Ask HN: Best way to create an AI chat interface for consulting a book content?

I want to create a public site where users use an AI chat interface to read/explore the content of a 600-page official document with educational guidelines.

My reference is Tyler Cowen’s project: https://goatgreatesteconomistofalltime.ai/en (check the “Explore with AI” link).

How should I proceed?

I am a frontend engineer with no AI/ML knowledge. Should I consume OpenAI API? How do I feed the model with the 600-page document content? Should I use hugging face?

I am willing to pay the cost of the AI service (as long is reasonable, like <$50 a month).

Any help is appreciated.

Thanks