This uses LLM Tools to pick between outputting an SVG or plugging in a virtual keyboard to type. The keyboard is much more reliable, and that's what you see in the screenshot.
If nothing else it could use an SVG font that has handwriting; you'd need to bundle that for rendering via reSVG or use some other technique.
But if I ever make a pen-backend to reSVG then it would be even cooler, you would be able to see it trace out the letters.
That would be next-level immersion! You could probably achieve this by rendering the LLM’s response using a handwritten font—maybe even train a model on your own handwriting to make it feel truly personal.