Do Safety Guardrails Need to Reason? LeanGuard: A Fast and Light Approach for Robust Moderation

In order to screen a prompt or a response, the recent guardrail methods generate a chain-of-thought (CoT) before they issue a verdict. This design follows a common belief that step-by-step reasoning improves a decision. However, CoT also makes the guard heavy and slow, because the model must generat...