AI apps charge a flat subscription but pay a variable cost. A light user costs cents; a heavy user (or one stuck in an agent loop) can cost more than they pay. The AI invoice shows tokens, RevenueCat shows payments, and nothing joins them per user, so you find out from the bill. I built FiscaLLM to join the two. Your backend reports the model name and token counts after each AI call (never prompts or answers). RevenueCat or Stripe (beta) reports payments. You see margin per user, plan and free trial, plus budget alerts and optional spend caps that fail open. Honest status: it's a side project, shipped last week, MIT licensed, TypeScript and Python SDKs, self-hostable (or free hosted). No customers yet; the demo dashboard runs on sample data. It needs a backend between your app and the AI provider.   submitted by   /u/Agreeable-Worker6465 [link]   [comments]