Defending APIs: Uncover Advanced Defense Techniques to Craft Secure Application Programming Interfaces

APIs connect applications, services, and data—but that connectivity also creates pathways attackers can probe. Defending APIs gives developers and security practitioners a structured way to understand those risks, explore how API attacks work, and build protections into both software design and operation.

Colin Domoney organizes the subject into three stages: understand API security, examine the attacker’s perspective, then put defensive practices to work. The result is a practical, security-focused look at APIs across their lifecycle, from foundational concepts to runtime safeguards.

Start with the foundations of API security

The opening section explains the building blocks that shape API behavior, including protocols, data formats, cryptography, transport security, and rate limiting. It also considers why conventional security tools may not fully address API-specific risks, and introduces security goals, abuse cases, data governance, and the OWASP API Security Top 10.

This grounding helps readers connect technical details to the larger security picture: protecting an API is not simply a matter of adding a gateway or scanning code once. Design, development, and operation all matter.

See the API through an attacker’s eyes

Understanding how vulnerabilities are discovered and exploited can make defensive decisions more concrete. The book explores API attack methods and the tools used in security testing, alongside examples and breach case studies. That perspective gives developers and defenders a clearer basis for anticipating misuse and assessing where an API may be exposed.

Build defenses across the lifecycle

Domoney then turns to practical approaches for strengthening APIs, including early security practices and protections that remain important after deployment. The coverage addresses common authentication, authorization, data, and implementation vulnerabilities, as well as defenses involving API gateways and firewalls.

The book also considers API security in microservices environments and discusses approaches applicable across frameworks and languages such, Python, and Java. Its emphasis on both development-time and runtime measures helps readers think beyond a single tool or stage of delivery.

Who may find this book useful

Application security engineers, security professionals, API developers, and penetration testers will find relevant perspectives here. Developers can use the attacker-focused material to better anticipate threats; security teams can use the lifecycle framing to connect design practices with operational defense. A basic grounding in software and security will help readers follow the technical material.

For readers working to make APIs more resilient, Defending APIs brings the fundamentals, offensive perspective, and defensive practice into one focused guide.