diff --git a/src/Messaging/Events/ExportCompleteEvent.cs b/src/Messaging/Events/ExportCompleteEvent.cs
index 5a048df..8a809bf 100755
--- a/src/Messaging/Events/ExportCompleteEvent.cs
+++ b/src/Messaging/Events/ExportCompleteEvent.cs
@@ -64,6 +64,11 @@ public class ExportCompleteEvent : EventBase
         [JsonPropertyName("file_statuses")]
         public Dictionary<string, FileExportStatus> FileStatuses { get; set; }
 
+        /// <summary>
+        /// the target to export too
+        /// </summary>
+        public DataOrigin? Target { get; set; }
+
         [Newtonsoft.Json.JsonConstructor]
         [System.Text.Json.Serialization.JsonConstructor]
         public ExportCompleteEvent()
diff --git a/src/Messaging/Events/ExportRequestEvent.cs b/src/Messaging/Events/ExportRequestEvent.cs
index 0f0b036..8fa479a 100755
--- a/src/Messaging/Events/ExportRequestEvent.cs
+++ b/src/Messaging/Events/ExportRequestEvent.cs
@@ -101,6 +101,11 @@ public class ExportRequestEvent : EventBase
         [JsonPropertyName("plug_in_assemblies")]
         public List<string> PluginAssemblies { get; private set; }
 
+        /// <summary>
+        /// the target to export too
+        /// </summary>
+        public DataOrigin? Target { get; set; }
+
         public ExportRequestEvent()
         {
             ErrorMessages = new List<string>();
diff --git a/src/Messaging/Events/ExternalAppRequestEvent.cs b/src/Messaging/Events/ExternalAppRequestEvent.cs
new file mode 100755
index 0000000..b3982eb
--- /dev/null
+++ b/src/Messaging/Events/ExternalAppRequestEvent.cs
@@ -0,0 +1,145 @@
+/*
+ * Copyright 2021-2023 MONAI Consortium
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System.ComponentModel.DataAnnotations;
+using System.Text.Json.Serialization;
+using Ardalis.GuardClauses;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+namespace Monai.Deploy.Messaging.Events
+{
+    public class ExternalAppRequestEvent
+    {
+        /// <summary>
+        /// Gets or sets the workflow instanceID generated by the Workflow Manager.
+        /// </summary>
+        [JsonProperty(PropertyName = "workflow_instance_id")]
+        [JsonPropertyName("workflow_instance_id")]
+        [Required]
+        public string WorkflowInstanceId { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets the export task ID generated by the Workflow Manager.
+        /// </summary>
+        [JsonProperty(PropertyName = "export_task_id")]
+        [JsonPropertyName("export_task_id")]
+        [Required]
+        public string ExportTaskId { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or set the correlation ID.
+        /// For DIMSE, the correlation ID is the UUID associated with the first DICOM association received.
+        /// For ACR, use the Transaction ID in the original request.
+        /// </summary>
+        [JsonProperty(PropertyName = "correlation_id")]
+        [JsonPropertyName("correlation_id")]
+        [Required]
+        public string CorrelationId { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets the delivery tag or acknowledge token for the task.
+        /// </summary>
+        [JsonProperty(PropertyName = "delivery_tag")]
+        [JsonPropertyName("delivery_tag")]
+        public string DeliveryTag { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets the message ID set by the message broker.
+        /// </summary>
+        [JsonProperty(PropertyName = "message_id")]
+        [JsonPropertyName("message_id")]
+        public string MessageId { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets the state of the export task.
+        /// </summary>
+        [JsonProperty(PropertyName = "status")]
+        [JsonPropertyName("status")]
+        [Newtonsoft.Json.JsonConverter(typeof(StringEnumConverter))]
+        [System.Text.Json.Serialization.JsonConverter(typeof(JsonStringEnumConverter))]
+        [Required]
+        public ExportStatus Status { get; set; }
+
+        /// <summary>
+        /// Gets or sets error messages, if any, when exporting.
+        /// </summary>
+        [JsonProperty(PropertyName = "message")]
+        [JsonPropertyName("message")]
+        public string Message { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets a list of files to be exported.
+        /// </summary>
+        [JsonProperty(PropertyName = "files")]
+        [JsonPropertyName("files")]
+        [Required, MinLength(1)]
+        public IEnumerable<string> Files { get; set; } = default!;
+
+        /// <summary>
+        /// Gets or sets files exported with its status
+        /// </summary>
+        [JsonProperty(PropertyName = "file_statuses")]
+        [JsonPropertyName("file_statuses")]
+        public Dictionary<string, FileExportStatus> FileStatuses { get; set; }
+
+        /// <summary>
+        /// Gets or sets error messages related to this export task.
+        /// </summary>
+        [JsonProperty(PropertyName = "error_messages")]
+        [JsonPropertyName("error_messages")]
+        public List<string> ErrorMessages { get; private set; } = new List<string>();
+
+        /// <summary>
+        /// A list of data output plug-in type names to be executed by the export services.
+        /// Each string must be a fully-qualified type name.
+        /// E.g. <code>MyCompnay.MyProject.MyNamepsace.MyPlugin, MyCompnay.MyProject.MyNamepsace</code> where
+        /// <code>MyCompnay.MyProject.MyNamepsace</code> is the name of the assembly (DLL).
+        /// </summary>
+        [JsonProperty(PropertyName = "plug_in_assemblies")]
+        [JsonPropertyName("plug_in_assemblies")]
+        public List<string> PluginAssemblies { get; private set; } = new List<string>();
+
+        /// <summary>
+        /// the targets to export too
+        /// </summary>
+        public List<DataOrigin> Targets { get; set; } = new List<DataOrigin>();
+
+        [JsonProperty(PropertyName = "destination_folder")]
+        [JsonPropertyName("destination_folder")]
+        public string? DestinationFolder { get; set; }
+
+        [Newtonsoft.Json.JsonConstructor]
+        [System.Text.Json.Serialization.JsonConstructor]
+        public ExternalAppRequestEvent()
+        {
+            Status = ExportStatus.Unknown;
+            FileStatuses = new Dictionary<string, FileExportStatus>();
+        }
+
+        public ExternalAppRequestEvent(ExportRequestEvent exportRequest, ExportStatus exportStatus, Dictionary<string, FileExportStatus> fileStatuses)
+        {
+            Guard.Against.Null(exportRequest, nameof(exportRequest));
+            Guard.Against.Null(exportStatus, nameof(exportStatus));
+            Guard.Against.Null(fileStatuses, nameof(fileStatuses));
+
+            WorkflowInstanceId = exportRequest.WorkflowInstanceId;
+            ExportTaskId = exportRequest.ExportTaskId;
+            Message = string.Join(System.Environment.NewLine, exportRequest.ErrorMessages);
+            Status = exportStatus;
+            FileStatuses = fileStatuses;
+        }
+    }
+}