MCP Server Nu

An MCP (Model Context Protocol) server that allows AI assistants to execute Nushell scripts with full system access.

How it works

This server spawns nu -c "<script>" processes to execute commands. The nu process runs with the same permissions as the server process, giving it access to:

• File system (read/write/delete)
• Network (make requests, start servers)
• Environment variables
• System commands via nu's shell integration
• Any custom nu configurations you provide

Security implications: The AI can execute arbitrary code on your system. Only use with trusted AI assistants and in environments where this level of access is acceptable.

Tool: exec

Executes Nushell scripts and returns stdout, stderr, exit code.

Parameters:

• script (required): Nushell script to execute
• timeout_seconds (optional): Timeout in seconds (default: 30)

Example:

{
  "script": "ls | where size > 1MB | get name",
  "timeout_seconds": 10
}

Configuration

The server accepts optional CLI arguments to use custom nu config files:

mcp-server-nu --nu-config /path/to/config.nu --nu-env-config /path/to/env.nu

Options:

• --nu-config <path>: Custom config.nu file (sets up commands, aliases, etc.)
• --nu-env-config <path>: Custom env.nu file (sets up environment variables)

When provided, these configs are loaded for every script execution via nu --config <path> --env-config <path> -c "<script>".

Install & Test

cargo install --locked mcp-server-nu
npx @modelcontextprotocol/inspector mcp-server-nu

With custom config:

npx @modelcontextprotocol/inspector -- mcp-server-nu --nu-config /path/to/config.nu