darwin compatibility logic & darwin mcp

parts/core.nix

@@ -9,7 +9,10 @@ let
     };
 in
 {
-  systems = [ system ];
+  systems = [
+    system
+    "aarch64-darwin"
+  ];
   flake = {
     lib = {
       commonOverlays = mkpkgs: inputs: [

parts/devshells.nix

@@ -1,16 +1,23 @@
 { inputs, ... }:
 {
-  perSystem = _: {
-    devShells =
-      let
-        hostShells = inputs.self.nixosConfigurations.emacs.config.devShells;
-      in
-      inputs.self.lib.langList
-      |> builtins.filter (name: hostShells ? ${name})
-      |> map (name: {
-        inherit name;
-        value = hostShells.${name};
-      })
-      |> builtins.listToAttrs;
-  };
+  perSystem =
+    { pkgs, ... }:
+    {
+      devShells =
+        if pkgs.stdenv.isLinux then
+          let
+            hostShells = inputs.self.nixosConfigurations.emacs.config.devShells;
+          in
+          inputs.self.lib.langList
+          |> builtins.filter (name: hostShells ? ${name})
+          |> map (name: {
+            inherit name;
+            value = hostShells.${name};
+          })
+          |> builtins.listToAttrs
+        else
+          {
+            mcp = (import ../modules/dev/mcp/common.nix { inherit pkgs inputs; }).devShell;
+          };
+    };
 }

parts/packages.nix

@@ -52,12 +52,16 @@
       };
     in
     {
-      packages = (inputs.jawz-scripts.packages.${system} or { }) // {
-        emacs-vm = inputs.self.nixosConfigurations.emacs.config.system.build.vm;
-        vps-linode = vpsLinodeConfig.config.system.build.images.linode;
-        mcp-tests = mcpTests;
-        nixos-mcp = nixosMcp;
-        nixos-mcp-server = mcpServerPkg;
-      };
+      packages =
+        (inputs.jawz-scripts.packages.${system} or { })
+        // {
+          mcp-tests = mcpTests;
+          nixos-mcp = nixosMcp;
+          nixos-mcp-server = mcpServerPkg;
+        }
+        // pkgs.lib.optionalAttrs pkgs.stdenv.isLinux {
+          emacs-vm = inputs.self.nixosConfigurations.emacs.config.system.build.vm;
+          vps-linode = vpsLinodeConfig.config.system.build.images.linode;
+        };
     };
 }