An MCP server to run commands.

Published to npm as mcp-server-commands using this workflow

Tools are for LLMs to request, i.e. Claude Desktop app. Claude Sonnet 3.5 intelligently uses both tools, I was pleasantly surprised.

• run_command - run a command, i.e. hostname or ls -al or echo "hello world" etc
  • Returns STDOUT and STDERR as text
• run_script - run a script! (i.e. fish, bash, zsh, python)
  • Let your LLM run the code it writes!
  • script is passed over STDIN
  • run_script == run_command + script over STDIN
  • Claude has been pretty creative with this, i.e. using cat as the interpreter to create new files!

Prompts are for users to include in chat history, i.e. via Zed's slash commands (in its AI Chat panel)

• run_command - generate a prompt message with the command output

Install dependencies:

npm install

Build the server:

npm run build

For development with auto-rebuild:

npm run watch

To use with Claude Desktop, add the server config:

On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "mcp-server-commands": {
      "command": "npx",
      "args": ["mcp-server-commands"]
    }
  }
}

{
  "mcpServers": {
    "mcp-server-commands": {
      // works b/c of shebang in index.js
      "command": "/path/to/mcp-server-commands/build/index.js"
    }
  }
}

Claude Desktop app writes logs to ~/Library/Logs/Claude/mcp-server-mcp-server-commands.log

By default, only important messages are logged (i.e. errors). If you want to see more messages, add --verbose to the args when configuring the server.

By the way, logs are written to STDERR because that is what Claude Desktop routes to the log files. In the future, I expect well formatted log messages to be written over the STDIO transport to the MCP client (note: not Claude Desktop app).

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector, which is available as a package script:

npm run inspector

The Inspector will provide a URL to access debugging tools in your browser.