{
  description = "cc-ci — Co-op Cloud recipe CI server (NixOS)";

  inputs = {
    # Pinned to the exact revision cc-ci already runs, so the first rebuild from
    # this repo is a true no-op-then-base (M0). Bump deliberately, not drift.
    nixpkgs.url = "github:NixOS/nixpkgs/50ab793786d9de88ee30ec4e4c24fb4236fc2674";
  };

  outputs = { self, nixpkgs }:
    let
      system = "x86_64-linux";
      pkgs = nixpkgs.legacyPackages.${system};
    in
    {
      nixosConfigurations.cc-ci = nixpkgs.lib.nixosSystem {
        inherit system;
        modules = [ ./hosts/cc-ci/configuration.nix ];
      };

      # Devshell for working on the harness/bridge locally.
      devShells.${system}.default = pkgs.mkShell {
        packages = with pkgs; [ git jq curl nixpkgs-fmt ];
      };

      formatter.${system} = pkgs.nixpkgs-fmt;
    };
}