The original DrugEx articles describe six different generator architectures. The current DrugEx package includes four of these mod-els: two SMILES-based recurrent neural network (RNN) using GRU or LSTM units, and sequenceand graph-based transformers using fragments as starting blocks. The fragment-based LSTM models with and without attention from Ref. 8 have been discontinued as they were outperformed by the other models. The available models are shortly introduced below and the detailed model architectures are described in section S1.