Your book is thousands of words of things you half-remember writing. Ask Lume a question and it answers from your manuscript — an outline of the book plus the passages that best match what you asked.
Lume
Lume is a chat panel that answers questions about your manuscript. Open it from the Lume item on the icon rail; it slides in on the right, headed "Lume" with "Illuminated by your manuscript" underneath. The header has New chat, History and Close, plus a Topics menu once you have past conversations.
Lume is one of the AI features you can switch on or off in Settings › AI Configuration › AI features, where it is listed as "Lume chat". When it is off, the rail item disappears instead of sitting greyed out, so the app stays a plain writing tool. If you open the panel anyway, it says "Lume chat is off. Turn it on in Settings › AI Configuration › AI features." Your past conversations stay readable; only sending is blocked. Chat is also unavailable in a read-only project.
Asking Lume
Type a question, or start from a topic: Story overview, Brainstorm ideas, Character depth, Pacing advice, Improve a scene or App guidance. Lume answers from an outline of your book (chapter titles, word counts, synopses, character and location names, and analysis summaries) plus the five passages of your text that best match your question. If you are in the editor, the open scene is included too. Beyond questions about the book, it can brainstorm, give craft advice and explain how the app works.
Chapter and scene names in a reply become links. A scene link takes you to that scene, and a chapter link opens the Outline. Each reply has Copy and Save to Notebook; saved replies are tagged lume. The first question in a conversation gives it its title, and History lets you reopen, rename or delete past conversations. Conversations are saved in the project.
What Lume can and can't see
Lume does not read your whole book for every question. It works from the outline, the matching passages and, in the editor, the open scene (up to about 8,000 characters). If the answer lives in a passage that didn't match your question, Lume won't see it. Phrase questions with the names and words the book itself uses.
To find the matching passages, Lume builds a search index of your text on your device. While the index is building, the panel shows "Indexing N%". If indexing fails, it shows "Index error" and answers rely on summaries only. The index is deleted when you turn Lume chat off or engage Writing Only.
Replies are ordinary text, not structured citations. Lume may quote your text, but it isn't guaranteed to, so check anything important against the manuscript.