You can use the "providers" advanced search feature to limit the building block databases Spaya will have access to. When proposing a retrosynthesis, Spaya will be required to find routes which end in commercial molecules present in the allowed databases.
You can select any combination of building block databases, but note that when fewer building blocks are available, Spaya may take longer to find a retrosynthesis route or may not be able to propose a route.
