Security

Claude Code operates with explicit permissions to protect sensitive files and prevent dangerous operations.

---

Allowed Operations

npm Commands

npm run *       # Any npm script
npm install *   # Install packages
npm test *      # Run tests
npx *           # Run npx commands

Git Commands

git status      # Check status
git diff        # View changes
git log         # View history
git branch      # List branches
git checkout    # Switch branches
git add         # Stage files

File Operations

ls              # List files
mkdir           # Create directories
Read            # Read file contents
Edit            # Edit files
Write           # Create files
Glob            # Find files by pattern
Grep            # Search file contents

Web Operations

WebFetch        # Fetch web pages
WebSearch       # Search the web

---

Denied Operations

Sensitive Files

Claude cannot read:

Pattern	Reason
.env	Environment secrets
.env.local	Local secrets
.env.production	Production secrets
.env*.local	Any local env file
./secrets/**	Secrets directory
.git/config	Git credentials

Dangerous Commands

Claude cannot run:

Command	Reason
curl	Arbitrary network requests
wget	Arbitrary downloads
rm -rf	Destructive deletion

---

Configuration

Permissions are set in .claude/settings.json:

{
  "permissions": {
    "allow": [
      "Bash(npm run:*)",
      "Bash(git status:*)",
      "Read",
      "Edit",
      "Write"
    ],
    "deny": [
      "Read(.env)",
      "Read(.env.local)",
      "Read(./secrets/**)",
      "Bash(curl:*)",
      "Bash(rm -rf:*)"
    ]
  }
}

---

Local Overrides

Personal settings in .claude/settings.local.json (gitignored):

{
  "model": "opus",
  "env": {
    "MO_DOCS_PATH": "/path/to/mo-docs"
  }
}

---

MCP Servers

For additional integrations (GitHub, PostgreSQL), see the MCP setup guide in .claude/MCP_SETUP.md.

Security notes for MCP:

• Use environment variables for tokens
• Use read-only database credentials when possible
• Review MCP server permissions before enabling