★ FITS ON A FLOPPY💾338K
Download on GitHub

Control your monitor from the menu bar

Download on GitHub

Requires macOS Ventura 13.0 or later
Last updated: 2026-06-18

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Didact is a tiny macOS menu-bar app that controls your external monitor over DDC/CI. No settings window, no ~1 GB vendor control panel—just standard macOS menus.

Initially built for the BenQ RD280UG (which it ships with a profile for), Didact works toward supporting any DDC/CI monitor: a built-in wizard detects the standard controls and learns the rest, and every monitor-specific detail lives in a shareable JSON profile—so new monitors need no code changes.

Control From the Menu Bar

Click the menu bar icon and adjust your monitor directly:

  • Brightness, contrast, and volume—sliders right in the menu
  • Input source—switch DisplayPort, HDMI, or USB-C without reaching for the OSD
  • Colour modes and toggles—every feature your monitor exposes over DDC/CI
  • Live values are read back from the monitor, so the menu always reflects its real state
  • Displays are re-scanned automatically when you plug, unplug, or rearrange monitors

Tiny by Design

Didact does the controls you actually use, and nothing else.

DidactDisplay Pilot 2
Download338 KB404 MB
Installed360 KB936 MB

About 1,200× smaller to download and over 2,600× smaller installed.

Works Toward Any Monitor

Every monitor-specific detail lives in a shareable JSON profile—no code changes to add a new one:

  • Drop a profile into the app, or into the user Monitors folder, then Reload Configs
  • Profiles match by display name and, more robustly, by EDID—surviving renames and localisation
  • Ships with a ready-made profile for the BenQ RD280UG

Teach a New Monitor

A step-by-step wizard builds a profile for an unknown monitor:

  • Standard controls—brightness, contrast, volume, input—are auto-detected with no effort
  • Everything else is taught: work the monitor’s physical button while Didact watches which control responds
  • Each step ends on test-and-confirm—a live, working control you verify before saving
  • If your monitor resembles one already known, matching controls are filled in for you

Listen Mode

Discover features that aren’t mapped yet: open the Listen window, press the buttons on your monitor’s own on-screen display, and watch which control changes. Searchable, copyable log.

Make the Menu Yours

The menu editor lets you reorder the controls, remove ones you never touch, and insert dividers—saved as your own profile that overrides the default.

Share With the Community

Found the settings for a new monitor? One action packages your profile and submits it to the project on GitHub, so anyone with the same monitor benefits.

Requirements

  • Apple Silicon Mac—DDC is done via IOAVService, which is Apple Silicon only
  • A monitor connected over DisplayPort, USB-C, or HDMI with DDC/CI enabled
  • macOS Ventura 13.0 or later

A Good Mac Citizen

  • Free and open source—released under the MIT License
  • Notarized for Gatekeeper and distributed directly as a DMG
  • Hardened runtime enabled

Optimised

  • Only 338 KB app download size
  • Less than 40 MB base memory footprint
  • Almost zero CPU usage