{
  description = "NixOS at Home — Colmena Remote Management";

  inputs = {
    # ── Core channels ────────────────────────────────────────
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-24.11";

    # ── Remote deployment ────────────────────────────────────
    colmena.url = "github:zhaofengli/colmena";
    colmena.inputs.nixpkgs.follows = "nixpkgs";

    # ── User environment management ──────────────────────────
    home-manager = {
      url = "github:nix-community/home-manager";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    # ── Formatter ────────────────────────────────────────────
    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    { nixpkgs
    , nixpkgs-stable
    , colmena
    , home-manager
    , treefmt-nix
    , ...
    } @ inputs:
    let
      system = "x86_64-linux";
      lib = nixpkgs.lib;

      pkgs = import nixpkgs {
        inherit system;
        config.allowUnfree = true;
      };

      stable-pkgs = import nixpkgs-stable {
        inherit system;
        config.allowUnfree = true;
      };

      baseSpecialArgs = {
        inherit inputs stable-pkgs;
      };

      mkHost = hostName: hostModules:
        lib.nixosSystem {
          inherit system;
          specialArgs = baseSpecialArgs;
          modules =
            [
              home-manager.nixosModules.home-manager
              {
                home-manager.useGlobalPkgs = true;
                home-manager.useUserPackages = true;
                home-manager.users.phoenix = import ./home/phoenix.nix;
                home-manager.extraSpecialArgs = baseSpecialArgs;
              }
              ./modules/common
            ]
            ++ hostModules;
        };

      treefmtEval = treefmt-nix.lib.evalModule pkgs {
        projectRootFile = "flake.nix";
        settings.global.excludes = [ "*.lock" "secrets.yaml" ];
        programs.nixfmt.enable = true;
      };
    in
    {
      # ── Local build / nixos-rebuild compat ──────────────────
      nixosConfigurations = {
        blade = mkHost "blade" [ ./hosts/blade ];
      };

      # ── Colmena remote deployment ───────────────────────────
      colmena = {
        meta = {
          nixpkgs = import nixpkgs {
            inherit system;
            config.allowUnfree = true;
          };
          specialArgs = baseSpecialArgs;
        };

        blade = { ... }: {
          deployment = {
            targetHost = "192.168.1.70";
            targetPort = 22;
            targetUser = "phoenix";
            buildOnTarget = true;
            keys.phoenix.keyFile = "/home/nixos/.ssh/id_ed25519.pub";
            tags = [ "homelab" ];
          };
          imports = [ ./hosts/blade ];
        };
      };

      # ── Dev shell (enter with `nix develop`) ────────────────
      devShells.${system}.default = pkgs.mkShell {
        packages = with pkgs; [
          colmena
          sops
          age
          ssh-to-age
          jq
          yq
          just
          nixfmt-rfc-style
        ];
      };

      # ── Formatter (run with `nix fmt`) ──────────────────────
      formatter = treefmtEval.config.build.wrapper;
    };
}