A complete MCP server for Nix*

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

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

Using uvx:

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

Using nix run:

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

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";
}

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)

Use --exclude to disable specific tools:

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

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.

<!-- mcp-name: io.github.felixdorn/mcp-nix -->