This whitepaper outlines a comprehensive framework for understanding and addressing API security, specifically tailored for Chief Information Security Officers (CISOs). It emphasizes the critical role of APIs in business operations and the associated risks that can impact business outcomes. The document details the API threat landscape, categorizing threats into simple, stateless attacks, stateful attacks, and business logic abuse, each with specific examples and references to the OWASP API Top 10. Furthermore, it presents essential requirements for an effective API security program, including discovery, protection, response, and testing. The whitepaper highlights the necessity for continuous API discovery to identify vulnerabilities and the importance of real-time protection against various attack vectors. It also discusses the integration of API security measures with existing security frameworks to enhance organizational resilience against API-related threats. This guide serves as a critical resource for CISOs aiming to operationalize API security and align it with business objectives.