nixos-config/modules/workstation/home-manager/gpg.nix

{ config, lib, pkgs, ... }:
with lib;
{
  options.enableGPGKeyring = mkOption {
    type = types.bool;
    default = true;
    example = false;
    description = ''
      Add GPG keyring and GPG Agent configuration.
    '';
  };

  config = mkIf config.enableGPGKeyring {
    programs.gpg.enable = true;

    services.gpg-agent = {
      enable = true;
      enableScDaemon = true;
      enableSshSupport = true;
      sshKeys = [ "40DE2FEE4D3C5E2C" ];
      pinentryPackage = pkgs.pinentry-curses;
    };
  };
}