Hi,

I wanted to implement custom evaluating logic. Realizing that only the python implemention of LLamaIndex supports QuestionGenerator i thought that it would be more reasonable to the FastAPI backend + Next.js Frontend setup.

I managed to pass the data for images to the backend extending the handleSubmit of useChat for vercel/ai#725. I however don't know how to duplicate the functionality of StreamData in the FastAPI backend.

Can you make this example work out of the box or provide some further documentation of how to implement this? Currently the multi modality does not work, without multiple changes.

Thanks for taking your time and reading my request.