PenForge is an AI co-writer for indie novelists. Bring your own AI key, keep your canon on your computer, ship a full novel in weeks.
Four problems every indie novelist hits when they try to scale beyond 5-10 chapters.
By chapter 8 the AI has forgotten what your protagonist's sister is called. By chapter 30 you have a sister, a "sister figure," and a vaguely-related cousin.
Most AI writing subscriptions bundle AI usage into the price at a steep markup. PenForge's subscription is for the tool only — you bring your own AI key and pay your provider directly, often pennies per chapter.
Chapter 1 is Joo-Heon-style snark. Chapter 20 reads like a YA romance. The protagonist's voice silently mutates across the book.
Most AI writing tools upload your novel to their servers. You're feeding their training data. Your worldbuilding is no longer yours alone.
Three steps. No fluff. From idea to chapter 1 in 15 minutes.
Fill a friendly form: title, genre, summary, main character. Click ⚡ AI fill for any section you're not sure about. The wizard auto-saves your draft as you type.
Pick from 6 providers: Gemini (free tier!), DeepSeek (~$6–15 per novel), OpenAI, Claude, OpenRouter, or local Ollama. Paste your key once. Pennies per chapter forever.
Six-stage pipeline: beat sheet → hook engineer → prose → critique → revision → polish → continuity check. Revised toward a 9/10 bar — and you always see the score. Voice locked across all chapters.
PenForge enforces canon validation at every stage — the engine catches its own mistakes before you see them.
Every chapter goes through beat sheet design, hook engineering, prose draft, multi-axis critique, targeted revision, polish, and continuity audit — revised toward a 9/10 bar, with its real score shown.
After chapter 1 the engine extracts a "voice fingerprint" — sentence rhythm, verbal tics, dialogue habits — and locks it across every subsequent chapter. No drift.
Programmatic detector scans every chapter for canon violations (relics appearing before they should, POV slips, JSON leaks). Rejects polluted chapters before they pollute future ones.
Rolling chapter summaries + pinned canon facts + plot threads + early-chapter digest. Chapter 50 references the joke you made in chapter 3.
One-click fills your novel canon: summary, main character, voice, allies, villains, romance, world, tone, arcs. From one line of input to a full novel skeleton.
Your canon files stay on your computer. PenForge sends only the current chapter's prompt to your chosen AI provider. We collect nothing. Ever.
PenForge does what the subscription tools do — and more — while keeping your AI costs separate and transparent instead of bundled into a marked-up price. The columns below are general market categories, not specific products.
| Feature | PenForge | Subscription AI writers | Wiki-style story apps | A general chatbot |
|---|---|---|---|---|
| Canon stays on your computer | ✓ | usually cloud | varies | cloud |
| Bring your own AI key | ✓ (6 providers) | rarely | partial | — |
| Multi-stage canon enforcement | ✓ (6 stages) | partial | manual | none |
| Voice lock across chapters | ✓ | varies | manual | none |
| AI costs stay separate & transparent | ✓ — pay your provider directly | bundled, marked up | bundled, marked up | bundled, marked up |
| AI brainstorm wizard | ✓ | partial | ✓ | manual |
| Built for 200-chapter continuity | ✓ | varies | partial | no |
| Tool subscription (AI usage billed separately by your provider) | from $9/mo* | ~$14–25/mo (AI usually included) | ~$10–20/mo | ~$20/mo |
* You pay your chosen AI provider directly, separate from the PenForge subscription — often pennies per chapter, and a free tier exists. Category descriptions reflect typical market offerings as of 2026 and are not statements about any specific product. PenForge is independent and not affiliated with any other tool; check each vendor for their current features and pricing.
This is what you actually get the moment you open it — not screenshots of a someday roadmap.
Every chapter is scored on 15 axes and revised toward a 9/10 bar — and you always see the real score, so nothing sneaks past you.
See every arc and exactly where you are. Never lose the thread of a 200-chapter plot again.
Highlight any line → Describe, Rewrite, Shorten or Expand. Polish your prose sentence by sentence.
A living wiki of every character — voice, facts, relationships — so the AI never forgets who's who.
Compile every chapter into a print-ready manuscript — Save as PDF, or grab Markdown/text for KDP & Royal Road.
A chapter opening drafted through the engine — show-don't-tell, sensory, hook on the first line. This is the bar every chapter is graded against before it's saved.
I died on a Tuesday, and I have been holding a grudge about it ever since.
It is, currently, also a Tuesday. Different Tuesday. Eleven years earlier. The man who killed me is four floors above my desk right now, drinking the same overpriced single-origin coffee he will be drinking eleven years from now when he gives the order to have me knifed in a Norwegian vault. His name is Director Erik Adler. He aligns the pens on his desk parallel to the edge of the desk. If you have ever met a man who aligns pens, you already know everything you need to know about Adler.
— from Pantheon Hunter, chapter 1, drafted with Claude through PenForge — graded 9.67/10 by the built-in cross-model judge before saving
Start free — your first few chapters are on us, no card required. Subscribe to keep writing; your novels stay yours no matter what.
📖 Your book is always exportable — print-ready PDF, Markdown and text, on every plan, even Lite.
| PenForge Lite (1 month) — perfect for hobby writers who want powerful AI writing at the lowest cost | $9 |
| PenForge Pro (1 month) — built for serious authors who want maximum story quality, long-term consistency, planning tools, and professional workflows | $19 |
| Typical AI writing subscription (per month) | ~$20–30 |
PenForge Lite is built for writers who mainly want affordable AI writing. PenForge Pro is for serious novelists, screenwriters, and book authors who need advanced story memory, planning, consistency, and professional writing workflows. Studio turns PenForge into a full professional writing studio. AI costs remain separate — so you're never locked into an expensive provider's markup. Your novel stays on your machine either way. Competitor figures are typical 2026 market estimates — check each vendor for current pricing.
Real things people want to know before they pay.
No. Your novel canon (characters, world, chapters) lives on your machine. PenForge sends only the current chapter's prompt to the AI provider you chose. We collect nothing. The novel is yours, period.
Switch providers in one click. Gemini has a free tier that covers a lot of drafting for $0 (limits vary by model). Use it while drafting, then spend a few dollars on a DeepSeek or OpenAI top-up when you want the highest quality.
Yes — PenForge is subscription-only, billed monthly through Gumroad, with updates included the whole time you're subscribed. If you cancel, PenForge locks to reading and exporting the novels you've already written until you resubscribe — nothing is deleted.
All three. PenForge runs as a local Node.js server. You open it in your browser. Tested on Windows 11, macOS 14+, Ubuntu 22+.
Chapters auto-export as plain .txt and structured .json. ePub export is in v1.1 (free update). Royal Road / WattPad publishing flow is in v1.2.
No. PenForge is a co-writer — you set canon, voice, tone, beats. The engine drafts within your constraints. Many users hand-write key chapters and let the engine handle bulk. The novel is yours.
Three clicks: install Node.js (one-time), unzip PenForge, run one command. Then open localhost:3001 in your browser. Setup wizard handles everything else. No CLI knowledge required.
You can cancel from your Gumroad library. Your subscription runs through the end of the paid period, then billing stops — and your novels, chapters and exports stay on your machine.