A Model Context Protocol (MCP) server with tools for IP validation and filtering using FastMCP.

• IP address validation tool supporting both IPv4 and IPv6
• Configurable CIDR range checking for IP filtering
• Tor exit node detection capability
• Simple interface via MCP for use with AI assistants

1. Install dependencies:

yarn install

2. Start the server:

# Start with stdio transport (default)
yarn start

# Test with FastMCP CLI tool
yarn dev

# Inspect with FastMCP Inspector
yarn inspect

The main tool provided by this server is the IP filtering functionality:

• Validates both IPv4 and IPv6 addresses
• Checks if an IP is within specified CIDR ranges
• Detects if an IP is a Tor exit node (optional)
• Handles IPv4-mapped IPv6 addresses for compatibility

• ip_address: IPv4 or IPv6 address to check (string)
• cidr_ranges: Array of CIDR ranges to validate against (string[])
• check_tor: Whether to check if the IP is a Tor exit node (boolean, default: false)

{
  "ip_address": "192.168.1.1",
  "cidr_ranges": ["192.168.0.0/16", "10.0.0.0/8"],
  "check_tor": true
}

To use this server with Claude Desktop or other AI assistants that support MCP, follow the MCP Quickstart Guide and add the following configuration:

{
  "mcpServers": {
    "ip-filter-mcp": {
      "command": "yarn",
      "args": [
        "tsx",
        "/path/to/your/ip-filter-mcp/src/index.ts"
      ],
      "env": {
        "TRANSPORT_TYPE": "stdio"
      }
    }
  }
}

Replace /path/to/your/ip-filter-mcp with the actual path to your project directory.

• FastMCP - A TypeScript framework for building MCP servers
• Zod - TypeScript-first schema validation library
• ipaddr.js - IP address manipulation library