They say they're targeting Mac only for now, so it could be native code, or they could just have not tested/refined their prompt for other platforms yet.
> This was never the case for the desktop tools I mentioned.
I'd be curious how well Claude Code works for a native Swift app on macOS, if that's the platform you're on. I've found it extremely good at iOS apps so my guess is it would be equally good at building a native macOS app with the same stack.