AuthorKit

The editor

Write your book. Or let CoAuthor write with you.

Chapters, story bible, map, and Instant Ebook Auto on one desk. Type yourself — or open CoAuthor for this book. Nothing lands until you Accept.

Start free · manuscript yours · 19,000+ authors on Typewriter.

The Harbor Letters5,278 wordsCoauthor

The platform

Mira stood under the platform light with the letter in her coat. Jonah had not written in a week.

She was very tired and the train was late again, which made her feel sad. The train was late again. She leaned on the cold rail and let the night have her.

Somewhere down the line a horn sounded, long, then gone.

A man in a wet coat set his bag down at the far end of the bench and did not look at her. The clock over the ticket window had stopped at ten past nine; nobody had fixed it since spring.

She thought about the last card Jonah sent. The harbour on the front, the ink smudged where the rain had found it. Come when the ferry runs again, it said, and nothing after that.

The rails began to hum before she could see the light.

Write

Stay with the book.

Chapters and scenes live in one binder, with a word target and a status on each. Find and replace across the whole book. Take a snapshot before a big rewrite.

The Harbor Letters · Binder

09Platform2,140
10The letter1,890
11Coat pocket940
12Harbor station1,248
13Fog over the pier—
Chapter 12 · Harbor station

Harbor station

The clerk turned the ledger toward her. Jonah’s name was there, in his own slanted hand, under the date she had stopped counting from.

Mira read it twice. The ink had run where the rain had found the page, but the last ferry, 21:40 was clear.

Target1,248 / 2,500
Snapshot savedBefore the rewrite · 09:12

Coauthor

Every edit waits for your yes.

Select a passage and ask. The coauthor suggests a rewrite on the exact words, and nothing changes until you Accept. Close the panel and it is a plain editor.

You write. It suggests.

Ask for a sharper line, a scene that shows instead of tells, or a second opinion. Each change arrives as a suggestion you Accept or Reject.

Story bible

Chapter 40 still knows.

Characters, places, items and notes sit beside the page, with a picture when you add one. The coauthor reads them before it suggests a line, so names, eyes and dates stay right.

Mira Vale
CharacterMira Vale

Keeps every letter. Never says Jonah’s name.

Coauthor read the story bible before writing chapter 12.

Map

Finish the threads.

See who is tied to whom on one canvas instead of a spreadsheet. Pick a tie to see what it means for the story.

Mira Vale
Jonah Reed
Harbor station
The letter
The ring

Edit

Seven editing passes. You choose what lands.

Run one pass at a time on a chapter. Each fix shows on the exact words it changes. Decide every fix yourself, let small fixes go in, or apply them all with undo.

Edit passes · Chapter 12

A few places, not a rewrite.

Suggestion · Show it, instead of telling it

She felt nervous and touched the letter in her pocket. Mira’s hands found the letter before her mind did.

How fixes land

Every fix waits for you.

Format and publish

Leave with your files.

Pick the look and the front matter. The publish checklist tells you what is still missing. Export EPUB, HTML or Markdown whenever you want, and hand the jacket to Cover Designer.

Export

EPUB.epub
HTML5HTML.html
MarkdownMarkdown.md

Publish checklist 6 of 6

  • Text in every chapter
  • Every chapter marked done
  • Author name
  • House style
  • Blurb
  • ISBN
Cover DesignerThe Harbor Letters

Bring your own AI

Use the ChatGPT, Claude or Grok plan you already pay for.

Sign in once in Settings → Models and the coauthor runs on that plan. It keeps the same tools: suggestions, the story bible and Accept. No plan? Our hosted models run from your wallet.

ChatGPT
ChatGPTOpenAI · your plan
Signed in
Claude
ClaudeAnthropic · your plan
Signed in
Grok
GrokxAI · your plan
Signed in
Book AuthorSuggestions · Story bible · Accept
Hosted models from the wallet when you have no plan

How it works

Three steps.

  1. 01

    Open a manuscript

    Start blank, describe the book, or paste pages you already have.

  2. 02

    Write — or CoAuthor / Auto

    Type yourself. Open CoAuthor for this book. Or run Instant Ebook Auto.

  3. 03

    Export and own it

    Publish checks, then EPUB / HTML / Markdown. Nothing locked in.

FAQ

Questions

The editor, the coauthor and your files.

01What is this editor?

Book writing software: manuscript, outline, story bible, map, edit passes, and export — with CoAuthor you can open or close.

02What does it cost?

Start free. Full desk $2.99/month, $24.99/year, or $69.99 once. AI is separate — wallet or ChatGPT, Claude, or Grok.

03Will it write the book for me?

Only if you ask. Instant Ebook Auto takes idea → file. CoAuthor suggests changes you Accept. Panel closed = plain editor.

04Will it change chapters without asking?

No. Every change waits for Accept.

05Do I have to use AI?

No. Manuscript, outline, bible, map, format, and export work without CoAuthor. Tokens only when you ask.

06Can I bring a draft I already started?

Yes. Paste the pages you have. Snapshots keep a copy before a big rewrite.

07What files do I get?

EPUB, HTML, and Markdown from the same manuscript.

08Who owns the book?

You do. Your pages are not used to train models.

Start the book.

Write it yourself — or open CoAuthor. Same desk.