Write a book with MCP

Write an entire book inside the AI assistant you already use — over MCP.

The Model Context Protocol lets BookWriter plug straight into Claude, ChatGPT, or Cursor. You chat; it runs the whole book — outline, drafting, continuity, and a real last page — with every word you write kept verbatim.

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7-day free trial · $17/month for up to 30 books · your words kept verbatim.

The real problem

Your assistant is brilliant at a chapter and hopeless at a book

A chat window has no memory of a manuscript. MCP gives it one.

Every general assistant — Claude, ChatGPT, Cursor — will happily write you a gorgeous chapter one. Ask for chapter two and it has already forgotten the first: names drift, the timeline bends, the voice flattens. That is not a prompt problem. A chat window fills the box in front of it; it was never built to hold a hundred thousand words in its head.

The Model Context Protocol (MCP) is an open standard that lets an assistant call external tools and hold real project state. BookWriter runs an MCP server that turns your assistant into a book-finishing machine: a server-side book bible, continuity checks on every chapter, and a writing loop that keeps your exact words and finishes the rest in your voice.

So you keep the assistant you already love — and it finally remembers your book from the first page to the last.

How to connect and start writing

Your BookWriter MCP server URL

https://www.bookwriter.vip/api/mcp/v1

Public HTTPS endpoint. Your assistant signs you in over OAuth with your BookWriter account, so there’s no token to paste.

Connect your assistant

  1. 1Pick your assistant — Claude, ChatGPT, or Cursor all speak MCP.
  2. 2Open your connection page and add BookWriter’s server URL: https://www.bookwriter.vip/api/mcp/v1
  3. 3Approve over OAuth — you sign in with your BookWriter account, so there’s no token to paste.
  4. 4Say “Start a new book” and follow the prompts. You’re writing.
Open your connection pageWhat is the Model Context Protocol?

The write-a-book loop

  1. Set up the book

    Tell your assistant the premise, genre, and length. create_book spins up a real project — title, word target, and chapter plan — not a blank prompt box it will forget tomorrow.

  2. Write a seed paragraph

    Open the chapter with a paragraph or a few lines in your own words. Those sentences are your seed, kept exactly as you wrote them — verbatim, never overwritten.

  3. Hand it off

    handoff sends your seed to the writing engine, which finishes the chapter in your voice and built around your words — holding continuity against everything written so far.

  4. Sharpen, then accept

    sharpen nudges the draft lighter or stronger until it reads right. accept_chapter locks it in and advances you to the next chapter. Repeat to the final page.

How each one writes a book

Same goal, two completely different machines. Here is the actual path from idea to finished pages on each side.

How BookWriter writes a book

  1. 1

    Create the book in chat

    One sentence sets up a real project — title, length, chapter plan — held on the server.

  2. 2

    Seed each chapter

    You write the opening lines; they are kept verbatim as the chapter’s DNA.

  3. 3

    Hand off and it finishes

    The engine drafts the rest in your voice, checking continuity against the whole book.

  4. 4

    Sharpen and accept

    Nudge the prose, accept the chapter, and it advances — no copy-paste, no lost thread.

  5. 5

    Resume anytime

    catch_me_up recaps threads and characters so chapter 30 matches chapter 1.

How a plain assistant (no MCP) writes a book

  1. 1

    Prompt chapter one

    You ask for chapter one and paste the result into a doc somewhere.

  2. 2

    Prompt chapter two

    The model has forgotten chapter one — you re-explain the whole book.

  3. 3

    Become the continuity editor

    You reconcile names, timeline, and voice by hand, every chapter.

  4. 4

    Re-prompt, re-paste, repeat

    Each chapter is a fresh negotiation with a model that has no memory.

  5. 5

    Stall around chapter four

    The seams pile up faster than you can patch them and the book dies.

How it holds a whole book

Memory lives on the server, not in the chat

create_book makes a real project. Every tool call reads and writes to it.

When you say “start a new book,” the assistant calls create_book and a real project is born on BookWriter’s servers — a title, a word target, a chapter plan, and a bible of characters and rules. That state does not evaporate when the chat scrolls. Every later tool call — handoff, sharpen, accept_chapter, catch_me_up — reads and updates the same project.

This is the difference between a model guessing and a system remembering. Chapter thirty is drafted against the same bible that shaped chapter one, so the sister who was named Ruth in the first act is still Ruth in the last.

Because the state is portable, you can start a book in ChatGPT on your laptop, keep writing in Claude on your phone, and polish in Cursor at your desk. One book, one subscription, every assistant.

The writing loop

You steer, it drives — and your words are never overwritten

Seed a chapter, hand it off, sharpen, accept. Repeat to the end.

The loop is the same in every client. You open a chapter with a seed — a paragraph or a few lines in your own voice. handoff sends that seed to the engine, which finishes the chapter around your words, never on top of them. sharpen tunes the AI-added prose lighter or stronger; accept_chapter locks it in and advances you.

Because you seed every chapter, the book stays unmistakably yours. The engine is doing the heavy lifting of continuity, pacing, and prose — but the spine of each scene is a sentence you wrote. That is why authors describe it as steering a car rather than commissioning a ghostwriter.

Six free idea tools ride alongside the writing loop for when you’re still brainstorming — outlines, characters, titles, pitches, opening lines, and a plot-hole finder — all callable in plain language.

The tools your assistant gets

Nine writing tools run the book, plus six free idea tools for when you’re still brainstorming. You never call them by hand — you just talk, and your assistant runs the right one.

9 core writing tools

  • create_book — Start a real project with a title, target length, and chapter plan.
  • list_books — See every book on your account so you can pick one to keep writing.
  • get_book_status — Check progress — which chapters are drafted, sharpened, or accepted.
  • handoff — Send your seed paragraph; the engine finishes the chapter around your words.
  • retry_handoff — Re-run the draft if you want a fresh take on the same chapter.
  • sharpen — Refine the current chapter lighter or stronger, keeping your lines intact.
  • accept_chapter — Approve a chapter so it counts toward your finished book, then advance.
  • catch_me_up — Get a recap of where you left off — threads, characters, recent chapters.
  • get_credit_status — See how many books you have left in this billing period.

6 free idea tools

  • outline_generator — Turn a premise into a chapter-by-chapter outline.
  • character_builder — Flesh out a character with backstory, voice, and motivation.
  • title_generator — Brainstorm title options that fit your premise and genre.
  • pitch_generator — Draft a one-line hook or a back-cover blurb.
  • first_paragraph — Get opening-paragraph ideas to spark your seed.
  • plot_hole_finder — Surface gaps and inconsistencies in your story so far.

What you can say

Plain language is all it takes. Type these the way you’d say them out loud.

  • “Start a new book — a literary family drama, about 80,000 words.”
  • “Here’s my opening paragraph for chapter 1 — hand it off.”
  • “Sharpen this chapter a little — keep my sentences, just smooth the rhythm.”
  • “Accept this chapter and set up the next one.”
  • “Catch me up on where I left off in this book.”
  • “Outline a 20-chapter cozy mystery from this premise.”
$17 / month

One plan. Every assistant. Up to 30 books a month.

Steering Wheel Mode is $17/month after a 7-day free trial — the writing engine plus the connector for Claude, ChatGPT, and Cursor, with no per-app fees. Six idea tools are free on any account. Prefer to pay once instead of subscribing? The classic BookWriter app finishes a whole book for a flat $19.99, first chapter free.

  • Up to 30 books / month
  • Works in every assistant
  • Your voice, your words
  • Cancel anytime
Start your free trialSee full pricing

Your words stay verbatim

The engine writes around your sentences — it never overwrites what you typed.

Revoke anytime

Every connection is yours to control. Disconnect any assistant from your account in one click.

One plan, every app

The same subscription connects Claude, ChatGPT, and Cursor — no per-app fees.

Questions writers actually ask

What is MCP and why does it matter for writing a book?

MCP (the Model Context Protocol) is an open standard that lets an AI assistant call external tools and hold real project state instead of relying on the chat window’s short memory. For book writing it’s the missing piece: BookWriter’s MCP server gives your assistant a persistent book bible, continuity checks, and a chapter-by-chapter writing loop — so it can actually finish a book instead of forgetting it after chapter one.

Which AI assistants can I write a book in over MCP?

Claude (Desktop and web, via custom connectors), ChatGPT (Developer mode connectors on Plus, Pro, Business, and Enterprise), and Cursor all support remote MCP servers today. Any MCP-compatible client can connect to the same BookWriter server URL and get the same 15 writing and idea tools.

Does the AI overwrite what I write?

No. The writing loop is built so your seed sentences are kept verbatim. handoff and sharpen only add and refine the surrounding prose — they never touch the words you typed. You are the author; the engine is the finisher.

How much does it cost to write a book over MCP?

The MCP writing tools run on Steering Wheel Mode: a 7-day free trial, then $17/month for up to 30 new books per billing period, across every assistant. Six idea tools (outlines, characters, titles, and more) are free on any account. Prefer to pay once instead of subscribing? The classic BookWriter app finishes a whole book for a flat $19.99 with the first chapter free.

Do I own the book?

Yes — every word is yours to publish, sell, and keep. You’re responsible for disclosing AI involvement to your publishing platform (for example, Amazon KDP), the same as with any AI tool.

Keep exploring

Write a book in ChatGPTWrite a book with ClaudeWrite a book in CursorAI Book Writer — the AI that finishes

Stop collecting chapters. Finish the book in your assistant.

Connect BookWriter, seed your first chapter, and watch it finish in your voice. 7-day free trial, then $17/month for up to 30 books across every assistant.

Start your free trialOpen your connection page