 The retrosynthesis workflow predicts metabolic pathways for the prediction of compounds. Retropath2 uses reaction rules to search for a retrosynthetic network that would link the compound one wishes to produce, the target, to the set of available precursors that could be used as starting materials, the sink. From this, RP2Pass enumerates the pathways that lie in this predicted network. The final step, complete reactions, consists of refining the pathways by putting back co-substrates and co-products omitted during the retrosynthetic step. At the end, each pathway is outputted into a distinct SBML file that can be used by other SBML compliant tools. Here is the retrosynthesis workflow as it appears in the Galaxy workflow editor. We can see the three main steps, Retropath2, RP2Pass and complete reactions. The inputs are the inchi of the target to produce and the strain we want to produce the target from in SBML format. The set of reaction rules is automatically downloaded from Retrols database and the sink is extracted from the strain model. To run RetroThynthesis workflow, go to share data menu and select workflows. Then choose RetroThynthesis, click on it and choose run. Ok, now we can set inputs for the workflow. We choose here to produce the like a pin. We fetch its inchi online and we put it in the dedicating location. Then we choose the strain where we want to produce the like a pin from. Here is Ecoli IML1515. We can set all parameters of each step by clicking on different node of the workflow to modify them. Ok, so we can click now on Run workflow and see its execution and the history on the right panel. At the end of the execution, we can see that nine pathways have been predicted to produce the like a pin in Ecoli. We can click on the collection and access to each different pathway. Download it or read it. We can also visualize the set of pathways at the glance by using the Symbiocad visualization tool. Clicking on the icon, the set of pathways appears and one can interact with it. We can highlight each pathway by. If we click on a compound, we can see the details in the right panel. In the same way, if we click on a reaction, its characteristics appear in the right panel. Finally, one can see enzymes that catalyze the reaction.