Approval Is Not Enough: Building a Sub‑Microsecond Runtime Governance Gate in Rust

Most AI governance systems check approval once. Then they assume the agent is still authorised to act. That assumption fails silently. Policy changes. Delegation revokes. Evidence expires. Yet the agent continues executing under a stale authority context. I built Nanogate – a software‑only gate that re‑tests admissibility before every action, in ~530 nanoseconds. It answers the question that most governance tools ignore: “Does this agent still deserve to execute right now?” The Problem with Poin