Save and Reuse Payment Methods System

A comprehensive multi-language demonstration of multi-use one-click payment processing using the Global Payments SDK. This example showcases secure payment method storage, multi-use token creation with integrated customer data, and streamlined payment processing across multiple programming languages.

🚀 Features

Core Payment Capabilities

• Multi-Use Token Creation - Convert single-use tokens to stored payment tokens with customer data integration
• Payment Method Management - Store, retrieve, edit, and manage customer payment methods securely
• One-Click Payment Processing - Process immediate charges ($25) using stored payment methods
• Customer Data Integration - Associate billing information directly with payment tokens
• Real-Time Processing - Immediate transaction processing with live API integration

Development & Testing

• Mock Mode Support - Test payment flows with simulated responses without hitting live APIs
• Test Card Integration - Built-in Heartland certification test cards for development
• Comprehensive Web Interface - Complete UI with payment method management and transaction processing
• Global Payments SDK Integration - Secure tokenization using hosted payment fields

Technical Features

• Consistent API Structure - Identical endpoints and functionality across all language implementations
• JSON-Based Storage - Simple file-based persistence for payment methods and customer data
• Environment Configuration - Secure credential management with .env files
• Health Monitoring - System status endpoints for monitoring and debugging

🌐 Available Implementations

Each implementation provides identical functionality with language-specific best practices:

Language	Framework	Requirements	Status
.NET	ASP.NET Core	.NET 9.0+	✅ Complete
Java	Jakarta EE	Java 11+, Maven	✅ Complete
PHP	Native PHP	PHP 7.4+, Composer	✅ Complete

🏗️ Architecture Overview

Frontend Architecture

• Global Payments SDK Integration - Secure tokenization with hosted payment fields
• Responsive Web Interface - Complete payment management UI
• Test Card Helper - Integrated Heartland certification test cards
• Real-Time Validation - Client-side form validation and error handling

Backend Architecture

• RESTful API Design - Consistent endpoints across all implementations
• Multi-Use Token Creation - Secure conversion of single-use to stored payment tokens
• Customer Data Storage - Integrated billing information with payment methods
• Mock Mode Capability - Simulated responses for development and testing

API Endpoints

Method	Endpoint	Description
GET	/health	System health check and status
GET	/config	Frontend configuration (public API key, mock mode)
GET	/payment-methods	Retrieve all stored payment methods
POST	/payment-methods	Create new payment method or edit existing
POST	/charge	Process $25 charge using stored payment method
GET	/mock-mode	Get current mock mode status
POST	/mock-mode	Toggle mock mode on/off

🚀 Quick Start

Prerequisites

• Global Payments account with API credentials (Sign up here)
• Development environment for your chosen language
• Package manager (npm, composer, maven, dotnet, go mod)

Setup Instructions

1. Clone the repository

   git clone <repository-url>
   cd save-and-reuse-payment-methods

2. Choose your implementation

   cd dotnet  # or java, php

3. Configure environment

   cp .env.sample .env
   # Edit .env with your Global Payments GP API credentials:
   # GP_API_APP_ID=your_app_id
   # GP_API_APP_KEY=your_app_key
   # GP_API_ENVIRONMENT=sandbox

4. Install dependencies and run

   ./run.sh

   Or manually for each language:

   # .NET
   dotnet restore && dotnet run
   
   # Java
   mvn clean compile cargo:run
   
   # PHP
   composer install && php -S localhost:8000

5. Access the application Open http://localhost:8000 in your browser

🧪 Development & Testing

Mock Mode

Each implementation includes a mock mode that allows you to:

• Test payment flows without live API calls
• Use simulated responses for consistent testing
• Develop and debug without API costs
• Toggle between mock and live modes via the UI

Test Cards

Built-in Heartland certification test cards:

• Visa: 4012002000060016
• MasterCard: 2223000010005780, 5473500000000014
• Discover: 6011000990156527
• American Express: 372700699251018
• JCB: 3566007770007321

All test cards use:

• Expiry: 12/2028
• CVV: 123 (1234 for Amex)

Customer Data

The system includes pre-filled customer information for testing:

• Name: Jane Doe
• Email: jane.doe@example.com
• Phone: 5551112222
• Address: 1 Example Way, Jeffersonville, IN 47130, USA

💳 Payment Flow

Adding Payment Methods

1. Customer Information - Collect name, email, phone, and billing address
2. Payment Details - Secure tokenization using Global Payments SDK
3. Multi-Use Token Creation - Convert single-use token to multi-use token with customer data
4. Storage - Save payment method with optional nickname and default status

Processing Payments

1. Method Selection - Choose from stored payment methods
2. One-Click Processing - Immediate $25 charge processing
3. Real-Time Results - Live transaction status and details
4. Transaction History - Complete transaction information display

🔧 Customization

Extending Functionality

Each implementation provides a solid foundation for:

• Custom Payment Amounts - Modify charge amounts and currency
• Additional Payment Types - Add authorization/capture, refunds, voids
• Enhanced Customer Management - Expand customer data fields
• Subscription Processing - Recurring payment capabilities
• Advanced Reporting - Transaction history and analytics

Production Considerations

Before deploying to production:

• Security: Implement proper input validation and sanitization
• Logging: Add comprehensive logging and monitoring
• Error Handling: Enhance error handling and user feedback
• Database: Replace JSON storage with production database
• Authentication: Add user authentication and authorization
• Compliance: Ensure PCI DSS compliance measures

📚 Documentation

Each language implementation includes detailed documentation:

• Setup Instructions - Environment configuration and dependencies
• API Documentation - Endpoint specifications and examples
• Code Structure - File organization and architecture
• Troubleshooting - Common issues and solutions
• Recent Updates - Bug fixes and improvements

🛠️ Recent Improvements

Cross-Language Consistency

• ✅ Unified API Structure - Consistent endpoints across all implementations
• ✅ Payment Token Handling - Fixed frontend/backend data structure alignment
• ✅ Customer Data Integration - Standardized customer information collection
• ✅ Mock Mode Functionality - Consistent testing capabilities

Bug Fixes & Enhancements

• ✅ Java: Fixed compilation errors and response validation with Global Payments SDK
• ✅ .NET: Fixed CAPTURED response validation and multi-use token creation
• ✅ PHP: Implemented comprehensive GP API payment system
• ✅ All Languages: Migrated from Portico to GP API configuration

🤝 Contributing

This project serves as a comprehensive example for Global Payments SDK integration. When contributing:

• Maintain consistency across all language implementations
• Follow each language's best practices and conventions
• Ensure thorough testing with both mock and live modes
• Update documentation to reflect any changes

📄 License

This project is provided as an educational example for Global Payments SDK integration. Please review the license file for specific terms and conditions.

🆘 Support

For technical support:

• Global Payments Developer Documentation: https://developer.globalpay.com/
• SDK Documentation: Language-specific SDK guides
• Community Support: Developer forums and resources

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Note: This is a demonstration application for development and testing purposes. For production use, implement additional security measures, error handling, and compliance requirements specific to your use case.