Document Policies Edit on GitHub

Document Policies enable convention-based customizations to be applied across the Document Store. While Marten has some existing policies that can be enabled, any custom policy can be introduced through implementing the IDocumentPolicy interface and applying it on StoreOptions.Policies or through using the Policies.ForAllDocuments(Action<DocumentMapping> configure) shorthand.

The following sample demonstrates a policy that sets types implementing IRequireMultiTenancy marker-interface to be multi-tenanted (see Tenancy.

var store = DocumentStore.For(storeOptions =>
{
    // Apply custom policy
    storeOptions.Policies.OnDocuments<TenancyPolicy>();

public interface IRequireMultiTenancy
{
}

public class TenancyPolicy: IDocumentPolicy
{
    public void Apply(DocumentMapping mapping)
    {
        if (mapping.DocumentType.GetInterfaces().Any(x => x == typeof(IRequireMultiTenancy)))
        {
            mapping.TenancyStyle = TenancyStyle.Conjoined;
        }
    }
}

To set all types to be multi-tenanted, the prebaked Policies.AllDocumentsAreMultiTenanted could also have been used.

Remarks: Given the sample, you might not want to let tenancy concerns propagate to your types in a real data model.