This is really cool. It seems to me LLMs and books are a match made in heaven. An LLM query is more useful than a google search for most text.
Would be cool to see this more deeply integrated, in a koreader extension or something
You can edit the system prompt via the settings page, which gives the chat model additional context at the start of every chat.
E.g. You may tell it you're reading a particular novel, so each chat would begin `You are a helpful assistant. The user would like you to know they are reading Sapiens...`.