Change modifier keys behaviour

I can create shortcuts to perform different actions, but I miss ability to attach action to modifier key up or down. What I want to do, is remap and switch my left cmd and alt keys, but only the left ones. There is action "Opt key down", "Opt key up", and the same for "cmd" key, but there is no way to record necessary key sequence.

Actually I can record single modifier key up or down, but it just doesn't work :frowning:

Hi, I was looking to do the same. Was wondering if you'd found a solution for this?

Yes. I installed Karabiner-Elements, works like a charm. You can even choose keyboard on which remapping works, so in my case on external keyboard I have the keys remapped, but on my laptop keyboard they stay with original mapping. Precisely what I needed.

Yes, Karabiner is definitely the way to go here!