Lizhecheng02/RAG-ChatBot ? reverse-engineered prompt

Build me a simple document chat app that lets me upload one or more files like PDF, DOC, or TXT, then ask questions and get answers based on the content in those files.

I want a clean Streamlit web UI with a chat style interface, a file upload area on the left, and a way to index the documents behind the scenes so the app can answer from them using retrieval augmented generation. Please make it work locally with an API key from an env file, and if possible keep the setup easy enough that I can also run it on Streamlit Cloud. If you can, include a version that uses Groq for faster responses too, and keep the code organized so I can switch between models without rewriting everything.

It would be great if the app can remember the uploaded documents in a local vector store, and if there’s a simple way to compare the document based answer with a normal LLM answer, include that too. Use current docs online if you need to check anything.