claude-code-reactnative-expo-agent-system

# React Native/Expo Authentication Flow Implementation

## Overview
For [COMPANY], a fintech startup, we'll implement a secure authentication flow using Expo AuthSession and Firebase Authentication.

## Implementation Steps
1. **Set up Firebase project**: Create a new project in the Firebase console and enable Email/Password authentication.
2. **Install required packages**:
   ```bash
   expo install expo-auth-session expo-web-browser @react-native-firebase/app @react-native-firebase/auth
   ```
3. **Configure AuthSession**: Set up the OAuth redirect URL in your app's configuration.
4. **Implement authentication screens**: Create login, signup, and password reset screens with form validation.
5. **Secure data storage**: Use AsyncStorage to securely store user tokens and session data.

## Code Example
```javascript
// AuthenticationService.js
import auth from '@react-native-firebase/auth';

const signIn = async (email, password) => {
  try {
    await auth().signInWithEmailAndPassword(email, password);
    return { success: true };
  } catch (error) {
    return { success: false, error: error.message };
  }
};

const signUp = async (email, password) => {
  try {
    await auth().createUserWithEmailAndPassword(email, password);
    return { success: true };
  } catch (error) {
    return { success: false, error: error.message };
  }
};
```

## Security Considerations
- Implement password strength validation
- Use secure storage for sensitive data
- Enable biometric authentication for enhanced security