Working definition. Agency is the ability to begin rather than merely respond: to form an intention, choose among possibilities, and carry that choice into the world.
Inherited meaning
Political philosophy treats agency as the power to act; moral philosophy adds responsibility for action. Modern systems often reduce it to control—the ability to press the button. But control can be delegated, automated, or simulated. Agency begins earlier, in deciding what the button should do and whether it should exist.
Meaning in the imagination economy
Generative systems possess extraordinary capability without having a life to answer for. They can propose, combine, and execute, but they do not inhabit the consequences. In this context, agency is not proven by making every detail by hand. It is proven by originating the direction and accepting authorship of the result. The more execution is delegated, the more visible human agency must become.
What changes in practice
Before generating, name the change you are trying to cause. During selection, record why one possibility deserves reality. After release, stay present for its effects. “The model made it” is never an account of agency.