diff --git a/uncloud_django_based/uncloud/uncloud/urls.py b/uncloud_django_based/uncloud/uncloud/urls.py
index 5539846..05b1f0f 100644
--- a/uncloud_django_based/uncloud/uncloud/urls.py
+++ b/uncloud_django_based/uncloud/uncloud/urls.py
@@ -35,10 +35,10 @@ router = routers.DefaultRouter()
 router.register(r'beta/vm', vmviews.NicoVMProductViewSet, basename='nicovmproduct')
 
 # VM
-router.register(r'vm/snapshot', vmviews.VMSnapshotProductViewSet, basename='vmsnapshotproduct')
-router.register(r'vm/diskimage', vmviews.VMDiskImageProductViewSet, basename='vmdiskimageproduct')
-router.register(r'vm/disk', vmviews.VMDiskProductViewSet, basename='vmdiskproduct')
-router.register(r'vm/vm', vmviews.VMProductViewSet, basename='vmproduct')
+router.register(r'v1/vm/snapshot', vmviews.VMSnapshotProductViewSet, basename='vmsnapshotproduct')
+router.register(r'v1/vm/diskimage', vmviews.VMDiskImageProductViewSet, basename='vmdiskimageproduct')
+router.register(r'v1/vm/disk', vmviews.VMDiskProductViewSet, basename='vmdiskproduct')
+router.register(r'v1/vm/vm', vmviews.VMProductViewSet, basename='vmproduct')
 
 
 # creates VM from os image
@@ -47,35 +47,35 @@ router.register(r'vm/vm', vmviews.VMProductViewSet, basename='vmproduct')
 #router.register(r'vm/dualstackvm', vmviews.VMProductViewSet, basename='vmproduct')
 
 # Services
-router.register(r'service/matrix', serviceviews.MatrixServiceProductViewSet, basename='matrixserviceproduct')
-router.register(r'service/generic', serviceviews.GenericServiceProductViewSet, basename='genericserviceproduct')
+router.register(r'v1/service/matrix', serviceviews.MatrixServiceProductViewSet, basename='matrixserviceproduct')
+router.register(r'v1/service/generic', serviceviews.GenericServiceProductViewSet, basename='genericserviceproduct')
 
 
 # Net
-router.register(r'net/vpn', netviews.VPNNetworkViewSet, basename='vpnnet')
-router.register(r'net/vpnreservation', netviews.VPNNetworkReservationViewSet, basename='vpnnetreservation')
+router.register(r'v1/net/vpn', netviews.VPNNetworkViewSet, basename='vpnnet')
+router.register(r'v1/admin/vpnreservation', netviews.VPNNetworkReservationViewSet, basename='vpnnetreservation')
 
 
 # Pay
-router.register(r'address', payviews.BillingAddressViewSet, basename='address')
-router.register(r'bill', payviews.BillViewSet, basename='bill')
-router.register(r'order', payviews.OrderViewSet, basename='order')
-router.register(r'payment', payviews.PaymentViewSet, basename='payment')
-router.register(r'payment-method', payviews.PaymentMethodViewSet, basename='payment-method')
+router.register(r'v1/my/address', payviews.BillingAddressViewSet, basename='address')
+router.register(r'v1/my/bill', payviews.BillViewSet, basename='bill')
+router.register(r'v1/my/order', payviews.OrderViewSet, basename='order')
+router.register(r'v1/my/payment', payviews.PaymentViewSet, basename='payment')
+router.register(r'v1/my/payment-method', payviews.PaymentMethodViewSet, basename='payment-method')
 
 
 # admin/staff urls
-router.register(r'admin/bill', payviews.AdminBillViewSet, basename='admin/bill')
-router.register(r'admin/payment', payviews.AdminPaymentViewSet, basename='admin/payment')
-router.register(r'admin/order', payviews.AdminOrderViewSet, basename='admin/order')
-router.register(r'admin/vmhost', vmviews.VMHostViewSet)
-router.register(r'admin/vmcluster', vmviews.VMClusterViewSet)
-router.register(r'admin/vpnpool', netviews.VPNPoolViewSet)
-router.register(r'admin/opennebula', oneviews.VMViewSet, basename='opennebula')
+router.register(r'v1/admin/bill', payviews.AdminBillViewSet, basename='admin/bill')
+router.register(r'v1/admin/payment', payviews.AdminPaymentViewSet, basename='admin/payment')
+router.register(r'v1/admin/order', payviews.AdminOrderViewSet, basename='admin/order')
+router.register(r'v1/admin/vmhost', vmviews.VMHostViewSet)
+router.register(r'v1/admin/vmcluster', vmviews.VMClusterViewSet)
+router.register(r'v1/admin/vpnpool', netviews.VPNPoolViewSet)
+router.register(r'v1/admin/opennebula', oneviews.VMViewSet, basename='opennebula')
 
 # User/Account
-router.register(r'user', authviews.UserViewSet, basename='user')
-router.register(r'admin/user', authviews.AdminUserViewSet, basename='useradmin')
+router.register(r'v1/my/user', authviews.UserViewSet, basename='user')
+router.register(r'v1/admin/user', authviews.AdminUserViewSet, basename='useradmin')
 
 urlpatterns = [
     path('', include(router.urls)),
diff --git a/uncloud_django_based/uncloud/uncloud_pay/models.py b/uncloud_django_based/uncloud/uncloud_pay/models.py
index 55cf1ea..b06473e 100644
--- a/uncloud_django_based/uncloud/uncloud_pay/models.py
+++ b/uncloud_django_based/uncloud/uncloud_pay/models.py
@@ -825,7 +825,11 @@ class Order(models.Model):
 
     # Trigger initial bill generation at order creation.
     def save(self, *args, **kwargs):
-        super(Order, self).save(*args, **kwargs)
+        if self.ending_date and self.ending_date < self.starting_date:
+            raise ValidationError("End date cannot be before starting date")
+
+        super().save(*args, **kwargs)
+
         Bill.generate_for(self.starting_date.year, self.starting_date.month, self.owner)
 
     @property
diff --git a/uncloud_django_based/uncloud/uncloud_vm/models.py b/uncloud_django_based/uncloud/uncloud_vm/models.py
index 39a5f40..06b5386 100644
--- a/uncloud_django_based/uncloud/uncloud_vm/models.py
+++ b/uncloud_django_based/uncloud/uncloud_vm/models.py
@@ -69,9 +69,6 @@ class VMProduct(Product):
     cores = models.IntegerField()
     ram_in_gb = models.FloatField()
 
-    # Optional disk
-    primary_disk = models.ForeignKey('VMDiskProduct', on_delete=models.CASCADE, null=True)
-
     # Default recurring price is PER_MONTH, see uncloud_pay.models.Product.
     @property
     def recurring_price(self):
@@ -175,6 +172,7 @@ class VMDiskProduct(Product):
         super().save(*args, **kwargs)
 
 
+
 class VMNetworkCard(models.Model):
     vm = models.ForeignKey(VMProduct, on_delete=models.CASCADE)
 
diff --git a/uncloud_django_based/uncloud/uncloud_vm/serializers.py b/uncloud_django_based/uncloud/uncloud_vm/serializers.py
index 2c7137e..a04af8f 100644
--- a/uncloud_django_based/uncloud/uncloud_vm/serializers.py
+++ b/uncloud_django_based/uncloud/uncloud_vm/serializers.py
@@ -121,22 +121,17 @@ class OrderVMProductSerializer(VMProductSerializer):
 # Nico's playground.
 
 class NicoVMProductSerializer(serializers.ModelSerializer):
-    primary_disk = CreateVMDiskProductSerializer()
     snapshots = VMSnapshotProductSerializer(many=True, read_only=True)
-    disks = VMDiskProductSerializer(many=True, read_only=True)
 
     class Meta:
         model = VMProduct
         read_only_fields = ['uuid', 'order', 'owner', 'status',
-                            'vmhost', 'vmcluster',
+                            'vmhost', 'vmcluster', 'snapshots',
                             'extra_data' ]
         fields = read_only_fields + [ 'name',
                                       'cores',
-                                      'ram_in_gb',
-                                      'primary_disk',
-                                      'snapshots',
-                                      'disks' ]
-
+                                      'ram_in_gb'
+        ]
 
 
 class DCLVMProductSerializer(serializers.HyperlinkedModelSerializer):
diff --git a/uncloud_django_based/uncloud/uncloud_vm/views.py b/uncloud_django_based/uncloud/uncloud_vm/views.py
index 39b7668..2d0a693 100644
--- a/uncloud_django_based/uncloud/uncloud_vm/views.py
+++ b/uncloud_django_based/uncloud/uncloud_vm/views.py
@@ -195,6 +195,7 @@ class NicoVMProductViewSet(ProductViewSet):
         # Extract serializer data.
         serializer = self.get_serializer(data=request.data)
         serializer.is_valid(raise_exception=True)
+
         order_recurring_period = serializer.validated_data.pop("recurring_period")
         order_billing_address = serializer.validated_data.pop("billing_address")