Pulls the last week's worth of Claude Code transcripts from your ~/.claude/projects directory, crunches token usage, cache stats, subagent calls, and skill invocations, then drops a self-contained HTML report in your working directory. The template renders sortable tables and bar charts, while the skill injects a handful of one-line findings: which projects or skills are eating disproportionate tokens, where cache hit rates are sagging, whether a single expensive prompt is skewing your totals. It's forensics for your own usage. If you've ever wondered why your cache credits evaporated or which subagent type is burning through context, this gives you percentages and drill-downs instead of hunches.
npx skills add https://github.com/anthropics/claude-plugins-official --skill session-report