Shine

Control the brightness and volume of external monitors from your Mac —
with your keyboard's brightness and volume keys, over DDC/CI.

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Features

• 🌞 Brightness control for third-party external monitors via DDC/CI
• 🔊 Volume & mute control for monitor speakers
• ⌨️ Native keyboard keys — the brightness keys adjust the monitor under your mouse pointer; the volume keys adjust the monitor your audio is playing through
• 🖥 Multi-monitor aware — displays are matched to their DDC ports by EDID, and volume keys follow the system's default audio output device
• 📊 macOS-style on-screen HUD when using the keys
• 🫥 Lives in the menu bar; the icon can be hidden entirely

Requirements

• Apple Silicon Mac, macOS 14 (Sonoma) or later
• An external monitor connected over HDMI, DisplayPort, or USB-C with DDC/CI enabled (most monitors have it on by default; check the monitor's on-screen menu if controls don't respond)

Note: Displays connected through some docks/adapters, and monitors in certain HDR/picture modes, may not accept DDC commands.

Install

1. Download the latest Shine-x.y.dmg from Releases.
2. Drag Shine to Applications and open it.
3. macOS will warn that it "could not verify Shine is free of malware" — this is because the app is not notarized (notarization requires a paid Apple Developer membership; Shine is free and open source). To open it anyway:
   • Open System Settings → Privacy & Security, scroll down, and click "Open Anyway", then confirm.
   • Or from Terminal: xattr -d com.apple.quarantine /Applications/Shine.app
4. Grant Accessibility permission when prompted (System Settings → Privacy & Security → Accessibility). This is required to capture the keyboard brightness/volume keys; the menu bar sliders work without it.

Build from source

git clone https://github.com/ademayar/Shine.git
cd Shine
./scripts/make-dmg.sh   # builds Release and produces build/Shine-x.y.dmg

Or open Shine.xcodeproj in Xcode and run.

How it works

Shine talks to monitors over the DDC/CI protocol (VESA MCCS): brightness is VCP code 0x10, speaker volume 0x62, and mute 0x8D. On Apple Silicon the I2C channel is reached through the private IOAVService API, resolved at runtime — the same approach used by MonitorControl and Lunar. Media keys are intercepted with a CGEventTap, which is why the Accessibility permission is needed.

Because a private API is involved, Shine can never be on the App Store — but it is perfectly fine as a directly-distributed app.

FAQ

The volume keys change the HUD but I hear no difference. The keys control the speakers of the monitor that is the current audio output device. Check System Settings → Sound → Output.

Brightness keys still change my MacBook's screen. That's intentional: the keys target the display under the mouse pointer. Move the pointer onto the external monitor first.

Nothing responds at all. Enable DDC/CI in your monitor's on-screen menu, and try connecting the monitor directly rather than through a dock.

License

MIT