Agent skill · data analytics · juliusbrussee
caveman-stats
Show real token usage and estimated savings for the current session. Reads directly from the Claude Code session log — no AI estimation. Triggers on /caveman-stats. Output is injected by the mode-tracker hook; the model itself does not compute the numbers.
Why this skill is useful
Provides specific calculations for token usage and savings that the AI cannot estimate on its own.
What it needs
About 1k tokens when loaded. Last updated 2026-08-04. 96,517 stars on the source repository.
What this skill does
This skill is delivered by hooks/caveman-stats.js (read by hooks/caveman-mode-tracker.js on /caveman-stats). The model does not need to do anything when this skill fires — the hook returns decision: "block" with the formatted stats as the reason. The user sees the numbers immediately. Output also includes Est. rule overhead and Est. net lines wherever a savings estimate exists with a known turn count. Rule overhead is the estimated per-turn INPUT-token cost of the injected caveman rules (default 1,250 tokens/turn, override with CAVEMANRULEOVERHEADTOKENS) times the turn count. Net is savings minus that overhead — when negative, the output says so plainly and suggests turning caveman off for that workload, rather than hiding the net-negative regime behind a gross-savings number (see docs/HONEST-NUMBERS.md).
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills juliusbrussee/caveman-stats