The 3 AM incident A few months ago one of my AI agents got stuck in a retry loop overnight and quietly burned through a month of credits. The provider dashboard told me about it the next morning. The support ticket got a polite "usage is final." Provider dashboards are bills. I needed a brake. What's actually missing in the stack After looking at what exists, the gap was clear: AI gateways (LiteLLM, Portkey) — great at routing, not designed to stop you. Observability (Helicone, Langfuse) — great at explaining, after the fact. Provider dashboards — billing history, not real-time control. Nothing was sitting between "the agent is making a call" and "the agent has already burned $500." Cost Firewall Cost Firewall is a local plugin for the OpenClaw gateway.…