Story Sprout: A Picture-Book Studio Where Children Direct the AI and Keep the Pen

Story Sprout is a browser-based picture-book studio for children ages 7–9, built around an explicit allocation of agency to the child users, which is enforced in the system. The children originate every sentence of the story and every illustrated scene detail they specify. The children request each illustration and decide alone what will be in the book. The model's creative-production role is confined to drawing the illustration and redrawing it based on the child's requests for changes. The system design began in a community-center program, where facilitators watched children's descriptions grow more specific as LLM-generated pictures never quite matched the child's imagined scene. The studio makes that mismatch the center of the activity: the children describe, compare with the scene they imagined, then accept or revise by saying more, more precisely. The system asks the child whether the picture matches what they imagined. It never makes that judgment for the child. The finished work and its revision record live in a local file held by the supervising adult: no child accounts, no readable server-side project copy, an encrypted class relay the platform cannot read. The goal of the activity is to allow children to learn through making real things for a real audience, following Papert's constructionist tradition. In what follows, we present the agency framework, the deployed system, its layered safety mechanism, the aspects of the agency allocation that could be contested, how our system compares to what is currently available, and how our workshops enabled us to engage in iterative child-centered design.