Agent Platform Deep Dive (Part 5) — Policy Engine: Runtime Guards, Budget Control, Human Approval, and Loop Protection
The Policy Engine acts as the Agent Platform's constitution and enforcement layer: policies are versioned and bound to flows and presets; four guard layers enforce rules at step boundaries; budgets cap cost, tokens, runtime, iterations, and tool calls; external writes require human approval; loop detection trips circuit breakers; and escalation records provide an auditable trail. Rules are configuration-driven, so adding one means changing JSON rather than hard-coded logic.