diff --git a/samples/Demo/Beef.Demo.Api/Controllers/PersonController.cs b/samples/Demo/Beef.Demo.Api/Controllers/PersonController.cs
new file mode 100644
index 00000000..62e50ef9
--- /dev/null
+++ b/samples/Demo/Beef.Demo.Api/Controllers/PersonController.cs
@@ -0,0 +1,38 @@
+#nullable enable
+
+using CoreEx.Results;
+
+namespace Beef.Demo.Api.Controllers
+{
+    public partial class PersonController
+    {
+        /// <summary>
+        /// Extend Response.
+        /// </summary>
+        /// <returns>A resultant <c>string</c>.</returns>
+        [HttpPost("api/v1/persons/extend-response", Name = "Person_ExtendResponse")]
+        [ProducesResponseType(typeof(string), (int)HttpStatusCode.OK)]
+        [ProducesResponseType((int)HttpStatusCode.NoContent)]
+        public Task<IActionResult> ExtendResponse(string? name)
+            => _webApi.PostWithResultAsync(Request, p =>
+            {
+                return Result.GoAsync(() => _manager.ExtendResponseAsync(name))  // Execute the business logic.
+                    .ThenAs(r =>                                                 // Then handle response where Result.IsSuccess; otherwise, allow to bubble out.
+                    {
+                        var ia = ValueContentResult.CreateResult(r, HttpStatusCode.OK, null, _webApi.JsonSerializer, p.RequestOptions, false, null);  // Use standard CoreEx ValueContentResult to handle the response.
+                        if (ia is ValueContentResult vcr)                        // Ensure is a ValueContentResult, and if so, then manipulate.
+                        {
+                            vcr.BeforeExtension = hr =>                          // Extend the reponse by adding a new header.
+                            {
+                                hr.Headers.Add("X-Beef-Test", "123");
+                                return Task.CompletedTask;
+                            };
+                        }
+
+                        return ia;
+                    });
+            }, alternateStatusCode: HttpStatusCode.NoContent, operationType: CoreEx.OperationType.Unspecified);
+    }
+}
+
+#nullable restore
\ No newline at end of file
diff --git a/samples/Demo/Beef.Demo.Business/Data/Generated/IPersonData.cs b/samples/Demo/Beef.Demo.Business/Data/Generated/IPersonData.cs
index 7e3d05d6..19f37324 100644
--- a/samples/Demo/Beef.Demo.Business/Data/Generated/IPersonData.cs
+++ b/samples/Demo/Beef.Demo.Business/Data/Generated/IPersonData.cs
@@ -202,6 +202,13 @@ public partial interface IPersonData
     /// <param name="id">The <see cref="Person"/> identifier.</param>
     /// <returns>A resultant <see cref="string"/>.</returns>
     Task<Result<string?>> SimulateWorkAsync(Guid id);
+
+    /// <summary>
+    /// Extend Response.
+    /// </summary>
+    /// <param name="name">The Name.</param>
+    /// <returns>A resultant <see cref="string"/>.</returns>
+    Task<Result<string?>> ExtendResponseAsync(string? name);
 }
 
 #pragma warning restore
diff --git a/samples/Demo/Beef.Demo.Business/Data/Generated/PersonData.cs b/samples/Demo/Beef.Demo.Business/Data/Generated/PersonData.cs
index 2d02a4e1..4372172c 100644
--- a/samples/Demo/Beef.Demo.Business/Data/Generated/PersonData.cs
+++ b/samples/Demo/Beef.Demo.Business/Data/Generated/PersonData.cs
@@ -230,6 +230,9 @@ public Task DeleteWithEfAsync(Guid id) => DataInvoker.Current.InvokeAsync(this,
     /// <inheritdoc/>
     public Task<Result<string?>> SimulateWorkAsync(Guid id) => SimulateWorkOnImplementationAsync(id);
 
+    /// <inheritdoc/>
+    public Task<Result<string?>> ExtendResponseAsync(string? name) => ExtendResponseOnImplementationAsync(name);
+
     /// <summary>
     /// Provides the <see cref="Person"/> property and database column mapping.
     /// </summary>
diff --git a/samples/Demo/Beef.Demo.Business/Data/PersonData.cs b/samples/Demo/Beef.Demo.Business/Data/PersonData.cs
index aa1eb67b..e85c9ca0 100644
--- a/samples/Demo/Beef.Demo.Business/Data/PersonData.cs
+++ b/samples/Demo/Beef.Demo.Business/Data/PersonData.cs
@@ -166,5 +166,7 @@ private static Task Add3OnImplementationAsync(Person value)
             if (value == null) throw new ArgumentNullException(nameof(value));
             return Task.CompletedTask;
         }
+
+        private Task<Result<string?>> ExtendResponseOnImplementationAsync(string? name) => name is null ? Result<string?>.Fail("Name is needed dude!").AsTask() : Result.Ok<string?>(name).AsTask();
     }
 }
\ No newline at end of file
diff --git a/samples/Demo/Beef.Demo.Business/DataSvc/Generated/IPersonDataSvc.cs b/samples/Demo/Beef.Demo.Business/DataSvc/Generated/IPersonDataSvc.cs
index 6c55335f..fefd1419 100644
--- a/samples/Demo/Beef.Demo.Business/DataSvc/Generated/IPersonDataSvc.cs
+++ b/samples/Demo/Beef.Demo.Business/DataSvc/Generated/IPersonDataSvc.cs
@@ -221,6 +221,13 @@ public partial interface IPersonDataSvc
     /// <param name="id">The <see cref="Person"/> identifier.</param>
     /// <returns>A resultant <see cref="string"/>.</returns>
     Task<Result<string?>> SimulateWorkAsync(Guid id);
+
+    /// <summary>
+    /// Extend Response.
+    /// </summary>
+    /// <param name="name">The Name.</param>
+    /// <returns>A resultant <see cref="string"/>.</returns>
+    Task<Result<string?>> ExtendResponseAsync(string? name);
 }
 
 #pragma warning restore
diff --git a/samples/Demo/Beef.Demo.Business/DataSvc/Generated/PersonDataSvc.cs b/samples/Demo/Beef.Demo.Business/DataSvc/Generated/PersonDataSvc.cs
index 9e23ff32..0d4e5206 100644
--- a/samples/Demo/Beef.Demo.Business/DataSvc/Generated/PersonDataSvc.cs
+++ b/samples/Demo/Beef.Demo.Business/DataSvc/Generated/PersonDataSvc.cs
@@ -45,6 +45,7 @@ public partial class PersonDataSvc : IPersonDataSvc
     private Func<Guid, Task>? _deleteWithEfOnAfterAsync;
     private Func<FileContentResult, Guid, Task>? _getDocumentationOnAfterAsync;
     private Func<string?, Guid, Task<Result>>? _simulateWorkOnAfterAsync;
+    private Func<string?, string?, Task<Result>>? _extendResponseOnAfterAsync;
 
     #endregion
 
@@ -309,6 +310,13 @@ public async Task<FileContentResult> GetDocumentationAsync(Guid id)
                      .ThenAsync(r => _simulateWorkOnAfterAsync?.Invoke(r, id) ?? Result.SuccessTask)
                      .Then(r => _events.PublishValueEvent("WorkIt", new Uri($"/person/", UriKind.Relative), $"Work", "Simulated"));
     }, new InvokerArgs { IncludeTransactionScope = true, EventPublisher = _events });
+
+    /// <inheritdoc/>
+    public Task<Result<string?>> ExtendResponseAsync(string? name)
+    {
+        return Result.GoAsync(_data.ExtendResponseAsync(name))
+                     .ThenAsync(r => _extendResponseOnAfterAsync?.Invoke(r, name) ?? Result.SuccessTask);
+    }
 }
 
 #pragma warning restore
diff --git a/samples/Demo/Beef.Demo.Business/Generated/IPersonManager.cs b/samples/Demo/Beef.Demo.Business/Generated/IPersonManager.cs
index 0ebf4858..debd2583 100644
--- a/samples/Demo/Beef.Demo.Business/Generated/IPersonManager.cs
+++ b/samples/Demo/Beef.Demo.Business/Generated/IPersonManager.cs
@@ -242,6 +242,13 @@ public partial interface IPersonManager
     /// <param name="id">The <see cref="Person"/> identifier.</param>
     /// <returns>A resultant <see cref="string"/>.</returns>
     Task<Result<string?>> SimulateWorkAsync(Guid id);
+
+    /// <summary>
+    /// Extend Response.
+    /// </summary>
+    /// <param name="name">The Name.</param>
+    /// <returns>A resultant <see cref="string"/>.</returns>
+    Task<Result<string?>> ExtendResponseAsync(string? name);
 }
 
 #pragma warning restore
diff --git a/samples/Demo/Beef.Demo.Business/Generated/PersonManager.cs b/samples/Demo/Beef.Demo.Business/Generated/PersonManager.cs
index 3df39467..99755f71 100644
--- a/samples/Demo/Beef.Demo.Business/Generated/PersonManager.cs
+++ b/samples/Demo/Beef.Demo.Business/Generated/PersonManager.cs
@@ -167,6 +167,11 @@ public partial class PersonManager : IPersonManager
     private Func<Guid, Task<Result>>? _simulateWorkOnBeforeAsync;
     private Func<string?, Guid, Task<Result>>? _simulateWorkOnAfterAsync;
 
+    private Func<string?, Task<Result>>? _extendResponseOnPreValidateAsync;
+    private Action<MultiValidator, string?>? _extendResponseOnValidate;
+    private Func<string?, Task<Result>>? _extendResponseOnBeforeAsync;
+    private Func<string?, string?, Task<Result>>? _extendResponseOnAfterAsync;
+
     #endregion
 
     /// <summary>
@@ -674,6 +679,20 @@ await MultiValidator.Create()
                      .ThenAsync(r => _simulateWorkOnAfterAsync?.Invoke(r, id) ?? Result.SuccessTask)
                      .Then(r => Cleaner.Clean(r));
     }, InvokerArgs.Unspecified);
+
+    /// <inheritdoc/>
+    public Task<Result<string?>> ExtendResponseAsync(string? name) => ManagerInvoker.Current.InvokeAsync(this, (_, ct) =>
+    {
+        return Result.Go()
+                     .Then(() => Cleaner.CleanUp(name))
+                     .ThenAsync(() => _extendResponseOnPreValidateAsync?.Invoke(name) ?? Result.SuccessTask)
+                     .ValidateAsync(() => MultiValidator.Create()
+                         .Additional(mv => _extendResponseOnValidate?.Invoke(mv, name)), cancellationToken: ct)
+                     .ThenAsync(() => _extendResponseOnBeforeAsync?.Invoke(name) ?? Result.SuccessTask)
+                     .ThenAsAsync(() => _dataService.ExtendResponseAsync(name))
+                     .ThenAsync(r => _extendResponseOnAfterAsync?.Invoke(r, name) ?? Result.SuccessTask)
+                     .Then(r => Cleaner.Clean(r));
+    }, InvokerArgs.Unspecified);
 }
 
 #pragma warning restore
diff --git a/samples/Demo/Beef.Demo.CodeGen/entity.beef-5.yaml b/samples/Demo/Beef.Demo.CodeGen/entity.beef-5.yaml
index 9f06318c..667d5399 100644
--- a/samples/Demo/Beef.Demo.CodeGen/entity.beef-5.yaml
+++ b/samples/Demo/Beef.Demo.CodeGen/entity.beef-5.yaml
@@ -105,7 +105,8 @@ entities:
         parameters: [
           { name: Id, text: '{{Person}} identifier', type: Guid, isMandatory: true }
         ]},
-      { name: SimulateWork, type: Custom, withResult: true, returnType: string?, webApiRoute: simulate, webApiMethod: HttpGet, webApiStatus: OK, primaryKey: true, eventSubject: Work:Simulated, eventValue: '"WorkIt"' }
+      { name: SimulateWork, type: Custom, withResult: true, returnType: string?, webApiRoute: simulate, webApiMethod: HttpGet, webApiStatus: OK, primaryKey: true, eventSubject: Work:Simulated, eventValue: '"WorkIt"' },
+      { name: ExtendResponse, type: Custom, returnType: string?, excludeWebApi: true, webApiRoute: extend-response, withResult: true, parameters: [ { name: Name } ] }
     ]
   }
 
diff --git a/samples/Demo/Beef.Demo.Common/Agents/Generated/IPersonAgent.cs b/samples/Demo/Beef.Demo.Common/Agents/Generated/IPersonAgent.cs
index 6795834c..4949159f 100644
--- a/samples/Demo/Beef.Demo.Common/Agents/Generated/IPersonAgent.cs
+++ b/samples/Demo/Beef.Demo.Common/Agents/Generated/IPersonAgent.cs
@@ -349,6 +349,15 @@ public partial interface IPersonAgent
         /// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
         /// <returns>A <see cref="HttpResult"/>.</returns>
         Task<HttpResult<string?>> SimulateWorkAsync(Guid id, HttpRequestOptions? requestOptions = null, CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// Extend Response.
+        /// </summary>
+        /// <param name="name">The Name.</param>
+        /// <param name="requestOptions">The optional <see cref="HttpRequestOptions"/>.</param>
+        /// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
+        /// <returns>A <see cref="HttpResult"/>.</returns>
+        Task<HttpResult<string?>> ExtendResponseAsync(string? name, HttpRequestOptions? requestOptions = null, CancellationToken cancellationToken = default);
     }
 }
 
diff --git a/samples/Demo/Beef.Demo.Common/Agents/Generated/PersonAgent.cs b/samples/Demo/Beef.Demo.Common/Agents/Generated/PersonAgent.cs
index a51414fe..79d90e6f 100644
--- a/samples/Demo/Beef.Demo.Common/Agents/Generated/PersonAgent.cs
+++ b/samples/Demo/Beef.Demo.Common/Agents/Generated/PersonAgent.cs
@@ -170,6 +170,10 @@ public Task<HttpResult> GetDocumentationAsync(Guid id, HttpRequestOptions? reque
         /// <inheritdoc/>
         public Task<HttpResult<string?>> SimulateWorkAsync(Guid id, HttpRequestOptions? requestOptions = null, CancellationToken cancellationToken = default)
             => GetAsync<string?>("api/v1/persons/simulate", requestOptions: requestOptions, args: HttpArgs.Create(new HttpArg<Guid>("id", id)), cancellationToken: cancellationToken);
+
+        /// <inheritdoc/>
+        public Task<HttpResult<string?>> ExtendResponseAsync(string? name, HttpRequestOptions? requestOptions = null, CancellationToken cancellationToken = default)
+            => PostAsync<string?>("api/v1/persons/extend-response", requestOptions: requestOptions, args: HttpArgs.Create(new HttpArg<string?>("name", name)), cancellationToken: cancellationToken);
     }
 }
 
diff --git a/samples/Demo/Beef.Demo.Test/PersonTest.cs b/samples/Demo/Beef.Demo.Test/PersonTest.cs
index 6c3833f0..18ca2463 100644
--- a/samples/Demo/Beef.Demo.Test/PersonTest.cs
+++ b/samples/Demo/Beef.Demo.Test/PersonTest.cs
@@ -1312,5 +1312,30 @@ public void I420_Simulate_Perf()
         }
 
         #endregion
+
+        #region ExtendResponse
+
+        [Test, TestSetUp]
+        public void J110_ExtendResponse_Error()
+        {
+            AgentTester.Test<PersonAgent>()
+                .ExpectStatusCode(HttpStatusCode.BadRequest)
+                .ExpectError("Name is needed dude!")
+                .Run(a => a.ExtendResponseAsync(null));
+        }
+
+        [Test, TestSetUp]
+        public void J120_ExtendResponse_Success()
+        {
+            var resp = AgentTester.Test<PersonAgent, string>()
+                .ExpectStatusCode(HttpStatusCode.OK)
+                .ExpectValue("Sweet!")
+                .Run(a => a.ExtendResponseAsync("Sweet!"));
+
+            if (resp.Response.Headers.TryGetValues("X-Beef-Test", out var values))
+                Assert.That(values, Is.EquivalentTo(new string[] { "123" }));
+        }
+
+        #endregion
     }
 }
\ No newline at end of file