AI Agent Overspend Model Line Mistake 2026: How One Missing Config Burned Half My Budget
An AI agent overspend model line mistake is a configuration bug with a billing blast radius. In my case, a missing model value silently routed routine agent steps to a pro-tier model, and the fastest fix was not prompt tuning. It was tracing requested_model, response_model, tokens, tools, retries, and config diffs in one place. What actually happened when the model line was missing? The failure was boring, which is why it was expensive. ...