Formerly known as the InitialConditionsSolver module of GRChombo (ascl:2306.039), the multigrid solver GRTresna solves the constraint equations for the initial data required in numerical relativity simulations. In particular, it focuses on scenarios with fundamental fields around black holes and inhomogeneous cosmological spacetimes. GRTresna makes use of the Chombo library (ascl:1202.008) for adaptive mesh refinement to allow automatic increasing of the grid resolution in regions of arbitrary shape and topology.