Usage and specific settings will vary somewhat depending on the synthesizer you control. Hardware synths should recognize the Cyber Cat and "just work" however you can change the MIDI channel and CC#s in the code.py file if necessary.

Software synthesizers will usually recognize the Cyber Cat automatically, however if you need to pick the MIDI input device from a list, choose the one named KB2040 CircuitPython usb_midi.ports[0]

Some functions will work without adjustment, such as note on/off, octave switching, MIDI panic, and pitch bend. Others will require MIDI CC learning in software to pair a Cyber Cat button to a specific parameter of the synthesizer.

Here are the button functions for the Cyber Cat:

Here it is in action: