STEDY is a MATLAB Software for TEnsegrity DYnamics. In this software, the topology of the tensegrity network is described using connectivity matrices, with mass properties of the bars and cables. The dynamics is derived in the Lagrangian framework with non-minimal coordinates and holonomic constraints (paper). The software also accounts for errors in numerical integration by providing corrections for constraint violations and drifts in mechanical energy. Please see the user guide to get started.