payment-integration-skill_skill

Overview

This skill provides hands-on guidance for integrating payment gateways (Stripe, PayPal, Adyen) and designing PCI-compliant billing architectures. It focuses on checkout flows, subscription billing, webhook handling, and safe payment processing practices for production systems.

How this skill works

The skill inspects the payment use case and recommends an integration pattern: one-time checkout, subscription management, marketplace split payments, or global multi-gateway routing. It details provider-specific steps (API keys, products/prices, checkout sessions, webhooks) and enforces operational controls like signature verification, idempotency, and retry/dunning logic.

When to use it

• Integrating Stripe, PayPal, or Adyen into backend systems
• Implementing checkout flows or hosted checkout pages
• Building subscription models, trials, upgrades, and downgrades
• Designing PCI-DSS–aware billing and tokenization strategies
• Handling payment webhooks, retries, and reconciliation
• Creating multi-currency or marketplace/split-payment solutions

Best practices

• Never store full card numbers—use tokenization or provider vaults
• Verify webhook signatures and make handlers idempotent
• Use idempotency keys for payment operations to avoid duplicates
• Test thoroughly in sandbox/test mode before production
• Implement dunning and retry logic to recover failed payments
• Persist provider IDs and event logs for reconciliation and audits

Example use cases

• Server-side implementation of Stripe Checkout + webhook processor for one-time purchases
• Subscription engine using Stripe Billing: plans, trials, proration, and upgrades
• Marketplace payout flow with Stripe Connect or PayPal Commerce for split payments
• PCI-compliant architecture using tokenization and external hosted forms
• Webhook processing service that verifies signatures, deduplicates events, and triggers downstream updates