No. 11 of 27 ·AI Book Writing Software

Kosmos

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Freedom report

Two barsScore 6.4

Free tierA free tier is on its own pricing page
Open codeNo open-source code on record
Runs widely1 of 6 device platforms
DocumentedPlans, terms and facts published

Kosmos is ranked #11 of 27 in AI book writing software on Freedom251. It runs on Web. There is a free plan.

Kosmos plans and pricing

All plans

Beta Free Free during beta · requires your own Claude subscription · access approved manually kosmos.page · 9 Oct 2026

Compared on AI book writing software

Free plan: No
Book outlining: Yes
Chapter workspace: Yes
Continuity tools: Yes
Rewrite controls: No
Export formats: Markdown

Best Kosmos alternatives

See all 20

Two bars Jenova Creative Fiction Writer Free tier No. 1$20/mo6.6 Two bars Pendraic Free tier No. 2$14.99/mo6.6 One bar DeepQuill Free tier No. 3$3.33/mo6.5 One bar AI Novel Studio Free tier No. 4Free6.4 One bar AIWriteBook Audiobook Studio Free tier No. 5$12/mo6.4 One bar BookBud.ai Free tier No. 6$15.83/mo6.4

The record

Purpose: Kosmos is a structured methodology for producing nonfiction books that runs inside Claude Code.
AI role: The AI organizes research, tracks coverage, advises on structure, and reviews drafts; it does not write manuscript prose.
Process: Its four phases are ideation, research, structure, and writing.
Research: Kosmos organizes research into atomic tagged entries, tracks theme coverage, and identifies gaps for further research.
Draft review: During writing, AI reviews drafts against an 8-point checklist, tracks progress, and checks consistency.
Web research: Kosmos can search for material to fill research gaps when web access is available.
File format: Kosmos files are Markdown, and projects work as Obsidian vaults; the maker says users keep their files if they stop using Kosmos.
Editor compatibility: Obsidian is recommended, and the maker says any Markdown editor works.
Prerequisite: Kosmos requires Claude Code and a Claude Pro or Max subscription, which users provide themselves.
Setup: Claude Code handles installing the Kosmos CLI, authenticating, and setting up the project.
Access: During beta, the maker manually reviews and approves every signup.
Beta status: Kosmos is described as an early beta, and the maker says the tooling is new and feedback is welcome.
Intended users: The maker is seeking authors who want to try a structured approach to book production and are willing to give feedback.
Maker: The maker identifies himself as Joakim Achren and says he has self-published nonfiction books.
Price from: Free

Where it ranks on Freedom251

Best AI Book Writing Software in 2026#11 of 27

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Sources

kosmos.page· checked 8 Oct 2026