Capturing USB HID keys in OSX, for keyboard? I'm trying to find an application that allows me to understand which USB HID codes are being sent when pressing keys on my iMac keyboard?  Is anyone aware of how to do this?

I was going to ask on the Apple Developer forum, however believe you must pay $99 to join it.

Your guidance appreciated.
Key Codes by Many Tricks

https://manytricks.com/keycodes/


  Key Codes is a little utility that displays the key code, unicode value, and modifier keys state for any key combination you press. If you're a developer, this might be useful to you.