Git Guardrails Claude Code

Setup Git Guardrails

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

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. Build and copy the hook

The bundled TypeScript source is committed at scripts/block-dangerous-git.ts. From the skills repository root (repo root containing package.json for tooling):

npm install
npm run build

Copy the compiled file to your hooks directory (dist/ mirrors paths under the repo):

• Project: copy dist/skills/misc/git-guardrails-claude-code/scripts/block-dangerous-git.js → .claude/hooks/block-dangerous-git.js
• Global: same file → ~/.claude/hooks/block-dangerous-git.js

The hook runs with Node: use node in the Claude settings snippets below.

3. Add hook to settings

Add to the appropriate settings file:

Project (.claude/settings.json):

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

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

Use one "command" string that invokes Node on the copied .js. Example (POSIX):

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "node $HOME/.claude/hooks/block-dangerous-git.js"
          }
        ]
      }
    ]
  }
}

On Windows, use the absolute path to %USERPROFILE%\.claude\hooks\block-dangerous-git.js, or whatever path your hook runner resolves.

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 scripts/block-dangerous-git.ts and rerun npm run build, then recopy .js.

5. Verify

From this repository root, after npm run build:

echo '{"tool_input":{"command":"git push origin main"}}' | node dist/skills/misc/git-guardrails-claude-code/scripts/block-dangerous-git.js

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