Check for schema generation state when removing fields (#9236)

* Ensure notes are not removed when generating schema

* Skip remaining conditional field removals when generating schema, remove removable fields from required lists

* Update API version, add schema gen state check for api-doc endpoint

* Add test for generate schema state

* Add test for schema postprocessing function

* Filter nullable + read_only fields out of schema required lists

---------

Co-authored-by: Matthias Mair <code@mjmair.com>

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,13 +1,17 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 320
+INVENTREE_API_VERSION = 321
 
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 
 INVENTREE_API_TEXT = """
 
+v321 - 2025-03-06 : https://github.com/inventree/InvenTree/pull/9236
+    - Adds conditionally-returned fields to the schema to match API behavior
+    - Removes required flag for nullable read-only fields to match API behavior
+
 v320 - 2025-03-05 : https://github.com/inventree/InvenTree/pull/9243
     - Link fields are now up to 2000 chars long
 

src/backend/InvenTree/InvenTree/ready.py

@@ -1,5 +1,6 @@
 """Functions to check if certain parts of InvenTree are ready."""
 
+import inspect
 import os
 import sys
 
@@ -44,6 +45,14 @@ def isRunningBackup():
     )
 
 
+def isGeneratingSchema():
+    """Return true if schema generation is being executed."""
+    if 'schema' in sys.argv:
+        return True
+
+    return any('drf_spectacular' in frame.filename for frame in inspect.stack())
+
+
 def isInWorkerThread():
     """Returns True if the current thread is a background worker thread."""
     return 'qcluster' in sys.argv

src/backend/InvenTree/InvenTree/schema.py

@@ -0,0 +1,23 @@
+"""Schema processing functions for cleaning up generated schema."""
+
+
+def postprocess_required_nullable(result, generator, request, public):
+    """Un-require nullable fields.
+
+    Read-only values are all marked as required by spectacular, but InvenTree doesn't always include them in the response. This removes them from the required list to allow responses lacking read-only nullable fields to validate against the schema.
+    """
+    # Process schema section
+    schemas = result.get('components', {}).get('schemas', {})
+    for schema in schemas.values():
+        required_fields = schema.get('required', [])
+        properties = schema.get('properties', {})
+
+        # copy list to allow removing from it while iterating
+        for field in list(required_fields):
+            field_dict = properties.get(field, {})
+            if field_dict.get('readOnly') and field_dict.get('nullable'):
+                required_fields.remove(field)
+        if 'required' in schema and len(required_fields) == 0:
+            schema.pop('required')
+
+    return result

src/backend/InvenTree/InvenTree/serializers.py

@@ -22,6 +22,7 @@ from rest_framework.utils import model_meta
 from taggit.serializers import TaggitSerializer
 
 import common.models as common_models
+import InvenTree.ready
 from common.currency import currency_code_default, currency_code_mappings
 from InvenTree.fields import InvenTreeRestURLField, InvenTreeURLField
 
@@ -468,7 +469,10 @@ class NotesFieldMixin:
 
         if hasattr(self, 'context'):
             if view := self.context.get('view', None):
-                if issubclass(view.__class__, ListModelMixin):
+                if (
+                    issubclass(view.__class__, ListModelMixin)
+                    and not InvenTree.ready.isGeneratingSchema()
+                ):
                     self.fields.pop('notes', None)
 
 

src/backend/InvenTree/InvenTree/settings.py

@@ -1423,6 +1423,10 @@ SPECTACULAR_SETTINGS = {
     'VERSION': str(inventreeApiVersion()),
     'SERVE_INCLUDE_SCHEMA': False,
     'SCHEMA_PATH_PREFIX': '/api/',
+    'POSTPROCESSING_HOOKS': [
+        'drf_spectacular.hooks.postprocess_schema_enums',
+        'InvenTree.schema.postprocess_required_nullable',
+    ],
 }
 
 if SITE_URL and not TESTING:

src/backend/InvenTree/InvenTree/tests.py

@@ -37,7 +37,7 @@ from InvenTree.unit_test import InvenTreeTestCase, in_env_context
 from part.models import Part, PartCategory
 from stock.models import StockItem, StockLocation
 
-from . import config, helpers, ready, status, version
+from . import config, helpers, ready, schema, status, version
 from .tasks import offload_task
 from .validators import validate_overage
 
@@ -1116,6 +1116,10 @@ class TestStatus(TestCase):
         """Test isImportingData check."""
         self.assertEqual(ready.isImportingData(), False)
 
+    def test_GeneratingSchema(self):
+        """Test isGeneratingSchema check."""
+        self.assertEqual(ready.isGeneratingSchema(), False)
+
 
 class TestSettings(InvenTreeTestCase):
     """Unit tests for settings."""
@@ -1631,3 +1635,62 @@ class ClassProviderMixinTest(TestCase):
     def test_get_is_builtin(self):
         """Test the get_is_builtin function."""
         self.assertTrue(self.TestClass.get_is_builtin())
+
+
+class SchemaPostprocessingTest(TestCase):
+    """Tests for schema postprocessing functions."""
+
+    def create_result_structure(self):
+        """Create a schema dict structure representative of the spectacular-generated on."""
+        return {
+            'openapi': {},
+            'info': {},
+            'paths': {},
+            'components': {
+                'examples': {},
+                'parameters': {},
+                'requestBodies': {},
+                'responses': {},
+                'schemas': {},
+                'securitySchemes': {},
+            },
+            'servers': {},
+            'externalDocs': {},
+        }
+
+    def test_postprocess_required_nullable(self):
+        """Verify that only selected elements are removed from required list."""
+        result_in = self.create_result_structure()
+        schemas_in = result_in.get('components').get('schemas')
+
+        schemas_in['SalesOrder'] = {
+            'properties': {
+                'pk': {'type': 'integer', 'readOnly': True, 'title': 'ID'},
+                'customer_detail': {
+                    'allOf': [{'$ref': '#/components/schemas/CompanyBrief'}],
+                    'readOnly': True,
+                    'nullable': True,
+                },
+            },
+            'required': ['customer_detail', 'pk'],
+        }
+
+        schemas_in['SalesOrderShipment'] = {
+            'properties': {
+                'order_detail': {
+                    'allOf': [{'$ref': '#/components/schemas/SalesOrder'}],
+                    'readOnly': True,
+                    'nullable': True,
+                }
+            },
+            'required': ['order_detail'],
+        }
+
+        result_out = schema.postprocess_required_nullable(result_in, {}, {}, {})
+        schemas_out = result_out.get('components').get('schemas')
+
+        # only intended elements removed (read-only, required, and object type)
+        self.assertIn('pk', schemas_out.get('SalesOrder')['required'])
+        self.assertNotIn('customer_detail', schemas_out.get('SalesOrder')['required'])
+        # required key removed when empty
+        self.assertNotIn('required', schemas_out.get('SalesOrderShipment'))

src/backend/InvenTree/build/serializers.py

@@ -32,6 +32,7 @@ from common.serializers import ProjectCodeSerializer
 from common.settings import get_global_setting
 from generic.states.fields import InvenTreeCustomStatusSerializerMixin
 from importer.mixins import DataImportExportSerializerMixin
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.serializers import (
     InvenTreeDecimalField,
     InvenTreeModelSerializer,
@@ -126,7 +127,9 @@ class BuildSerializer(
 
     issued_by_detail = UserSerializer(source='issued_by', read_only=True)
 
-    responsible_detail = OwnerSerializer(source='responsible', read_only=True)
+    responsible_detail = OwnerSerializer(
+        source='responsible', read_only=True, allow_null=True
+    )
 
     barcode_hash = serializers.CharField(read_only=True)
 
@@ -177,6 +180,9 @@ class BuildSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not create:
             self.fields.pop('create_child_builds', None)
 
@@ -1204,6 +1210,9 @@ class BuildItemSerializer(DataImportExportSerializerMixin, InvenTreeModelSeriali
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not part_detail:
             self.fields.pop('part_detail', None)
 
@@ -1246,11 +1255,12 @@ class BuildItemSerializer(DataImportExportSerializerMixin, InvenTreeModelSeriali
         source='stock_item.part',
         many=False,
         read_only=True,
+        allow_null=True,
         pricing=False,
     )
 
     stock_item_detail = StockItemSerializerBrief(
-        source='stock_item', read_only=True, label=_('Stock Item')
+        source='stock_item', read_only=True, allow_null=True, label=_('Stock Item')
     )
 
     location = serializers.PrimaryKeyRelatedField(
@@ -1258,11 +1268,18 @@ class BuildItemSerializer(DataImportExportSerializerMixin, InvenTreeModelSeriali
     )
 
     location_detail = LocationBriefSerializer(
-        label=_('Location'), source='stock_item.location', read_only=True
+        label=_('Location'),
+        source='stock_item.location',
+        read_only=True,
+        allow_null=True,
     )
 
     build_detail = BuildSerializer(
-        label=_('Build'), source='build_line.build', many=False, read_only=True
+        label=_('Build'),
+        source='build_line.build',
+        many=False,
+        read_only=True,
+        allow_null=True,
     )
 
     supplier_part_detail = company.serializers.SupplierPartSerializer(
@@ -1270,6 +1287,7 @@ class BuildItemSerializer(DataImportExportSerializerMixin, InvenTreeModelSeriali
         source='stock_item.supplier_part',
         many=False,
         read_only=True,
+        allow_null=True,
         brief=True,
     )
 
@@ -1339,6 +1357,9 @@ class BuildLineSerializer(DataImportExportSerializerMixin, InvenTreeModelSeriali
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not part_detail:
             self.fields.pop('part_detail', None)
 

src/backend/InvenTree/common/serializers.py

@@ -333,7 +333,9 @@ class ProjectCodeSerializer(DataImportExportSerializerMixin, InvenTreeModelSeria
         model = common_models.ProjectCode
         fields = ['pk', 'code', 'description', 'responsible', 'responsible_detail']
 
-    responsible_detail = OwnerSerializer(source='responsible', read_only=True)
+    responsible_detail = OwnerSerializer(
+        source='responsible', read_only=True, allow_null=True
+    )
 
 
 @register_importer()

src/backend/InvenTree/company/serializers.py

@@ -14,6 +14,7 @@ import part.filters
 import part.serializers as part_serializers
 from importer.mixins import DataImportExportSerializerMixin
 from importer.registry import register_importer
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.serializers import (
     InvenTreeCurrencySerializer,
     InvenTreeDecimalField,
@@ -256,6 +257,9 @@ class ManufacturerPartSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if part_detail is not True:
             self.fields.pop('part_detail', None)
 
@@ -266,14 +270,14 @@ class ManufacturerPartSerializer(
             self.fields.pop('pretty_name', None)
 
     part_detail = part_serializers.PartBriefSerializer(
-        source='part', many=False, read_only=True
+        source='part', many=False, read_only=True, allow_null=True
     )
 
     manufacturer_detail = CompanyBriefSerializer(
-        source='manufacturer', many=False, read_only=True
+        source='manufacturer', many=False, read_only=True, allow_null=True
     )
 
-    pretty_name = serializers.CharField(read_only=True)
+    pretty_name = serializers.CharField(read_only=True, allow_null=True)
 
     manufacturer = serializers.PrimaryKeyRelatedField(
         queryset=Company.objects.filter(is_manufacturer=True)
@@ -306,11 +310,11 @@ class ManufacturerPartParameterSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if not man_detail:
+        if not man_detail and not isGeneratingSchema():
             self.fields.pop('manufacturer_part_detail', None)
 
     manufacturer_part_detail = ManufacturerPartSerializer(
-        source='manufacturer_part', many=False, read_only=True
+        source='manufacturer_part', many=False, read_only=True, allow_null=True
     )
 
 
@@ -389,6 +393,9 @@ class SupplierPartSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if part_detail is not True:
             self.fields.pop('part_detail', None)
 
@@ -409,20 +416,28 @@ class SupplierPartSerializer(
             self.fields.pop('availability_updated')
 
     # Annotated field showing total in-stock quantity
-    in_stock = serializers.FloatField(read_only=True, label=_('In Stock'))
+    in_stock = serializers.FloatField(
+        read_only=True, allow_null=True, label=_('In Stock')
+    )
 
-    on_order = serializers.FloatField(read_only=True, label=_('On Order'))
+    on_order = serializers.FloatField(
+        read_only=True, allow_null=True, label=_('On Order')
+    )
 
     available = serializers.FloatField(required=False, label=_('Available'))
 
     pack_quantity_native = serializers.FloatField(read_only=True)
 
     part_detail = part_serializers.PartBriefSerializer(
-        label=_('Part'), source='part', many=False, read_only=True
+        label=_('Part'), source='part', many=False, read_only=True, allow_null=True
     )
 
     supplier_detail = CompanyBriefSerializer(
-        label=_('Supplier'), source='supplier', many=False, read_only=True
+        label=_('Supplier'),
+        source='supplier',
+        many=False,
+        read_only=True,
+        allow_null=True,
     )
 
     manufacturer_detail = CompanyBriefSerializer(
@@ -430,9 +445,10 @@ class SupplierPartSerializer(
         source='manufacturer_part.manufacturer',
         many=False,
         read_only=True,
+        allow_null=True,
     )
 
-    pretty_name = serializers.CharField(read_only=True)
+    pretty_name = serializers.CharField(read_only=True, allow_null=True)
 
     supplier = serializers.PrimaryKeyRelatedField(
         label=_('Supplier'), queryset=Company.objects.filter(is_supplier=True)
@@ -443,6 +459,7 @@ class SupplierPartSerializer(
         source='manufacturer_part',
         part_detail=False,
         read_only=True,
+        allow_null=True,
     )
 
     MPN = serializers.CharField(
@@ -529,6 +546,9 @@ class SupplierPriceBreakSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not supplier_detail:
             self.fields.pop('supplier_detail', None)
 
@@ -553,10 +573,10 @@ class SupplierPriceBreakSerializer(
     )
 
     supplier_detail = CompanyBriefSerializer(
-        source='part.supplier', many=False, read_only=True
+        source='part.supplier', many=False, read_only=True, allow_null=True
     )
 
     # Detail serializer for SupplierPart
     part_detail = SupplierPartSerializer(
-        source='part', brief=True, many=False, read_only=True
+        source='part', brief=True, many=False, read_only=True, allow_null=True
     )

src/backend/InvenTree/order/serializers.py

@@ -44,6 +44,7 @@ from InvenTree.helpers import (
     normalize,
     str2bool,
 )
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.serializers import (
     InvenTreeCurrencySerializer,
     InvenTreeDecimalField,
@@ -128,11 +129,13 @@ class AbstractOrderSerializer(DataImportExportSerializerMixin, serializers.Seria
     reference = serializers.CharField(required=True)
 
     # Detail for point-of-contact field
-    contact_detail = ContactSerializer(source='contact', many=False, read_only=True)
+    contact_detail = ContactSerializer(
+        source='contact', many=False, read_only=True, allow_null=True
+    )
 
     # Detail for responsible field
     responsible_detail = OwnerSerializer(
-        source='responsible', read_only=True, many=False
+        source='responsible', read_only=True, allow_null=True, many=False
     )
 
     project_code_label = serializers.CharField(
@@ -149,7 +152,7 @@ class AbstractOrderSerializer(DataImportExportSerializerMixin, serializers.Seria
 
     # Detail for address field
     address_detail = AddressBriefSerializer(
-        source='address', many=False, read_only=True
+        source='address', many=False, read_only=True, allow_null=True
     )
 
     # Boolean field indicating if this order is overdue (Note: must be annotated)
@@ -275,7 +278,7 @@ class AbstractExtraLineSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if order_detail is not True:
+        if order_detail is not True and not isGeneratingSchema():
             self.fields.pop('order_detail', None)
 
     quantity = serializers.FloatField()
@@ -343,7 +346,7 @@ class PurchaseOrderSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if supplier_detail is not True:
+        if supplier_detail is not True and not isGeneratingSchema():
             self.fields.pop('supplier_detail', None)
 
     def skip_create_fields(self):
@@ -384,7 +387,7 @@ class PurchaseOrderSerializer(
     )
 
     supplier_detail = CompanyBriefSerializer(
-        source='supplier', many=False, read_only=True
+        source='supplier', many=False, read_only=True, allow_null=True
     )
 
 
@@ -518,6 +521,9 @@ class PurchaseOrderLineItemSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if part_detail is not True:
             self.fields.pop('part_detail', None)
             self.fields.pop('supplier_part_detail', None)
@@ -608,11 +614,11 @@ class PurchaseOrderLineItemSerializer(
     total_price = serializers.FloatField(read_only=True)
 
     part_detail = PartBriefSerializer(
-        source='get_base_part', many=False, read_only=True
+        source='get_base_part', many=False, read_only=True, allow_null=True
     )
 
     supplier_part_detail = SupplierPartSerializer(
-        source='part', brief=True, many=False, read_only=True
+        source='part', brief=True, many=False, read_only=True, allow_null=True
     )
 
     purchase_price = InvenTreeMoneySerializer(allow_null=True)
@@ -633,7 +639,9 @@ class PurchaseOrderLineItemSerializer(
         help_text=_('Purchase price currency')
     )
 
-    order_detail = PurchaseOrderSerializer(source='order', read_only=True, many=False)
+    order_detail = PurchaseOrderSerializer(
+        source='order', read_only=True, allow_null=True, many=False
+    )
 
     merge_items = serializers.BooleanField(
         label=_('Merge Items'),
@@ -699,7 +707,9 @@ class PurchaseOrderExtraLineSerializer(
 ):
     """Serializer for a PurchaseOrderExtraLine object."""
 
-    order_detail = PurchaseOrderSerializer(source='order', many=False, read_only=True)
+    order_detail = PurchaseOrderSerializer(
+        source='order', many=False, read_only=True, allow_null=True
+    )
 
     class Meta(AbstractExtraLineMeta):
         """Metaclass options."""
@@ -1025,7 +1035,7 @@ class SalesOrderSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if customer_detail is not True:
+        if customer_detail is not True and not isGeneratingSchema():
             self.fields.pop('customer_detail', None)
 
     def skip_create_fields(self):
@@ -1069,7 +1079,7 @@ class SalesOrderSerializer(
         return queryset
 
     customer_detail = CompanyBriefSerializer(
-        source='customer', many=False, read_only=True
+        source='customer', many=False, read_only=True, allow_null=True
     )
 
     shipments_count = serializers.IntegerField(read_only=True, label=_('Shipments'))
@@ -1135,6 +1145,9 @@ class SalesOrderLineItemSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if part_detail is not True:
             self.fields.pop('part_detail', None)
 
@@ -1233,10 +1246,14 @@ class SalesOrderLineItemSerializer(
 
         return queryset
 
-    order_detail = SalesOrderSerializer(source='order', many=False, read_only=True)
+    order_detail = SalesOrderSerializer(
-    part_detail = PartBriefSerializer(source='part', many=False, read_only=True)
+        source='order', many=False, read_only=True, allow_null=True
+    )
+    part_detail = PartBriefSerializer(
+        source='part', many=False, read_only=True, allow_null=True
+    )
     customer_detail = CompanyBriefSerializer(
-        source='order.customer', many=False, read_only=True
+        source='order.customer', many=False, read_only=True, allow_null=True
     )
 
     # Annotated fields
@@ -1289,7 +1306,7 @@ class SalesOrderShipmentSerializer(NotesFieldMixin, InvenTreeModelSerializer):
 
         super().__init__(*args, **kwargs)
 
-        if not order_detail:
+        if not order_detail and not isGeneratingSchema():
             self.fields.pop('order_detail', None)
 
     @staticmethod
@@ -1306,7 +1323,9 @@ class SalesOrderShipmentSerializer(NotesFieldMixin, InvenTreeModelSerializer):
         read_only=True, label=_('Allocated Items')
     )
 
-    order_detail = SalesOrderSerializer(source='order', read_only=True, many=False)
+    order_detail = SalesOrderSerializer(
+        source='order', read_only=True, allow_null=True, many=False
+    )
 
 
 class SalesOrderAllocationSerializer(InvenTreeModelSerializer):
@@ -1352,6 +1371,9 @@ class SalesOrderAllocationSerializer(InvenTreeModelSerializer):
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not order_detail:
             self.fields.pop('order_detail', None)
 
@@ -1378,16 +1400,20 @@ class SalesOrderAllocationSerializer(InvenTreeModelSerializer):
     )
 
     # Extra detail fields
-    order_detail = SalesOrderSerializer(source='line.order', many=False, read_only=True)
+    order_detail = SalesOrderSerializer(
-    part_detail = PartBriefSerializer(source='item.part', many=False, read_only=True)
+        source='line.order', many=False, read_only=True, allow_null=True
+    )
+    part_detail = PartBriefSerializer(
+        source='item.part', many=False, read_only=True, allow_null=True
+    )
     item_detail = stock.serializers.StockItemSerializerBrief(
-        source='item', many=False, read_only=True
+        source='item', many=False, read_only=True, allow_null=True
     )
     location_detail = stock.serializers.LocationBriefSerializer(
-        source='item.location', many=False, read_only=True
+        source='item.location', many=False, read_only=True, allow_null=True
     )
     customer_detail = CompanyBriefSerializer(
-        source='line.order.customer', many=False, read_only=True
+        source='line.order.customer', many=False, read_only=True, allow_null=True
     )
 
     shipment_detail = SalesOrderShipmentSerializer(
@@ -1833,7 +1859,9 @@ class SalesOrderExtraLineSerializer(
 
         model = order.models.SalesOrderExtraLine
 
-    order_detail = SalesOrderSerializer(source='order', many=False, read_only=True)
+    order_detail = SalesOrderSerializer(
+        source='order', many=False, read_only=True, allow_null=True
+    )
 
 
 @register_importer()
@@ -1869,7 +1897,7 @@ class ReturnOrderSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if customer_detail is not True:
+        if customer_detail is not True and not isGeneratingSchema():
             self.fields.pop('customer_detail', None)
 
     def skip_create_fields(self):
@@ -1902,7 +1930,7 @@ class ReturnOrderSerializer(
         return queryset
 
     customer_detail = CompanyBriefSerializer(
-        source='customer', many=False, read_only=True
+        source='customer', many=False, read_only=True, allow_null=True
     )
 
 
@@ -2081,6 +2109,9 @@ class ReturnOrderLineItemSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not order_detail:
             self.fields.pop('order_detail', None)
 
@@ -2090,17 +2121,21 @@ class ReturnOrderLineItemSerializer(
         if not part_detail:
             self.fields.pop('part_detail', None)
 
-    order_detail = ReturnOrderSerializer(source='order', many=False, read_only=True)
+    order_detail = ReturnOrderSerializer(
+        source='order', many=False, read_only=True, allow_null=True
+    )
 
     quantity = serializers.FloatField(
         label=_('Quantity'), help_text=_('Quantity to return')
     )
 
     item_detail = stock.serializers.StockItemSerializer(
-        source='item', many=False, read_only=True
+        source='item', many=False, read_only=True, allow_null=True
     )
 
-    part_detail = PartBriefSerializer(source='item.part', many=False, read_only=True)
+    part_detail = PartBriefSerializer(
+        source='item.part', many=False, read_only=True, allow_null=True
+    )
 
     price = InvenTreeMoneySerializer(allow_null=True)
     price_currency = InvenTreeCurrencySerializer(help_text=_('Line price currency'))
@@ -2117,4 +2152,6 @@ class ReturnOrderExtraLineSerializer(
 
         model = order.models.ReturnOrderExtraLine
 
-    order_detail = ReturnOrderSerializer(source='order', many=False, read_only=True)
+    order_detail = ReturnOrderSerializer(
+        source='order', many=False, read_only=True, allow_null=True
+    )

src/backend/InvenTree/part/serializers.py

@@ -35,6 +35,7 @@ import users.models
 from build.status_codes import BuildStatusGroups
 from importer.mixins import DataImportExportSerializerMixin
 from importer.registry import register_importer
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.tasks import offload_task
 from users.serializers import UserSerializer
 
@@ -94,7 +95,7 @@ class CategorySerializer(
 
         super().__init__(*args, **kwargs)
 
-        if not path_detail:
+        if not path_detail and not isGeneratingSchema():
             self.fields.pop('path', None)
 
     def get_starred(self, category) -> bool:
@@ -133,7 +134,10 @@ class CategorySerializer(
     starred = serializers.SerializerMethodField()
 
     path = serializers.ListField(
-        child=serializers.DictField(), source='get_path', read_only=True
+        child=serializers.DictField(),
+        source='get_path',
+        read_only=True,
+        allow_null=True,
     )
 
     icon = serializers.CharField(
@@ -383,7 +387,7 @@ class PartBriefSerializer(InvenTree.serializers.InvenTreeModelSerializer):
 
         super().__init__(*args, **kwargs)
 
-        if not pricing:
+        if not pricing and not isGeneratingSchema():
             self.fields.pop('pricing_min', None)
             self.fields.pop('pricing_max', None)
 
@@ -444,15 +448,20 @@ class PartParameterSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not part_detail:
             self.fields.pop('part_detail', None)
 
         if not template_detail:
             self.fields.pop('template_detail', None)
 
-    part_detail = PartBriefSerializer(source='part', many=False, read_only=True)
+    part_detail = PartBriefSerializer(
+        source='part', many=False, read_only=True, allow_null=True
+    )
     template_detail = PartParameterTemplateSerializer(
-        source='template', many=False, read_only=True
+        source='template', many=False, read_only=True, allow_null=True
     )
 
 
@@ -782,6 +791,9 @@ class PartSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not category_detail:
             self.fields.pop('category_detail', None)
 
@@ -923,14 +935,19 @@ class PartSerializer(
         return part in self.starred_parts
 
     # Extra detail for the category
-    category_detail = CategorySerializer(source='category', many=False, read_only=True)
+    category_detail = CategorySerializer(
+        source='category', many=False, read_only=True, allow_null=True
+    )
 
     category_path = serializers.ListField(
-        child=serializers.DictField(), source='category.get_path', read_only=True
+        child=serializers.DictField(),
+        source='category.get_path',
+        read_only=True,
+        allow_null=True,
     )
 
     default_location_detail = DefaultLocationSerializer(
-        source='default_location', many=False, read_only=True
+        source='default_location', many=False, read_only=True, allow_null=True
     )
 
     category_name = serializers.CharField(
@@ -1003,7 +1020,7 @@ class PartSerializer(
         source='pricing_data.updated', allow_null=True, read_only=True
     )
 
-    parameters = PartParameterSerializer(many=True, read_only=True)
+    parameters = PartParameterSerializer(many=True, read_only=True, allow_null=True)
 
     # Extra fields used only for creation of a new Part instance
     duplicate = DuplicatePartSerializer(
@@ -1617,6 +1634,9 @@ class BomItemSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not part_detail:
             self.fields.pop('part_detail', None)
 
@@ -1648,10 +1668,12 @@ class BomItemSerializer(
         help_text=_('Select the parent assembly'),
     )
 
-    substitutes = BomItemSubstituteSerializer(many=True, read_only=True)
+    substitutes = BomItemSubstituteSerializer(
+        many=True, read_only=True, allow_null=True
+    )
 
     part_detail = PartBriefSerializer(
-        source='part', label=_('Assembly'), many=False, read_only=True
+        source='part', label=_('Assembly'), many=False, read_only=True, allow_null=True
     )
 
     sub_part = serializers.PrimaryKeyRelatedField(
@@ -1661,7 +1683,11 @@ class BomItemSerializer(
     )
 
     sub_part_detail = PartBriefSerializer(
-        source='sub_part', label=_('Component'), many=False, read_only=True
+        source='sub_part',
+        label=_('Component'),
+        many=False,
+        read_only=True,
+        allow_null=True,
     )
 
     on_order = serializers.FloatField(label=_('On Order'), read_only=True)
@@ -1867,7 +1893,9 @@ class CategoryParameterTemplateSerializer(
         source='parameter_template', many=False, read_only=True
     )
 
-    category_detail = CategorySerializer(source='category', many=False, read_only=True)
+    category_detail = CategorySerializer(
+        source='category', many=False, read_only=True, allow_null=True
+    )
 
 
 class PartCopyBOMSerializer(serializers.Serializer):

src/backend/InvenTree/stock/serializers.py

@@ -30,6 +30,7 @@ from common.settings import get_global_setting
 from generic.states.fields import InvenTreeCustomStatusSerializerMixin
 from importer.mixins import DataImportExportSerializerMixin
 from importer.registry import register_importer
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.serializers import InvenTreeCurrencySerializer, InvenTreeDecimalField
 from users.serializers import UserSerializer
 
@@ -218,13 +219,16 @@ class StockItemTestResultSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if user_detail is not True:
             self.fields.pop('user_detail', None)
 
         if template_detail is not True:
             self.fields.pop('template_detail', None)
 
-    user_detail = UserSerializer(source='user', read_only=True)
+    user_detail = UserSerializer(source='user', read_only=True, allow_null=True)
 
     template = serializers.PrimaryKeyRelatedField(
         queryset=part_models.PartTestTemplate.objects.all(),
@@ -236,7 +240,7 @@ class StockItemTestResultSerializer(
     )
 
     template_detail = part_serializers.PartTestTemplateSerializer(
-        source='template', read_only=True
+        source='template', read_only=True, allow_null=True
     )
 
     attachment = InvenTree.serializers.InvenTreeAttachmentSerializerField(
@@ -442,6 +446,9 @@ class StockItemSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if not part_detail:
             self.fields.pop('part_detail', None)
 
@@ -473,7 +480,10 @@ class StockItemSerializer(
     )
 
     location_path = serializers.ListField(
-        child=serializers.DictField(), source='location.get_path', read_only=True
+        child=serializers.DictField(),
+        source='location.get_path',
+        read_only=True,
+        allow_null=True,
     )
 
     in_stock = serializers.BooleanField(read_only=True, label=_('In Stock'))
@@ -617,18 +627,23 @@ class StockItemSerializer(
         part_detail=False,
         many=False,
         read_only=True,
+        allow_null=True,
     )
 
     part_detail = part_serializers.PartBriefSerializer(
-        label=_('Part'), source='part', many=False, read_only=True
+        label=_('Part'), source='part', many=False, read_only=True, allow_null=True
     )
 
     location_detail = LocationBriefSerializer(
-        label=_('Location'), source='location', many=False, read_only=True
+        label=_('Location'),
+        source='location',
+        many=False,
+        read_only=True,
+        allow_null=True,
     )
 
     tests = StockItemTestResultSerializer(
-        source='test_results', many=True, read_only=True
+        source='test_results', many=True, read_only=True, allow_null=True
     )
 
     quantity = InvenTreeDecimalField()
@@ -1184,7 +1199,7 @@ class LocationSerializer(
 
         super().__init__(*args, **kwargs)
 
-        if not path_detail:
+        if not path_detail and not isGeneratingSchema():
             self.fields.pop('path', None)
 
     @staticmethod
@@ -1219,7 +1234,10 @@ class LocationSerializer(
     tags = TagListSerializerField(required=False)
 
     path = serializers.ListField(
-        child=serializers.DictField(), source='get_path', read_only=True
+        child=serializers.DictField(),
+        source='get_path',
+        read_only=True,
+        allow_null=True,
     )
 
     # explicitly set this field, so it gets included for AutoSchema
@@ -1263,6 +1281,9 @@ class StockTrackingSerializer(
 
         super().__init__(*args, **kwargs)
 
+        if isGeneratingSchema():
+            return
+
         if item_detail is not True:
             self.fields.pop('item_detail', None)
 
@@ -1271,9 +1292,13 @@ class StockTrackingSerializer(
 
     label = serializers.CharField(read_only=True)
 
-    item_detail = StockItemSerializerBrief(source='item', many=False, read_only=True)
+    item_detail = StockItemSerializerBrief(
+        source='item', many=False, read_only=True, allow_null=True
+    )
 
-    user_detail = UserSerializer(source='user', many=False, read_only=True)
+    user_detail = UserSerializer(
+        source='user', many=False, read_only=True, allow_null=True
+    )
 
     deltas = serializers.JSONField(read_only=True)
 

src/backend/InvenTree/users/serializers.py

@@ -8,6 +8,7 @@ from django.utils.translation import gettext_lazy as _
 from rest_framework import serializers
 from rest_framework.exceptions import PermissionDenied
 
+from InvenTree.ready import isGeneratingSchema
 from InvenTree.serializers import InvenTreeModelSerializer
 
 from .models import ApiToken, Owner, RuleSet, UserProfile, check_user_role
@@ -44,12 +45,12 @@ class GroupSerializer(InvenTreeModelSerializer):
         super().__init__(*args, **kwargs)
 
         try:
-            if not permission_detail:
+            if not permission_detail and not isGeneratingSchema():
                 self.fields.pop('permissions', None)
         except AppRegistryNotReady:
             pass
 
-    permissions = serializers.SerializerMethodField()
+    permissions = serializers.SerializerMethodField(allow_null=True)
 
     def get_permissions(self, group: Group):
         """Return a list of permissions associated with the group."""
@@ -74,7 +75,7 @@ class RoleSerializer(InvenTreeModelSerializer):
 
     user = serializers.IntegerField(source='pk')
     roles = serializers.SerializerMethodField()
-    permissions = serializers.SerializerMethodField()
+    permissions = serializers.SerializerMethodField(allow_null=True)
 
     def get_roles(self, user: User) -> dict:
         """Roles associated with the user."""