I got hit with a $400 AI agent bill overnight. Here's the 5-line fix.

My LangChain agent entered a loop at 2am. By morning: $400 gone. The problem isn't the loop. The problem is nothing stopped it. Logging doesn't stop it. Alerts don't stop it. They tell you after. What you need is a gate that fires before the LLM call — not after. I built Valta for exactly this. Here's how it works in 5 lines: python from langchain_valta import ValtaBudgetTool from langchain.agents import initialize_agent guard = ValtaBudgetTool(api_key="vk_live_...", agent_id="my-agent"...