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

  outputs = { self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };

        ebook-convert = with pkgs; writeShellScriptBin "ebook-convert" ''
          set -euo pipefail
          ${calibre}/bin/ebook-convert "$@"
        '';
      in with pkgs; {
        devShell = mkShell {
          buildInputs = [
            esbuild
            nodePackages.typescript
            psmisc # fuser
            watchexec

            # CLI
            python311
            python311Packages.pillow
            python311Packages.pytest
            python311Packages.requests
            ebook-convert
          ];
        };
      }
    );
}