Stripe

1. Payments overview

   Ways to accept payments with Stripe, choosing between Checkout, Payment Element and direct API integrations.

2. API keys and testing

   Publishable vs secret and restricted keys, test mode, sandboxes and test cards.

3. PaymentIntents

   PaymentIntent lifecycle and statuses, client_secret, confirmation, capture, amount and currency.

4. Checkout

   Stripe-hosted Checkout Sessions, line items, success and cancel URLs, mode payment/subscription/setup.

5. Payment Element

   Embedded UI component, dynamic payment methods, Stripe.js, confirmPayment.

6. Payment methods

   Cards, wallets, bank debits and redirects, payment method objects and attaching to customers.

7. SetupIntents and saved payment methods

   Saving payment methods for future use, off-session payments, customers.

8. 3D Secure and SCA

   Strong customer authentication, next_action handling, requires_action status.

9. Webhooks

   Event delivery to endpoints, event types, responding 2xx quickly, retries, handling payment_intent.succeeded.

10. Webhook signature verification

    Stripe-Signature header, signing secret, constructEvent with raw body, replay tolerance.

11. Events

    Event objects, event types, retrieving events, event ordering and duplicates.

12. Idempotent requests

    Idempotency-Key header, safe retries, key reuse behavior and expiry.

13. Error handling

    Error types (card_error, invalid_request_error), decline codes, handling failures.

14. Rate limits

    API request rate limits, 429 responses, backoff strategies.

15. API versioning

    Pinned API versions, upgrading, webhook endpoint versions.

16. Refunds and disputes

    Refunding charges, partial refunds, disputes and chargebacks, evidence.

17. Billing and subscriptions

    Products, prices, customers, subscriptions, trials, proration, invoices and billing cycles.

18. Subscription webhooks

    Provisioning access from events: invoice.paid, customer.subscription.updated, invoice.payment_failed.

19. Usage-based billing

    Metered billing, meters and meter events, usage aggregation.

20. Connect

    Platforms and marketplaces, connected accounts, onboarding, account types.

21. Connect charge types

    Direct, destination and separate charges and transfers, application fees, on_behalf_of.

22. Radar and fraud

    Fraud detection, rules, risk scores, 3D Secure rules.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.