AI-based API security focuses on identifying unauthorized API access and abnormal request behavior by applying machine learning techniques to application programming interfaces. It involves analyzing API access-control patterns, evaluating object-level authorization, monitoring request behavior, and identifying deviations from normal API usage to detect potential security threats. By combining supervised classification and unsupervised anomaly detection, this approach helps identify unauthorized access to protected resources and suspicious API-call patterns, improving API threat visibility and supporting timely investigation and enforcement of appropriate access-control measures.