Which integrations are available for this server?

Provides tools for searching and managing nix-darwin configuration options for macOS systems, including searching options, retrieving option details, and reading declaration references. Provides tools for searching and exploring the Nix ecosystem, including package search in Nixpkgs, NixOS configuration options, Home Manager options, Nixvim and nix-darwin configurations, and package version tracking through NixHub. Enables reading Nix source code for derivations and module declarations.

How do I use mcp-nix?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@mcp-nix search for a package called neovim in nixpkgs" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

A complete MCP server for Nix*

Tests

Features

Search Nixpkgs and read package derivations
Broad options coverage
- NixOS
- Home Manager
- Nix Darwin
- Nixvim
- Impermanence
- MicroVM.nix
- nix-nomad
- simple-nixos-mailserver
- sops-nix
- nixos-hardware
- disko
Search the nix standard library and read function definitions
Find versions of nixpkgs in which a package exists

Installation

Use the following configuration to add the MCP server to your client:

Using uvx:

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

Add to cursor

Using nix run:

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

Add to cursor

Declaratively:

Add the flake input:

{ inputs.mcp-nix.url = "github:felixdorn/mcp-nix"; }

Then reference the package:

{ command = "${inputs.mcp-nix.packages.${system}.default}/bin/mcp-nix"; }

Tools

Tool	Description
`search_nixpkgs`	Search Nixpkgs packages
`read_derivation`	Read package source code
`search_options`	Search options for many projects
`list_versions`	List available versions for a project
`show_option_details`	Get option details or list children
`read_option_declaration`	Read option source code
`find_nixpkgs_commit_with_package_version`	Get nixpkgs commit for a version, shows available versions if not found (NixHub)
`search_nix_stdlib`	Search Nix stdlib functions (Noogle)
`help_for_stdlib_function`	Get help for a stdlib function (Noogle)

Excluding Tools

Use --exclude to disable specific tools:

{ "mcpServers": { "nix": { "command": "uvx", "args": ["mcp-nix", "--exclude=read_derivation,read_option_declaration"] } } }

Contributing

Read CONTRIBUTING.md

Acknowledgments

Thanks to the NixOS Search Team, ExtraNix, NüschtOS, nix-nomad, NixHub, Noogle for maintaining the backends and pipeline this server uses and for the Nix community for making any of this possible.