Copperas is a writing application for novelists. Your manuscript is a file on your computer. The AI is an editorial collaborator that reads your work, remembers your project, and holds your prose to your standards. Every word lives on your machine, not in a cloud database.

A Place to Write

Writing a novel takes months. The tool you write in becomes the place where you spend those months — the room you think in. It should feel good to be there.

Copperas is designed to disappear. The interface is quiet. The typography is clean. Six handcrafted themes let you choose the light, warmth, and mood that suit the way you work. The editor shows your chapter with the surrounding scenes visible for context, and everything else stays out of the way until you need it.

Joy in the Craft

The best writing sessions are the ones where time disappears. You sit down, you find the thread, and the next thing you know two hours have passed and the chapter is alive.

Copperas is built to protect those sessions. Voice input lets you talk through a scene without breaking eye contact with the page. The AI responds in conversation, not in forms and buttons. Timeline snapshots happen silently in the background so you never have to stop and save.

Your Work, Your Files

Your manuscript is a file, not a database row. It is a Markdown file on your hard drive. You can open it in any text editor, back it up however you like, and keep writing even if Copperas disappeared tomorrow. No other AI writing tool gives you this.

Free local mode. The writing environment — editor, chapter navigation, version timeline, import, export — works without an account and costs nothing. AI features are the only paid tier.

Purpose-Built AI

Most AI writing tools use a single general-purpose model for everything. Copperas is different. Each stage of the writing process has its own carefully crafted AI, with its own instructions, its own expertise, and its own way of reading your work.

• The AI Assistant understands your project — characters, plot, chapter structure, reference files. You talk to it in plain language and the right specialist picks up the work.
• The Editing Assistant reads your chapter with a critical eye. Three depths: Quick Read, Close Read, and Deep Read.
• The Drafting Assistant drafts and revises prose to your style contract. Its real strength is revision — making your prose sharper, tighter, and more consistent with your voice.
• Beta Readers — three independent AI readers, each with a different lens, responding without seeing each other's reactions.
• The Agent Assessment — a senior literary agent reads your manuscript and gives you an honest professional evaluation.

The AI remembers your project. Session memory harvests facts from every working session and feeds them back into future sessions automatically. The more you write, the sharper every role becomes.

Who Copperas Is For

Copperas is for writers who take their craft seriously — novelists who want editorial feedback between human editor passes, writers who want AI assistance but refuse to hand their manuscript to a cloud service, and anyone who has tried AI writing tools and found them shallow, generic, or uncomfortable to depend on.