American contract law treats relational autonomy as prior to assent. Contractual obligation becomes intelligible only when the parties' interaction preserves relational adequacy, meaning each has a meaningful capacity to refuse and a meaningful capacity to participate in shaping the terms. When that relational structure is present, courts enforce agreements across wide inequalities and hard bargains. When it is absent, courts refuse enforcement or constrain enforcement through doctrines conventionally treated as exceptions. This Article makes that boundary condition explicit. It argues that duress, undue influence, and unconscionability operate as classificatory doctrines that identify when assent cannot justify obligation because bargaining collapsed into extraction. The same relational logic appears in ordinary doctrine through implication, interpretation, good faith, and modification, which preserve relational adequacy over time by preventing contractual form from becoming a vehicle of unilateral control. Reframing doctrine around relational autonomy clarifies why fairness pervades contract law without operating as a freestanding standard, explains the patterned stability of judicial outcomes across doctrinal categories, and recasts contract theory around the structural conditions under which reciprocal commitment can arise and endure.