APR-Lite Phase 4 Technical Note Governed Memory Layer: Policy Enforcement, Session Isolation, and Drift-Aware Memory Governance in Regulated AI Agent Systems

This technical note describes the Governed Memory Layer implemented in APR-Agentic v4.0.0 as Phase 4 of the APR-Lite governance platform. The Governed Memory Layer introduces policy-enforced memory write governance, drift-aware read filtering, session-scoped isolation, and role-based access control over memoryoperations in regulated multi-agent AI systems. Every memory write is evaluated against sector rules via the APR-Lite substrate, role-based policy constraints from the memory_policy table, and current session drift severity. Every memory retrieval is filtered by sensitivity ceiling, role permissions, session scope, and drift state. Evidenceis emitted for all governed operations. The implementation is validated against a 14-test smoke suite including positive, negative, and governance-blocked scenarios.