SHRIKEFail closed vs fail open
Fail closed means a security control that cannot complete its check refuses the action; fail open means it lets the action proceed. Neither is universally right: the choice weighs the harm of a wrongly allowed action against the harm of a wrongly stopped system, decided per control, not per product.
Agent governance uses both, deliberately. A check that gates an irreversible action (a deletion, a payment, an external send) usually fails closed: better a delayed task than an unreviewed loss. A check that only enriches context or attribution can fail open: better a less-informed verdict than a stalled pipeline. What matters is that each control's failure posture is an explicit, documented decision, because the accidental version of this choice is how outages become incidents and incidents become outages.
Related
Shrike governs AI agent actions in real time: every command, query, and tool call evaluated against policy before it executes. Start with what is action governance or the quickstart.