Can Proctors Detect a Bluetooth Keyboard on Mac?

Some proctors care about external keyboards because students have used keyboard macros or programmed function keys to inject pre-written essays. Detection of Bluetooth peripherals is patchy and varies by proctor.

macOS exposes Bluetooth peripherals through IOBluetooth APIs. A proctor that wants to detect external keyboards can enumerate this list. In practice, doing so reliably distinguishes a "second" keyboard (Apple Magic Keyboard plus a built-in MacBook keyboard, for example) from anything more sinister. Most proctors don't bother. OnVUE asks during the system check if you have unusual peripherals and may flag if you do; Examplify's strictest configurations also enumerate. The overlay's global hotkey works with any Mac keyboard - built-in, USB, Bluetooth.

Probably not on most proctors. A Magic Keyboard plus the built-in MacBook keyboard is a common setup that proctors expect.

They can see the screen (which shows what you type into the exam), but they cannot read keystrokes for non-exam apps in flight.

It can replay text, but the proctor records the screen and may notice unusual typing speed. A live human proctor especially.