Your LLM budget alerts won't save you if you can't map costs to users

Most devs think they have AI costs under control because they set a $500 hard cap on OpenAI. tbh, that's not cost control. That's just setting a timer for when your app goes down. Here's the problem: when you hit $400 and get that warning email, what do you do? You look at the dashboard and see a massive spike in GPT-4o usage. But who caused it? Was it your new enterprise client onboarding? (Good, increase the limit). Was it a free-tier user who figured out how to loop your agent? (Bad, ban them