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Claude Code Hooks

A battle-tested guide to writing, testing, registering and debugging Claude Code PreToolUse/PostToolUse/SessionStart/Stop hooks.

Dev & CodingAdvanced★ 1,323⑂ 212AI score 9/10Last updated: Aug 8, 2026

What it does

Turns a rule Claude keeps talking itself past into a structural wall — a hook — instead of another line of prose in CLAUDE.md.

  • Clear map of every hook type, when it fires, and what each exit code means (0 = allow, 2 = block)
  • Ready-to-copy PreToolUse Bash guard skeleton plus runnable patterns (references/hook_patterns.md)
  • Token-level matching with shlex.shlex(punctuation_chars=True) so healthy commands aren't false-blocked (no awk splitting)
  • A hard pre-registration gate: bash -n plus real JSON event end-to-end tests, with a bundled test harness script
  • SSOT + symlink layout so a ~/.claude reinstall can't silently disarm a guard
  • Multi-profile convergence and human-only release valves (osascript dialog, typed YES on /dev/tty)
  • Termination proofs (loop variant V) so a Stop hook can't spin forever

Who it's for

  • Developers who want to hard-block irreversible actions: force pushes, file deletion, secrets leaving the machine
  • Team leads tired of repeating a rule that keeps getting violated anyway
  • Anyone whose existing hook misfires, silently misses, or "poisons the session"
  • Operators rolling guardrails out consistently across profiles and machines

Examples

  1. "Block git push --force for good" → generates a PreToolUse guard that checks command position and still lets grep, comments and commit-message mentions through.
  2. "My new hook blocks perfectly fine commands" → diagnoses raw-string/awk splitting and replaces it with the shlex command-position walker.
  3. "Stop Claude from believing it committed when it didn't" → designs a PostToolUse hook that re-reads real git HEAD and injects authoritative context.

· · · Install guide · · ·

Install in the Claude app (no terminal)
  1. Download the ZIP with the button below.
  2. In Claude, open Settings → Capabilities and turn on 'Code execution and file creation'. (one time)
  3. Go to Customize → Skills → + → 'Upload a skill' and upload the ZIP.
↓ Download ZIP
Install in Claude Code

Let Claude do it — paste this into Claude Code

Install the skill I found on Claude Skill Mart.
Copy the daymade-claude-code/claude-code-hooks folder from the GitHub repo daymade/claude-code-skills into my ~/.claude/skills/claude-code-hooks/.
When it's done, tell me in one line what this skill can do.

Install with a command instead

git clone https://github.com/daymade/claude-code-skills.git /tmp/daymade-skills && mkdir -p ~/.claude/skills && cp -r /tmp/daymade-skills/daymade-claude-code/claude-code-hooks ~/.claude/skills/

⚠ This is a third-party skill. Check the source repository before installing.

  1. Open a terminal.
  2. Make sure the skills folder exists: mkdir -p ~/.claude/skills
  3. Clone the repo to a temp dir: git clone https://github.com/daymade/claude-code-skills.git /tmp/daymade-skills
  4. Copy just this skill: cp -r /tmp/daymade-skills/daymade-claude-code/claude-code-hooks ~/.claude/skills/
  5. Verify: ls ~/.claude/skills/claude-code-hooks — you should see SKILL.md, references/ and scripts/.
  6. Restart Claude Code and try a prompt like "write a hook that blocks rm -rf"; the skill triggers automatically.
  7. Important: before registering any generated hook, run bash -n hook.sh and scripts/test_hook.sh. A broken PreToolUse hook can break every Bash call in the session.
  8. To roll back, delete the hook entry from ~/.claude/settings.json (and remove the symlink in ~/.claude/hooks/).
View source on GitHub ↗License: MIT