a:

modules/cosmic/cosmic-greeter.nix

@@ -0,0 +1,52 @@
+{ config, pkgs, lib, ... }:
+
+let
+  cfg = config.services.xserver.displayManager.cosmic-greeter;
+in
+{
+  meta.maintainers = with lib.maintainers; [ nyanbinary ];
+
+  options.services.xserver.displayManager.cosmic-greeter = {
+    enable = lib.mkEnableOption (lib.mdDoc "COSMIC greeter");
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.greetd = {
+      enable = true;
+      settings = {
+        default_session = {
+          user = "cosmic-greeter";
+          command = "${pkgs.coreutils}/bin/env XCURSOR_THEME=Pop systemd-cat -t cosmic-greeter ${pkgs.cosmic-comp}/bin/cosmic-comp ${pkgs.cosmic-greeter}/bin/cosmic-greeter";
+        };
+      };
+    };
+
+    systemd.services.cosmic-greeter-daemon = {
+      wantedBy = [ "multi-user.target" ];
+      before = [ "greetd.service" ];
+      serviceConfig = {
+        ExecStart = "${pkgs.cosmic-greeter}/bin/cosmic-greeter-daemon";
+        Restart = "on-failure";
+      };
+    };
+
+    systemd.tmpfiles.rules = [
+      "d '/var/lib/cosmic-greeter' - cosmic-greeter cosmic-greeter - -"
+    ];
+
+    users.users.cosmic-greeter = {
+      isSystemUser = true;
+      home = "/var/lib/cosmic-greeter";
+      group = "cosmic-greeter";
+    };
+
+    users.groups.cosmic-greeter = { };
+
+    hardware.opengl.enable = true;
+    services.xserver.libinput.enable = true;
+
+    security.pam.services.cosmic-greeter = {};
+
+    services.dbus.packages = with pkgs; [ cosmic-greeter ];
+  };
+}