  We study the recently discovered q-deformed Poincare' supersymmetry of the
AdS_3/CFT_2 integrable massless scattering, and demonstrate how the S-matrix is
invariant under boosts. The boost generator has a non-local coproduct, which
acts on the scattering matrix as a differential operator, annihilating it. We
propose to reinterpret the boost action in terms of covariant derivatives on
bundles, and derive an expression for the S-matrix as the path-ordered
exponential of a flat connection. We provide a list of possible alternative
interpretations of this emergent geometric picture, including a one-dimensional
auxiliary Schroedinger problem. We support our claims by performing a
simplified algebraic Bethe ansatz, which bears some resemblance to
antiferromagnets.
