🚀 Expo + AWS Amplify: Auth That Actually Works in Expo Go

TL;DR: Full-stack mobile auth with AWS Amplify Gen 2 that runs in Expo Go—no native build required for development.

Read my Blog about it: https://towardsaws.com/weekend-mvp-expo-go-aws-amplify-gen-2-for-startups-b42e3d62fff1

What You Get

✅ Email auth with OTP verification
✅ Session persistence across app restarts
✅ GraphQL API with real-time sync
✅ Auto-created user profiles via Lambda triggers
✅ Works in Expo Go (the secret: USER_PASSWORD_AUTH flow)

Stack: React Native · Expo · TypeScript · AWS Cognito · AppSync · DynamoDB

🚀 Quick Start

npm install
npx ampx sandbox --profile <your-aws-profile>  # Terminal 1
npx expo start                                   # Terminal 2
# Scan QR → Open in Expo Go → Done ✨

🧹 Cleaning up the sandbox

# Delete the sandbox for this app (same profile you used to create it)
npx ampx sandbox delete --profile <your-aws-profile>

# If you used a named sandbox identifier
npx ampx sandbox delete --name <your-sandbox-name> --profile <your-aws-profile>

Note: This only deletes the Amplify sandbox resources for this project, not other environments or AWS resources in your account.

📁 Key Files

app/(auth)/          # Sign in/up screens
amplify/auth/        # Cognito config + Lambda triggers
amplify/data/        # GraphQL schema
amplify_outputs.json # Auto-generated (gitignored)

Production tip: Switch to USER_SRP_AUTH with a native build for enhanced security.

📖 Resources

• Deep dive: See DEVELOPER_GUIDE.md for step-by-step setup
• AWS Amplify Docs
• Expo Documentation

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Built by Matthew Enarle · Powered by AWS Amplify Gen 2