diff --git a/src/Tingle.AspNetCore.Swagger/Filters/Operations/ErrorCodesOperationFilter.cs b/src/Tingle.AspNetCore.Swagger/Filters/Operations/ErrorCodesOperationFilter.cs
index a6beed6..fff33a6 100644
--- a/src/Tingle.AspNetCore.Swagger/Filters/Operations/ErrorCodesOperationFilter.cs
+++ b/src/Tingle.AspNetCore.Swagger/Filters/Operations/ErrorCodesOperationFilter.cs
@@ -24,12 +24,17 @@ public void Apply(OpenApiOperation operation, OperationFilterContext context)
         attributes.AddRange(methodAttributes);
 
         // get attributes from the controller
-        if (context.ApiDescription.ActionDescriptor is ControllerActionDescriptor cad)
+        var actionDescriptor = context.ApiDescription.ActionDescriptor;
+        if (actionDescriptor is ControllerActionDescriptor cad)
         {
             var controllerAttributes = cad.ControllerTypeInfo.GetCustomAttributes(inherit: true).OfType<OperationErrorCodesAttribute>();
             attributes.AddRange(controllerAttributes);
         }
 
+        // get attributes from the endpoint metadata
+        var metadataAttributes = actionDescriptor.EndpointMetadata.OfType<OperationErrorCodesAttribute>();
+        attributes.AddRange(metadataAttributes);
+
         // make unique error codes
         var uniqueErrorCodes = attributes.SelectMany(attr => attr.Errors)
                                          .ToHashSet(StringComparer.OrdinalIgnoreCase);
diff --git a/src/Tingle.AspNetCore.Swagger/Filters/Operations/ExtraTagsOperationFilter.cs b/src/Tingle.AspNetCore.Swagger/Filters/Operations/ExtraTagsOperationFilter.cs
index d224383..5262659 100644
--- a/src/Tingle.AspNetCore.Swagger/Filters/Operations/ExtraTagsOperationFilter.cs
+++ b/src/Tingle.AspNetCore.Swagger/Filters/Operations/ExtraTagsOperationFilter.cs
@@ -22,21 +22,24 @@ public void Apply(OpenApiOperation operation, OperationFilterContext context)
         attributes.AddRange(methodAttributes);
 
         // get attributes from the controller
-        if (context.ApiDescription.ActionDescriptor is ControllerActionDescriptor cad)
+        var actionDescriptor = context.ApiDescription.ActionDescriptor;
+        if (actionDescriptor is ControllerActionDescriptor cad)
         {
             var controllerAttributes = cad.ControllerTypeInfo.GetCustomAttributes(inherit: true).OfType<OperationExtraTagAttribute>();
             attributes.AddRange(controllerAttributes);
         }
 
+        // get attributes from the endpoint metadata
+        var metadataAttributes = actionDescriptor.EndpointMetadata.OfType<OperationExtraTagAttribute>();
+        attributes.AddRange(metadataAttributes);
+
         // make the attributes unique by name
-        var uniqueAttributes = attributes.ToDictionary(attr => attr.Name, StringComparer.OrdinalIgnoreCase);
+        var uniqueAttributes = attributes.DistinctBy(attr => attr.Name, StringComparer.OrdinalIgnoreCase);
 
         operation.Tags ??= [];
 
-        foreach (var kvp in uniqueAttributes)
+        foreach (var attr in uniqueAttributes)
         {
-            var attr = kvp.Value;
-
             operation.Tags.Add(new OpenApiTag
             {
                 Name = attr.Name,
diff --git a/src/Tingle.AspNetCore.Swagger/Filters/Operations/InternalOnlyOperationFilter.cs b/src/Tingle.AspNetCore.Swagger/Filters/Operations/InternalOnlyOperationFilter.cs
index 32dec68..cdd8467 100644
--- a/src/Tingle.AspNetCore.Swagger/Filters/Operations/InternalOnlyOperationFilter.cs
+++ b/src/Tingle.AspNetCore.Swagger/Filters/Operations/InternalOnlyOperationFilter.cs
@@ -18,12 +18,15 @@ public class InternalOnlyOperationFilter : IOperationFilter
     /// <inheritdoc/>
     public void Apply(OpenApiOperation operation, OperationFilterContext context)
     {
-        // Check if the method or controller has the attribute declared/annotated
+        // check attribute on the method
         var attr = context.MethodInfo.GetCustomAttribute<InternalOnlyAttribute>(inherit: true);
-        if (attr is null && context.ApiDescription.ActionDescriptor is ControllerActionDescriptor cad)
-        {
-            attr = cad.ControllerTypeInfo.GetCustomAttribute<InternalOnlyAttribute>(inherit: true);
-        }
+
+        // check attribute on the controller
+        var actionDescriptor = context.ApiDescription.ActionDescriptor;
+        attr ??= (actionDescriptor as ControllerActionDescriptor)?.ControllerTypeInfo.GetCustomAttribute<InternalOnlyAttribute>(inherit: true);
+
+        // check the endpoint metadata
+        attr ??= actionDescriptor.EndpointMetadata.OfType<InternalOnlyAttribute>().FirstOrDefault();
         if (attr is null) return;
 
         // At this point, the API is internal only, so just set the extension value