diff --git a/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentInput.cs b/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentInput.cs
index cc5ee3efec..d17e8c9deb 100644
--- a/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentInput.cs
+++ b/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentInput.cs
@@ -21,5 +21,6 @@ public class CreateCommentInput : ExtensibleObject
     
     public string Url { get; set; }
 
+    [Required]
     public string IdempotencyToken { get; set; }
 }
diff --git a/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentWithParametersInput.cs b/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentWithParametersInput.cs
index ec7aad1398..fda4856ffb 100644
--- a/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentWithParametersInput.cs
+++ b/modules/cms-kit/src/Volo.CmsKit.Public.Application.Contracts/Volo/CmsKit/Public/Comments/CreateCommentWithParametersInput.cs
@@ -26,5 +26,6 @@ public class CreateCommentWithParametersInput
 
     public string Url { get; set; }
 
+    [Required]
     public string IdempotencyToken { get; set; }
 }
diff --git a/modules/cms-kit/test/Volo.CmsKit.Application.Tests/Comments/CommentPublicAppService_Tests.cs b/modules/cms-kit/test/Volo.CmsKit.Application.Tests/Comments/CommentPublicAppService_Tests.cs
index cbb165c1cd..d01fc295cf 100644
--- a/modules/cms-kit/test/Volo.CmsKit.Application.Tests/Comments/CommentPublicAppService_Tests.cs
+++ b/modules/cms-kit/test/Volo.CmsKit.Application.Tests/Comments/CommentPublicAppService_Tests.cs
@@ -1,4 +1,5 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
 using NSubstitute;
@@ -48,7 +49,8 @@ public class CommentPublicAppService_Tests : CmsKitApplicationTestBase
             new CreateCommentInput
             {
                 RepliedCommentId = null,
-                Text = "newComment"
+                Text = "newComment",
+                IdempotencyToken = Guid.NewGuid().ToString("N")
             }
         );
 
@@ -75,7 +77,8 @@ public class CommentPublicAppService_Tests : CmsKitApplicationTestBase
             new CreateCommentInput
             {
                 RepliedCommentId = null,
-                Text = text
+                Text = text,
+                IdempotencyToken = Guid.NewGuid().ToString("N")
             }
         );
     }
@@ -95,6 +98,25 @@ public class CommentPublicAppService_Tests : CmsKitApplicationTestBase
                 {
                     RepliedCommentId = null,
                     Text = text, //not allowed URL
+                    IdempotencyToken = Guid.NewGuid().ToString("N")
+                }
+            ));
+    }
+
+    [Fact]
+    public async Task CreateAsync_ShouldThrowUserFriendlyException_If_IdempotencyToken_Not_Unique() 
+    {
+        _currentUser.Id.Returns(_cmsKitTestData.User2Id);
+
+        await Should.ThrowAsync<UserFriendlyException>(async () =>
+            await _commentAppService.CreateAsync(
+                _cmsKitTestData.EntityType1,
+                _cmsKitTestData.EntityId1,
+                new CreateCommentInput 
+                {
+                    RepliedCommentId = null,
+                    Text = "<text>", 
+                    IdempotencyToken = _cmsKitTestData.IdempotencyToken_1
                 }
             ));
     }
diff --git a/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitDataSeedContributor.cs b/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitDataSeedContributor.cs
index af5ee0754a..f17a95ddba 100644
--- a/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitDataSeedContributor.cs
+++ b/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitDataSeedContributor.cs
@@ -194,7 +194,7 @@ public class CmsKitDataSeedContributor : IDataSeedContributor, ITransientDepende
             "comment",
             null,
             _cmsKitTestData.User1Id
-        ));
+        ){ IdempotencyToken = _cmsKitTestData.IdempotencyToken_1 });
 
         await _commentRepository.InsertAsync(new Comment(_guidGenerator.Create(),
             _cmsKitTestData.EntityType1,
diff --git a/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitTestData.cs b/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitTestData.cs
index cfa54d2e55..8c4c07e283 100644
--- a/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitTestData.cs
+++ b/modules/cms-kit/test/Volo.CmsKit.TestBase/CmsKitTestData.cs
@@ -131,4 +131,6 @@ public class CmsKitTestData : ISingletonDependency
     public string PollName { get; } = "Poll";
 
     public string WidgetName { get; } = "CmsPollByCode";
+
+    public string IdempotencyToken_1 { get; } = Guid.NewGuid().ToString("N");
 }