Payment Gateway API with PayPal

A RESTful API for small businesses to accept payments from customers using PayPal Sandbox.

Features

• Process payments with minimal customer information (name, email, amount)
• Integration with PayPal Sandbox for testing
• RESTful API with versioning
• Automated testing and deployment through CI/CD

API Endpoints

Initiate a Payment

POST /api/v1/payments/

Request Body:

{
  "customer_name": "John Doe",
  "customer_email": "[email protected]",
  "amount": 50.00,
  "currency": "USD"
}

Response:

{
  "payment": {
    "id": "PAY-12345678",
    "customer_name": "John Doe",
    "customer_email": "[email protected]",
    "amount": 50.00,
    "currency": "USD",
    "status": "processing"
  },
  "redirect_url": "https://www.sandbox.paypal.com/checkoutnow?token=ABC123XYZ",
  "status": "success",
  "message": "Payment initiated successfully. Redirect the customer to complete payment."
}

Get Payment Status

GET api/v1/payments/all/

Response:

{
    "payments": [
        {
            "id": "bc8797f0-a847-4d96-88a2-fc3a32e1a39a",
            "customer_name": "John Doe",
            "customer_email": "[email protected]",
            "amount": "50.00",
            "currency": "USD",
            "status": "failed",
            "created_at": "2025-03-24T15:59:18.913491Z"
        },
        {
            "id": "444bcdc4-0340-47eb-ac4b-cffd16f27592",
            "customer_name": "John Doe",
            "customer_email": "[email protected]",
            "amount": "50.00",
            "currency": "USD",
            "status": "failed",
            "created_at": "2025-03-24T16:02:46.925681Z"
        },
        {
            "id": "03d280e2-1704-426a-a3c8-3610b7964a15",
            "customer_name": "John Doe",
            "customer_email": "[email protected]",
            "amount": "50.00",
            "currency": "USD",
            "status": "failed",
            "created_at": "2025-03-24T16:07:45.091864Z"
        },
        {
            "id": "38db523e-b739-4387-972f-d1efd2317b58",
            "customer_name": "John Doe",
            "customer_email": "[email protected]",
            "amount": "50.00",
            "currency": "USD",
            "status": "processing",
            "created_at": "2025-03-24T16:12:20.356695Z"
        }
    ],
    "status": "success",
    "message": "All payments retrieved successfully."
}

PayPal Integration Flow

1. Customer submits payment information
2. Your server initiates a PayPal payment and receives a redirect URL
3. Redirect the customer to the PayPal page to complete payment
4. PayPal redirects back to your success/cancel endpoints
5. Your server captures the payment and updates the status

Installation

Prerequisites

• Python 3.8+
• PostgreSQL
• PayPal Developer Account with Sandbox credentials

PayPal Sandbox Setup

1. Create a PayPal Developer account at developer.paypal.com
2. Create a Sandbox app to get your CLIENT_ID and CLIENT_SECRET
3. Set up a Sandbox account for testing

Local Setup

1. Clone the repository:

   git clone https://github.com/yourusername/payment-gateway-api.git
   cd payment-gateway-api
   

2. Create a virtual environment and activate it:

   python -m venv venv
   source venv/bin/activate  # On Windows, use: venv\Scripts\activate
   

3. Install dependencies:

   pip install -r requirements.txt
   

4. Set up environment variables: Create a .env file in the project root with the following variables:

   DEBUG=True
   SECRET_KEY=your_secret_key
   DATABASE_URL=postgres://user:password@localhost:5432/payment_gateway_db
   BASE_URL=http://localhost:8000
   
   # PayPal Sandbox API Credentials
   PAYPAL_CLIENT_ID=your_paypal_sandbox_client_id
   PAYPAL_CLIENT_SECRET=your_paypal_sandbox_client_secret
   PAYPAL_API_URL=https://api-m.sandbox.paypal.com
   

5. Apply migrations:

   python manage.py migrate
   

6. Run the development server:

   python manage.py runserver
   

Testing

Manual Testing with PayPal Sandbox

1. Use the /api/v1/payments endpoint to create a payment
2. Use the returned redirect_url to simulate a customer payment
3. Log in with your PayPal Sandbox buyer account
4. Complete the payment
5. PayPal will redirect to your success URL
6. Check the payment status using the payment ID

Automated Testing

Run the tests with:

python manage.py test

CI/CD Pipeline

This project uses GitHub Actions for continuous integration and deployment:

1. Test: Runs the Django test suite on each push and pull request
2. Deploy: Automatically deploys to Render when changes are pushed to the main branch

Going to Production

When ready to move to production:

1. Create a PayPal live account and obtain production credentials
2. Update your environment variables with the production credentials
3. Change the PayPal API URL to the production endpoint
4. Ensure your server has HTTPS enabled for secure payments
5. Thoroughly test the payment flow before going live

License

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