Plasma Login Manager

Plasma Login Manager (PLM) is a fork of SDDM for KDE Plasma. PLM is only available in NixOS 26.05 or above.

Installation

Plasma Login Manager can be enabled as follows:

❄︎ /etc/nixos/configuration.nix

services.displayManager.plasma-login-manager.enable = true;

Configuration

Autologin

❄︎ /etc/nixos/configuration.nix

services.displayManager = {
  plasma-login-manager = true;
  autoLogin.user = "user"; # Replace with the desired user
};

fprint

With fprint enabled on the system, PLM will expect a fingerprint after entering any password. PLM does not show any prompt for this and this will time out after some time and PLM will attempt to use your entered password. If you have your fingerprints enrolled, you can press enter and use your fingerprint reader. You may find additional options for fprint as well as information on enrolling fingerprints on the Fingerprint scanner page.

KDE Wallet cannot be unlocked using fprint.

Enable fprint system wide

You can enable this behavior by enabling fprint.

❄︎ /etc/nixos/configuration.nix

services.fprintd.enable = true;

Disable fprint for login

Stops PLM from prompting for fingerprint.

❄︎ /etc/nixos/configuration.nix

security.pam.services.login.fprintAuth = false;

Troubleshooting

PLM hangs after entering password

If you have fprint enabled, disable it for PLM.