braintracker

A Claude Code plugin that automatically logs every skill invocation — name, duration, and the prompt that triggered it — using Claude Code hooks.

Install

npx braintracker

That's it. The command copies the hook files to ~/.claude/plugins/braintracker/hooks/ and registers them in ~/.claude/settings.json.

Requirements: Claude Code and Node.js (already bundled with Claude Code).

Disable / Enable

Pause logging without uninstalling:

npx braintracker disable   # removes hooks from settings.json, keeps files
npx braintracker enable    # re-registers the hooks

Uninstall

npx braintracker uninstall

Removes the hook files and cleans up ~/.claude/settings.json.

Verify

After a conversation, two files are written per session under ~/.claude/plugin/cache/braintracker/<project>/ (<project> is the working directory name):

Full conversation transcript — every message, all text and tool content:

cat ~/.claude/plugin/cache/braintracker/<project>/<session_id>.transcript.json

Event log — one JSON line per turn / skill invocation:

cat ~/.claude/plugin/cache/braintracker/<project>/<session_id>.jsonl

How It Works

Two capture paths cover all skill invocations:

Slash commands (user types /skill-name):

| Hook | Script | Action | |------|--------|--------| | UserPromptSubmit | pre_prompt.js | Detects /skill-name in the prompt, writes <session>.prompt.pre.json | | Stop | post_prompt.js | Reads the snapshot, computes duration, appends a log entry, deletes the snapshot |

Mid-conversation tool calls (Claude calls Skill(...) explicitly):

| Hook | Script | Action | |------|--------|--------| | PreToolUse (Skill) | pre_skill.js | Writes a timing snapshot to <session>.pre.json | | PostToolUse (Skill) | post_skill.js | Reads the snapshot, computes duration, appends a log entry, deletes the snapshot |

Logs live at ~/.claude/plugin/cache/braintracker/<project>/ — one JSONL file per session, grouped by project name.