Autocomplete and AI assistant for Mac and Windows, built on a private account of your work
Context-aware AI book editor for authors
Stage
Startup
Not given
Founded
2026
Not given
Based in
AU
AT
Pricing model
Freemium
Freemium
Pricing
Not given
Octavo: Free forever (1 project, 3 research files, limited AI usage). Quarto: $20/month or $200/year (unlimited projects, 50 files per project, 10× more AI usage). Folio: $100/month or $1,000/year (unlimited research files, 5× more AI usage than Quarto, priority queue, early access to new models).
Key features
Autocomplete with Tab to accept drafts
Error detection and fact-checking
Cross-app integration
Source attribution for every suggestion
Context-aware AI assistance
One-click pause and privacy control
Encrypted data storage
Read-only app connections
Natural writing style matching
Context-aware AI suggestions that read your chapters first
Source-grounded edits from PDFs, URLs, and YouTube transcripts
Red and green diffs requiring your approval
Export to Amazon KDP, Apple Books, Lulu, IngramSpark, Google Play Books, Draft2Digital
Chapter-aware AI agent
Citation engine with Chicago-formatted bibliography
Front matter and back matter editor
Version history to save and restore manuscript versions
Clean PDF and EPUB export with professional typography
What makes it different
Finishes sentences from your actual work history and connected files, not generic AI
Shows source for every suggestion so you can verify it before accepting
Catches mistakes and contradictions between what you're writing and your work history
Works inline in the apps you already use without installation
You stay the author with full control over what gets written
Keeps your entire book and research in context, unlike chat windows that start fresh each session
Returns edits as approvable diffs you control, not auto-inserted changes
Built specifically for book publishing with real front matter, back matter, and professional export formats
Opsis
Chaptora