{
  description = "flake for matt-nixos";

  inputs = {
    # Common
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    chaotic.url = "github:chaotic-cx/nyx/nyxpkgs-unstable";

    # Desktop
    nix-flatpak.url = "github:gmodena/nix-flatpak";
    impermanence.url = "github:nix-community/impermanence";
    home-manager.url = "github:nix-community/home-manager";
    home-manager.inputs.nixpkgs.follows = "nixpkgs";
    lanzaboote = {
      url = "github:nix-community/lanzaboote/v0.3.0";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixos-apple-silicon.url = "github:tpwrules/nixos-apple-silicon";

    nix-darwin.url = "github:LnL7/nix-darwin";

    # Pi4
    nixos-hardware.url = "github:NixOS/nixos-hardware/master";
  };

  outputs = { self, nixpkgs, chaotic, lanzaboote, impermanence, nix-flatpak, home-manager
    , nixos-hardware, nix-darwin, nixos-apple-silicon }@inputs: {
    nixosConfigurations = {
      # Desktop
      "matt-nixos" = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          impermanence.nixosModules.impermanence
          lanzaboote.nixosModules.lanzaboote
          nix-flatpak.nixosModules.nix-flatpak
          ./hosts/desktop/configuration.nix
          ./share/impermanence
          chaotic.nixosModules.default
          home-manager.nixosModules.home-manager
          {
            home-manager.useGlobalPkgs = true;
            home-manager.useUserPackages = true;
            home-manager.users.matt = import ./hosts/desktop/home.nix;
          }
        ];
      };

      # mac nix
      "mac-nixos" = nixpkgs.lib.nixosSystem {
        system = "aarch64-linux";
        modules = [
          nixos-apple-silicon.nixosModules.apple-silicon-support
          ./hosts/mac-nixos/configuration.nix
          home-manager.nixosModules.home-manager
          {
            home-manager.useGlobalPkgs = true;
            home-manager.useUserPackages = true;
            home-manager.users.matt = import ./hosts/mac-nixos/home.nix;
          }
        ];
      };

      # Pi4
      "nixos-pi4" = nixpkgs.lib.nixosSystem {
        system = "aarch64-linux";
        modules = [
          nixos-hardware.nixosModules.raspberry-pi-4
          ./hosts/pi4/configuration.nix
        ];
      };
    };

    darwinConfigurations = {
      "MacBook-Pro" = nix-darwin.lib.darwinSystem {
        system = "aarch64-darwin";
        modules = [
          ./hosts/mac/configuration.nix
          home-manager.darwinModules.home-manager
          {
            home-manager.useGlobalPkgs = true;
            home-manager.useUserPackages = true;
            home-manager.users.mattjallen = import ./hosts/mac/home.nix;
          }
        ];
      };
    };

    # Expose the package set, including overlays, for convenience.
    darwinPackages = self.darwinConfigurations."MacBook-Pro".pkgs;

    # Set Git commit hash for darwin-version.
    system.configurationRevision = self.rev or self.dirtyRev or null; 
  };
}