set up nix mcp server

README.md

@@ -62,7 +62,6 @@ nix multi user, multi system, configuration with `sops` secret management, `home
 - Create Tor guard/relay server
 - migrate away from flakes and move to npins
 - whisper
-- nix mcp
 - zfs encryption FIDO2 2fa (look into shavee)
 - Secure Boot - https://github.com/nix-community/lanzaboote
 - rotate sops encryption keys periodically (and somehow sync between devices?)

configurations/home-manager/leyla/packages/vscode/default.nix

@@ -68,7 +68,10 @@ in {
             go.enable = true;
 
             # claude development
-            claudeDev.enable = ai-tooling-enabled;
+            claudeDev = lib.mkIf ai-tooling-enabled {
+              enable = true;
+              mcp.nixos.enable = true;
+            };
 
             # misc extensions
             evenBetterToml.enable = true;

flake.lock

@@ -1,5 +1,23 @@
 {
   "nodes": {
+    "devshell": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1741473158,
+        "narHash": "sha256-kWNaq6wQUbUMlPgw8Y+9/9wP0F8SHkjy24/mN3UAppg=",
+        "owner": "numtide",
+        "repo": "devshell",
+        "rev": "7c9e793ebe66bcba8292989a68c0419b737a22a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "devshell",
+        "type": "github"
+      }
+    },
     "disko": {
       "inputs": {
         "nixpkgs": [
@@ -75,6 +93,24 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "home-manager": {
       "inputs": {
         "nixpkgs": [
@@ -110,6 +146,28 @@
         "type": "github"
       }
     },
+    "mcp-nixos": {
+      "inputs": {
+        "devshell": "devshell",
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1755372538,
+        "narHash": "sha256-iWhsf1Myk6RyQ7IuNf4bWI3Sqq9pgmhKvEisCXtkxyw=",
+        "owner": "utensils",
+        "repo": "mcp-nixos",
+        "rev": "46b4d4d3d6421bfbadc415532ef74433871e1cda",
+        "type": "github"
+      },
+      "original": {
+        "owner": "utensils",
+        "repo": "mcp-nixos",
+        "type": "github"
+      }
+    },
     "nix-darwin": {
       "inputs": {
         "nixpkgs": [
@@ -153,7 +211,7 @@
     },
     "nix-vscode-extensions": {
       "inputs": {
-        "flake-utils": "flake-utils",
+        "flake-utils": "flake-utils_2",
         "nixpkgs": [
           "nixpkgs"
         ]
@@ -189,6 +247,22 @@
       }
     },
     "nixpkgs": {
+      "locked": {
+        "lastModified": 1722073938,
+        "narHash": "sha256-OpX0StkL8vpXyWOGUD6G+MA26wAXK6SpT94kLJXo6B4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e36e9f57337d0ff0cf77aceb58af4c805472bfae",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
       "locked": {
         "lastModified": 1755615617,
         "narHash": "sha256-HMwfAJBdrr8wXAkbGhtcby1zGFvs+StOp19xNsbqdOg=",
@@ -211,11 +285,12 @@
         "flake-compat": "flake-compat",
         "home-manager": "home-manager",
         "impermanence": "impermanence",
+        "mcp-nixos": "mcp-nixos",
         "nix-darwin": "nix-darwin",
         "nix-syncthing": "nix-syncthing",
         "nix-vscode-extensions": "nix-vscode-extensions",
         "nixos-hardware": "nixos-hardware",
-        "nixpkgs": "nixpkgs",
+        "nixpkgs": "nixpkgs_2",
         "secrets": "secrets",
         "sops-nix": "sops-nix",
         "steam-fetcher": "steam-fetcher"
@@ -291,6 +366,21 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -76,6 +76,12 @@
       url = "github:nix-community/steam-fetcher";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    # MCP NixOS server for Claude Dev
+    mcp-nixos = {
+      url = "github:utensils/mcp-nixos";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = {
@@ -157,6 +163,8 @@
           disko
           # for viewing dconf entries
           dconf-editor
+          # for MCP NixOS server support in development
+          inputs.mcp-nixos.packages.${system}.default
         ];
 
         SOPS_AGE_KEY_DIRECTORY = import ./const/sops_age_key_directory.nix;

modules/home-manager-modules/programs/vscode/claudeDev.nix

@@ -2,10 +2,27 @@
   lib,
   pkgs,
   config,
+  inputs,
   ...
 }: let
   pkgsRepositories = pkgs.nix-vscode-extensions.forVSCodeVersion config.programs.vscode.package.version;
   pkgsRepository = pkgsRepositories.open-vsx;
+
+  mcp-nixos = inputs.mcp-nixos.packages.${pkgs.stdenv.hostPlatform.system}.default;
+
+  anyProfileHasMcpNixos = lib.any (
+    profile:
+      profile.extraExtensions.claudeDev.enable
+      && profile.extraExtensions.claudeDev.mcp.nixos.enable
+  ) (lib.attrValues config.programs.vscode.profiles);
+
+  mcpServersConfig = lib.mkMerge [
+    (lib.mkIf anyProfileHasMcpNixos {
+      nixos = {
+        command = "${mcp-nixos}/bin/mcp-nixos";
+      };
+    })
+  ];
 in {
   options.programs.vscode.profiles = lib.mkOption {
     type = lib.types.attrsOf (lib.types.submodule ({config, ...}: {
@@ -15,6 +32,12 @@ in {
           extension = lib.mkPackageOption pkgsRepository "claude-dev" {
             default = ["saoudrizwan" "claude-dev"];
           };
+
+          mcp = {
+            nixos = {
+              enable = lib.mkEnableOption "enable NixOS MCP server for Claude Dev";
+            };
+          };
         };
       };
       config = lib.mkIf config.extraExtensions.claudeDev.enable {
@@ -24,4 +47,17 @@ in {
       };
     }));
   };
+
+  config = lib.mkIf anyProfileHasMcpNixos {
+    home.file."${config.xdg.configHome}/VSCodium/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json" = {
+      text = builtins.toJSON {
+        mcpServers = mcpServersConfig;
+      };
+      force = true;
+    };
+
+    home.packages = [
+      mcp-nixos
+    ];
+  };
 }