{
  description = "My NixOS/home-manager configuration.";

  nixConfig = {
    extra-substituters = [
      "https://cache.nixos.org/?priority=2&want-mass-query=true"
      "https://cache.tmmworkshop.com/?priority=2&want-mass-query=true"
      "https://nix-community.cachix.org/?priority=10&want-mass-query=true"
    ];
    extra-trusted-public-keys = [
      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
      "cache.tmmworkshop.com:jHffkpgbmEdstQPoihJPYW9TQe6jnQbWR2LqkNGV3iA="
      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      "cache-nix-dot:Od9KN34LXc6Lu7y1ozzV1kIXZa8coClozgth/SYE7dU="
    ];
  };

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-24.05";
    nixpkgs-master.url = "github:nixos/nixpkgs/master";
    systems.url = "github:nix-systems/default-linux";

    nixos-hardware.url = "github:nixos/nixos-hardware/master";

    home-manager = {
      url = "github:nix-community/home-manager";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    firefox-addons = {
      url = "gitlab:rycee/nur-expressions?dir=pkgs/firefox-addons";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    system_tools = {
      url = "github:RichieCahill/system_tools";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixos-cosmic = {
      url = "github:lilyinstarlight/nixos-cosmic";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = {
    self,
    nixpkgs,
    home-manager,
    systems,
    nixos-cosmic,
    ...
  } @ inputs: let
    inherit (self) outputs;
    lib = nixpkgs.lib // home-manager.lib;
    forEachSystem = f: lib.genAttrs (import systems) (system: f pkgsFor.${system});
    pkgsFor = lib.genAttrs (import systems) (
      system:
        import nixpkgs {
          inherit system;
          config.allowUnfree = true;
        }
    );
  in {
    inherit lib;
    overlays = import ./overlays {inherit inputs outputs;};

    devShells = forEachSystem (pkgs: import ./shell.nix {inherit pkgs;});
    formatter = forEachSystem (pkgs: pkgs.alejandra);

    nixosConfigurations = {
      bob = lib.nixosSystem {
        modules = [./systems/bob];
        specialArgs = {inherit inputs outputs;};
      };
      jeeves = lib.nixosSystem {
        modules = [./systems/jeeves];
        specialArgs = {inherit inputs outputs;};
      };
      rhapsody-in-green = lib.nixosSystem {
        modules = [./systems/rhapsody-in-green];
        specialArgs = {inherit inputs outputs;};
      };
      muninn = lib.nixosSystem {
        modules = [./systems/muninn];
        specialArgs = {inherit inputs outputs;};
      };
    };
  };
}