Paypal Integration

When to use this skill

Use Paypal Integration when an AI agent needs a reusable SKILL.md workflow for this job: Integrate PayPal payment processing with support for express checkout, subscriptions, and refund management. Use when implementing PayPal payments, processing online transactions, or building e-commerce checkout flows.

When not to use it

Skip Paypal Integration when the task is outside the coding category, or when a more specific skill in this directory already covers the same workflow with clearer triggers.

How to install

1. Personal install: create ~/.claude/skills/paypal-integration/SKILL.md (and any bundled scripts) so Claude Code, Claude Desktop, and compatible agents can load it in every project.
2. Project install: commit the same folder at .claude/skills/paypal-integration/ so teammates get the skill with the repo.
3. Restart the agent session after copying files so it re-scans the skills directory, then ask for the task in words that match the skill description.

Full install guide for Claude, Cursor, and Codex

What this skill does

# 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

```javascript // 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> ```

```python # Backend - Verify and capture order from paypalrestsdk import Payment import paypalrestsdk

paypalrestsdk.configure({ "mode": "sandbox", # or "live" "client_id": "YOUR_CLIENT_ID", "client_secret": "YOUR_CLIENT_SECRET" })

def capture_paypal_order(order_id): """Capture a PayPal order.""" payment = Payment.find(order_id)

if payment.execute({"payer_id": payment.payer.payer_info.payer_id}): # Payment successful return { 'status': 'success', 'transaction_id': payment.id, 'amount': payment.transactions[0].amount.total } else: # Payment failed return { 'status': 'failed', 'error': payment.error } ```

## Detailed patterns and worked examples

Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.

## Testing

```python # Use sandbox credentials SANDBOX_CLIENT_ID = "..." SANDBOX_SECRET = "..."

# Test accounts # Create test buyer and seller accounts at developer.paypal.com

def test_payment_flow(): """Test complete payment flow.""" client = PayPalClient(SANDBOX_CLIENT_ID, SANDBOX_SECRET, mode='sandbox')

# Create order order = client.create_order(10.00) assert 'id' in order

# Get approval URL approval_url = next((link['href'] for link in order['links'] if link['rel'] == 'approve'), None) assert approval_url is not None

# After approval (manual step with test account) # Capture order # captured = client.capture_order(order['id']) # assert captured['status'] == 'COMPLETED' ```

Intended uses

• 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