API Documentation Analysis

API Documentation Analysis is a reconnaissance subtechnique focusing on extracting valuable information from officially published API documentation to understand the target application's functionality and architecture. Attackers methodically review documentation found on developer portals, GitHub repositories, Swagger/OpenAPI specifications, and other public sources to identify endpoints, parameters, authentication mechanisms, and data structures. This analysis reveals the application's capabilities, potential attack vectors, business logic flows, and security controls. Well-documented APIs inadvertently provide attackers with a comprehensive map of the application surface, detailing available methods, expected request formats, response codes, error handling procedures, and even architectural dependencies. By analyzing these resources, adversaries can identify vulnerable endpoints, discover undocumented features, understand parameter validation logic, and develop targeted exploitation strategies without triggering detection mechanisms. This passive reconnaissance approach yields high-quality intelligence while maintaining low visibility, making it a critical first step in sophisticated application attacks.