diff --git a/src/Client/Core/PurgeResult.cs b/src/Client/Core/PurgeResult.cs
index be4c61257..2d96bd0f9 100644
--- a/src/Client/Core/PurgeResult.cs
+++ b/src/Client/Core/PurgeResult.cs
@@ -18,9 +18,29 @@ public PurgeResult(int count)
         this.PurgedInstanceCount = count;
     }
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="PurgeResult" /> class.
+    /// </summary>
+    /// <param name="count">The number of instances deleted.</param>
+    /// <param name="isComplete">A value indicating whether the purge operation is complete.
+    /// If true, the purge operation is complete. All instances were purged.
+    /// If false, not all instances were purged. Please purge again.
+    /// If null, whether or not all instances were purged is undefined.</param>
+    public PurgeResult(int count, bool? isComplete)
+        : this(count)
+    {
+        this.IsComplete = isComplete;
+    }
+
     /// <summary>
     /// Gets the number of purged instances.
     /// </summary>
     /// <value>The number of purged instances.</value>
     public int PurgedInstanceCount { get; }
+
+    /// <summary>
+    /// Gets a value indicating whether the purge operation is complete.
+    /// </summary>
+    /// <value>A value indicating whether the purge operation is complete.</value>
+    public bool? IsComplete { get; }
 }
diff --git a/src/Client/Grpc/GrpcDurableTaskClient.cs b/src/Client/Grpc/GrpcDurableTaskClient.cs
index 32c95b64b..4d32093e9 100644
--- a/src/Client/Grpc/GrpcDurableTaskClient.cs
+++ b/src/Client/Grpc/GrpcDurableTaskClient.cs
@@ -446,7 +446,7 @@ async Task<PurgeResult> PurgeInstancesCoreAsync(
         {
             P.PurgeInstancesResponse response = await this.sidecarClient.PurgeInstancesAsync(
                 request, cancellationToken: cancellation);
-            return new PurgeResult(response.DeletedInstanceCount);
+            return new PurgeResult(response.DeletedInstanceCount, response.IsComplete);
         }
         catch (RpcException e) when (e.StatusCode == StatusCode.Cancelled)
         {
diff --git a/src/Grpc/orchestrator_service.proto b/src/Grpc/orchestrator_service.proto
index 64e752818..5dd39cfe6 100644
--- a/src/Grpc/orchestrator_service.proto
+++ b/src/Grpc/orchestrator_service.proto
@@ -463,6 +463,7 @@ message PurgeInstanceFilter {
 
 message PurgeInstancesResponse {
     int32 deletedInstanceCount = 1;
+    google.protobuf.BoolValue isComplete = 2;
 }
 
 message CreateTaskHubRequest {
@@ -617,6 +618,30 @@ message StartNewOrchestrationAction {
     google.protobuf.Timestamp scheduledTime = 5;
 }
 
+message AbandonActivityTaskRequest {
+    string completionToken = 1;
+}
+
+message AbandonActivityTaskResponse {
+    // Empty.
+}
+
+message AbandonOrchestrationTaskRequest {
+    string completionToken = 1;
+}
+
+message AbandonOrchestrationTaskResponse {
+    // Empty.
+}
+
+message AbandonEntityTaskRequest {
+    string completionToken = 1;
+}
+
+message AbandonEntityTaskResponse {
+    // Empty.
+}
+
 service TaskHubSidecarService {
     // Sends a hello request to the sidecar service.
     rpc Hello(google.protobuf.Empty) returns (google.protobuf.Empty);
@@ -678,6 +703,15 @@ service TaskHubSidecarService {
 
     // clean entity storage
     rpc CleanEntityStorage(CleanEntityStorageRequest) returns (CleanEntityStorageResponse);
+
+    // Abandons a single work item
+    rpc AbandonTaskActivityWorkItem(AbandonActivityTaskRequest) returns (AbandonActivityTaskResponse);
+
+    // Abandon an orchestration work item
+    rpc AbandonTaskOrchestratorWorkItem(AbandonOrchestrationTaskRequest) returns (AbandonOrchestrationTaskResponse);
+
+    // Abandon an entity work item
+    rpc AbandonTaskEntityWorkItem(AbandonEntityTaskRequest) returns (AbandonEntityTaskResponse);
 }
 
 message GetWorkItemsRequest {
diff --git a/src/Grpc/versions.txt b/src/Grpc/versions.txt
index c016c8199..733b20c07 100644
--- a/src/Grpc/versions.txt
+++ b/src/Grpc/versions.txt
@@ -1,2 +1,2 @@
-# The following files were downloaded from branch main at 2025-03-19 19:55:31 UTC
-https://raw.githubusercontent.com/microsoft/durabletask-protobuf/4792f47019ab2b3e9ea979fb4af72427a4144c51/protos/orchestrator_service.proto
+# The following files were downloaded from branch main at 2025-03-24 23:37:31 UTC
+https://raw.githubusercontent.com/microsoft/durabletask-protobuf/c85ef11430ff8e10e21105abb545b0803bb86c66/protos/orchestrator_service.proto
diff --git a/test/Client/OrchestrationServiceClientShim.Tests/ShimDurableTaskClientTests.cs b/test/Client/OrchestrationServiceClientShim.Tests/ShimDurableTaskClientTests.cs
index cf67af96b..a9a5d7caa 100644
--- a/test/Client/OrchestrationServiceClientShim.Tests/ShimDurableTaskClientTests.cs
+++ b/test/Client/OrchestrationServiceClientShim.Tests/ShimDurableTaskClientTests.cs
@@ -174,6 +174,7 @@ public async Task PurgeInstanceMetadata()
         // assert
         this.orchestrationClient.VerifyAll();
         result.PurgedInstanceCount.Should().Be(1);
+        result.IsComplete.Should().BeNull();
     }
 
     [Fact]
diff --git a/test/Grpc.IntegrationTests/GrpcDurableTaskClientIntegrationTests.cs b/test/Grpc.IntegrationTests/GrpcDurableTaskClientIntegrationTests.cs
index a208671ff..50fe6e070 100644
--- a/test/Grpc.IntegrationTests/GrpcDurableTaskClientIntegrationTests.cs
+++ b/test/Grpc.IntegrationTests/GrpcDurableTaskClientIntegrationTests.cs
@@ -150,6 +150,80 @@ await server.Client.ScheduleNewOrchestrationInstanceAsync(
         page.ContinuationToken.Should().NotBeNull();
     }
 
+    [Fact]
+    public async Task PurgeInstance_EndToEnd()
+    {
+        // Arrange
+        await using HostTestLifetime server = await this.StartAsync();
+
+        // Create and complete an orchestration instance
+        string instanceId = await server.Client.ScheduleNewOrchestrationInstanceAsync(
+            OrchestrationName, input: false);
+
+        // Wait for it to start and raise event to complete it
+        await server.Client.WaitForInstanceStartAsync(instanceId, default);
+        await server.Client.RaiseEventAsync(instanceId, "event", default);
+        await server.Client.WaitForInstanceCompletionAsync(instanceId, default);
+
+        // Verify instance exists before purge
+        OrchestrationMetadata? metadata = await server.Client.GetInstanceAsync(instanceId, false);
+        metadata.Should().NotBeNull();
+        metadata!.InstanceId.Should().Be(instanceId);
+        metadata.RuntimeStatus.Should().Be(OrchestrationRuntimeStatus.Completed);
+
+        // Act
+        PurgeResult result = await server.Client.PurgeInstanceAsync(
+            instanceId,
+            new PurgeInstanceOptions { Recursive = true });
+
+        // Assert
+        result.Should().NotBeNull();
+        result.PurgedInstanceCount.Should().Be(1);
+        result.IsComplete.Should().NotBeFalse();
+        // Verify instance no longer exists
+        OrchestrationMetadata? instance = await server.Client.GetInstanceAsync(instanceId, false);
+        instance.Should().BeNull();
+    }
+
+    [Fact]
+    public async Task PurgeInstances_WithFilter_EndToEnd()
+    {
+        // Arrange
+        await using HostTestLifetime server = await this.StartAsync();
+        List<string> instanceIds = new List<string>();
+
+        // Create multiple instances
+        for (int i = 0; i < 3; i++)
+        {
+            string instanceId = await server.Client.ScheduleNewOrchestrationInstanceAsync(
+                OrchestrationName, input: false);
+            instanceIds.Add(instanceId);
+
+            // Wait for it to start and raise event to complete it
+            await server.Client.WaitForInstanceStartAsync(instanceId, default);
+            await server.Client.RaiseEventAsync(instanceId, "event", default);
+            await server.Client.WaitForInstanceCompletionAsync(instanceId, default);
+        }
+
+        // Act
+        PurgeResult result = await server.Client.PurgeAllInstancesAsync(
+            new PurgeInstancesFilter(
+                CreatedFrom: DateTime.UtcNow.AddMinutes(-5),
+                CreatedTo: DateTime.UtcNow,
+                Statuses: new[] { OrchestrationRuntimeStatus.Completed }));
+
+        // Assert
+        result.Should().NotBeNull();
+        result.PurgedInstanceCount.Should().BeGreaterThan(3);
+        result.IsComplete.Should().NotBeFalse();
+        // Verify instances no longer exist
+        foreach (string instanceId in instanceIds)
+        {
+            OrchestrationMetadata? instance = await server.Client.GetInstanceAsync(instanceId, false);
+            instance.Should().BeNull();
+        }
+    }
+
     Task<HostTestLifetime> StartAsync()
     {
         static async Task<string> Orchestration(TaskOrchestrationContext context, bool shouldThrow)