A caddy carries the bag. You keep the swing.

You arrive with an intent, or only a rough idea of the book. WriterDesk walks that through the chapters, the pages a real book grows around them, and the rules of the house you are sending it to. Sign in, and the same manuscript opens on the next device.

The house comes first. Custom format, if you have not chosen one. Or Amazon KDP, IngramSpark, Barnes & Noble Press, Lulu, Draft2Digital, Apple Books, or Kobo. Each one changes the trim list, the margins, and what the ISBN field is allowed to say. Print and ebook can travel together, or you can hide the print pages when the book is an ebook only.

The page sizes cover the books people actually make. A pocket book for a child or a mass-market novel. A trade size a series can share, including the expanded-distribution trim. A handbook or a technical guidebook. A square or a landscape picture book.

While you write, the book is already on the screen. Front cover, spine, and back cover. The spine width is an estimate from the word count, because the printer’s paper changes the real measurement. The barcode appears when a 13-digit ISBN is in place. Language, rights, and a data-protection line sit with the other facts a submission asks for.

WriterDesk opens on a finished sample, The Dragon Who Kept the List, so you can read a dragon guarding a book of names before you start a book of your own. The watermarked EPUB, the manuscript, and the handoff of that sample can be downloaded. Clean files come with the WriterCaddy plan, after a 7-day free trial.

An optional AI assistant stays on standby at every step, in case you want that extra intelligent push. It stays off until you open it and agree. The draft is not written into the book. Five questions are free to try; after that it is the AI add-on.

Vellum, on a Mac, is still the tool people choose when they want the deepest interior styles and they already have a manuscript. Atticus writes and formats in one place, on any computer, for a single license commonly listed around $147. Reedsy Studio lets you write and export in the browser without a license. Kindle Create builds a file for Amazon. WriterCaddy is the path that starts from the idea and keeps the house’s own rules in front of you. Seeing and editing your book is never behind a paywall; the monthly plan is for the clean files and the vault.