How far can ChatGPT go in automatically writing a full-length AI novel if you load the settings into a ChatGPT Project? Using the canonical version of The Library Duke, published on Kakuyomu, as a case study, this production log looks back on the ambitions and setbacks of creating a novel with AI. By my rough estimate, 90 percent of the structural design came from the author, while 90 percent of the prose was generated by ChatGPT. Even so, putting a full-length novel on autopilot proved to be wildly unrealistic. Saved conversation threads, configuration files on Google Drive, output templates, first drafts, revisions, and the management of differences in what each character knows—this essay examines how much could be entrusted to AI, and where a human needed to take the wheel. The example discussed in this essay is the following work published on Kakuyomu. For convenience, I refer to it here as the canonical version of The Library Duke. The initial concept and setting development for The Library Duke began around June 2025. The early trials and errors discussed in this essay reflect the features and specifications of ChatGPT at that time. New capabilities that did not yet exist then have since been added, including ChatGPT’s Work feature, released in July 2026. The behavior and results of carrying out similar work today may therefore differ. The Library Duke: A Royal Command to the Chancellor’s Daughter—Marry the Duke Who Serves as Adviser to the Royal Library Original Japanese version: 図書館公爵 〜急転直下の王命婚で、王立図書館顧問の公爵殿下に嫁ぐことになりました〜 https://kakuyomu.jp/works/2912051599120083143 この英訳版の元になったエッセイ、日本語版はこちらです。 GPT丸投げAI小説の野望と頓挫 　『図書館公爵』正史編 - カクヨム https://kakuyomu.jp/works/2912051599194717193