There are 2 options:
a.) You can use our REST API. For details click here.
b.) Using the Upload page SDFiles can be uploaded. It is possible to keep the original PCN and CN provided with the record if there is no match to a previously registered compound. Different mappings can be set between the SDF fields and the system (e.g. salts and multiplicities, additional data fields, users, etc.). Note that using the Upload page only single structures can be registered.