MacBook keyboard and screen backlight adjust on the ambient light. Internally, macbook-lighter reads the following files:

• /sys/devices/platform/applesmc.768/light
• /sys/class/backlight/intel_backlight/brightness
• /sys/class/backlight/intel_backlight/max_brightness
• /sys/class/leds/smc::kbd_backlight/brightness
• /sys/class/leds/smc::kbd_backlight/max_brightness

So you're expected to install corresponding Nvidia/Intel drivers first.

All commands including macbook-lighter-kbd, macbook-lighter-screen will be available with sudo previledge once macbook-lighter finished install.

To use in non-root environment such as xbindkeys, it's recommended to setup an "udev" rule to allow users in the "video" group to set the backlights. Place a file /etc/udev/rules.d/90-backlight.rules containing:

SUBSYSTEM=="backlight", ACTION=="add", \
  RUN+="/bin/chgrp video /sys/class/backlight/%k/brightness", \
  RUN+="/bin/chmod g+w /sys/class/backlight/%k/brightness"

And a file /etc/udev/rules.d/91-leds.rules containing:

SUBSYSTEM=="leds", ACTION=="add", \
  RUN+="/bin/chgrp video /sys/class/leds/%k/brightness", \
  RUN+="/bin/chmod g+w /sys/class/leds/%k/brightness"

# Increase keyboard backlight by 50
macbook-lighter-kbd --inc 50
# Increase screen backlight by 50
macbook-lighter-screen --inc 50
# Set screen backlight to max
macbook-lighter-screen --max
# start auto adjust daemon
systemctl start macbook-lighter
# start auto adjust interactively, root previlege needed
macbook-lighter-ambient

• MacBook Pro Late 2013 (11,1)
• Macbook Air 2012