Expo × Antigravity: Build Cross-Platform Apps at Lightning

Setup and context

Expo is an open-source framework that dramatically simplifies React Native app development. Its powerful ecosystem allows you to simultaneously build apps for iOS, Android, and the web without writing native code.

Combined with Google Antigravity's AI agents, you can automate a large portion of the workflow — from component generation all the way to deployment. This article walks you through how to efficiently develop Expo projects with Antigravity.

Prerequisites

Node.js 20 or higher installed
Basic understanding of Antigravity (see the Getting Started guide)
Basic knowledge of React / React Native

Setting Up an Expo Project

Start by creating a new Expo project. Open Antigravity's Manager Surface and instruct a new agent:

npx create-expo-app@latest MyApp --template blank-typescript
cd MyApp
npx expo install

Antigravity's agent automatically analyzes the project structure and proposes an optimized configuration for package.json, app.json, and tsconfig.json.

Delegating Initial Setup to Antigravity

In Manager Surface, give the following instruction:

Set up the Expo project "MyApp":
- Enable TypeScript strict mode
- Install Expo Router v3
- Configure styling with NativeWind
- Set up state management with Zustand

The agent handles everything from installing the required packages to creating config files automatically.

Working with Expo Router

Expo Router uses file-based routing — the file structure under the app/ directory directly maps to your navigation hierarchy.

Auto-Generating Screen Components

In Antigravity's Editor View, type the following to batch-generate routing-ready screen components:

Create the following screens under app/:
- (tabs)/_layout.tsx  ← Tab navigation
- (tabs)/index.tsx    ← Home screen
- (tabs)/explore.tsx  ← Explore screen
- modal.tsx           ← Modal screen

The generated code has accurate TypeScript types and fully conforms to Expo Router conventions:

// app/(tabs)/index.tsx (sample generated by Antigravity)
import { StyleSheet, Text, View } from 'react-native';
import { Link } from 'expo-router';
 
export default function HomeScreen() {
  return (
    <View style={styles.container}>
      <Text style={styles.title}>Home</Text>
      <Link href="/modal">Open Modal</Link>
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
  },
  title: {
    fontSize: 24,
    fontWeight: 'bold',
  },
});

EAS Build Configuration and Automation

EAS (Expo Application Services) Build is Expo's official cloud build service. Let Antigravity automate your EAS configuration.

Optimizing eas.json

Create eas.json with three profiles: development, preview, and production.
For iOS: distribution: internal. For Android: buildType: apk (preview) and buildType: app-bundle (production).

The eas.json Antigravity generates:

{
  "cli": {
    "version": ">= 7.0.0"
  },
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal",
      "ios": {
        "simulator": true
      }
    },
    "preview": {
      "distribution": "internal",
      "ios": {
        "distribution": "internal"
      },
      "android": {
        "buildType": "apk"
      }
    },
    "production": {
      "ios": {
        "distribution": "store"
      },
      "android": {
        "buildType": "app-bundle"
      }
    }
  }
}

GitHub Actions Integration

Using Antigravity's GitHub Actions MCP, you can set up a workflow that automatically triggers a build on every push:

Create .github/workflows/eas-build.yml.
Trigger an EAS preview build automatically on push to the main branch.
Send a Slack notification when the build completes.

Over The Air (OTA) Updates

Expo's EAS Update lets you push JavaScript bundle updates directly to users without going through the app store review process — ideal for bug fixes and UI changes.

# Example of shipping an OTA update via Antigravity agent
npx eas update --branch production --message "Fix: Validation error on login screen"

Just tell the Antigravity agent "ship an OTA update to production" and it will handle the build, test, and distribution pipeline end to end.

Handling Custom Native Modules

When using Expo's Bare Workflow or Config Plugins, native code edits may be required. Antigravity handles native code generation and modification as well.

Create a Config Plugin that adds a camera access usage description to iOS Info.plist.
Add the corresponding permission to Android's AndroidManifest.xml too.

Antigravity understands the Expo Config Plugin spec and generates the appropriate native configuration for each platform.

Debugging and Testing

Testing on Device with Expo Go

npx expo start

Once the server is running, ask the Antigravity agent "write unit tests for this component" and it will auto-generate test code using Jest and React Native Testing Library.

Error Analysis

When a crash occurs on a real device, just paste the stack trace into Antigravity and it will analyze the cause and propose a fix:

Analyze this crash report and fix it:
TypeError: undefined is not an object (evaluating 'user.profile.avatar')
  at ProfileScreen (app/(tabs)/profile.tsx:42)

Conclusion

The combination of Expo and Antigravity dramatically accelerates cross-platform mobile app development:

Project setup: Automate everything from create-expo-app to dependency configuration
Component generation: Instantly generate Expo Router and NativeWind-ready code
Build & deploy: Let Antigravity agents manage EAS Build and EAS Update pipelines
Debugging: Automatically analyze crash reports and apply fixes

By leveraging Antigravity's AI agents, you minimize time spent on boilerplate and stay focused on your app's core logic and UX design. Give it a try today.

Expo × Antigravity: Build Cross-Platform Apps at Lightning Speed