Claude Desktop

How to use open-mcp-guardrails with Claude Desktop.

Basic Setup

Place guardrails.config.ts in your home config directory:

mkdir -p ~/.config/open-mcp-guardrails
bunx open-mcp-guardrails init
mv guardrails.config.ts ~/.config/open-mcp-guardrails/

Then in claude_desktop_config.json, wrap your MCP server:

{
  "mcpServers": {
    "filesystem": {
      "command": "bunx",
      "args": [
        "open-mcp-guardrails",
        "--",
        "bunx", "@modelcontextprotocol/server-filesystem", "/tmp"
      ]
    }
  }
}

open-mcp-guardrails automatically discovers ~/.config/open-mcp-guardrails/guardrails.config.ts — no -c flag needed.

Everything before -- is for guardrails, everything after is the original MCP server command.

Explicit path

You can still use -c to specify a config file explicitly:

["open-mcp-guardrails", "-c", "/path/to/guardrails.config.ts", "--", "bunx", "..."]

Guarding Multiple Servers

All servers share the same auto-discovered config:

{
  "mcpServers": {
    "filesystem": {
      "command": "bunx",
      "args": [
        "open-mcp-guardrails",
        "--",
        "bunx", "@modelcontextprotocol/server-filesystem", "/tmp"
      ]
    },
    "github": {
      "command": "bunx",
      "args": [
        "open-mcp-guardrails",
        "--",
        "bunx", "@modelcontextprotocol/server-github"
      ],
      "env": {
        "GITHUB_TOKEN": "..."
      }
    }
  }
}

Config Resolution

When -c is not specified, open-mcp-guardrails searches for config in this order:

1. ./guardrails.config.ts (current directory)
2. ~/.config/open-mcp-guardrails/guardrails.config.ts (XDG user config)

Claude Desktop launches MCP servers from the home directory, so option 2 is the recommended approach.

Next Steps

• Configuration — Detailed config options
• Rules — Available rule types