A writing buddy that knocks first.

Manuscript-aware AI that proposes. You accept. Your voice stays yours.

Propose-only by default

Your coauthor should knock. The coauthor never silent-overwrites your page. Suggestions show as proposals. Accept, reject, or discuss.

Auto-accept is an optional preference for draft mode. Never forced. Never the default for serious work.

Tools, not just chat

Create or rename chapters. Update synopsis. Touch bible and map edges. Search the manuscript. Propose prose. Agent loop with streaming.

Built as workspace tools, not a toy autocomplete that forgets where the book lives.

Honest billing

CoAuthor is separate from the desk. Free (limited). Pro $9/mo. Max $19/mo. Max+ $49/mo. Desk plans never force AI.

Write free forever. Add Pro for bible and map at $4.99 if you want craft depth without AI. Stack only what you use.

FAQ

Does the AI read my whole book?

It works with open chapters, outline and bible context, and keyword manuscript search. Full multi-book vector RAG is intentionally deferred until needed.

Can it match my voice?

Author DNA can sync from your writing and optional templates. Voice is a first-class preference, not an afterthought prompt.

Open the book. Leave the tabs.

Free forever · Pro $4.99/mo · Typewriter 1.0 one-time · CoAuthor from $9/mo. CoAuthor knocks. You accept. Or never turn AI on at all.

Start free See pricing