I got hit with a surprise AI bill, so I built TokenBar

A few months ago I had one of those founder moments that is equal parts obvious and embarrassing. I opened my AI provider dashboard, looked at the bill, and realized I could explain exactly why it was high in a vague emotional sense, but not in an operational one. I knew I was shipping fast. I knew I was iterating prompts. I knew I had a bunch of models, playground tabs, API tests, and app sessions running. What I did not know was the simple thing that actually mattered: Where were the tokens go