Chapbook is an AI writing studio for coaches, consultants, creators and solopreneurs who need a lead magnet, a workbook or a short nonfiction book. You describe the book in one paragraph, add notes, PDFs or web pages as sources, and Chapbook proposes titles and a chapter-by-chapter outline you can reorder and rewrite. Once you approve it, it drafts up to 40,000 words in the background, matched to your own writing samples, and a read-through flags unsupported claims and contradictions. Pick one of eight looks or describe your own, generate or upload a cover, and export a digital PDF, an EPUB 3 and a 1600 x 2560 cover sized for Amazon KDP. Every action shows its credit price before it runs, and you own everything you make. The outline and first chapter are free.