paypal-integration

PayPal Integration

Master PayPal payment integration including Express Checkout, IPN handling, recurring billing, and refund workflows.

When to Use This Skill

• Integrating PayPal as a payment option
• Implementing express checkout flows
• Setting up recurring billing with PayPal
• Processing refunds and payment disputes
• Handling PayPal webhooks (IPN)
• Supporting international payments
• Implementing PayPal subscriptions

Core Concepts

1. Payment Products

PayPal Checkout

• One-time payments
• Express checkout experience
• Guest and PayPal account payments

PayPal Subscriptions

• Recurring billing
• Subscription plans
• Automatic renewals

PayPal Payouts

• Send money to multiple recipients
• Marketplace and platform payments

2. Integration Methods

Client-Side (JavaScript SDK)

• Smart Payment Buttons
• Hosted payment flow
• Minimal backend code

Server-Side (REST API)

• Full control over payment flow
• Custom checkout UI
• Advanced features

3. IPN (Instant Payment Notification)

• Webhook-like payment notifications
• Asynchronous payment updates
• Verification required

Quick Start

// Frontend - PayPal Smart Buttons
<div id="paypal-button-container"></div>

<script src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID&currency=USD"></script>
<script>
  paypal.Buttons({
    createOrder: function(data, actions) {
      return actions.order.create({
        purchase_units: [{
          amount: {
            value: '25.00'
          }
        }]
      });
    },
    onApprove: function(data, actions) {
      return actions.order.capture().then(function(details) {
        // Payment successful
        console.log('Transaction completed by ' + details.payer.name.given_name);

        // Send to backend for verification
        fetch('/api/paypal/capture', {
          method: 'POST',
          headers: {'Content-Type': 'application/json'},
          body: JSON.stringify({orderID: data.orderID})
        });
      });
    }
  }).render('#paypal-button-container');
</script>