Refusal Rails are the foundational enforcement mechanism of Codex Sovereign™. They are not post‑generation filters that attempt to catch bad outputs after the fact. Instead, they form a structural governance layer at the decision boundary. Before any consequential action executes, the system performs a deterministic evaluation of the full decision state — verifying authority, contextual completeness, risk thresholds, and compliance with safety invariants.

If the decision state is incomplete, indeterminate, or fails any required condition, execution is blocked at the governance level through a non‑bypassable Refusal Rail. No valid Governance Authorization Artifact means no action proceeds.

This shifts AI governance from reactive suppression to proactive, architectural control — ensuring that only admissible actions can ever be executed. It is designed for high‑stakes environments where silent failure, regulatory exposure, or loss of human sovereignty cannot be tolerated.