The first step in the workflow is to input query species, here defined as user-supplied reactants, reagents, solvents, and main products that may interact with each other, in the form of a reaction SMILES (Simplified Molecular-Input Line-Entry System) string, which is the most widely adopted form of representation. Reactants, reagents, and solvents are not distinguished in this step as all query species are assumed to potentially react. Additionally, distinguishing these species would require a priori knowledge and would defeat the motives behind reaction prediction. However, reaction conditions can be optionally provided separately (e.g. catalyst, temperature, special processes) if already known. In this case, query species 1 -4 are inputted.