ProselonAn AI co-writer with your whole book on its desk.
Proselon is a writing app for Mac and Windows whose co-writer lives inside your book — reading any chapter on demand, drafting where you point it, and keeping your story straight. Works with your existing AI subscriptions, no API keys necessary.
From quiet reader to full producer.
The co-writer does whatever you assign it: an editor, a drafting partner, or a full producer. It’s up to you, and you can change your mind anytime.
A role is nothing more than what you ask for. Set it per conversation, and change your mind whenever it suits you.
Ask it to do anything.
Drafting the next scene is the smallest thing you can ask for. Because the co-writer can open and edit every file in your book, an instruction that would have cost you an afternoon of searching costs a sentence instead, and a question about your own story is answered by reading it.
Or whatever else the book needs
- “Rename Aldric to Aldous everywhere he appears.”
- “Where have I promised the reader something the book never delivers?”
- “Cut the harbourmaster subplot and mend the chapters it ran through.”
- “Everything the book says about Nora’s grandfather, and where it says it.”
It writes like you, not like a chatbot.
Most AI prose reads like AI because it doesn’t have an example to follow. Proselon provides that example, giving its AI an accumulated record of your voice it can use to draft every time.
In that moment, Nora couldn’t help but feel a profound sense of purpose wash over her. The lighthouse stood as a testament to her grandfather’s unwavering dedication, a beacon of hope that had guided countless souls home. For forty years he had tended its light, and now it was her turn to carry that torch forward. Little did she know, everything was about to change.
Another person might have been driven mad long ago by the lighthouse beam, but not Nora. For her, the lighthouse was a welcome reminder. Her grandfather had kept its light for forty years. Now it was her turn to do the same.
- Define
Three ways to pin it down
A Style Guide sets the rules. A Voice Reference describes how the narration sounds. A Voice Corpus collects the passages that demonstrate it. Your own writing outranks anything the app proposes.
- Enforce
Judged against your prose
Every draft passes through a voice rewrite measured against your model passages rather than a house style. Drafting and editing fall to different agents, so the editor never grades its own work.
- Hunt
Repeat offenders get a list
Pet phrases, sentence shapes that recur, cadences that announce the machine. A tell that keeps returning goes onto your project’s red-flag list and is then hunted across the whole manuscript rather than line by line.
Your whole book is on its desk.
No need to copy-and-paste your story into the chat window. The co-writer can read any part of your story anytime.
- Reads
Any page, on demand
It opens any chapter, any scene, or any bible page the moment it needs one, and where the question warrants it, it will read the entire manuscript before venturing an opinion.
- Holds
A freeform story bible
Characters, locations, plot, world, style, research. A home for whatever your particular book runs on. The templates are starting points and never forms to be filled in.
- Remembers
One continuity ledger, the whole series
A running record of what is true, checked on request and carried across every book in the series, so that a contradiction is flagged before a reader ever finds it. Book four delivers on what book one promised.
- Guards
Posting as you go
When chapter one is already published and cannot be retconned, the co-writer measures each new chapter against everything your readers have seen. Lock a posted chapter and the co-writer can read it but never edit it.
Sign in the way you always do.
The co-writer runs on the AI account you already hold, signed in the way you always sign in, or on a free local model that never leaves your computer. We meter nothing. Six engines are built in.
- Claude
- ChatGPT
- Grok
- Gemini
- Ollama
- LM Studio
None of these require an API key. Should you prefer to bring your own, Proselon accepts that too, whether from OpenRouter, xAI, or any OpenAI-compatible endpoint.
Six dollars a month. The whole writing room.
One product, with everything included on both plans. The only decision is how often you would like to be billed. The first 30 days are free.
Billed monthly. Cancel any time.
- The AI co-writer, on all six engines
- Continuity across a whole book or series
- Automatic version history
- Export to Word, EPUB, and more
- All seven themes, light and dark
- No API keys, credits, or meters
Two months on the house, which works out at about $4.17 a month.
- The AI co-writer, on all six engines
- Continuity across a whole book or series
- Automatic version history
- Export to Word, EPUB, and more
- All seven themes, light and dark
- No API keys, credits, or meters
30 days free, no credit card · $6/month after, only if you subscribe · we email you before your trial ends · cancel in one click · refunds within 30 days of a charge
The eight steps, in order.
Proselon develops a book in eight steps, arranged in the order that produces the best results. It is not a checklist you must march through. Draft a scene on the first day if that is what you want. The list reports where things stand rather than issuing orders, and the co-writer picks up wherever you want.
- 1Your premise, on the page
Getting Started
The co-writer gets to know your story, what it is about, the feeling you are after and who it is for, and then sets sensible opening defaults for a book of that kind. Every one of them is yours to change.
- 2A series plot
Plot, Themes & Conflict
The large shape first. Premise, arc, the major movements and the threads that carry from one book to the next. Then what the story is about beneath that, which is to say its themes, the central outer conflict, and the inner one each character is carrying.
- 3A story bible
Worldbuilding
Every person and place the plot has committed to acquires a page of its own. The co-writer asks what you already know about each, whether that is everything, a little, or nothing whatever.
- 4A style guide & voice corpus
Style & Voice
How the prose ought to sound. Point of view, tense, sentence style, vocabulary, and the things your narrator would never say. Then the model passages, which demonstrate the voice instead of describing it.
- 5Scene-by-scene plans
Outlining
The plot worked out at every level, from the arc of the book down to what belongs in each chapter and a specific plan for every scene, all of it stress-tested before a word is drafted.
- 6A first draft
Drafting
The co-writer works prose from the scene plans you have approved, held to your style guide throughout, one scene at a time.
- 7A finished manuscript
Editing
Developmental notes, a voice pass, line and copy edits, continuity checks and a proofread, followed by a whole-book read before anything ships. The agent that edits is not the agent that drafted, so the editor never grades its own work.
- 8Your book, on sale
Publishing
Title selection, the store listing with its blurb and categories and keywords and author bio, cover, ebook formatting, and then the walkthrough that takes you live. Pricing, royalties, upload.
Books written with Proselon.
Real novels, by real writers, available today.
Proselon is not a someday promise. Writers have already carried books through it and published them. These are on Amazon today. Tap a cover to read one.
Your writing room is ready.
A co-writer with your whole book on its desk, and a manuscript that belongs to you from the first line. Free for 30 days, no card; $6 a month thereafter, on your own Claude or ChatGPT account or a free local model. No API keys.