A flexible payment gateway integration system that supports multiple payment providers with a clean, extensible architecture.

• Docker
• Docker Compose

1. Clone this repository
2. Make sure the docker/php directory exists
3. Copy the .env.example file to .env and update the values as needed
4. Run docker-compose up -d to start the containers
5. Access the PHP container: docker exec -it payment_php bash
6. Install dependencies: composer install
7. Access the API at http://localhost:8080/api/payment/process

payment-gateway/
├── config/
│   └── certificates/            # SSL certificates for API authentication
│       ├── example_client_tls.cer
│       └── example_client_tls.key
├── src/
│   ├── DTO/                     # Data Transfer Objects
│   │   ├── PaymentRequest.php
│   │   └── PaymentResponse.php
│   ├── Exception/               # Custom exception classes
│   │   └── BankingGatewayException.php
│   ├── Gateway/                 # Payment gateway implementation
│   │   ├── BankingGatewayLauncher.php
│   │   ├── PaymentConnector.php
│   │   ├── PaymentMethodIDs.php
│   │   └── PaymentMethods/      # Specific payment method implementations
│   │       └── ING/             # ING Open Banking implementation
│   │           ├── IngOpenBankingPaymentConnector.php
│   │           ├── IngPaymentRequestBuilder.php
│   │           ├── IngPaymentSender.php
│   │           └── IngPaymentResponseProcessor.php
│   └── Service/                 # Service classes
│       └── Logger/              # Logging services
│           └── PaymentLoggerService.php
├── tests/                       # Test suite (mirrors src structure)
│   └── Gateway/
│       └── PaymentMethods/
│           └── ING/
│               ├── IngOpenBankingPaymentConnectorTest.php
│               ├── IngPaymentRequestBuilderTest.php
│               ├── IngPaymentSenderTest.php
│               └── IngPaymentResponseProcessorTest.php
└── var/                         # Runtime files
    └── log/                     # Log files
        └── payments/
            └── ing/             # ING payment logs

The payment gateway system follows a modular, layered architecture:

1. Launcher Layer: BankingGatewayLauncher serves as the entry point, handling payment requests and selecting the appropriate connector.

2. Connector Layer: Connectors like IngOpenBankingPaymentConnector implement the PaymentConnector interface and orchestrate the payment flow for specific payment providers.

3. Processing Layer: Each connector delegates to specialized components:

   • IngPaymentRequestBuilder: Builds payment requests according to API specifications
   • IngPaymentSender: Handles API communication with the payment provider
   • IngPaymentResponseProcessor: Processes API responses into standardized PaymentResponse objects

4. Support Services:

   • PaymentLoggerService: Provides specialized logging for payment transactions

To add a new payment method:

1. Create a new folder under src/Gateway/PaymentMethods/ for your provider
2. Create implementation classes following the Single Responsibility Principle:
   • A main connector class implementing PaymentConnector
   • Helper classes for request building, API communication, and response processing
3. Add the payment method ID to PaymentMethodIDs.php
4. Update BankingGatewayLauncher.php to handle the new payment method

You can test the API endpoints using command-line tools like curl:

curl -X GET http://localhost:8080/api/payment/process

# Execute tests from outside the container
docker exec payment_php bin/phpunit

# Or access the container first
docker exec -it payment_php bash
bin/phpunit

• GET /api/payment/process - Process a payment

Designed for multi-method banking integration; at the moment, only the ING method is implemented.

• Symfony 6.4 framework
• RESTful API architecture
• Docker containerization