MCP Shell Server

A server that uses the Model Context Protocol (MCP) to execute shell commands. It functions as a bridge that allows AI agents to safely execute shell commands.

Features

• Execute shell commands (single-line and multi-line support)
• Support for various shells (bash, zsh, fish, powershell, cmd, etc.)
• Detailed error handling and logging
• MCP Inspector compatible

Installation

From npm (as a user)

# Using npm
npm install -g @mkusaka/mcp-shell-server

# Using yarn
yarn global add @mkusaka/mcp-shell-server

# Using pnpm
pnpm add -g @mkusaka/mcp-shell-server

From source (for development)

# Clone the repository
git clone https://github.com/mkusaka/mcp-shell-server.git
cd mcp-shell-server

# Install dependencies
pnpm install

# Build the project
pnpm build

MCP Configuration

Cursor Configuration

Add the following to your Cursor configuration file (~/.cursor/config.json):

{
  "mcpServers": {
    "shell": {
      "command": "npx",
      "args": ["-y", "@mkusaka/mcp-shell-server"]
    }
  }
}

Rule Configuration

Add the following to your Cursor rules file:

You have tools at your disposal to solve the coding task. Follow these rules regarding tool calls:
1. ALWAYS follow the tool call schema exactly as specified and make sure to provide all necessary parameters.
2. The conversation may reference tools that are no longer available. NEVER call tools that are not explicitly provided.
3. **NEVER refer to tool names when speaking to the USER.** For example, instead of saying 'I need to use the shell_exec tool to execute your command', just say 'I will execute your command'.
4. Only calls tools when they are necessary. If the USER's task is general or you already know the answer, just respond without calling tools.
5. Before calling each tool, first explain to the USER why you are calling it.

Usage

Direct Execution

node dist/index.js
# or as an executable
./dist/index.js

Development Mode

pnpm dev

Testing with MCP Inspector

pnpm inspect

Command Line Arguments

-s, --shell <shell>  Specify the path to the shell to use
-h, --help           Display help message
-V, --version        Display version information

Tool Reference

shell_exec

Executes commands in the specified shell.

Parameters:

• command (string, required): The shell command to execute

Resource Reference

The server provides the following system information as resources:

hostname

Returns the hostname of the system.

URI: hostname://

platform

Returns the operating system platform.

URI: platform://

shell

Returns the shell path being used by the server.

URI: shell://

username

Returns the current username.

URI: username://

system-info

Returns comprehensive system information in JSON format, including:

• hostname
• platform
• shell
• username
• CPU count
• Total memory
• Free memory
• System uptime

Usage Examples

Basic Command Execution

{
  "name": "shell_exec",
  "parameters": {
    "command": "echo Hello, World!"
  }
}

Multi-line Command (Heredoc) Execution

{
  "name": "shell_exec",
  "parameters": {
    "command": "cat << EOF | grep 'example'\nThis is an example text.\nAnother line without the keyword.\nEOF"
  }
}

Development

Project Structure

src/
├── index.ts                # Main entry point
└── shell-server/
    ├── index.ts            # Shell server implementation
    └── lib/
        └── logger.ts       # Logging configuration

Logging

Logs are written to the mcp-shell.log file.

License

MIT