diff --git a/flake.lock b/flake.lock
index 30de46b..72c3644 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,5 +1,25 @@
 {
   "nodes": {
+    "darwin": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1622060422,
+        "narHash": "sha256-hPVlvrAyf6zL7tTx0lpK+tMxEfZeMiIZ/A2xaJ41WOY=",
+        "owner": "LnL7",
+        "repo": "nix-darwin",
+        "rev": "007d700e644ac588ad6668e6439950a5b6e2ff64",
+        "type": "github"
+      },
+      "original": {
+        "owner": "LnL7",
+        "repo": "nix-darwin",
+        "type": "github"
+      }
+    },
     "futils": {
       "locked": {
         "lastModified": 1620759905,
@@ -52,6 +72,7 @@
     },
     "root": {
       "inputs": {
+        "darwin": "darwin",
         "futils": "futils",
         "home-manager": "home-manager",
         "nixpkgs": "nixpkgs"
diff --git a/flake.nix b/flake.nix
index fadf1c8..5ec4b1d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,6 +3,10 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs";
+    darwin = {
+      url = "github:LnL7/nix-darwin";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     home-manager = {
       url = "github:nix-community/home-manager";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -10,7 +14,7 @@
     futils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, home-manager, futils } @ inputs:
+  outputs = { self, nixpkgs, darwin, home-manager, futils } @ inputs:
     let
       inherit (nixpkgs) lib;
       inherit (lib) recursiveUpdate;
@@ -42,6 +46,9 @@
 
         nixosModules = (import ./modules) // { soxin = import ./modules/soxin.nix; };
         nixosModule = self.nixosModules.soxin;
+        /* For now they are the same. */
+        darwinModules = self.nixosModules;
+        darwinModule = self.darwinModules.soxin;
 
         defaultTemplate = {
           path = ./template;
diff --git a/lib/darwin-system.nix b/lib/darwin-system.nix
new file mode 100644
index 0000000..c7778e4
--- /dev/null
+++ b/lib/darwin-system.nix
@@ -0,0 +1,93 @@
+{ self, lib, darwin, home-manager }:
+
+with lib;
+
+{
+  # The global modules are included in both Darwin and home-manager.
+  globalModules ? [ ]
+
+  # Darwin specific modules.
+, darwinModules ? [ ]
+
+  # Home-manager specific modules.
+, hmModules ? [ ]
+
+  # The global extra arguments are included in both Darwin and home-manager.
+, globalSpecialArgs ? { }
+
+  # Darwin specific extra arguments.
+, darwinSpecialArgs ? { }
+
+  # Home-manager specific extra arguments.
+, hmSpecialArgs ? { }
+
+, ...
+} @ args:
+let
+  args' = removeAttrs args [
+    "globalModules"
+    "darwinModules"
+    "hmModules"
+
+    "globalSpecialArgs"
+    "darwinSpecialArgs"
+    "hmSpecialArgs"
+  ];
+in
+darwin.lib.darwinSystem (recursiveUpdate args' {
+  specialArgs = {
+    # send home-manager down to the Darwin modules
+    inherit home-manager;
+
+    # the mode allows us to tell at what level we are within the modules.
+    mode = "Darwin";
+
+    # send soxin down to NixOS.
+    soxin = self;
+  }
+  # include the global special arguments.
+  // globalSpecialArgs
+  # include the NixOS special arguments.
+  // darwinSpecialArgs;
+
+  modules =
+    # include the global modules
+    globalModules
+    # include the Darwin modules
+    ++ darwinModules
+    # include Soxin modules
+    ++ (singleton self.darwinModule)
+    # include home-manager modules
+    ++ (singleton home-manager.darwinModules.home-manager)
+    # configure Nix registry so users can find soxin
+    ++ singleton { nix.registry.soxin.flake = self; }
+    # configure home-manager
+    ++ (singleton {
+      # tell home-manager to use the global (as in Darwin system-level) pkgs
+      # and install all user packages through the users.users.<name>.packages.
+      home-manager.useGlobalPkgs = true;
+      home-manager.useUserPackages = true;
+
+      home-manager.extraSpecialArgs = {
+        # send home-manager down to the home-manager modules
+        inherit home-manager;
+
+        # the mode allows us to tell at what level we are within the modules.
+        mode = "home-manager";
+        # send soxin down to home-manager.
+        soxin = self;
+      }
+      # include the global special arguments.
+      // globalSpecialArgs
+      # include the home-manager special arguments.
+      // hmSpecialArgs;
+
+      home-manager.sharedModules =
+        # include the global modules
+        globalModules
+        # include the home-manager modules
+        ++ hmModules
+        # include Soxin module
+        ++ (singleton self.nixosModule);
+    });
+})
diff --git a/lib/default.nix b/lib/default.nix
index 102651c..560ed42 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -1,6 +1,7 @@
-{ lib, self, home-manager, ... }:
+{ lib, self, darwin, home-manager, ... }:
 
 rec {
+  darwinSystem = import ./darwin-system.nix { inherit self lib darwin home-manager; };
   homeManagerConfiguration = import ./home-manager-configuration.nix { inherit self lib home-manager; };
   mkSoxinModule = import ./mk-soxin-module.nix { inherit lib modules; };
   modules = import ./modules { inherit lib; };
diff --git a/modules/programs/keybase/default.nix b/modules/programs/keybase/default.nix
index b50a84a..9abf0fc 100644
--- a/modules/programs/keybase/default.nix
+++ b/modules/programs/keybase/default.nix
@@ -16,9 +16,9 @@ in
   };
 
   config = mkIf cfg.enable (mkMerge [
-    {
+    (optionalAttrs (mode == "NixOS" || mode == "home-manager") {
       services.keybase.enable = true;
       services.kbfs.enable = cfg.enableFs;
-    }
+    })
   ]);
 }