AWS Rex Is a Big Step for Agentic AI Security, But Not the Final Layer

AWS open-sourced Trusted Remote Execution (Rex), a runtime that intercepts AI-generated script system calls and enforces host-defined Cedar policies to limit actions; the analysis applauds the runtime inversion but cautions that Rex does not solve data-layer security, purpose limitation, identity delegation, or tamper-evident audit requirements necessary for regulatory compliance, and recommends adopting Rex while explicitly building data-layer controls and audit trails.