```
  systemd.user.services.weechat-daemon = {
    description = "Weechat daemon";
    serviceConfig = {
      User = "nix";
      Type = "oneshot";
      ExecStart = "${pkgs.tmux} -2 new-session -d -s irc ${pkgs.weechat}";
      ExecStop = "${pkgs.tmux} kill-session -t irc";
    };
    wantedBy = [ "default.target" ];
  };
  systemd.services.weechat-daemon.enable = true;
```