Hallucinate some kinda flake business

configuration.nix

@@ -2,11 +2,11 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running 'nixos-help').
 
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, inputs, ... }:
 with lib;
 
 let
-  unstable = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/nixpkgs-unstable.tar.gz") { config = { allowUnfree = true; }; };
+  unstable = import inputs.nixpkgs-unstable { inherit (config.nixpkgs) config; };
 in
 
 {
@@ -257,4 +257,7 @@ in
   # Before changing this value read the documentation for this option
   # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
   system.stateVersion = "25.05"; # Did you read the comment?
+
+  # Enable flakes
+  nix.settings.experimental-features = [ "nix-command" "flakes" ];
 }

flake.nix

@@ -0,0 +1,18 @@
+{
+  description = "NixOS configuration";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-unstable, ... }@inputs: {
+    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
+      system = "x86_64-linux";
+      specialArgs = { inherit inputs; };
+      modules = [
+        ./configuration.nix
+      ];
+    };
+  };
+}

sync-sparky.yml

@@ -15,6 +15,9 @@
 - source: configuration.nix
   target: /etc/nixos/configuration.nix
   delete: true
+- source: flake.nix
+  target: /etc/nixos/flake.nix
+  delete: true
 
 - source: sparky.gitconfig
   target: /home/dave/.gitconfig