ProselonAn AI co-writer with your whole book on its desk.
Proselon is a Mac writing app whose co-writer lives inside your book — reading any chapter on demand, drafting where you point it, keeping the story straight. Works with your existing AI subscriptions, no API keys necessary.
From quiet reader to full producer.
The co-writer takes whatever role you give it — a cold reader, an editor, a drafting partner, a full production crew. Where it sits is your call, scene to scene, and you can change your mind anytime.
A role is just what you ask for — set it per conversation, and change your mind anytime.
It writes like you, not like a chatbot.
Most AI prose reads like AI prose because it’s written to a generic house voice. Proselon does the opposite. Every project builds a picture of how your book sounds, and the co-writer is held to that on every page.
Three ways to pin down your voice
A Style Guide sets the rules: point of view, tense, sentence style, what to avoid. A Voice Reference describes how the narration sounds. And a Voice Corpus collects passages that demonstrate it, model prose you pick or write yourself. Your own passages always outrank anything the app suggests.
A rewrite that’s judged against your prose
Every draft passes through a dedicated voice rewrite, checked for fidelity to your model passages, not a house style. Drafting and editing are done by different agents, so the editor never grades its own work. It stays objective about what reads machine-made.
It hunts the tells
AI readers that can see only your book, none of your story bible or notes, flag prose that reads dull or samey. Recurring offenders (pet phrases, sentence shapes that repeat, rhythms that scream AI) go on your project’s red-flag list and get hunted across whole manuscripts, not just line by line.
Six dollars a month. The whole writing room.
One product, everything included — the only choice is how you’d like to pay. Your 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 — 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 with a card to start · we email before any charge · cancel in one click · refunds on request
Sign in the way you always do.
Your $6 pays for the writing room — no API keys or metered usage from us. The co-writer works with your own Claude, ChatGPT, or Grok account, signed in the way you always do, or a free local model on your own Mac. Six engines, all built in:
Claude
Your Claude Pro or Max account
ChatGPT
Any ChatGPT account — even the free one
Grok
Your X Premium+ or SuperGrok account
Gemini
Free Google AI Studio key — metered past the free tier
Ollama
Free — models run on your own computer
LM Studio
Free — models run on your own computer
Sign in the way you always do and you’re writing: no API keys to mint, no dashboards, no usage meters, no lock-in.
Your whole book is on its desk.
The longer your story — a serial, a series, a very long book — the more this matters.
Any page, on demand
It reads any chapter, any scene, or any bible page when it needs to, and it can read the entire manuscript before it weighs in.
A running ledger of what’s true
A record of the facts of your story, checked on request, so a contradiction gets flagged before a reader finds it.
A freeform story bible
Characters, locations, plot, world, style, research: a home for whatever your book runs on. Templates are starting points, never forms.
Series, built in, not bolted on
A series-level plot, per-book folders, and a continuity ledger carried across books, so book four remembers what book one promised and the wrong eye color doesn’t slip into chapter ninety.
Posting as you go
When chapter one is already published and can’t be retconned, continuity is a promise to your readers. The co-writer checks new chapters against everything they’ve already read.
Seven phases, start to shelf
Every book moves through the same seven phases, from book specs to publishing. A quiet tracker in the header shows exactly where yours stands, and it advances as you work.
The problem was never the writing. It was the forgetting.
One writing room, seven moods.
Seven built-in themes, each in light and dark, including four that match the reading views serial writers already live in. Try them:
Warm paper with a burnt-terracotta accent — the Proselon default. Every theme comes in light and dark — and you can build your own from any two colors you pick.
AO3, FanFiction.net, Wattpad, and Royal Road are trademarks of their respective owners. Proselon is not affiliated with or endorsed by them; these themes only recreate the look of each site’s reader.
Export a finished manuscript — Word, EPUB, ready to publish.
Books written with Proselon.
Real novels, by real writers, available today.
Proselon isn’t a someday promise. Writers are already taking books through it and publishing them, and these are on Amazon now. Tap a cover to read one.
Three steps, then you’re writing.
Download and open
The download is free. On first launch, create your Proselon account — an email, a password, done — and your free 30-day trial begins.
Sign into your AI
Pick your writing engine and sign in the way you always do — Claude, ChatGPT, or Grok with your regular account, no API keys necessary — or a free local model you run yourself. The app walks you through it.
Open your book
Start something new, or pick up a book you’ve begun. Your books live as plain files in Documents › Proselon, and the co-writer is already there, with the whole book within reach.
Your writing room is ready.
A co-writer with your whole book on its desk, and a manuscript that’s yours from the first line. Free for 30 days, then $6 a month — with your own Claude or ChatGPT account, or a free local model. No API keys necessary.