Novel Mode · Long-form writing
AI book writer — full-length novels, chapter by chapter
Pick a length, a genre and a point of view, type a premise, and SynergyAI plans a story bible before it writes a word. Then it writes, continuity-checks, updates the bible and polishes every chapter in turn, on Claude Sonnet 5.5. Targets run from 1,000 to 80,000 words, and the manuscript exports as EPUB, DOCX, PDF, Markdown or plain text.
Starting a book takes four decisions
Choose Write a book in chat, make four choices, and see the estimate before you commit.
- Pick a lengthAnything from 1,000 to 80,000 words, with presets at 10k, 25k (the default), 50k and 80k.
- Choose a genreEight fiction genres: Literary, Fantasy, Sci-Fi, Romance, Thriller, Mystery, Horror and Historical.
- Set the point of viewFirst, second, third limited (the default) or third omniscient, fixed before chapter one.
- Describe your premiseOne line is enough. It is expanded with setting, stakes and a theme before planning begins.
In detail
Before it starts writing
- At 25,000 words and up, a confirmation shows the price range and the estimated minutes
- Time guide: about 2.2 minutes per chapter, 3 minutes minimum
- One book writes at a time
- Talk about a novel or memoir in chat and the assistant points you to Write a book, remembering the premise for later
- Mobile has the same options and defaults
- Not available in Forget & Burn mode, because a book must keep your premise between stages
How the AI writes a whole book, chapter by chapter
Your premise becomes a Story Bible, then each chapter is written, checked against it, folded back in and polished before the next begins.
- ExpandYour one-line premise gains setting, stakes and a thematic question.
- PlanThe Story Bible: characters, world, themes, a chapter outline and planted foreshadowing.
- WriteOne chapter, given the bible and the end of the chapter before.
- CheckA continuity editor reads it against the bible and rates any problems.
- UpdateNew facts fold back into character states, the timeline and the world.
- PolishA senior-editor pass before the next chapter begins.
In detail
Standard and Pro book tiers
| Stage | Standard | Pro |
|---|---|---|
| Expand, plan, write, update | Claude Sonnet 5.5 | Claude Sonnet 5.5 |
| Continuity check | Claude Sonnet 5.5 | Claude Opus 5.5 |
| Polish | Claude Sonnet 5.5 | Claude Opus 5.5 |
| Where you choose it | Chat, agent or API | Agent or API |
Long books and progress
- Progress updates every five seconds: stage, chapter, word count and an estimated finish
- Stop halts the book within a chapter and keeps every completed chapter
- Phrasing varies from chapter to chapter, and the bible is condensed every 8 chapters as the book grows
- Character names avoid the defaults a language model tends to reach for
Characters, names and clues checked in every chapter
Every chapter is checked against a Story Bible written before chapter one, so drifting eye colours, name spellings and planted clues are caught.
- Every character tracked3–6 major characters, each tracked for appearance, voice, motivation, arc and current state.
- Every clue tied to its payoff5–10 planted foreshadowing items, each tied to the chapter it pays off in.
- Serious slips rewrittenA severe continuity problem rewrites the whole chapter. Minor and moderate issues go to the polish pass.
- Small errors flaggedA separate scan flags missing headings, short chapters, name drift and first-person point-of-view drift.
In detail
What each chapter is checked for
- Name spelling drift (Vex vs Vexx vs Veks)
- Physical details such as eye colour, age and scars
- Character voice, world rules and head-hopping
- Planted foreshadowing that has been contradicted
- Prose measured against the book's voice and style spec
- When a long bible is condensed, the characters and your prose style are never cut
Read, rewrite and export the finished manuscript
A finished book opens in chat as a formatted manuscript, with a chapter menu, a rewrite button per chapter and five export formats.
- Read it in the appA sticky chapter menu, your place saved, and long books kept responsive.
- Rewrite any chapterRewrites from the bible as it stood before that chapter, and shows the price first.
- Export in five formatsMarkdown, plain text, PDF, Word and EPUB 3, named after the title and date.
- Keep it in your librarySaved to your account, so books survive a new device or a cleared browser.
- Get a cover with every bookMade at no charge from the title, genre and premise, with no invented text.
- Hear when it is doneBy email, an in-app notice, and an optional browser notification.
In detail
Exports and rewrites
- PDF: A4, a title page with the date, and each chapter on a new page
- Word (.docx): headings mapped to Word heading levels
- EPUB 3: one file per chapter, with a navigation document
- Mobile offers a plain-text download
- Rewrites work on completed, stopped or partial books, and a stopped book stays stopped
Library, cover and files
- My Books lists title, genre, word count, date and status, filterable by title and genre
- Each book is also filed in Workspace Files, with a link that reopens it in the reader
- Covers are 1024 × 1536 portrait, and a failed cover never fails the book
After a rewrite, later chapters are not re-checked against the new version.
Memoir, life story and non-fiction
The same pipeline writes books that are not novels: your life story from what you have recorded, or non-fiction through an agent.
- Your life story, as a memoirWrite my book, in your Neural Network, turns the life stories you have recorded into a memoir.
- Your voice, tone and shapeFirst, second or third person; literary, plain or warm; chronological or thematic.
- Three lengths, quoted firstShort, full or epic, each priced before you commit and billed chapter by chapter.
- Non-fiction booksHow-to, business, self-help, cookbook, textbook and more switch to a non-fiction editor who checks figures and definitions.
In detail
Memoir and non-fiction details
- Short memoir: about 20,000 words in 8 chapters. Full: about 50,000 in 18. Epic: 28 chapters
- Memories you marked sensitive are left out entirely
- A thin record gets a readiness meter naming what to record next
- Non-fiction genres: how-to, guide, business, self-help, memoir, educational, manual, handbook, cookbook, textbook, reference and playbook
Non-fiction genres are set through an agent or the API; the chat picker lists the eight fiction genres.
Agents can start, check, read and extend a book
SynergyAI's agents can make a book one step in a larger job, rather than something you sit and watch.
- Start a bookFrom your premise and title, on the Standard or Pro tier.
- Check and read itProgress and word count while it writes; then one chapter, or the manuscript with its bible.
- Extend itAdd 1–24 chapters or up to 80,000 words on the same bible, charged for the added words only.
In detail
Extensions, results and the API
- An optional direction for the new arc is added to the bible, never replacing it
- A book can reach 48 chapters; one that never got past planning cannot be extended
- An agent shows a book's estimate before you approve it, and pauses rather than go over the job's budget
- Agent-written books come back as a card with the cover, chapter progress and a link
- A signed-in API creates, starts, stops, reads, regenerates, continues and deletes your own books
- Rate limits: 120 reads and 60 writes per minute, per user
Extending a book is an agent capability today, with no button in chat or mobile. Output is prose; there is no screenplay formatter.
Also for documents and research reports
The same menu that starts a book also drafts legal and business documents, writes research reports and saves your own instruction.
- Document draft26 legal and business document types, with every fillable field marked in [SQUARE BRACKETS].
- Research reportEvidence-led reports that separate established fact from contested areas, from 500 to 5,000+ words.
- Custom skillOne reusable instruction set of up to 27,500 characters, synced to your account.
- Real files you can openPDF, Word, PowerPoint and Excel. Formats a text model cannot really produce are refused.
In detail
Document and research options
- Jurisdictions: UK, US, EU, Australia, Canada, India, UAE and International
- Research depths: Overview, Deep dive or Systematic review
- Both skills are on mobile with the same options
Story Mode is a different thing: scene-by-scene video, not prose. See the AI video generator.
Pay as the book writes, and see the estimate first
The estimate comes before you start, billing follows the writing, and running low pauses the book instead of failing it.
- See the estimate firstThe estimate on the Send button is a range, with a worst case 20% higher for continuity rewrites.
- Pay as it writesBilled for the writing as it happens, not a flat rate, so a long book can be topped up mid-way.
- Running low pauses the bookTop up within 48 hours to resume from the same chapter. After that it stops, keeping finished chapters.
- A refused premise costs nothingPremises are screened before a book exists, so a refusal means no charge.
- Repeated failures are refundedA book that keeps failing is refunded automatically. A Stop you choose keeps its charges.
- Finished books are always deliveredOnce every chapter is written, the final step never waits on your balance.
One account covers every studio: top up as you go, or choose a monthly Pro or Studio plan.
Frequently asked questions
How long a book can the AI actually write?
Targets run from 1,000 to 80,000 words, with presets at 10k, 25k, 50k and 80k and a default of 25,000. Chapters aim for about 5,000 words, so 80,000 words is planned as roughly 16 chapters. A book extended through an agent is capped at 48 chapters.
How is a book priced?
You pay as the book writes rather than a flat rate. The Send button shows an estimate range first, with a worst case that allows for continuity rewrites, and books of 25,000 words or more ask you to confirm it.
Which AI model writes the book?
Claude Sonnet 5.5, locked for the whole book when you start from chat. On the Pro book tier, chosen per book through an agent or the API, the continuity check and the final polish run on Claude Opus 5.5 instead.
What happens if my balance runs out halfway through a book?
The book pauses instead of failing and continues from the same chapter once you top up, without charging again for anything already written. After 48 hours it stops, keeping every completed chapter.
Can I export the finished book to EPUB or Word?
Yes — Markdown, plain text, PDF, Word (.docx) and EPUB 3. PDF and EPUB are split one chapter at a time, and filenames come from the book title plus the date.
Can I rewrite a single chapter without redoing the book?
Yes. Every chapter heading in a finished book has a regenerate button. It rewrites that chapter from the story bible as it stood before, shows the price first, and warns that later chapters are not re-checked against it.
Can it write a memoir or a non-fiction book?
Yes. The Write my book composer in the Neural Network turns your recorded memories into a memoir. Non-fiction genres such as how-to, business and cookbook switch every stage to a non-fiction editor, and are set through an agent or the API rather than the chat picker.
Can I stop a book and pick it up later?
Yes. Stop halts the book within a chapter and keeps every completed chapter. A book that halts part-way in chat offers Continue from here, and one paused for balance resumes when you top up. Other restarts need the API for now. A restart never rewrites or re-charges a finished chapter.
Write the book you keep describing to people
Give it a one-line premise and it plans, writes, checks and polishes every chapter, ready to export as EPUB, Word or PDF.