A checkpoint between decision and actuation
AI Agent Security covers how to guard against a digital agent making a bad decision, like calling a tool it shouldn't or leaking data it shouldn't share. A physical agent needs that same kind of guarding, but it isn't enough to catch a bad decision after the fact, because by the time a physical action has executed, it has already happened in the real world. A safety gate is a distinct architectural layer that sits between the agent's decision and the actual physical actuation, with the authority to block, limit, or modify an action before it ever reaches a motor.
This separation matters because the safety gate does not need to trust, or even fully understand, the agent's reasoning. It can enforce hard limits independently of whatever the language model decided: an arm should never move faster than a set speed near a detected person, a gripper should never apply more than a certain force, a mobile base should never enter a zone marked off-limits. Those limits hold even if the agent's reasoning went wrong somewhere upstream, which is exactly the point.