add nix config in home/modules/nix.nix when not nixos

home/modules/default.nix

@@ -1 +1,17 @@
-{ ... }: { }
+{ lib, ... }:
+{
+  imports = [
+    ./nix.nix
+  ];
+
+  options = {
+    youthlic.nixos.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = ''
+        whether the os is nixos
+      '';
+    };
+  };
+}

home/modules/nix.nix

@@ -0,0 +1,51 @@
+{
+  inputs,
+  lib,
+  config,
+  pkgs,
+  outputs,
+  ...
+}:
+{
+  config =
+    let
+      cfg = config.youthlic.nixos;
+    in
+    (lib.mkIf (!cfg.enable) {
+      nixpkgs = {
+        config = {
+          allowUnfree = true;
+          allowUnfreePredicate = (_: true);
+        };
+        overlays = [
+          outputs.overlays.modifications
+          outputs.overlays.additions
+        ];
+      };
+      nix = {
+        package = pkgs.nix;
+        settings = {
+          inherit (outputs.nix.settings) substituters;
+          trusted-public-keys = [
+            "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+            "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+            "cosmic.cachix.org-1:Dya9IyXD4xdBehWjrkPv6rtxpmMdRel02smYzA85dPE="
+          ];
+          auto-optimise-store = lib.mkDefault true;
+          experimental-features = [
+            "nix-command"
+            "flakes"
+          ];
+          warn-dirty = false;
+          use-xdg-base-directories = true;
+        };
+        registry.home = lib.mkDefault {
+          from = {
+            type = "indirect";
+            id = "home";
+          };
+          flake = inputs.nixpkgs;
+        };
+      };
+    });
+}

nixos/modules/home.nix

@@ -50,6 +50,10 @@
               outputs.homeManagerModules."${unixName}"
               (rootPath + "/home/${unixName}/configurations/${hostName}")
             ];
+
+            config = {
+              youthlic.nixos.enable = true;
+            };
           }
         );
         extraSpecialArgs = {