Generative AI is an advancement of machine learning technologies, offering sociologists new methods for understanding social life while intervening in a society already shaped by algorithmic systems. Yet one feature sets it apart from earlier computational tools and also makes it distinctly sociological: its interactivity. These systems are trained on social exchanges, refined by human feedback, and used through dialogue and delegation, so that interaction runs throughout their development and use. We conceptualize this interactivity and introduce a framework for understanding how generative AI intervenes in social processes across individual, organizational, and institutional levels. The framework describes how generative AI expands users, functions as a proxy for society, and expresses power, in sociological practice and in society. We conclude with three dynamics that will challenge sociology in the near future: the transformation of scientific practice, the reorganization of social interaction, and the acceleration of algorithmic governance.