{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs";
    systems.url = "github:nix-systems/default";
    esp-idf.url = "github:mirrexagon/nixpkgs-esp-dev";
  };

  outputs = { nixpkgs, systems, esp-idf, ... }: let
    inherit (nixpkgs) lib;
    eachSystem = lib.genAttrs (import systems);
    pkgsFor = eachSystem (system:
      import nixpkgs {
        inherit system;
      });
  in {
    devShells = eachSystem(system: let
      inherit (esp-idf.packages.${system}) esp-idf-full;
      pkgs = pkgsFor.${system};
    in {
      default = pkgs.mkShell {
        inputsFrom = [
          # for building and flashing the sketch
          esp-idf-full
        ];

        packages = [
          esp-idf-full

          # for the `fontconvert.py` script of epdiy
          (pkgs.python3.withPackages(ps: [ps.freetype-py]))
        ];
      };
    });
  };
}