tool-call-logger

tool-call-logger

A Claude Code hook that records every tool call to a JSONL file so you can audit, debug, or analyse what happened in a session. It runs as a command hook: Claude Code pipes the tool event to the script on stdin, and the script appends one sanitized line per call.

• Non-blocking: swallows every error and always exits 0, so it can never interrupt or fail a tool call.
• Zero dependencies: Node standard library only (node >= 18).
• Safe by default: redacts secret-looking keys (token, password, apiKey, authorization, …) and truncates oversized fields.

Files

After npx shadcn@latest add KhaledSaeed18/dotclaude/tool-call-logger, both land in .claude/hooks/tool-call-logger/.

Activate it (required manual step)

The installer copies the files but cannot edit your settings.json, hooks are configuration, not loadable files, so you wire it up once by hand. Add this to .claude/settings.json (project), or ~/.claude/settings.json (global):

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "*",
        "hooks": [
          {
            "type": "command",
            "command": "node \"$CLAUDE_PROJECT_DIR/.claude/hooks/tool-call-logger/log-tool-calls.mjs\""
          }
        ]
      }
    ]
  }
}

• matcher: "*" logs every tool. Narrow it to specific tools with a regex, e.g. "Edit|Write|Bash".
• $CLAUDE_PROJECT_DIR is set by Claude Code to the project root, so the path resolves no matter the working directory. If you installed the script globally under ~/.claude/, point the command there instead.
• PostToolUse captures the tool input and its response. To log the intent before a tool runs (no response yet), add the same block under PreToolUse: the script handles both events. Wiring both gives you a before/after trail.

Run /hooks in Claude Code (or restart the session) to load the change. For safety, Claude Code captures a snapshot of hooks at startup, so external edits aren't applied mid-session until you review them via /hooks.

Output

Records are appended as JSON Lines (one object per line) to:

$CLAUDE_PROJECT_DIR/.claude/logs/tool-calls.jsonl

Each line:

{
  "ts": "2026-06-08T12:34:56.789Z",
  "event": "PostToolUse",
  "session_id": "abc123",
  "cwd": "/path/to/project",
  "tool_name": "Bash",
  "tool_input": { "command": "git status", "description": "Show working tree status" },
  "tool_response": { "stdout": "…", "stderr": "", "interrupted": false }
}

Read it back with standard tools, e.g. the last 20 Bash calls:

grep '"tool_name":"Bash"' .claude/logs/tool-calls.jsonl | tail -20 | jq .

Configuration

Set them in the hook command if you want, e.g.:

"command": "CLAUDE_TOOL_LOG=/tmp/claude-tools.jsonl node \"$CLAUDE_PROJECT_DIR/.claude/hooks/tool-call-logger/log-tool-calls.mjs\""

Keep logs out of Git

The log can grow quickly and may contain repo paths or snippets. Add it to .gitignore:

.claude/logs/

Troubleshooting

• No file appears. Confirm the hook is registered (/hooks), that node is on PATH, and that the command path is correct. The script fails silently by design, so test it directly:

  echo '{"hook_event_name":"PostToolUse","tool_name":"Bash","tool_input":{"command":"ls"},"tool_response":{"stdout":"ok"}}' \
    | node .claude/hooks/tool-call-logger/log-tool-calls.mjs
  cat .claude/logs/tool-calls.jsonl
  

• A value shows [redacted]. That key matched the secret pattern, expected. Adjust the SECRET_KEY regex in the script if it's over-eager for your data.
• Lines are cut with …(+N chars). Raise CLAUDE_TOOL_LOG_MAXLEN.

Hooks run arbitrary commands on your machine with your credentials whenever their event fires. Read any hook script (including this one) before enabling it, and only register hooks you trust.