## Table of Contents

1. [Core Concepts](#core-concepts)
2. [Billing Models](#billing-models)
3. [Stripe Products & Prices](#stripe-products--prices)
4. [Checkout Sessions](#checkout-sessions)
5. [Stripe Tax](#stripe-tax)
6. [Adaptive Pricing (Local-Currency Checkout)](#adaptive-pricing-local-currency-checkout)
7. [Subscription Lifecycle](#subscription-lifecycle)
8. [Webhook Handling](#webhook-handling)
9. [API Key Provisioning](#api-key-provisioning)
10. [Customer Portal](#customer-portal)
11. [Metered / Usage-Based Billing](#metered--usage-based-billing)
12. [Dunning & Failed Payments](#dunning--failed-payments)
13. [Security](#security)
14. [Testing](#testing)
15. [Common Mistakes](#common-mistakes)
16. [Complete Express.js Server Example](#complete-expressjs-server-example)

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