tl;dr: Declarative dragging lets interface authors make elements draggable by specifying which future model states a drag should reach, rather than hand-coding geometry, feedback, and animations. The system speculatively renders those candidate states, extracts element positions, and synthesizes a smooth drag-and-drop interaction automatically. The authors implemented this as Dragology, an SVG web library, and demonstrate it on math explorables, programming environments (Hazel), and games; it won Best Paper at UIST 2026.