{
  description = "NixOS configuration for RAD-Development Servers";

  nixConfig = {
    substituters = [
      "https://cache.nixos.org/?priority=1&want-mass-query=true"
      "https://attic.alicehuston.xyz/cache-nix-dot?priority=4&want-mass-query=true"
      "https://cache.alicehuston.xyz/?priority=5&want-mass-query=true"
      "https://nix-community.cachix.org/?priority=10&want-mass-query=true"
    ];
    trusted-substituters = [
      "https://cache.nixos.org"
      "https://attic.alicehuston.xyz/cache-nix-dot"
      "https://cache.alicehuston.xyz"
      "https://nix-community.cachix.org"
    ];
    trusted-public-keys = [
      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
      "cache.alicehuston.xyz:SJAm8HJVTWUjwcTTLAoi/5E1gUOJ0GWum2suPPv7CUo=%"
      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      "cache-nix-dot:0hp/F6mUJXNyZeLBPNBjmyEh8gWsNVH+zkuwlWMmwXg="
    ];
    trusted-users = [ "root" ];
  };

  inputs = {
    flake-compat.url = "https://flakehub.com/f/edolstra/flake-compat/1.tar.gz";
    flake-parts.url = "github:hercules-ci/flake-parts";
    nixos-hardware.url = "github:NixOS/nixos-hardware";
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable-small";
    nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-23.11";
    systems.url = "github:nix-systems/default";

    attic = {
      url = "github:zhaofengli/attic";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        nixpkgs-stable.follows = "nixpkgs-stable";
        flake-utils.follows = "flake-utils";
      };
    };

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

    flake-utils = {
      url = "github:numtide/flake-utils";
      inputs.systems.follows = "systems";
    };

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

    hyprland-contrib = {
      url = "github:hyprwm/contrib";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nix = {
      url = "github:NixOS/nix/latest-release";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-compat.follows = "flake-compat";
        flake-parts.follows = "flake-parts";
        pre-commit-hooks.follows = "pre-commit-hooks";
      };
    };

    nix-index-database = {
      url = "github:Mic92/nix-index-database";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixos-modules = {
      url = "github:SuperSandro2000/nixos-modules";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
      };
    };

    pre-commit-hooks = {
      url = "github:cachix/pre-commit-hooks.nix";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        nixpkgs-stable.follows = "nixpkgs-stable";
        flake-compat.follows = "flake-compat";
      };
    };

    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs = {
        flake-utils.follows = "flake-utils";
        nixpkgs.follows = "nixpkgs";
      };
    };

    sops-nix = {
      url = "github:Mic92/sops-nix";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        nixpkgs-stable.follows = "nixpkgs-stable";
      };
    };

    wired-notify = {
      url = "github:Toqozz/wired-notify";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        rust-overlay.follows = "rust-overlay";
        flake-parts.follows = "flake-parts";
      };
    };
  };

  outputs =
    { self, nixpkgs, ... }@inputs:
    let
      systems = [
        "x86_64-linux"
        # disable arm for now as hydra isn't set up for it
        # "aarch64-linux"
      ];

      forEachSystem = lib.genAttrs systems;

      # gets the base path of the repo
      src = builtins.path { path = ./.; };

      # adds our lib functions to lib namespace
      lib = nixpkgs.lib.extend (
        self: _:
        import ./lib {
          inherit nixpkgs inputs;
          lib = self;
        }
      );
      inherit (lib.rad-dev.systems) genSystems;
      inherit (self) outputs; # for hydra
    in
    rec {
      inherit lib; # for allowing use of custom functions in nix repl

      hydraJobs = import ./hydra/jobs.nix { inherit inputs outputs; };
      formatter = forEachSystem (system: nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);

      nixosConfigurations = genSystems inputs src (src + "/systems");
      checks = import ./checks.nix { inherit inputs forEachSystem formatter; };
      devShells = import ./shell.nix { inherit inputs forEachSystem checks; };
    };
}