This document outlines the security measures implemented in the Fact Pulse application.

All sensitive API keys and credentials are stored in environment variables:

• ✅ Perplexity API Key - AI fact-checking service
• ✅ Google OAuth Client IDs - For Google Sign-in authentication
• ✅ Firebase Project Configuration - Project ID and messaging sender ID

Sensitive configuration files are not committed to version control:

• ✅ android/app/google-services.json - Android Firebase config
• ✅ ios/Runner/GoogleService-Info.plist - iOS Firebase config
• ✅ macos/Runner/GoogleService-Info.plist - macOS Firebase config
• ✅ ios/Runner/Info.plist - iOS OAuth client configuration
• ✅ macos/Runner/Info.plist - macOS OAuth client configuration
• ✅ web/index.html - Web OAuth client configuration

1. Environment Variable Loading: All API keys loaded from .env file at runtime
2. Cross-platform Compatibility: Uses Flutter's rootBundle for web compatibility
3. Error Handling: App throws clear errors if required keys are missing
4. No Hardcoded Secrets: All hardcoded credentials removed from source code

1. Client vs Server Keys:
   • ✅ Client-safe Firebase API keys remain in firebase_options.dart
   • ❌ Sensitive OAuth secrets moved to environment variables
2. Security Rules: Firebase access controlled by server-side security rules
3. Configuration Separation: Config files with secrets separated from public config

1. Client ID Protection: Google OAuth client IDs secured in environment variables
2. Platform-specific Setup: Each platform has its own OAuth configuration
3. URL Scheme Security: Proper URL schemes configured for OAuth callbacks

./setup_templates.sh

This script:

• Copies template files to correct locations
• Injects OAuth client IDs from .env file
• Sets up proper URL schemes automatically
• Validates configuration

# Check that sensitive files are not tracked
git status --porcelain | grep -E "(\.env|google-services|GoogleService-Info|Info\.plist|index\.html)$"

# Should return empty (no results)

• All API keys moved to environment variables
• Sensitive config files added to .gitignore
• Template files created for developers
• Automated setup script provided
• Documentation updated with security practices
• Cross-platform compatibility maintained
• Error handling for missing credentials
• OAuth client IDs properly secured

1. Never commit .env files or Firebase config files to version control
2. Always validate that sensitive files are in .gitignore before committing
3. Use the setup script (./setup_templates.sh) for consistent environment setup
4. Keep credentials private - never share API keys in public channels
5. Rotate credentials if they may have been compromised

Last security review: $(date)

• All hardcoded credentials removed ✅
• Environment variable system implemented ✅
• Cross-platform compatibility verified ✅
• Developer documentation complete ✅

For setup instructions, see FIREBASE_SETUP.md