Try this

flake.nix

@@ -0,0 +1,21 @@
+{
+  description = "Haschel Proxy Server";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
+  };
+
+  outputs = { self, nixpkgs, ... }@inputs:
+    let
+      settings = import ./settings.nix;
+      system = "x86_64-linux";
+    in {
+    nixosConfigurations."${settings.hostname}" = nixpkgs.lib.nixosSystem {
+      inherit system;
+      specialArgs = { inherit inputs; };
+      modules = [
+        ./configuration.nix
+      ];
+    };
+  };
+}