After every Claude Code session, you're left wondering what you just spent on API calls. This skill solves that by reading the session jsonl, tallying token usage per model (including prompt cache hits), calculating actual USD cost from Anthropic's pricing tiers, and persisting everything to the cost-tracking namespace so other skills like cost-report can query it. Run it after a chunk of work or at session end. The markdown output shows per-model breakdowns and cache efficiency. Honest take: if you're working on anything beyond hobby scripts, this is table stakes for not getting surprised by your bill.
npx skills add https://github.com/ruvnet/ruflo --skill cost-track