barbican

barbican is the enforcement layer of the governance suite. It sits transparently on the Model Context Protocol wire — a stdio proxy between an agent and its tool servers — and binds a verdict (allow, deny, or ask) to every tool call before it reaches the server. The decision comes from warden; barbican is the gate that makes it real at runtime, with no change required from the agent or the servers it talks to.

A barbican is the fortified outwork that guards a castle’s gate. This one guards the gate between an AI agent and the tools it can reach.