How to Build a Mobile App With Claude Code: My Expo Workflow

If you have tried to build a mobile app before without a native development background, you know the pain: Xcode configuration errors, Android Studio setup, conflicting dependencies, and simulator issues that eat entire afternoons. Expo exists to remove all of that. It wraps React Native in a managed build system so you write JavaScript components and Expo handles the native layer.

The Expo Go app on your phone is the magic piece. You run one command, scan the QR code, and your app loads on your actual device in real time. No simulator setup, no cable, no build wait. Claude Code generates the component code; Expo Go shows it on your screen in under a minute.

Start by opening the Claude Code desktop app and creating a new project. Tell Claude Code: 'I want to build a mobile app using Expo and React Native. Start by scaffolding a new Expo project called [your app name].' Claude Code will run the Expo CLI commands and set up the project structure.

If you are running this in a terminal, the command is 'npx create-expo-app your-app-name' but you do not need to type it yourself. Describe what you want and Claude Code executes it. Once the scaffold is done, tell Claude Code what the app needs to do and it will start planning the file structure before writing a single component.

This is where the workflow is different from traditional development. You do not write component code directly - you describe the screen to Claude Code in plain terms. 'Build a home screen with a header showing the app name, a scrollable list of cards, and a floating action button in the bottom right.' Claude Code reads the project structure and writes the component.

For navigation between screens, tell Claude Code how the flow should work. 'When the user taps a card, take them to a detail screen showing the full information.' Claude Code adds the navigation stack, the route, and the detail component. It keeps the project consistent as it grows because it reads the existing files before adding new ones.

The CCC Build Loop applies here: use Plan Mode for anything bigger than a single screen so Claude Code reads the project first and plans what it will change before touching any files. For a single new component, let it run. For a multi-screen feature or a navigation rework, plan first to avoid contradictions across files.

Most useful apps need data from somewhere. Tell Claude Code where the data lives and what format it is in. 'The app needs to fetch a list of items from this API endpoint and display them on the home screen. The response returns an array of objects with id, title, and description fields.' Claude Code writes the fetch logic, the state management, and the component that renders the data.

For apps that need local data that persists between sessions, Claude Code can add AsyncStorage - the React Native equivalent of localStorage. Describe what needs to be saved and it handles the storage logic. For more complex data needs, it can set up a Supabase connection with the same plain-English briefing.

Install the Expo Go app on your iPhone or Android. Then tell Claude Code to start the development server. It will run 'npx expo start' and generate a QR code. Scan it with your camera. The app loads on your phone. Every change Claude Code makes to the code updates on your device in real time.

When the app is ready for a real build (for App Store or Google Play submission), you will need an Expo account and the EAS Build service. Tell Claude Code 'set up EAS Build for this project' and it will walk through the configuration. This is the step that goes beyond the Expo Go preview and produces the actual binary for submission.