cc-when

Analyze when in a session each Claude Code tool appears — from first call to last.

npx cc-when

Zero dependencies. Reads ~/.claude/projects/ directly.

Output

cc-when — Tool Position in Session
====================================
Sessions: 1,835 | 0% = first call, 100% = last call

Tool            ├── early ─────────────── late ──┤  median
────────────────┼──────────────────────────────────┼────────
Glob            │ ░░░░░▓░░░░░░░░░░░░░░░░░░░ │   20% ← front-loaded
TaskCreate      │ ░░░░░░░░░▓░░░░░░░░░░░░░░░ │   36%
WebSearch       │ ░░░░░░░░░░░▓░░░░░░░░░░░░░ │   45%
TaskUpdate      │ ░░░░░░░░░░░▓░░░░░░░░░░░░░ │   45%
Read            │ ░░░░░░░░░░░░▓░░░░░░░░░░░░ │   50%
Bash            │ ░░░░░░░░░░░░▓░░░░░░░░░░░░ │   50%
Edit            │ ░░░░░░░░░░░░▓░░░░░░░░░░░░ │   52%
Grep            │ ░░░░░░░░░░░░▓░░░░░░░░░░░░ │   52%
ExitPlanMode    │ ░░░░░░░░░░░░░░░░░▓░░░░░░░ │   72% ← back-loaded

What it tells you

• Glob is the most front-loaded tool (median 20%) — file-finding happens at the very start. Half of all Glob calls occur in the first 20% of a session
• ExitPlanMode is back-loaded (median 72%) — planning takes up a significant chunk of the session before transitioning to implementation
• Bash, Read, Edit, Write, Grep are flat (~50%) — spread evenly throughout. No preferred moment
• TaskCreate appears earlier (36%) than TaskUpdate (45%) — you create tasks, then work on them, then update them as you go

Dig into a specific tool

npx cc-when --tool=Glob          # 10-bucket histogram
npx cc-when --tool=ExitPlanMode  # planning exit timing
npx cc-when --tool=WebSearch     # when research happens
npx cc-when --json               # raw data

Browser version

yurukusa.github.io/cc-when — drag and drop your projects folder. Includes a timeline visualization of all tools.

Part of cc-toolkit — tools for understanding your Claude Code sessions.

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Source: yurukusa/cc-when