While building claudebill we ran it over our own Claude Code history: 81 sessions, 7 billion tokens, about $7,600 in API-equivalent spend. Three things we did not expect:
- One session cost $481. It was a long homelab automation task that kept a huge context alive for hours. Nobody noticed at the time, because on a Max plan nothing shows a dollar figure.
- One project was 96% of all spend. Everything else combined was 4%.
- Prompt caching saved about $44,000. Without it the same work would have cost six times more.