About
AI costs are invisible until they aren't. You ship a feature, customers start using it, and somewhere in the next billing cycle you notice a number that doesn't match your intuition. The provider dashboard shows aggregate spend. Your code doesn't know which customer caused it.
Costr is a proxy that sits between your application and the AI provider. It records metadata about each call — token counts, model, cost — and tags it with the customer ID and feature name you send in the request headers. Nothing else is stored. No prompts, no completions, no content. Just the ledger.
The result is a dashboard where you can see, per customer, how much they cost you to serve — and compare that against what they pay. Margin, not just spend. The signal that tells you whether a customer is profitable or a slow drain.
This is a solo project. No team, no investors, no growth roadmap. Built because the tool didn't exist in a form I wanted to use. The goal is to stay small, stay focused, and be genuinely useful to the people who pay for it.
If something is broken, confusing, or missing — email support@costr.dev. I read every message and reply.