Setup Git Guardrails

Sets up a PreToolUse hook that intercepts and blocks dangerous git commands before Claude executes them.

Invocation Position

This is an infrastructure safety skill, not a feature-delivery step.

Use /git-guardrails-claude-code when the project or user wants stronger protection against destructive git operations in Claude-driven workflows.

Do not treat it as part of the normal feature pipeline. It is a repo or user setup action that makes later work safer.

What Gets Blocked

• git push --force / git push -f (regular pushes are allowed)
• git reset --hard
• git clean -f / git clean -fd
• git branch -D
• git checkout . / git restore .

When blocked, Claude sees a message telling it that it does not have authority to access these commands.

Steps

1. Ask scope

Ask the user: install for this project only (.claude/settings.json) or all projects (~/.claude/settings.json)?

2. Copy the hook script

The bundled script is at: scripts/block-dangerous-git.sh

Copy it to the target location based on scope:

• Project: .claude/hooks/block-dangerous-git.sh
• Global: ~/.claude/hooks/block-dangerous-git.sh

Make it executable with chmod +x.

3. Add hook to settings

Add to the appropriate settings file:

Project (.claude/settings.json):

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/block-dangerous-git.sh"
          }
        ]
      }
    ]
  }
}

Global (~/.claude/settings.json):

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "~/.claude/hooks/block-dangerous-git.sh"
          }
        ]
      }
    ]
  }
}

If the settings file already exists, merge the hook into existing hooks.PreToolUse array — don't overwrite other settings.

4. Ask about customization

Ask if user wants to add or remove any patterns from the blocked list. Edit the copied script accordingly.

5. Verify

Run a quick test:

# Should be BLOCKED (exit 2):
echo '{"tool_input":{"command":"git push --force origin main"}}' | <path-to-script>

# Should be ALLOWED (exit 0):
echo '{"tool_input":{"command":"git push origin feature/my-branch"}}' | <path-to-script>

The force-push command should exit with code 2 and print a BLOCKED message to stderr. The regular push should exit with code 0.

Handoff

• Expected input: a project or user environment that needs stronger git safety controls
• Produces: installed guardrail hooks and safer Claude git behavior
• Supports downstream: all implementation and review work by reducing destructive-command risk
• What comes next: return to normal workflow with the guardrails in place