nixpkgs/nixos/modules/services/networking/keybase.nix

{ config, lib, pkgs, ... }:
with lib;
let
  cfg = config.services.keybase;

in {

  ###### interface

  options = {

    services.keybase = {

      enable = mkOption {
        type = types.bool;
        default = false;
        description = "Whether to start the Keybase service.";
      };

    };
  };

  ###### implementation

  config = mkIf cfg.enable {

    systemd.user.services.keybase = {
      description = "Keybase service";
      serviceConfig = {
        ExecStart = ''
          ${pkgs.keybase}/bin/keybase -d service --auto-forked
        '';
        Restart = "on-failure";
        PrivateTmp = true;
      };
      wantedBy = [ "default.target" ];
    };

    environment.systemPackages = [ pkgs.keybase ];
  };
}