Commands MCP server

runProcess tool

The runProcess tool runs processes on the host machine. There are two mutually exclusive ways to invoke it:

1. commandline** (string) — Executed via the system's default shell (just like typing into bash/fish/pwsh/etc). Shell features like pipes, redirects, and variable expansion all work.
2. argv (string array) — Direct executable invocation. argv[0] is the executable, the rest are arguments. No shell interpretation.

You cannot pass both. The tool infers whether to use a shell from which parameter you provide.

If you want your model to use specific shell(s) on a system, I would list them in your system prompt. Or, maybe in your tool instructions, though models tend to pay better attention to examples in a system prompt.

Let me know if you encounter problems!

Tools

Tools are for LLMs to request. Claude Sonnet 3.5 intelligently uses run_process. And, initial testing shows promising results with Groq Desktop with MCP and llama4 models.

Currently, just one command to rule them all!

• run_process - run a command, i.e. hostname or ls -al or echo "hello world" etc
• Returns STDOUT and STDERR as text
• Optional stdin parameter means your LLM can
• pass scripts over STDIN to commands like fish, bash, zsh, python
• create files with cat >> foo/bar.txt from the text in stdin

[!WARNING]

Be careful what you ask this server to run!

In Claude Desktop app, use Approve Once (not Allow for This Chat) so you can review each command, use Deny if you don't trust the command.

Permissions are dictated by the user that runs the server.

DO NOT run with sudo.

Video walkthrough

Prompts

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

• run_process - generate a prompt message with the command output

• FYI this was mostly a learning exercise... I see this as a user requested tool call. That's a fancy way to say, it's a template for running a command and passing the outputs to the model!

Development

Install dependencies:

npm install

Build the server:

npm run build

For development with auto-rebuild:

npm run watch

Installation

To use with Claude Desktop, add the server config:

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

Groq Desktop (beta, macOS) uses ~/Library/Application Support/groq-desktop-app/settings.json

Use the published npm package

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

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

Use a local build (repo checkout)

Make sure to run npm run build

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

Local Models

• Most models are trained such that they don't think they can run commands for you.
• Sometimes, they use tools w/o hesitation... other times, I have to coax them.
• Use a system prompt or prompt template to instruct that they should follow user requests. Including to use run_processs without double checking.
• Ollama is a great way to run a model locally (w/ Open-WebUI)

# NOTE: make sure to review variants and sizes, so the model fits in your VRAM to perform well!

Shortened. The full README is on GitHub.