NixOS MCP server

MCP-NixOS is a Model Context Protocol server that gives AI assistants accurate, real-time information about NixOS packages, configuration options, Home Manager settings, and more. It allows AI to access factual data about the Nix ecosystem instead of generating potentially incorrect information about packages and configurations.

Quick Start

No Nix/NixOS installation is required! This tool works on any system - Windows, macOS, or Linux.

Installation with uvx (Recommended)

{
  "mcpServers": {
    "nixos": {
      "command": "uvx",
      "args": ["mcp-nixos"]
    }
  }
}

Installation with Nix

{
  "mcpServers": {
    "nixos": {
      "command": "nix",
      "args": ["run", "github:utensils/mcp-nixos", "--"]
    }
  }
}

Installation Options

You don't need Nix/NixOS installed to use this tool. It runs anywhere Python runs.

Standard Installation

# Run directly with uvx (no installation needed)
uvx mcp-nixos

# Or install globally
pip install mcp-nixos
uv pip install mcp-nixos

For Nix Users

# Run without installing
nix run github:utensils/mcp-nixos

# Install to profile
nix profile install github:utensils/mcp-nixos

Available Tools

NixOS Tools

• nixos_search(query, type, channel) - Search packages, options, or programs
• nixos_info(name, type, channel) - Get detailed info about packages/options
• nixos_stats(channel) - Package and option counts
• nixos_channels() - List all available channels
• nixos_flakes_search(query) - Search community flakes
• nixos_flakes_stats() - Flake ecosystem statistics

Version History Tools

• nixhub_package_versions(package, limit) - Get version history with commit hashes
• nixhub_find_version(package, version) - Smart search for specific versions

Home Manager Tools

• home_manager_search(query) - Search user config options
• home_manager_info(name) - Get option details (with suggestions!)
• home_manager_stats() - See what's available
• home_manager_list_options() - Browse all 131 categories
• home_manager_options_by_prefix(prefix) - Explore options by prefix

Darwin Tools

• darwin_search(query) - Search macOS options
• darwin_info(name) - Get option details
• darwin_stats() - macOS configuration statistics
• darwin_list_options() - Browse all 21 categories
• darwin_options_by_prefix(prefix) - Explore macOS options

Features

• Real-time data - Always current, never stale
• Plain text output - Human and AI readable
• Smart suggestions - Helps when you typo option names
• Cross-platform - Works on Linux, macOS, and even Windows
• No configuration - It just works

Environment Variables

Variable	Description	Default
ELASTICSEARCH_URL	NixOS API endpoint	https://search.nixos.org/backend

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "nixos" '{"command":"uvx","args":["mcp-nixos"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "nixos": {
            "command": "uvx",
            "args": [
                "mcp-nixos"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "nixos": {
            "command": "uvx",
            "args": [
                "mcp-nixos"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect