Love the idea. Since this is a consumer product, making it clear you can try the product before buying is critical. I clicked on the paid plan option, created an account but then was surprised to see that I ended up in the product.

I'd consider a react framework for the UI, shadcn or similar. The overall vibe of the UI doesn't present as cutting edge or on par with other AI based products out there.

In the product, I'd bring the recommended prompts to the surface the user enters the AI prompting mode, rather than hiding them behind the "show prompt tips" button.

The line height on the diff view is a little short, the text is crowded.

Tooltips on the toolbar buttons would be very helpful. Also, creating some hierarchy in the toolbar by dividing into logical sections grouped by tool type would help. Font foratting, node types, etc.

Overall, great job, product itself works really well.

there is also backend open-source version https://github.com/achromic-labs/potext-backend