At 3 AM, My AI Agent Spent $2,800 in 60 Seconds. Here's What I Built to Stop It. August 11, 2026 At 3 AM last Tuesday, an AI agent I built made 21 API calls to a premium LLM endpoint. Each call cost $133. That's $2,800 gone in 60 seconds — while I was asleep. The budget alert email arrived at 6:14 AM. By then, the agent had already moved on to its next task, oblivious to the damage. This is the dark side of autonomous AI agents. They're powerful, fast, and relentless — and they ca...