PDF generation from Generation models

I have been wanting to try to create pdfs where someone will upload a pdf, i give it to the model with a prompt on how to change it, and it spits it back with those changes. Does anyone know if that exists? And if not then how i could go about making it? I noticed this is a particularly hard problem because text generators like ChatGPT can create pdfs from HTML or SVG, but they are not long enough for more complex documents, and image generators are bad with text. PDFs are like the mix in between.
I would love to hear any suggestions from the community.