08-24/ZObpn_5XsfYX-My6d9n4Zw.avif) ![](/blog/images/2023-08-24/S6bzPlLbnM_Li_0Rh7mmWw.avif) _Left: cats, right: dogs_ As shown in the above screenshots, these two apps have the same branding and reuse all components. This blog will go through: - How to create a monorepo workspace with Nx - How to share a React Native library - How to build an Expo app - How to submit an Expo app to the app store Github repo: [xiongemi/nx-expo-monorepo](https://github.com/xiongemi/nx-expo-monorepo) ## Creating an Nx Workspace To create a new Nx workspace, run the command `npx create-nx-workspace ` in the terminal. In this example, let's name it `nx-expo-monorepo`: ``` ✔ Where would you like to create your workspace? · create-nx-monorepo ✔ Which stack do you want to use? · react ✔ What framework would you like to use? · expo ✔ Application name · cats ✔ Enable distributed caching to make your CI faster · No ``` This will create an [integrated](/deprecated/integrated-vs-package-based) repo. What is an integrated repo? > An integrated repo contains projects that depend on each other through standard import statements. There is typically a [single version of every dependency](/concepts/decisions/dependency-management) defined at the root. > [/deprecated/integrated-vs-package-based](/deprecated/integrated-vs-package-based) Now, your Nx workspace should have cats and cats-e2e under the `apps` folder and an empty libs folder: ![](/blog/images/2023-08-24/9yWjfR4oV5B0KFSdNgCH0g.avif) ### Existing Nx Workspace If you already have an Nx workspace, you need to install the @nx/expo package: ```shell \# npm npm install @nx/expo --save-dev \# yarn yarn add @nx/expo --dev \# pnpm pnpm add @nx/expo --save-dev ``` To create an Expo app, run: ```shell npx nx generate @nx/expo:app cats ``` Alternatively, if you use Visual Studio Code as your code editor, you can also create apps using [Nx Console](https://marketplace.visualstudio.com/items?itemName=nrwl.angular-console): ![](/blog/images/2023-08-24/WB17bHQ4p3nXJYWJ_IHGaw.avif) ## Install Tech Stacks Here are the tech stacks this example is going to use: - Material design library: [react-native-paper](https://callstack.github.io/react-native-paper/) ```shell \# npm npm install react-native-paper react-native-safe-area-context --save \# yarn yarn add react-native-paper react-native-safe-area-context \# pnpm pnpm add react-native-paper react-native-safe-area-context --save ``` - Routing: [@react-navigation/native](https://reactnavigation.org/) ```shell \# npm npm install react-native-paper react-native-screens @react-navigation/native-stack --save \# yarn yarn add react-native-paper react-native-screens @react-navigation/native-stack \# pnpm pnpm add react-native-paper react-native-screens @react-navigation/native-stack --save ``` ## Create a Shareable UI Library With all the required libraries installed, you need to create a sharable UI library: ```shell npx nx generate @nx/expo:lib ui ``` Now under the `libs` folder, a `ui` folder has been created: ![](/blog/images/2023-08-24/evR014EchmXEWHJfJnbJRg.avif) _ui folder_ To create a component in the `ui` library, run: ```shell npx nx generate @nx/expo:component carousel --project=ui --export ``` You can see that a `carousel` folder has been created in the `libs/ui/src/lib` folder: ![](/blog/images/2023-08-24/s_zYPQv0QVg5-juNRXmedw.avif) _carousel folder_ Next, modify this component to display the content with props passed in: ```tsx import React from 'react'; import { Card, Title, Paragraph } from 'react-native-paper'; export interface CarouselProps { imageUri?: string; title?: string; content: string; } export function Carousel({ imageUri, title, content }: CarouselProps) { return ( {imageUri && } {title && {title}} {content} ); } export default Carousel; ``` Now you can use this component in your app directly using an import: ``` import { Carousel } from '@nx-expo-monorepo/ui'; ``` ## Add Navigation This project is going to use the [stack navigator](https://reactnavigation.org/docs/stack-navigator) from [@react-navigation/native](https://reactnavigation.org/). So the app needs to import from @react-navigation/stack. In `apps/cats/src/app/App.tsx`, you can change the UI to have one screen displaying a carousel with mock data: ```tsx import React from 'react'; import { NavigationContainer } from '@react-navigation/native'; import { createNativeStackNavigator } from '@react-navigation/native-stack'; import { Carousel } from '@nx-expo-monorepo/ui'; const App = () => { const Stack = createNativeStackNavigator(); return ( ( )} /> ); }; export default App; ``` Run the app with`nx start cats`, and you should be able to see the app on the simulator: ![](/blog/images/2023-08-24/1hFA_7uBgU2GpFofNtHBiQ.avif) _Page on the simulator (left: iOS, right: Android)_ ## Add Another App In this example, there is already a `Cats` app. To create the `Dogs` app, run the command: ```shell npx nx generate @nx/expo:app dogs ``` Alternatively, if you use Visual Studio Code as your code editor, you can also create apps using [Nx Console](https://marketplace.visualstudio.com/items?itemName=nrwl.angular-console): ![](/blog/images/2023-08-24/8ut9KSAOn-UBBNxHJMtVXQ.avif) Under the apps folder, there should be `cats/`, `dogs/` and their e2es. ![](/blog/images/2023-08-24/juth4jstENJ4h1AvIibujA.avif) _apps folder_ You can reuse the UI library in the Dogs app in `apps/dogs/src/app/App.tsx` with the below code: ```tsx import React from 'react'; import { NavigationContainer } from '@react-navigation/native'; import { createNativeStackNavigator } from '@react-navigation/native-stack'; import { Carousel } from '@nx-expo-monorepo/ui'; const App = () => { const Stack = createNativeStackNavigator(); return ( ( )} /> ); }; export default App; ``` ## Build Expo Apps [EAS Build](https://docs.expo.dev/build/introduction/) is a hosted service for building app binaries for your Expo and React Native projects. To set up EAS locally: ### 1. Install EAS CLI EAS CLI is the command-line app to interact with EAS services in the terminal. To install it, run the command: ``` npm install -g eas-cli ``` ### 2. Login To EAS If you are not logged in, run the command: ``` eas login ``` ### 3. Build the Apps After the EAS setup, you can build apps by running the command: ```shell npx nx build cats npx nx build dogs ``` There are different options you can specify with the build command. For example, you can specify the platform you want to build: ```shell npx nx build cats --platform=all npx nx build cats --platform=android npx nx build cats --platform=ios ``` Alternatively, if you want to create a build to run on a simulator/emulator, you can run: ```shell npx nx build cats --profile=preview ``` You can view your build status at [https://expo.dev/](https://expo.dev/): ![](/blog/images/2023-08-24/pQxTgypzL10_SmI71jaWVQ.avif) If you want to create a build locally using your own infrastructure: ```shell npx nx build cats --local ``` Here is the complete list of flags for the build command: [/nx-api/expo/executors/build](/nx-api/expo/executors/build). ## Submit to the App Store Before you submit, you need to have paid developer accounts for iOS and Android. - iOS: You need to create an Apple Developer account on the Apple [Developer Portal](https://developer.apple.com/account/). - Android: You need to create a Google Play Developer account on the [Google Play Console sign-up page](https://play.google.com/apps/publish/signup/). You also need to manually create an app on [Google Play Console](https://play.google.com/apps/publish/) and upload your app for the first time. ### 1\. Run the production build To submit to the app store, you can build the app by running: ```shell npx nx build cats --profile=production ``` ### 2\. Submit the Build You can manually upload the build bundle binary to the app store, or you can submit it through EAS. First, in `app.json` under the project `apps/cats/app.json`, you need to make sure`ios.bundleIdentifier` and `android.package` keys are correct: ![](/blog/images/2023-08-24/j9TAZZgqplZCcjD4hiWNpg.avif) _app.json_ To submit your app to the app stores, run: ```shell npx nx submit cats ``` Nx will prompt you to choose the platform to which you want to submit: ![](/blog/images/2023-08-24/PcBvY1SJCHZyOnJI1hskAQ.avif) Or you can also specify the platform directly in the initial command: ```shell npx nx submit cats --platform=all npx nx submit cats --platform=android npx nx submit cats --platform=ios ``` It will then ask you to choose which binary to submit from one of the following options: - The latest finished Android build for the project on EAS servers. - Specific build ID. It can be found on the [builds dashboard](https://expo.dev/builds). - Path to an .apk or .aab or .ipa archive on your local filesystem. - URL to the app archive. Alternatively, you can submit your app on the [expo.dev](https://expo.dev/) site. Go to your build, under options, choose "Submit to an app store": ![](/blog/images/2023-08-24/yQlEmKOy3TXdWPCk9ILiZA.avif) ## Summary In this article, you have learned how to: - Create multiple apps in a monorepo using @nx/expo - Create a shared library - Build your app using EAS - Submit your app to the App Store With Nx, it is easy to create and scale up an Expo app. Even though this app is currently a simple 2-page app, you can easily scale it up with more libraries and components. Furthermore, you can also reuse those libraries in the future if you decide to add another app to the repo. ## Learn more - [Unit Testing Expo Apps With Jest](/blog/unit-testing-expo-apps-with-jest) - 👩‍💻 [Nx GitHub](https://github.com/nrwl/nx) - 💬 [Nx Official Discord Server](https://go.nx.dev/community) - 📹 [Nx Youtube Channel](https://www.youtube.com/@nxdevtools) - 🚀 [Speed up your CI](https://nx.app/)