claude-skill-tracker

Zero-dependency CLI to track Claude Code skill usage. See what you actually use, find the zombies lurking in your skill library, and keep your AI toolchain lean.

Why?

Claude Code skills are amazing — until you install 50 of them and forget which ones you even have. Every unused skill is noise in your system prompt, slower discovery, and mental overhead every time you browse your skill list.

claude-skill-tracker quietly logs every skill invocation, then gives you a beautiful terminal report showing exactly which skills you use and which ones are just collecting dust.

Features

• Zero dependencies — 100% Node.js built-ins, no node_modules bloat
• Automatic tracking — Hooks into Claude Code via PostToolUse, records every Skill invocation
• Beautiful terminal reports — Unicode box-drawn tables with ANSI color coding (active / stale / zombie / never-used)
• Smart insights — Instantly see your most-used skills and zero-usage candidates for deletion
• Time & project filters — Drill down by date range or project
• Symlink-aware — Correctly discovers symlinked skills
• Cross-machine — npm install -g and you're ready

Installation

npm install -g claude-skill-tracker

Then register the tracking hook:

claude-skill-tracker init

That's it. Every skill you invoke from now on is logged automatically.

Commands

Example Output

┌──────────────────────────────────────────────────────────────────────┐
│ Skill Usage Report — 2026-05-15 · 21 skills                          │
│ 45 total calls  ● 8 active  ◐ 3 stale  ○ 5 zombie  · 5 unused       │
├──────────────────────────────────────────────────────────────────────┤
│                                                                      │
│  🔥  Used Skills                                                     │
│                                                                      │
│ Rank   Skill               Count   Last Used    Status   Projects    │
│ ─────  ─────────────────── ──────  ──────────   ──────   ──────────  │
│ 1.     neat-freak             12   2026-05-15   active   visio,my-ai │
│ 2.     canvas                  8   2026-05-14   active   visio       │
│ 3.     hv-analysis             5   2026-05-13   active   my-ai       │
│ 4.     khazix-writer           4   2026-05-10   active   my-ai       │
│ 5.     codebase-analysis       2   2026-05-08   active   visio       │
│ 6.     review                  1   2026-04-20   zombie   visio  💀   │
│                                                                      │
│  💤  Never Used (15 skills)                                          │
│                                                                      │
│  · aihot                   · migrate-to-skills                      │
│  · babysit                 · quant-analyst                          │
│  · create-hook             · shell                                  │
│  · create-rule             · split-to-prs                           │
│  · create-subagent         · statusline                             │
│  · cursor-sdk              · update-cli-config                      │
│  · find-skills             · update-cursor-settings                 │
│  · loop                    · ...                                    │
│                                                                      │
│  45 total calls · 21 skills · 6 used · 15 never touched             │
└──────────────────────────────────────────────────────────────────────┘

Status legend

How It Works

Skill invoked → PostToolUse hook fires → track-skill.sh appends JSONL
                                              ↓
                              ~/.claude/skill-usage.jsonl
                                              ↓
                              claude-skill-tracker stats
                                              ↓
                                   Beautiful terminal report

1. init writes a PostToolUse hook into ~/.claude/settings.json that matches the Skill tool
2. Each time Claude Code calls a skill, the hook script appends one JSON line to ~/.claude/skill-usage.jsonl
3. stats reads the JSONL, cross-references your installed skills from ~/.claude/skills/, and produces the report

All data stays on your machine. No telemetry, no network calls, no tracking.

Use Cases

• Quarterly skill cleanup: run stats -d 90, delete anything with a 💀 or ·
• Onboarding teammates: run stats before sharing your skill config — only export what's proven
• Toolchain audit: check which skills actually survived the hype cycle in your daily workflow
• Cross-project insight: stats -p project-a vs stats -p project-b to see different workflows

FAQ

Q: Will this slow down Claude Code? A: No. The hook script is a single bash command that appends to a file (~0.1ms).

Q: Can I use it without `init`? A: stats works standalone if you already have data. But without init, nothing gets logged.

Q: Where is the data stored? A: ~/.claude/skill-usage.jsonl — plain text, one JSON object per line. You can inspect or delete it at any time.

Q: Does it track anything besides skill names? A: Only { skill, project, timestamp }. No prompt content, no file paths, no personal data.

Q: How do I reset my stats? A: Delete or truncate ~/.claude/skill-usage.jsonl.

Related

• Claude Code — The AI coding assistant this tool tracks
• Claude Code Hooks — The hook system that makes this possible

License

MIT © kevinwang04