Adyen

1. Online payments

   Integration options for online payments.

2. API credentials

   API credentials and API keys.

3. Sessions flow

   The Sessions flow for creating payment sessions.

4. Advanced flow

   The advanced flow with separate payments calls.

5. Drop-in and Components

   Drop-in and Components for client-side UI.

6. Webhooks

   Webhook notifications and HMAC verification.

7. Payment methods

   Supported payment methods.

8. Tokenization

   Storing payment details as tokens.

9. 3D Secure

   3D Secure authentication.

10. Risk management

    Risk management and fraud rules.

11. Testing

    Test card numbers and test scenarios.

12. Capture and refunds

    Capturing authorised payments and refunds.

13. Platforms

    Platforms and marketplaces.

14. In-person payments

    In-person payments with terminals.

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