We have releases two pieces of code: Firstly the xIST package, an extension of the xAct tensor algebra system, which implements a framework to investigate general scalar-tensor theories at the level of linear perturbations. Secondly, based on xIST, a Mathematica notebook we dub COPPER (COsmological Parametrized PERturbations), which reproduces the calculations carried out in the paper arxiv:1604.01396 and can be straightforwardly adapted to investigate more complicated setups