Abstract:  I will describe a construction of a q-series invariant (BPS q-series, also known as the Z-hat invariant) associated to a 3-manifold decorated by an embedded link. These q-series depend only on the class of the link in the skein module, and hence define a homomorphism from the skein module to the space of q-series. The image of this homomorphism is conjectured to exhibit holomorphic quantum modularity, which suggests a new approach to Langlands duality for skein modules via q-series.