{ ... }:
{
  programs.ssh.extraConfig = ''
    Host eu.nixbuild.net
      PubkeyAcceptedKeyTypes ssh-ed25519
      ServerAliveInterval 60
      IPQoS throughput
      IdentityFile /home/builder/.ssh/id_ed25519
  '';

  programs.ssh.knownHosts.nixbuild = {
    hostNames = [ "eu.nixbuild.net" ];
    publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPIQCZc54poJ8vqawd8TraNryQeJnvH1eLpIDgbiqymM";
  };

  nix.settings.trusted-public-keys = [
    "nixbuild.net/7M7RXY-1:cbc+CQirMbg9SlQxAatEYd4sZYXWOjN3OJi6sH+KK68="
  ];

  # Do not register nixbuild.net as an automatic builder. Ordinary nrsp builds
  # stay local; heavy builds opt in through the documented remote-store command.
}