a:

flake.nix

@@ -2,7 +2,11 @@
   description = "My flakes configuration";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    nixos-cosmic = {
+      url = "github:lilyinstarlight/nixos-cosmic";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     master.url = "github:NixOS/nixpkgs/master";
     home-manager.url = "github:nix-community/home-manager";
     nixvim = {
@@ -12,14 +16,22 @@
     home-manager.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  outputs = { self, nixpkgs, home-manager, master, nixvim }@inputs:
+  outputs = { self, nixpkgs, nixos-cosmic, home-manager, master, nixvim }@inputs:
     {
       nixosConfigurations = {
         nixos = nixpkgs.lib.nixosSystem {
           system = "x86_64-linux";
 	  specialArgs = {inherit nixvim;};
-          modules = [ ./configuration.nix
-            home-manager.nixosModules.home-manager 
+          modules = [
+            {
+              nix.settings = {
+                substituters = [ "https://cosmic.cachix.org/" ];
+                trusted-public-keys = [ "cosmic.cachix.org-1:Dya9IyXD4xdBehWjrkPv6rtxpmMdRel02smYzA85dPE=" ];
+              };
+            }
+	    nixos-cosmic.nixosModules.default
+            ./configuration.nix
+	    home-manager.nixosModules.home-manager 
 	    {
 	      home-manager.useUserPackages = true;
 	      home-manager.users.joshuaelm = {