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.

Source: [Dev.to](https://dev.to/billionaire664/i-got-hit-with-a-400-ai-agent-bill-overnight-heres-the-5-line-fix-611)