keyd

Start and enable the keyd service

$ systemctl enable keyd --now

$ sudo keyd -m

$ sudo keyd reload

$ keyd list-keys

$ keyd check

$ sudo keyd bind "[pressed_key] = [output_key]"

keyd [options] [command]

keyd is a key remapping daemon that operates at the kernel level using evdev. It allows remapping keys system-wide, independent of the display server (works with X11, Wayland, and virtual consoles).
Configuration files in /etc/keyd define key mappings, layers, and macros. The daemon intercepts input events and transforms them according to the configuration before passing them to applications.

-m, monitor

Display keypress information in real-time

Reset bindings and reload configuration from /etc/keyd

Display all valid key names

Validate configuration files for syntax errors

Create a temporary key binding

Requires root privileges for most operations. Configuration changes require reload. Works at a lower level than X11 keymaps, so remappings apply everywhere.

keyd was developed as a modern, simple key remapping solution that works universally across display servers. It provides functionality similar to tools like xmodmap but operates at the kernel input level.

xmodmap(1), setxkbmap(1), evtest(1)