There are so many libraries and frameworks out there, from LangChain to Ollama. While I could just use OpenAI's Assistants API, I want to compose my LLM responses in a way that's unique to my app; I don't want to build yet another thin wrapper around ChatGPT, where the only selling point is the proprietary prompt behind the app. Additionally, I would like to be able to switch to a different LLM provider (e.g. in case OpenAI fails on us or local LLMs have finally caught up to the same quality).

What are your recommendations for AI libraries? Tell me about your experience.