API / serializer updates

src/backend/InvenTree/common/api.py

@@ -819,6 +819,47 @@ class AttachmentDetail(AttachmentMixin, RetrieveUpdateDestroyAPI):
         return super().destroy(request, *args, **kwargs)
 
 
+class NoteFilter(FilterSet):
+    """Filterset class for the NoteList API endpoint."""
+
+    class Meta:
+        """Metaclass options for the filterset."""
+
+        model = common.models.Note
+        fields = ['model_type', 'model_id', 'updated_by']
+
+    model_type = rest_filters.CharFilter(method='filter_model_type', label='Model Type')
+
+    def filter_model_type(self, queryset, name, value):
+        """Filter queryset to include only Parameters of the given model type."""
+        return common.filters.filter_content_type(
+            queryset, 'model_type', value, allow_null=False
+        )
+
+
+class NoteMixin:
+    """Mixin class for the Note views."""
+
+    queryset = common.models.Note.objects.all()
+    serializer_class = common.serializers.NoteSerializer
+    permission_classes = [IsAuthenticatedOrReadScope]
+
+
+class NoteList(NoteMixin, ListCreateAPI):
+    """List API endpoint for Note objects."""
+
+    filter_backends = SEARCH_ORDER_FILTER
+    filterset_class = NoteFilter
+
+    ordering_fields = ['model_id', 'model_type', 'user', 'creation']
+    search_fields = ['content', 'model_id', 'model_type', 'user__username']
+    unique_create_fields = ['model_type', 'model_id']
+
+
+class NoteDetail(NoteMixin, RetrieveUpdateDestroyAPI):
+    """Detail API endpoint for Note objects."""
+
+
 class ParameterTemplateFilter(FilterSet):
     """FilterSet class for the ParameterTemplateList API endpoint."""
 
@@ -1477,6 +1518,20 @@ common_api_urls = [
             path('', AttachmentList.as_view(), name='api-attachment-list'),
         ]),
     ),
+    # Notes
+    path(
+        'note/',
+        include([
+            path(
+                '<int:pk>/',
+                include([
+                    meta_path(common.models.Note),
+                    path('', NoteDetail.as_view(), name='api-note-detail'),
+                ]),
+            ),
+            path('', NoteList.as_view(), name='api-note-list'),
+        ]),
+    ),
     # Parameters and templates
     path(
         'parameter/',

src/backend/InvenTree/common/migrations/0042_note.py

@@ -1,4 +1,4 @@
-# Generated by Django 5.2.14 on 2026-05-18 13:55
+# Generated by Django 5.2.14 on 2026-05-18 14:16
 
 import InvenTree.models
 import django.db.models.deletion
@@ -62,6 +62,12 @@ class Migration(migrations.Migration):
                         verbose_name="Description",
                     ),
                 ),
+                (
+                    "content",
+                    models.TextField(
+                        blank=True, help_text="Note content", verbose_name="Content"
+                    ),
+                ),
                 (
                     "model_type",
                     models.ForeignKey(

src/backend/InvenTree/common/models.py

@@ -2987,6 +2987,10 @@ class Note(
         help_text=_('Optional description field'),
     )
 
+    content = models.TextField(
+        blank=True, verbose_name=_('Content'), help_text=_('Note content')
+    )
+
 
 class BarcodeScanResult(InvenTree.models.InvenTreeModel):
     """Model for storing barcode scans results."""

src/backend/InvenTree/common/serializers.py

@@ -809,6 +809,82 @@ class AttachmentSerializer(FilterableSerializerMixin, InvenTreeModelSerializer):
         return super().save(**kwargs)
 
 
+class NoteSerializer(InvenTreeModelSerializer):
+    """Serializer for the Note model."""
+
+    class Meta:
+        """Meta options for NoteSerializer."""
+
+        model = common_models.Note
+        fields = [
+            'pk',
+            'model_type',
+            'model_id',
+            'title',
+            'description',
+            'content',
+            'updated',
+            'updated_by',
+        ]
+
+        read_only_fields = ['updated', 'updated_by']
+
+    def save(self, **kwargs):
+        """Save the Note instance."""
+        from InvenTree.models import InvenTreeNoteMixin
+        from users.permissions import check_user_permission
+
+        model_type = self.validated_data.get('model_type', None)
+
+        if model_type is None and self.instance:
+            model_type = self.instance.model_type
+
+        # Ensure that the user has permission to modify notes for the specified model
+        user = self.context.get('request').user
+
+        target_model_class = model_type.model_class()
+
+        if not issubclass(target_model_class, InvenTreeNoteMixin):
+            raise PermissionDenied(_('Invalid model type specified for note'))
+
+        permission_error_msg = _(
+            'User does not have permission to create or edit notes for this model'
+        )
+
+        if not check_user_permission(user, target_model_class, 'change'):
+            raise PermissionDenied(permission_error_msg)
+
+        if not target_model_class.check_related_permission('change', user):
+            raise PermissionDenied(permission_error_msg)
+
+        instance = super().save(**kwargs)
+        instance.updated_by = user
+        instance.save()
+
+        return instance
+
+    # Note: The choices are overridden at run-time on class initialization
+    model_type = ContentTypeField(
+        mixin_class=InvenTreeParameterMixin,
+        choices=common.validators.note_model_options,
+        label=_('Model Type'),
+        default='',
+        allow_null=False,
+    )
+
+    updated_by_detail = OptionalField(
+        serializer_class=UserSerializer,
+        serializer_kwargs={
+            'source': 'updated_by',
+            'read_only': True,
+            'allow_null': True,
+            'many': False,
+        },
+        default_include=True,
+        prefetch_fields=['updated_by'],
+    )
+
+
 @register_importer()
 class ParameterTemplateSerializer(
     DataImportExportSerializerMixin, InvenTreeModelSerializer

src/backend/InvenTree/common/validators.py

@@ -9,6 +9,23 @@ import common.icons
 from common.settings import get_global_setting
 
 
+def note_model_types():
+    """Return a list of valid note model choices."""
+    import InvenTree.models
+
+    return list(
+        InvenTree.helpers_model.getModelsWithMixin(InvenTree.models.InvenTreeNotesMixin)
+    )
+
+
+def note_model_options():
+    """Return a list of options for models which support notes."""
+    return [
+        (model.__name__.lower(), model._meta.verbose_name)
+        for model in note_model_types()
+    ]
+
+
 def parameter_model_types():
     """Return a list of valid parameter model choices."""
     import InvenTree.models