---
name: payment-gateway-integration
description: Integrates payment processing with Stripe, PayPal, or Square including subscriptions, webhooks, and PCI compliance. Use when implementing checkout flows, recurring billing, or handling refunds and disputes.
license: MIT
---

# Payment Gateway Integration

Integrate secure payment processing with proper error handling and compliance.

## Stripe Integration (Node.js)

```javascript
const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);

class PaymentService {
  async createPaymentIntent(amount, currency, customerId) {
    return stripe.paymentIntents.create({
      amount: Math.round(amount * 100), // Convert to cents
      currency,
      customer: customerId,
      automatic_payment_methods: { enabled: true }
    });
  }

  async createSubscription(customerId, priceId) {
    return stripe.subscriptions.create({
      customer: customerId,
      items: [{ price: priceId }],
      payment_behavior: 'default_incomplete',
      expand: ['latest_invoice.payment_intent']
    });
  }

  async refund(paymentIntentId, amount = null) {
    const params = { payment_intent: paymentIntentId };
    if (amount) params.amount = Math.round(amount * 100);
    return stripe.refunds.create(params);
  }
}
```

## Webhook Handling

```javascript
app.post('/webhooks/stripe', express.raw({ type: 'application/json' }), (req, res) => {
  const sig = req.headers['stripe-signature'];

  let event;
  try {
    event = stripe.webhooks.constructEvent(req.body, sig, process.env.STRIPE_WEBHOOK_SECRET);
  } catch (err) {
    return res.status(400).send(`Webhook Error: ${err.message}`);
  }

  switch (event.type) {
    case 'payment_intent.succeeded':
      await handlePaymentSuccess(event.data.object);
      break;
    case 'invoice.payment_failed':
      await handlePaymentFailed(event.data.object);
      break;
  }

  res.json({ received: true });
});
```

## PayPal Integration

See [references/paypal-integration.md](references/paypal-integration.md) for complete PayPal implementation with:
- Order creation and capture
- Refund processing
- Webhook handling
- Frontend SDK integration
- Success/cancel callbacks

## Security Checklist

- [ ] Use official SDK only
- [ ] Verify webhook signatures
- [ ] Never log full card numbers
- [ ] Store minimal payment data
- [ ] Test in sandbox first
- [ ] HTTPS for all payment routes
- [ ] Handle all error cases
- [ ] Use idempotency keys
- [ ] Implement retry logic

## Best Practices

**Do:**
- Use official SDK libraries
- Verify all webhook signatures
- Log transaction IDs (not card data)
- Test in sandbox environment
- Handle all payment states
- Implement proper error messages

**Don't:**
- Process raw card data directly
- Store sensitive payment info
- Hardcode API keys
- Skip webhook signature validation
- Ignore failed payment events
- Use test keys in production


---
Source attribution: secondsky
Original project: https://github.com/secondsky/claude-skills/blob/88378361314f558fb719aec0af9fd898ab36f0b2/plugins/payment-gateway-integration/skills/payment-gateway-integration/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2025 Claude Skills Maintainers

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: secondsky
Original project: https://github.com/secondsky/claude-skills/blob/88378361314f558fb719aec0af9fd898ab36f0b2/plugins/payment-gateway-integration/skills/payment-gateway-integration/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering, Marketing, Sales
Roles: Backend Developer, DevOps / SRE, Growth Marketer, Product Marketer, Sales Engineer
Specialties: API, Backend, Frontend, Stripe, Testing
Tools: PayPal, Square, Stripe
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: a367abdda25aef43b793599914e904cf66e47bf8c0ee1e587d6c765acf815687