In contemporary life, people increasingly encounter AI not as an autonomous intelligence or distant technical infrastructure, but as an interface that quietly organizes perception, judgment, and action. Recommendation feeds shape what comes into view and what is ignored, generative systems influence how questions are asked and how answers appear, and automated labels, scores, and rankings signal what counts as credible, risky, or acceptable. Navigation tools determine routes, hiring platforms order candidates, and decision support systems suggest outcomes, often without issuing explicit instructions. Individuals are rarely coerced or commanded; instead, they move through environments of preconfigured options that present themselves as neutral, efficient, and helpful. This book argues that such interfaces are reshaping the conditions of human agency by positioning people as interface users who choose among alternatives already filtered, ranked, and framed by AI systems. Freedom is not removed, but reorganized, as choice persists within environments where scope, visibility, and friction are designed in advance. By shifting attention away from models, data, and abstract ethics toward lived experience, the book conceptualizes interfaces as architectures of action that redistribute authority, normalize automated trust, and subtly displace responsibility. Its central claim is that the most consequential power of AI today operates neither through command nor persuasion, but through interface design that quietly reorganizes how people decide, act, and understand their own choices.