Is there any way to fine-tune GPT to make documentation a part of its training set, so you won't need embeddings? OpenAI lets you fine-tune GPT-3, but I don't know how well that works.
OpenAI doesn't let you fine-tune GPT-4 or GPT-3.5 yet (https://platform.openai.com/docs/guides/fine-tuning), but fine-tuning models on a set of documents is still an option but not really scalable if you want to keep feeding it more relevant information over time. I guess it could depend on the base model you are using and its size.