RAscore is designed as a retrosynthetic accessibility score, i.e. score for fast prescreening molecules for the AiZynthFinder tool. It was trained on over 200000 molecules from ChEMBL . For every molecule, a synthesis route was generated using AiZynthFinder to assess if the molecule is synthesizable. Two models were trained on these outcomes: neural network and gradient boosting machine . RAscore implementation is publicly available at . com/reymond-group/RAscore.