I've been using IOHIDManager to capture keyboard strokes and was able to capture them inside Handle_InputCallback while using IOHIDManagerRegisterInputValueCallback(manager, Handle_InputCallback, NULL);

So far I've been able to block all keys from reaching the OS using kIOHIDOptionsTypeSeizeDevice but I don't want to handle all the keyboard actions.

My goal is to filter out just the key x and block it from reaching to the OS.

Is there a way for me to block and handle just the x key and pass everything else to the OS for it to handle, or am I forced to handle all events for that device once kIOHIDOptionsTypeSeizeDevice is used?