Application Programming Interfaces (APIs) sit at the heart of modern digital infrastructure, serving as the connective tissue between services, devices, and data. As organizations expose more functionality through APIs — from payment processing to healthcare records to AI agents — the attack surface expands dramatically. APIs now represent the dominant vector for data breaches, accounting for over 60% of malicious traffic in 2026. Unlike traditional web applications, APIs expose structured data and business logic directly, making authorization flaws, injection attacks, and excessive data exposure far more impactful. The key insight: API security isn't web security. APIs require fundamentally different defenses — property-level authorization, schema validation, behavior monitoring, and comprehensive inventory management — because attackers exploit the machine-readable nature of APIs to automate data exfiltration and privilege escalation at scale.