diff --git a/flake.nix b/flake.nix
index 6355d16..6acaf0b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -40,9 +40,7 @@
       overlays.madd = final: prev: mkPackages final;
       overlays.default = overlays.madd;
 
-      nixosModules.madd = {
-
-      };
+      nixosModules.madd = import ./nixos.nix;
       nixosModules.default = nixosModules.madd;
     };
 }
diff --git a/nixos.nix b/nixos.nix
new file mode 100644
index 0000000..ee9b5c6
--- /dev/null
+++ b/nixos.nix
@@ -0,0 +1,12 @@
+{ lib, config, ... }:
+
+with lib;
+{
+  option.madd-client = {
+    enable = mkEnableOption "MADD client";
+  };
+
+  options.madd-server = {
+    enable = mkEnableOption "MADD server";
+  };
+}