Can the native file upload UX with GPT be recreated with assistants API?

Trying to create a data analysis bot whereby I can upload a CSV in the same way you can with custom GPT or assistant when testing in the playground.

After 1-week of trying different approaches, I’m stuck.

Sending the data via HTTP post method is a no-go. You can’t send very much data that way. It seems the same way of passing data to GPT like a copy/paste into the prompt.

The closest I’ve come is using Pandas to convert to a data frame then use langchain. However, that comes with a couple big sacrifices when unable to create an assistant from the playground (e.g. auto-memory management to maintain the history of the thread for context, functions)

Isn’t this a server setting you can adjust if you want higher file size upload limit?