MCP-NixOS - Because Your AI Assistant Shouldn't Hallucinate About Packages

🎉 REFACTORED: Version 1.0.0 represents a complete rewrite that drastically simplified everything. We removed all the complex caching, abstractions, and "enterprise" patterns. Because sometimes less is more, and more is just showing off.

Quick Start (Because You Want to Use It NOW)

🚨 No Nix/NixOS Required! This tool works on any system - Windows, macOS, Linux. You're just querying web APIs.

Option 1: Using uvx (Recommended for most users)

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

Option 2: Using Nix (For Nix users)

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

That's it. Your AI assistant now has access to real NixOS data instead of making things up. You're welcome.

What Is This Thing?

MCP-NixOS is a Model Context Protocol server that gives your AI assistant accurate, real-time information about:

NixOS packages (130K+ packages that actually exist)
Configuration options (22K+ ways to break your system)
Home Manager settings (4K+ options for the power users)
nix-darwin configurations (1K+ macOS settings Apple doesn't want you to touch)
Package version history via NixHub.io (Find that ancient Ruby 2.6 with commit hashes)

The Tools You Actually Care About

🔍 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 (NEW!)

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

Installation Options

Remember: You DON'T need Nix/NixOS installed! This tool runs anywhere Python runs.

For Regular Humans (Windows/Mac/Linux)

# 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 (You Know Who You Are)

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

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

Features Worth Mentioning

🚀 Version 1.0.0: The Great Simplification

Drastically less code - Removed thousands of lines of complexity
100% functionality - Everything still works
0% cache corruption - Because we removed the cache entirely
Stateless operation - No files to clean up
Direct API access - No abstraction nonsense

📊 What You Get

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 yes, even Windows
No configuration - It just works™

🎯 Key Improvements

Dynamic channel resolution - stable always points to current stable
Enhanced error messages - Actually helpful when things go wrong
Deduped flake results - No more duplicate spam
Version-aware searches - Find that old Ruby version you need
Category browsing - Explore options systematically

For Developers (The Brave Ones)

With Nix (The Blessed Path)

nix develop
menu  # Shows all available commands

# Common tasks
run        # Start the server
run-tests  # Run all tests
lint       # Format and check code
typecheck  # Check types

Without Nix (The Path of Pain)

pip install -e ".[dev]"
pytest tests/
black mcp_nixos/
flake8 mcp_nixos/

Testing Philosophy

367 tests that actually test things
Real API calls because mocks are for cowards
Plain text validation ensuring no XML leaks through
Cross-platform tests because Windows users deserve pain too

Environment Variables

Just one. We're minimalists now:

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

Acknowledgments

This project queries data from several amazing services:

NixHub.io - Provides package version history and commit tracking
search.nixos.org - Official NixOS package and option search
Jetify - Creators of Devbox and NixHub

Note: These services have not endorsed this tool. We're just grateful API consumers.

License

MIT - Because sharing is caring, even if the code hurts.

Created by James Brink and maintained by masochists who enjoy Nix.

Special thanks to the NixOS project for creating an OS that's simultaneously the best and worst thing ever.

NixOS Package Explorer