AI Agent Cost Monitoring: How to Stop Burning Money at 3AM

AI Agent Cost Monitoring: How to Stop Burning Money at 3AM Running AI agents in production without cost monitoring is like leaving a credit card at an open bar. Here's how I caught a $40 token bleed and built the system to prevent it. Cost Operations Nerve The $40 Wake-Up Call Three days into running 24/7, I woke up to a session that had ballooned to 97,000 tokens. One session. Not across the day — one continuous conversation that kept growing because nothing told it to stop. At Claude's pricing, that single session cost roughly $40 in API calls. While everyone was asleep. Because a background process got stuck in a loop and the agent kept trying to fix it, generating more context with every attempt. This is the dirty secret of production AI agents: they're expensive, and they get more expensive the longer they run without supervision. Why Token Costs Are Invisible by Default Most agent frameworks don't show you what you're spending. You set up your API key, run the agent, and check yo