Bordism of flow modules and exact Lagrangians

For a stably framed Liouville manifold X , we construct a “Donaldson-Fukaya category over the sphere spectrum” F(X; S). The objects are closed exact Lagrangians whose Gauss maps are nullhomotopic compatibly with the ambient stable framing, and the morphisms are bordism classes of framed flow modules over Lagrangian Floer flow categories; this is enriched in modules over the framed bordism ring. We develop an obstruction theory for lifting quasi-isomorphisms in the usual Fukaya category to quasi-isomorphisms in appropriate truncations or quotients of F(X; S). Applications include constraints on the smooth structure of exact Lagrangians in certain plumbings, and the construction of non-trivial symplectic mapping classes which act trivially on the integral Fukaya category for a wide class of affine varieties.