Sooner or later, someone asks a writer who used AI a simple question: how much of this did you write? It might be a form, a publishing platform, an agent reading a query letter, or a reader in the comments. The question sounds like it wants a percentage. What it is really after is authorship - whether a person made the creative choices that shaped the book - and the way to answer it well is to understand what counts as authorship before anyone asks, and to keep a record that shows it. This guide covers both. It is general information about how authors think about the question, not legal advice.
What the question is really asking
When a copyright office, a publisher or a platform asks about AI, they are usually asking some version of one thing: which parts of this work came from a human mind, and which came out of a machine? Each of them asks it for a different reason, but they share the same underlying idea of what authorship is.
In the United States, the Copyright Office's position is that copyright protects only material a human created. Its registration guidance, published in March 2023, asks applicants to disclose AI-generated material that is more than minimal, to exclude that material from the claim, and to describe what the human author contributed. Its 2025 report on copyrightability added an important line for anyone writing with AI: on its reading, prompts alone generally do not give a person enough control over the output to make them its author, while a human's selection, arrangement or modification of AI material can be protected when it is creative enough. The Office has said it may update its guidance over time, so check copyright.gov for the current version before you file anything.
The same distinction runs through the other places the question comes up. It is the distinction between deciding and receiving. Typing a request and accepting what comes back is receiving. Choosing what happens, in what order, to whom and why - and then shaping the words until they say what you meant - is deciding.
Where human authorship lives in a novel
A novel is an unusually good place to make authorship visible, because so much of a novel is decisions. Before a single sentence exists, someone has to decide who the protagonist is and what she wants, what the world allows and forbids, which secret gets revealed in which chapter, where the midpoint turns, and how it ends. Those choices are the selection and arrangement that the Copyright Office's reasoning points at. They are also what a reader experiences as the story.
It helps to think of a book as built from beats: the small units of story where something happens and something changes. If you decided the beats - what each one does, the order they come in, how a character moves through them - you made the story's structure, even if an AI drafted the first pass of the sentences inside them. If you then rewrote those sentences, cut some, added others, and pushed the voice toward your own, your hand is in the prose too.
The opposite case looks different on the record. A single prompt asking for a fantasy novel about a dragon, followed by light proofreading, leaves almost no human decisions to point to. Most writers working seriously with AI are somewhere in between, and that middle ground is exactly why the question is hard to answer from memory. It also explains why so many writers feel that an AI-written book isn't theirs: the feeling tracks how much of the deciding they did.
A final file proves almost nothing
Suppose you did make every important decision in your book. What can you show anyone?
The finished manuscript cannot tell you. A clean, final file looks the same whether a person built it over eighteen months of plotting and revision or pasted it out of a chatbot in an afternoon. AI-detection tools are not reliable enough to settle the question either way. And memory fades: by the time someone asks, you may not remember which scene you rebuilt three times and which one survived its first draft.
What does show authorship is a record of decisions made over time. A history of your outline changing as you changed your mind. Notes on why a character's arc went one way and not another. Earlier drafts of a chapter alongside the version you kept. Dates that show the work unfolding across weeks and months. A record like that answers the question directly: here is what I decided, here is when, here is what the AI did with it, and here is what I did after.
Writers have long leaned on the same kind of material when authorship was in doubt: dated drafts, notebooks and correspondence show the work being made in a way a polished final copy cannot. The only new part is that some of the drafting now happens in a tool, and the tool's share needs to be visible alongside yours.
Three people who might ask
A copyright registration. If you register a book in the US that contains AI-generated material, the Office's guidance asks you to say so, describe your own contribution, and leave the AI material out of what you claim. A written account of your contribution is far easier to give accurately when you have a record to work from: which elements of the plot, characters and structure you created, and which passages you wrote or substantially reworked. The Office has said that failing to disclose AI material can put a registration at risk. Rules in other countries differ, and if real money or rights are at stake, a copyright lawyer is the person to ask.
A publisher or an agent. Some publishing contracts now include clauses about AI use, and some agents ask about it before they take a book on. They want to know what they are buying and whether they can stand behind it. A short, honest description of your process - what you decided, what the AI drafted, how you revised - goes over better than either silence or vagueness, and a record lets you give that description with specifics instead of reassurances.
A self-publishing platform. Amazon KDP, for example, asks you to disclose AI-generated content when you publish or republish a book. Its help pages draw a line between AI-generated content (text, images or translations created by an AI tool, which its current wording says still counts as AI-generated even after substantial edits) and AI-assisted content (work you created yourself, where AI helped you edit, refine or check it), which you are not required to disclose. Which side of that line a given book falls on is your call to make honestly, and KDP updates its wording from time to time, so read the current policy when you publish. A record of what you wrote and what the tool wrote is what lets you make that call accurately rather than by guesswork.
Keeping the record as you go
The useful habit is simple: keep the record while you write, because it is very hard to rebuild afterwards.
If you work across documents and chat windows, that means saving dated versions of your outline, keeping your notes on characters and world in one place you revise rather than scatter, and holding on to drafts you replace instead of overwriting them. When you use AI for a passage, note what you asked for and what you changed. None of this is complicated. It just has to happen at the time, and most writers stop doing it a month in.
The better arrangement is a writing environment that keeps the record for you, so the evidence builds itself as a side effect of working.
How Novelmint keeps the record
Novelmint is built on the idea at the center of this guide: the author makes the decisions, and the record of making them keeps itself. Here is how each point above plays out in it.
The decisions sit in the structure, and the structure is yours. A book in Novelmint is planned before any prose exists, on a Timeline: chapter by chapter, beat by beat. You decide what each beat does and the order they come in, which characters are in it and which plot threads it moves. Your characters, places and world rules live in one story bible that every chapter is written from. The prose is then built from that plan, so the selection and arrangement the Copyright Office's reasoning points at are on the page as your plan, not buried in a chat log. Minty, the editor built into the Studio, can suggest beats or draft a plan with you, and a beat you make with her, or keep from an agent's draft, still counts as your decision.
A record of decisions over time, not a final file. Beside each book sits a measure of how much of it you made and how much AI made. Decisions count most: whose beats, characters, places and plot threads they are. After that come the words, and any sentence you change, even by a comma, counts as yours. Hover the number to see the record behind it, or open View log for a dated log of everything you did on the book, day by day, which you can print or save as a PDF. Each chapter also keeps its own versions: save a checkpoint and any earlier version opens later with the plan and the prose as they stood. You can ask Minty where a beat went or who changed a chapter, and she checks the book's record of recent changes and tells you which edits were yours and which an AI made. And when you want to test a big change, you can branch the book from a chapter, try the other direction on a private copy, and keep whichever version you prefer, with the other one kept as a branch.
For the three people who might ask. For a copyright registration, the log and the measure give you the inventory to describe your contribution from: the beats, characters and plot threads you made, and the passages you wrote or changed. For a publisher or an agent, the printed log shows the book being made week by week, and the whole series downloads as one open project file - its plan, beats, story bible and prose - if they want to see the working. For a platform like KDP, the measure shows how much of the book the AI made and how much you did, which is the line its disclosure question turns on.
The measure is Novelmint's own, not a legal one, and it counts work from the day the record began, so it supports your answer rather than replacing your judgment or a lawyer's. The authorship record page shows how it works in more detail.
Whatever you use, the principle holds. Make the decisions that make the book yours, keep the record of making them, and when someone asks, you will be able to show them.