Abstract We associate vertex operator algebras to (p, q)-webs of interfaces in the topologically twisted N = 4 $$ \mathcal{N}=4 $$ super Yang-Mills theory. Y-algebras associated to trivalent junctions are identified with truncations of W $$ \mathcal{W} $$ 1+∞ algebra. Starting with Y-algebras as atomic elements, we describe gluing of Y-algebras analogous to that of the topological vertex. At the level of characters, the construction matches the one of counting D0-D2-D4 bound states in toric Calabi-Yau threefolds. For some configurations of interfaces, we propose a BRST construction of the algebras and check in examples that both constructions agree. We define generalizations of W $$ \mathcal{W} $$ 1+∞ algebra and identify a large class of g...