nixos/home/ssh/default.nix

{...}: {
  programs.ssh = {
    enable = true;
    forwardAgent = true;
    serverAliveInterval = 15;
    serverAliveCountMax = 3;
    controlMaster = "auto";
    controlPersist = "10s";
    matchBlocks."git*".user = "git";
    extraConfig = ''
      AddKeysToAgent=yes
    '';
  };
}