Abstract: The present disclosure relates to systems and methods for application programming interface (API) mapping to address security and operational challenges in modern software ecosystems. The disclosed system introduces an API map that associates API calls with session identifiers, enabling the construction of detailed API transaction lineages and providing attribution to organizational teams, hardware infrastructure, and customer identities. Telemetry data from API gateways, service meshes, and event buses is captured to construct a central API inventory and identify business flows, such as “move money” or “file tax.” The system facilitates anomaly detection, blast radius analysis, incident tracing, and fraud behavior investigation, while reducing mean time to detect (MTTD) and mean time to remediate (MTTR). The non-intrusive design integrates session IDs into HTTP headers, ensuring seamless compatibility with existing systems.