Pendusk

Why I'm Building It

Every AI writing tool I tried had the same tell: it wanted to write the book for you. Paste a chapter, get back a rewrite. And once a model has rewritten your prose, an honest question appears that never goes away — whose book is this?

Pendusk is built on the opposite bet. It's a writing environment for novelists that's genuinely good with the AI turned off — fast, local-first, offline-capable — and when you do turn the AI on, it's held to one hard rule enforced in the architecture, not the marketing: it proposes, it never writes. There is no mode, setting, or prompt that lets a model type into your manuscript. Feedback arrives as margin comments and chat; story-bible entries the AI drafts land as pending proposals until you accept them. Every word on the page is yours, and the app can prove it.

The page is the interface — prose front and center, everything else stays quiet

How It Works

The manuscript lives in your browser first: TipTap (ProseMirror) for the editor, Yjs CRDTs for the document model, IndexedDB for persistence. Offline isn't a degraded mode — reading, writing, importing, exporting, and your story bible all work with no connection, and a Hocuspocus sync server reconciles across devices when you're back. Spell-check runs entirely on-device with Hunspell dictionaries, and every project keeps its own custom dictionary — invented names get learned once and travel with the book.

Around the page sits the craft tooling: a story bible (characters, places, lore — twelve categories), a versioned constitution that sets the rules every AI surface must obey (style, banned words, point of view, content lines), chapter snapshots, and clean exports — Markdown always and forever, EPUB 3, and standard-manuscript DOCX.

The writing partner reads the chapter you're in — and answers like an editor, not a cheerleader

The AI layer is deliberately quiet. A chat partner that has read your constitution, your accepted bible, and the open chapter. Anchored margin comments you accept or dismiss. And the Editorial Pass — a cold read of chapters you choose by a different model family than your partner, through four lenses: prose, structure, continuity, character. Costs are honest: every call is ledgered with tokens and dollars, and expensive actions show an estimate before you run them.

Pick your editor like you'd pick an editor — each model card says what it's good at and what your manuscript would cost

Because nothing can write into the manuscript, Pendusk can generate an Authorship Record — a dated evidence document from the provenance trail showing what was proposed versus what you accepted, useful for copyright registration and publisher disclosure in a world that increasingly asks.

The story bible — and anything the AI proposes stays pending until you accept it

The stack: Vue 3 SPA on Cloudflare Pages, REST API and sync server as Node 24 containers on Fly.io, Supabase for Postgres (row-level security on every table) and auth, Stripe for billing. AI calls route through OpenRouter with a bring-your-own-key model — you pay the provider directly, and the app shows you every cent.

Excellent with the AI turned off

What's Next

Pendusk is live at pendusk.com. The Writer plan ($10/mo) covers cross-device sync and BYO-key AI; a Partner tier with managed keys is wired and waiting. On the roadmap: a desktop client, richer editorial lenses, and dogfooding it on an actual novel — which is, after all, the only benchmark that matters.