Free: 10 credits (one-time). Monthly: $7/mo for 70 credits. Yearly: $65/yr for 600 credits.
Core Plan: $19/month (200,000 words of editing per month, limited rewriting ability). Pro Plan: $29/month (300,000 words of editing per month, able to rewrite entire chapters and books). A one-time free word sample is available for new accounts.
Key features
TYPE-FORMULA pipeline that extracts insight types (diagnostic, wisdom, contrarian, data-backed, framework, story) and applies viral structures
Knowledge Bank to store, browse, and reuse extracted insights
10+ viral formula structures including parallel repetition, conditional framework, and bridge analogy
Chrome extension for scheduling posts directly to Substack
Rich-text editor with HTML and plain text export
MCP integration for Claude and Cursor
Automatic article URL processing from published or draft posts
Priority processing for paid plan users
Sentence-level literary feedback
Paragraph-level literary feedback
Passage-level literary feedback in context
Chapter-level literary feedback in context
Book-level literary feedback in entire context
One-click text rewriting with AI
Entire chapter rewriting on Pro Plan
Entire book rewriting on Pro Plan
300,000-word context window on Pro Plan
Progressive learning through interactive Q&A
What makes it different
Designed specifically for Substack writers with formulas trained on viral patterns
Two-stage TYPE-FORMULA process instead of generic AI summarization
Knowledge Bank compounds over time as more articles are processed
From URL to scheduled post in minutes with no copy-paste needed
Credits never expire at your own publishing pace
Human book editors charge thousands but AI Book Editor starts at $19 per month
Gives almost immediate feedback while human editors take weeks
300,000-word context window three times more than average novel
All output belongs 100% to the user for commercial use
Quick Viral Notes
AI Book Editor