ProselonAll comparisonsLast reviewed September 17, 2026
Claude Projects vs Proselon
If you have written a book in a Claude Project, you know the loop: upload your story bible, work on a scene, copy it into your editor, revise it, upload it again. We built Proselon to end this tedious cycle. With Proselon, Claude drafts directly into your manuscript where you want it to, when you want it to, automatically updating your story bible along the way if you want that.
Runs on the Claude Pro or Max plan you already have. $6 a month.
The loop a Project puts you in
Most of the work of a chapter is carrying it, and it starts again at the next one.
A project works from the files you upload to it. Upload the story bible, ask for a chapter, and what comes back arrives in the chat, so you copy it into your editor and revise it there. Now the project holds a chapter that is a draft behind, and the bible describes a book that has moved, so you upload both again before the next request can see what happened.
Then you tell it which documents to read, because everything you have ever uploaded sits in the project together, and the scene you want depends on four pages out of ninety. Read this, then this, then that, and now draft.
A manuscript changes every day, and a project holds the copy you carried into it. Keeping the two in step is the work, and it is work the book never sees.
We built Proselon to get away from that cycle. Ask for the scene, and the co-writer opens the chapters it needs, writes the page into the file where that page belongs, and leaves the book current, having never left the book. There is no copy of your manuscript anywhere that can fall behind the one in front of you, because there is only the one.
None of that asks you to write on something else. The co-writer is signed in to your own Claude account, on the plan you pay for today, and the model drafting the scene is the model you chose for its prose. What changes is the ten minutes of carrying that used to sit around every request.
It reads what the job needs
You ask for the scene, and the co-writer looks up the story bible pages the scene needs by itself.
Everything in a project sits in its context together, the scene plan beside the canon beside a year of chapters, and the writer is what sorts it. So you direct the traffic yourself: read the outline, then the character page, then chapter eleven, and now write chapter twelve. Get the order wrong and the page comes back wrong, and the work of getting it right is yours every single time.
Proselon’s co-writer goes looking for itself. Ask for chapter twelve and it searches the book for the names the scene turns on, opens the outline, the character pages and the chapters leading up to it, and reads them through before it writes a word. You gave it no reading list. Your book is laid out the way a book is, in acts and chapters, characters and places, and the co-writer can see that layout as plainly as you can.
The trail beside every answer names each page the co-writer opened, searched or changed, so nothing about what it read has to be taken on trust. Ask it to move a revelation two chapters later and it reads the pages either side, makes the change in the files, and tells you which passages it touched.
Nobody hands a good assistant a list of which drawers to open. They walk the office once, and after that they go to the right cabinet unasked. The co-writer works in your book the same way, on the first day and in the ninth month, however large the book has grown by then.
Two workspaces for one book, side by side
Claude is the AI in both columns. What differs is what holds the book, how Claude reaches it, and who carries the text between the two.
Proselon is free for 30 days, unlimited, and takes no card. It signs in to the Claude account you already have.
| Where they differ | A Claude Project | Claude With Proselon |
|---|---|---|
| Where the book is stored | Wherever you keep it. Chapters travel in and out by copy-paste | Plain files in your own Documents folder |
| How Claude gets at it | Through the files you have uploaded to the project. Anthropic describes retrieval taking over on paid plans as a project's knowledge grows | The co-writer opens the pages a job needs and reads them as they stand that morning |
| Who moves the text | You, between the chat and wherever you keep the manuscript | The co-writer, which writes into the files themselves |
| Structure | Chats, grouped into projects that hold your uploaded files and your instructions | Projects, which hold your entire file set, your editor, and your AI chat in one window, all readable and editable at any time |
| A workflow from premise to revision | You have to research or invent a workflow for Claude to use | The Proselon template, from premise through structure to the editing passes, with you approving each stage |
| Continuity across a long book | Memory saved as individual topics as you chat, plus a memory and a summary for each project | A Story State ledger of facts, promises and reveals, and continuity checks measured against it |
| Your voice | Whatever your project instructions describe, and whatever samples you have uploaded | A Style Guide, a Voice Corpus of your own passages, and an Anti-Pattern Corpus of the tells to hunt |
| Versions | You have to handle this yourself, either in your writing app or some other way | Every save kept, and any of them can be read or brought back in an instant |
| Export | You have to handle this yourself, again, either in your writing app or some other way | Word, EPUB, HTML, plain text, all packaged right in |
| Runs on | Web, plus mobile and desktop apps | macOS (Apple Silicon and Intel), Windows 10/11 |
| Works offline | No | Yes — the app and your files are local. A local model keeps the AI offline too |
| Cost | Included in your Claude plan | $6 a month (or $50 a year) |
Proselon's price assumes the Claude plan you already pay for, and is not a price for the AI. Last reviewed September 17, 2026.
A long book, without the drift
Nothing is lost when a conversation ends, because the book was never in the conversation.
Anyone who has written a long story in one chat has watched it happen. Deep into the conversation the thread goes: a character’s eyes change color, a settled plot point comes unsettled, and the voice you spent a week tuning slides back toward the default. So you open a fresh chat, explain the book again from the top, and spend the first hour getting the voice back. We wrote up why it happens in why AI forgets your story.
Proselon has no long chat to outgrow. Every request starts from the book as it stands today, the chapters, the canon and the samples of your own voice alike, so a new conversation costs you nothing and an old one has nothing to forget. What must carry from chapter to chapter, the names and the dates and who knows what, is kept in a Story State ledger, and the continuity check reads each draft against it.
- Template
- 100,000
- Project canon
- 46,000
- Voice corpusprose
- 60,000
- Book and chapter canon
- 25,000
- Scene plan and sheets
- 34,000
- Preceding scenesprose
- 75,000
- Headroom
- 60,000
Better prose, and where it comes from
The model is the one you already chose. What changes is that it drafts from your pages rather than from your description of them, and that it is made to go back over what it wrote.
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.
Three records hold a voice, and the co-writer drafts against all of them. A Style Guide sets the rules, a Voice Corpus collects the passages that prove them, and an Anti-Pattern Corpus records what the co-writer does when it goes wrong. A scene therefore begins from examples of your own writing rather than from an adjective about it.
Then the book is edited in passes rather than in one read. One pass reads the whole book for the constructions it keeps reaching for and proposes them for your Anti-Pattern Corpus. A later pass rewrites every drafted scene against your voice corpus, by a different model than the one that drafted it, with diction, rhythm and imagery open and the events fixed. In our experience that is where the difference shows.
Six dollars, added to the plan you keep
For six dollars more a month, on top of your Claude subscription, you get the whole writing room. One product, with everything included on both plans, and the first 30 days are free.
- The AI co-writer, on all six engines
- Continuity across a whole book or series
- Automatic version history
- Export to Word, EPUB, and more
- Every theme, in a light half and a dark one
- No 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
Proselon’s price assumes the Claude plan you already pay for, Pro or Max, and adds no markup and no meter to it. Should you ever drop that plan, the same co-writer signs in to ChatGPT, Grok or Gemini instead, takes your own key from OpenRouter, or runs a free local model through Ollama or LM Studio.
Questions people ask
Can I write a novel in a Claude Project?
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You can, and plenty of writers do. It is a tedious way to do it. A project works from the files you upload, so every chapter Claude drafts has to be copied into your editor, revised there and uploaded again before the next request can see it, and the story bible goes out of date the same way. Proselon keeps one copy of the book, on your own disk, and the co-writer opens and edits that copy, so the carrying stops.
Do I have to upload my chapters to Proselon?
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No. The book is already there. Proselon writes your chapters as plain text files in your own Documents folder, one per page, and the co-writer opens whichever of them a job needs, reads them as they stand that morning, and writes the change back into the same files. Nothing is carried in and nothing is carried out, so there is no version of your book anywhere that can fall behind the one you are working on.
Will it still be my Claude subscription doing the writing?
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Yes, and that is the design. You sign in to your own Claude account inside the app the way you sign in on the web, on a Pro or Max plan, and that subscription does the writing at no extra charge. No API keys, no markup from us, and no second AI bill. If you ever want to write on something else, the same app signs in to ChatGPT, Grok or Gemini, accepts your own key from OpenRouter, xAI or any OpenAI-compatible endpoint, and runs a free local model through Ollama or LM Studio.
If it is still Claude, how is the writing any better?
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It is the same Claude model, on your own account. What changes is how closely it stays aligned to your story, and that comes from how Proselon manages what the model reads. In a long chat the model works from whatever remains of the conversation. In Proselon every request starts from the book as it stands today, with the chapters the scene depends on, your canon and samples of your own voice in front of it. The same model, reading the right pages every time, stays nearer to your story and to the way you write.
What does it cost on top of Claude?
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$6 a month, or $50 a year, with everything included. No tiers, no credits, no per-word charge. The first 30 days are free and take no credit card. That $6 assumes you already pay for an AI, which as a Claude subscriber you do, and Proselon adds no AI bill of its own.
Keep your Claude plan, and give it the book
Download Proselon, sign in to the Claude account you already have, and let it work inside the manuscript rather than beside it. Free for 30 days, $6 a month after, and not a chapter uploaded anywhere.
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Last reviewed September 17, 2026.
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Claude is a trademark of Anthropic PBC, and the other products named on this page are trademarks of their respective owners. Proselon is not affiliated with, endorsed by, or sponsored by any of them, and the comparison rests on their publicly available materials as of the date above.