Sddm

Simple Desktop Display Manager (SDDM) is a modern display manager for X11 and Wayland sessions.

Installation

SDDM can be enabled as the display manager with these lines.

❄︎ /etc/nixos/configuration.nix

services.displayManager.sddm = {
  enable = true;

  # Enables experimental Wayland support
  wayland.enable = true;
};

Configuration

Wayland

❄︎ /etc/nixos/configuration.nix

services.displayManager.sddm = {
  enable = true;

  wayland = {
    enable = true;

    # default compositor is "weston", you can optionally change it to kwin
    #compositor = "kwin";
    };
  };
};

Autologin

❄︎ /etc/nixos/configuration.nix

services.displayManager = {
  sddm = {
    enable = true;
    wayland.enable = true;
  };
  autoLogin = {
    enable = true;    
    user = "user"; # Replace with the desired user
  };
};

Installing themes

You can install and configure a theme like so

❄︎ /etc/nixos/configuration.nix

{ pkgs, ... }:
{
  services.displayManager.sddm = {
    enable = true;
    theme = "catppuccin-mocha-mauve";
  };

  environment.systemPackages = [ 
    (pkgs.catppuccin-sddm.override {
      flavor = "mocha";
      accent = "mauve";
    })
  ];
}