This article addresses how capacity is conceived of and understood in youth media/civic education programming, and how beliefs about agency, development, relationality and youth manifests in the discourses, programmes, and practices of organizations operating youth media programmes. Through attention to a youth media and development programme in rural Nicaragua, the article addresses a key gap in theorizing "how" capacity operates within discourses and related practices that constitute "youth media" and, in particular, it critically investigates how youth media discourse rests on an assumed foundation where capacity is defined as agency, empowerment or voice. This article situates youth media production within modernist discourses about education, development and "change," in order to re-conceptualize agency through a mobilities framework that more fully attends to the complex and affective moments in youth media discourses.