You wire up the OpenAI SDK, ship the feature, and it works. Three weeks later someone in finance forwards a screenshot of a bill that tripled and asks what happened. You open the provider dashboard, see one big number, and… that's it. No per-feature breakdown, no idea which change caused it, no way to tell whether it's a bug or just growth. I've watched this happen at enough teams that I now treat "we can't explain our AI bill" as a predictable stage every company hits about two months after ...