PCAS: First Measured Agent Policy Enforcement (48% to 93%)

A new arXiv paper introduces PCAS (Policy Compiler for Secure Agentic Systems) — deterministic policy enforcement for LLM agents that models system state as a dependency graph and enforces policies via a reference monitor. On customer service tasks, PCAS improved policy compliance from 48% to 93% across frontier models with zero violations in instrumented runs. This fills a critical gap: prior work focused on threat modeling, while PCAS provides actual enforcement with measured results.