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.
Inherits all available tools
Additional assets for this skill
This skill inherits all available tools. When active, it can use any tool Claude has access to.
Master PayPal payment integration including Express Checkout, IPN handling, recurring billing, and refund workflows.
PayPal Checkout
PayPal Subscriptions
PayPal Payouts
Client-Side (JavaScript SDK)
Server-Side (REST API)
// Frontend - PayPal Smart Buttons
<div id="paypal-button-container"></div>
<script src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID¤cy=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>
# 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
}
import requests
import json
class PayPalClient:
def __init__(self, client_id, client_secret, mode='sandbox'):
self.client_id = client_id
self.client_secret = client_secret
self.base_url = 'https://api-m.sandbox.paypal.com' if mode == 'sandbox' else 'https://api-m.paypal.com'
self.access_token = self.get_access_token()
def get_access_token(self):
"""Get OAuth access token."""
url = f"{self.base_url}/v1/oauth2/token"
headers = {"Accept": "application/json", "Accept-Language": "en_US"}
response = requests.post(
url,
headers=headers,
data={"grant_type": "client_credentials"},
auth=(self.client_id, self.client_secret)
)
return response.json()['access_token']
def create_order(self, amount, currency='USD'):
"""Create a PayPal order."""
url = f"{self.base_url}/v2/checkout/orders"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {self.access_token}"
}
payload = {
"intent": "CAPTURE",
"purchase_units": [{
"amount": {
"currency_code": currency,
"value": str(amount)
}
}]
}
response = requests.post(url, headers=headers, json=payload)
return response.json()
def capture_order(self, order_id):
"""Capture payment for an order."""
url = f"{self.base_url}/v2/checkout/orders/{order_id}/capture"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {self.access_token}"
}
response = requests.post(url, headers=headers)
return response.json()
def get_order_details(self, order_id):
"""Get order details."""
url = f"{self.base_url}/v2/checkout/orders/{order_id}"
headers = {
"Authorization": f"Bearer {self.access_token}"
}
response = requests.get(url, headers=headers)
return response.json()
from flask import Flask, request
import requests
from urllib.parse import parse_qs
app = Flask(__name__)
@app.route('/ipn', methods=['POST'])
def handle_ipn():
"""Handle PayPal IPN notifications."""
# Get IPN message
ipn_data = request.form.to_dict()
# Verify IPN with PayPal
if not verify_ipn(ipn_data):
return 'IPN verification failed', 400
# Process IPN based on transaction type
payment_status = ipn_data.get('payment_status')
txn_type = ipn_data.get('txn_type')
if payment_status == 'Completed':
handle_payment_completed(ipn_data)
elif payment_status == 'Refunded':
handle_refund(ipn_data)
elif payment_status == 'Reversed':
handle_chargeback(ipn_data)
return 'IPN processed', 200
def verify_ipn(ipn_data):
"""Verify IPN message authenticity."""
# Add 'cmd' parameter
verify_data = ipn_data.copy()
verify_data['cmd'] = '_notify-validate'
# Send back to PayPal for verification
paypal_url = 'https://ipnpb.sandbox.paypal.com/cgi-bin/webscr' # or production URL
response = requests.post(paypal_url, data=verify_data)
return response.text == 'VERIFIED'
def handle_payment_completed(ipn_data):
"""Process completed payment."""
txn_id = ipn_data.get('txn_id')
payer_email = ipn_data.get('payer_email')
mc_gross = ipn_data.get('mc_gross')
item_name = ipn_data.get('item_name')
# Check if already processed (prevent duplicates)
if is_transaction_processed(txn_id):
return
# Update database
# Send confirmation email
# Fulfill order
print(f"Payment completed: {txn_id}, Amount: ${mc_gross}")
def handle_refund(ipn_data):
"""Handle refund."""
parent_txn_id = ipn_data.get('parent_txn_id')
mc_gross = ipn_data.get('mc_gross')
# Process refund in your system
print(f"Refund processed: {parent_txn_id}, Amount: ${mc_gross}")
def handle_chargeback(ipn_data):
"""Handle payment reversal/chargeback."""
txn_id = ipn_data.get('txn_id')
reason_code = ipn_data.get('reason_code')
# Handle chargeback
print(f"Chargeback: {txn_id}, Reason: {reason_code}")
def create_subscription_plan(name, amount, interval='MONTH'):
"""Create a subscription plan."""
client = PayPalClient(CLIENT_ID, CLIENT_SECRET)
url = f"{client.base_url}/v1/billing/plans"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {client.access_token}"
}
payload = {
"product_id": "PRODUCT_ID", # Create product first
"name": name,
"billing_cycles": [{
"frequency": {
"interval_unit": interval,
"interval_count": 1
},
"tenure_type": "REGULAR",
"sequence": 1,
"total_cycles": 0, # Infinite
"pricing_scheme": {
"fixed_price": {
"value": str(amount),
"currency_code": "USD"
}
}
}],
"payment_preferences": {
"auto_bill_outstanding": True,
"setup_fee": {
"value": "0",
"currency_code": "USD"
},
"setup_fee_failure_action": "CONTINUE",
"payment_failure_threshold": 3
}
}
response = requests.post(url, headers=headers, json=payload)
return response.json()
def create_subscription(plan_id, subscriber_email):
"""Create a subscription for a customer."""
client = PayPalClient(CLIENT_ID, CLIENT_SECRET)
url = f"{client.base_url}/v1/billing/subscriptions"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {client.access_token}"
}
payload = {
"plan_id": plan_id,
"subscriber": {
"email_address": subscriber_email
},
"application_context": {
"return_url": "https://yourdomain.com/subscription/success",
"cancel_url": "https://yourdomain.com/subscription/cancel"
}
}
response = requests.post(url, headers=headers, json=payload)
subscription = response.json()
# Get approval URL
for link in subscription.get('links', []):
if link['rel'] == 'approve':
return {
'subscription_id': subscription['id'],
'approval_url': link['href']
}
def create_refund(capture_id, amount=None, note=None):
"""Create a refund for a captured payment."""
client = PayPalClient(CLIENT_ID, CLIENT_SECRET)
url = f"{client.base_url}/v2/payments/captures/{capture_id}/refund"
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {client.access_token}"
}
payload = {}
if amount:
payload["amount"] = {
"value": str(amount),
"currency_code": "USD"
}
if note:
payload["note_to_payer"] = note
response = requests.post(url, headers=headers, json=payload)
return response.json()
def get_refund_details(refund_id):
"""Get refund details."""
client = PayPalClient(CLIENT_ID, CLIENT_SECRET)
url = f"{client.base_url}/v2/payments/refunds/{refund_id}"
headers = {
"Authorization": f"Bearer {client.access_token}"
}
response = requests.get(url, headers=headers)
return response.json()
class PayPalError(Exception):
"""Custom PayPal error."""
pass
def handle_paypal_api_call(api_function):
"""Wrapper for PayPal API calls with error handling."""
try:
result = api_function()
return result
except requests.exceptions.RequestException as e:
# Network error
raise PayPalError(f"Network error: {str(e)}")
except Exception as e:
# Other errors
raise PayPalError(f"PayPal API error: {str(e)}")
# Usage
try:
order = handle_paypal_api_call(lambda: client.create_order(25.00))
except PayPalError as e:
# Handle error appropriately
log_error(e)
# 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'