rs232-mcp

rs232-mcp

MCP server for RS232 serial communication with Cisco network equipment.

Lets AI assistants interact with Cisco routers and switches over serial console connections. Handles prompt detection, -- More -- pagination, and connection lifecycle management.

Supported platforms: macOS, Linux, and Windows.

Install

Codex

codex mcp add rs232 -- npx github:xnetcat/rs232-mcp

Claude Code

claude mcp add rs232 -- npx github:xnetcat/rs232-mcp

To add it to a specific project instead of globally:

claude mcp add --scope project rs232 -- npx github:xnetcat/rs232-mcp

Manual configuration

For any stdio MCP client, configure the server command like this:

{
  "mcpServers": {
    "rs232": {
      "command": "npx",
      "args": ["github:xnetcat/rs232-mcp"]
    }
  }
}

If your Windows client does not resolve npm shims correctly, use npx.cmd as the command instead of npx.

Tools

| Tool | Description | |------|-------------| | list_ports | List available serial ports on the system | | open_port | Open a serial connection (path, baudRate, dataBits, stopBits, parity) | | close_port | Close an open serial connection | | send_command | Send a command and wait for Cisco prompt. Handles -- More -- pagination automatically | | write_raw | Write raw string data to a port (no prompt waiting) | | read_buffer | Read buffered data from a port (non-blocking) | | get_connections | List all open connections and their settings |

Example usage

Once configured, your AI assistant can:

> List serial ports
> Open /dev/tty.usbserial-110 at 9600 baud
> Open COM3 at 9600 baud
> Send "show version"
> Send "show running-config"
> Close the port

The send_command tool automatically:

• Sends the command with CRLF
• Waits for a Cisco prompt (Router#, Switch>, Router(config)#, etc.)
• Presses space through -- More -- prompts
• Strips the echoed command from output
• Returns clean output

Default serial settings

| Parameter | Default | |-----------|---------| | Baud rate | 9600 | | Data bits | 8 | | Stop bits | 1 | | Parity | none |

Windows notes

• Serial ports usually appear as COM3, COM4, COM10, and similar names.
• list_ports returns the identifier to use with open_port, so you usually do not need any path conversion.
• The runtime uses the serialport package directly, so Windows port handling follows the native COMx behavior provided by that library.

Development

git clone https://github.com/xnetcat/rs232-mcp.git
cd rs232-mcp
npm install
npm run build
npm test

License

MIT