git-guardrails-claude-code

name	git-guardrails-claude-code
description	Set up Claude Code hooks to block dangerous git commands (push, reset --hard, clean, branch -D, etc.) before they execute. Use when user wants to prevent destructive git operations, add git safety hooks, or block git push/reset in Claude Code.

Setup Git Guardrails

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

Windows default: use the bundled .ps1 script invoked via pwsh. Unix/WSL users use the .sh script.

What Gets Blocked

• git push (all variants including --force)
• 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

Two versions are bundled:

• Windows (default): scripts/block-dangerous-git.ps1
• Unix / WSL: scripts/block-dangerous-git.sh

Copy the one matching the user's shell to the target location based on scope:

• Project: .claude/hooks/block-dangerous-git.ps1 (or .sh)
• Global: ~/.claude/hooks/block-dangerous-git.ps1 (or .sh)

On Unix, make the .sh executable with chmod +x. The .ps1 needs no chmod; it is invoked through pwsh.

3. Add hook to settings

Add to the appropriate settings file. Windows / PowerShell invokes the script through pwsh:

Project (.claude/settings.json):

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "pwsh -NoProfile -File \"$CLAUDE_PROJECT_DIR/.claude/hooks/block-dangerous-git.ps1\""
          }
        ]
      }
    ]
  }
}

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

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "pwsh -NoProfile -File \"$HOME/.claude/hooks/block-dangerous-git.ps1\""
          }
        ]
      }
    ]
  }
}

On Unix/WSL, point command at the .sh script instead (e.g. "$CLAUDE_PROJECT_DIR"/.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.

Windows / PowerShell:

'{"tool_input":{"command":"git push origin main"}}' | pwsh -NoProfile -File <path-to-script.ps1>
$LASTEXITCODE   # expect 2

Unix / WSL:

echo '{"tool_input":{"command":"git push origin main"}}' | <path-to-script.sh>

Should exit with code 2 and print a BLOCKED message to stderr.