Payment Processing Simulator

A robust payment transaction simulator designed to test and demonstrate payment processing workflows, built with React, TypeScript, and Supabase. This application simulates real-world payment processing scenarios, including transaction processing, load testing, and ISO8583-like message generation. Perfect for testing the resilience of payment platforms and understanding payment workflows.

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🚀 Features

Transaction Processing

• Support for multiple transaction types:
  • Purchases
  • Refunds
  • Reversals
• Real-time transaction status updates
• ISO8583-like message generation
• Secure card number handling with masking
• Merchant ID tracking

Load Testing

• Configurable transactions per second (TPS)
• Adjustable test duration
• Customizable transaction amounts
• Real-time performance metrics
• Batch simulation tracking

Analytics

• Transaction success rate monitoring
• Actual TPS calculations
• Total amount tracking
• Detailed transaction logs

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🛠️ Technology Stack

• Frontend: React with TypeScript
• Styling: Tailwind CSS
• Icons: Lucide React
• Database: Supabase
• Build Tool: Vite
• Backend: Express.js with Apollo Server (TypeScript)
• Deployment: AWS (Terraform + GitHub Actions)
• Containerization: Docker

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🚀 Getting Started

Prerequisites

• Node.js (v18 or higher)
• npm (comes with Node.js)
• Docker (optional)

Steps to Run Locally

1. Clone the repository:

   git clone https://github.com/4Min4m/TransactionSimulator.git
   cd TransactionSimulator

2. Install dependencies:

   # Frontend
   cd frontend
   npm install
   
   # Backend
   cd ../backend
   npm install

3. Set up environment variables:

   • Create a .env file in the backend directory:

     SUPABASE_URL=your-supabase-url
     SUPABASE_KEY=your-supabase-key
     

4. Start the development servers:

   • Frontend:

     cd frontend
     npm run dev

   • Backend:

     cd backend
     npm run dev

5. Open your browser and navigate to http://localhost:5173.

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🗄️ Database Schema

Tables

• transactions: Stores individual transaction records
• simulation_batches: Tracks load test simulation runs

Security

• Row Level Security (RLS) enabled
• Policies for authenticated users
• Secure data access controls

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🐛 Known Issues and Resolutions

Resolved Issues

1. RLS Policy Violations

   • Issue: Initial transactions failed due to RLS policy restrictions
   • Resolution: Implemented proper RLS policies for authenticated users

2. Supabase Client Export

   • Issue: Supabase client export was missing
   • Resolution: Fixed the supabaseClient.ts file to properly export the client

Current Limitations

1. Transaction Simulation

   • Currently simulates basic approval/decline scenarios
   • Future enhancement: Add more complex validation rules

2. Load Testing

   • Limited to single-instance testing
   • Future enhancement: Distributed load testing support

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🌟 Future Plans

1. Enhanced Transaction Processing

   • Add support for more transaction types
   • Implement advanced fraud detection simulation
   • Add support for different card types

2. Advanced Load Testing

   • Distributed load testing capabilities
   • Custom scenario creation
   • Advanced metrics and reporting

3. Analytics Dashboard

   • Real-time transaction monitoring
   • Advanced analytics and reporting
   • Custom metric tracking

4. Security Enhancements

   • Additional authentication methods
   • Enhanced encryption simulation
   • PCI compliance demonstration

5. API Integration

   • External payment gateway simulation
   • Webhook support
   • Third-party integration examples

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🤝 Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues for any bugs or feature requests.

1. Fork the repository.
2. Create a new branch:

   git checkout -b feature/your-feature-name

3. Commit your changes:

   git commit -m "Add your feature"

4. Push to the branch:

   git push origin feature/your-feature-name

5. Open a pull request.

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📜 License

This project is licensed under the MIT License - see the LICENSE file for details.

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🙏 Acknowledgments

• Built with Supabase for real-time database capabilities
• UI components powered by Tailwind CSS
• Icons provided by Lucide
• Backend powered by Express.js and Apollo Server

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🔗 Links

• Live Demo: Transaction Simulator
• GitHub Repository: GitHub Repo

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📊 Infrastructure and Deployment

Production Environment

• Frontend Hosting: Amazon S3 static website
• Backend Hosting: AWS Lambda behind API Gateway
• Infrastructure as Code: Terraform
• CI/CD: GitHub Actions (manual approval + smoke tests)
• Database: Supabase

Environment Variables

VITE_SUPABASE_URL=your-production-supabase-url
VITE_SUPABASE_ANON_KEY=your-production-anon-key

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🛡️ Security Measures

1. Frontend Security

   • Enable HTTPS
   • Configure CSP headers
   • Enable rate limiting

2. Database Security

   • RLS policies
   • API key rotation
   • Regular security audits

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📈 Performance Optimization

1. Database Optimization

   -- Example index creation for frequently accessed columns
   CREATE INDEX idx_transactions_timestamp ON transactions(timestamp);
   CREATE INDEX idx_simulation_batches_status ON simulation_batches(status);

2. Frontend Optimization

   • Code splitting
   • Asset optimization
   • Caching strategies

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💡 Best Practices

1. Version Control

   • Use feature branches
   • Follow conventional commits
   • Require pull request reviews

2. CI/CD

   • Automate all deployments
   • Include automated tests
   • Implement staging environments

3. Security

   • Regular dependency updates
   • Security scanning in CI
   • Environment variable management

4. Monitoring

   • Set up alerts
   • Monitor error rates
   • Track performance metrics

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📝 Documentation

• API Documentation: Available at /docs when running the backend locally.
• User Guide: Coming soon!
• Developer Guide: Check the GitHub Wiki.

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🌐 Community

Join the discussion and share your feedback:

• GitHub Issues: Open an Issue
• LinkedIn Post: Project Announcement

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