alin23/lunar

Lunar is a macOS application written in Swift for controlling external monitors. It lets you adjust brightness, contrast, volume, and input selection directly through the app rather than fumbling with physical buttons on your monitor. Both Intel and Apple Silicon Macs are supported. The key technical detail is that Lunar changes brightness at the hardware level using a protocol called DDC/CI, which is a standard way to send control commands to a monitor over the same cable carrying the video signal. This means the brightness change is real: the monitor's own hardware dims or brightens, rather than a software overlay darkening the pixels on-screen. The result is better for battery life and looks more natural, especially in dark environments. Lunar offers several ways to adjust brightness automatically. Sync mode ties your external monitor's brightness to the MacBook's built-in ambient light sensor. Location mode adjusts brightness based on sunrise and sunset times for wherever you are. A separate external hardware sensor is also supported for more precise ambient light readings. You can also set per-app presets so, for example, a video editing app automatically gets a different brightness than a code editor. Other features include a BlackOut mode that turns a monitor off completely while keeping USB-C charging, audio, and hub functions running through it. Screen orientation can be changed from the menu bar. Hidden display resolutions that macOS does not normally surface are accessible from a dropdown. Keyboard shortcuts can be assigned for brightness, volume, contrast, and input switching. Installation is through a downloaded disk image or via Homebrew. The source code for paid Pro features is not included in the repository, so the app cannot be built from this repo.