Fcitx5

Fcitx5 is a lightweight input method framework with addon support.

Setup

The following is a simple NixOs configuration that'll setup fcitx5, its GUI config tool, and two addons.

i18n.inputMethod = {
    enabled = "fcitx5";
    fcitx5.addons = with pkgs; [
        fcitx5-mozc
        fcitx5-gtk
    ];
};

Notably, NixOs automagically sets session variables that are required for fcitx5.

Troubleshooting

Add-ons Not Detected

Installing fcitx5 using environment.systemPackages can interfere with add-on detection.

Fcitx5 Doesn't Start When Using WM

As of NixOS 23.11 i18n.inputMethod.enabled no longer creates systemd services for fcitx5. Instead it relies on XDG autostart files. If using a Window Manager (WM), such as Sway, you may need to add services.xserver.desktopManager.runXdgAutoStartIfNone to your NixOS configuration.

See the NixOS 23.11 Release Notes for more information.