Open Source for personal GPT

Before I start from scratch, I wanted to reach out and ask if there were any good open source code bases for a personal GPT.

I am looking for something relatively basic. I want to use the OpenAI API for the LLM. I wanted to also use OpenAI to embed my data into a vector DB for RAG. I don't care much if it is Pinecone, Supabase, etc. I am guessing I can change those out if needed.

Any suggestions?

Thanks!