diff --git a/temporal-sdk/src/main/java/io/temporal/activity/ActivityExecutionContext.java b/temporal-sdk/src/main/java/io/temporal/activity/ActivityExecutionContext.java
index 6c1247ca7..5eebf0770 100644
--- a/temporal-sdk/src/main/java/io/temporal/activity/ActivityExecutionContext.java
+++ b/temporal-sdk/src/main/java/io/temporal/activity/ActivityExecutionContext.java
@@ -22,6 +22,7 @@
 
 import com.uber.m3.tally.Scope;
 import io.temporal.client.ActivityCompletionException;
+import io.temporal.client.WorkflowClient;
 import io.temporal.serviceclient.WorkflowServiceStubsOptions;
 import io.temporal.worker.WorkerOptions;
 import java.lang.reflect.Type;
@@ -140,4 +141,10 @@ public interface ActivityExecutionContext {
    * WorkflowServiceStubsOptions.Builder#setMetricsScope(Scope)} when a worker starts up.
    */
   Scope getMetricsScope();
+
+  /**
+   * Get a {@link WorkflowClient} that can be used to start interact with the Temporal service from
+   * an activity.
+   */
+  WorkflowClient getWorkflowClient();
 }
diff --git a/temporal-sdk/src/main/java/io/temporal/common/interceptors/ActivityExecutionContextBase.java b/temporal-sdk/src/main/java/io/temporal/common/interceptors/ActivityExecutionContextBase.java
index 654a6cdf3..bb62067d2 100644
--- a/temporal-sdk/src/main/java/io/temporal/common/interceptors/ActivityExecutionContextBase.java
+++ b/temporal-sdk/src/main/java/io/temporal/common/interceptors/ActivityExecutionContextBase.java
@@ -25,6 +25,7 @@
 import io.temporal.activity.ActivityInfo;
 import io.temporal.activity.ManualActivityCompletionClient;
 import io.temporal.client.ActivityCompletionException;
+import io.temporal.client.WorkflowClient;
 import java.lang.reflect.Type;
 import java.util.Optional;
 
@@ -85,4 +86,9 @@ public ManualActivityCompletionClient useLocalManualCompletion() {
   public Scope getMetricsScope() {
     return next.getMetricsScope();
   }
+
+  @Override
+  public WorkflowClient getWorkflowClient() {
+    return next.getWorkflowClient();
+  }
 }
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextFactoryImpl.java b/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextFactoryImpl.java
index 00f51f8c6..49193362b 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextFactoryImpl.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextFactoryImpl.java
@@ -21,15 +21,15 @@
 package io.temporal.internal.activity;
 
 import com.uber.m3.tally.Scope;
+import io.temporal.client.WorkflowClient;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.internal.client.external.ManualActivityCompletionClientFactory;
-import io.temporal.serviceclient.WorkflowServiceStubs;
 import java.time.Duration;
 import java.util.Objects;
 import java.util.concurrent.ScheduledExecutorService;
 
 public class ActivityExecutionContextFactoryImpl implements ActivityExecutionContextFactory {
-  private final WorkflowServiceStubs service;
+  private final WorkflowClient client;
   private final String identity;
   private final String namespace;
   private final Duration maxHeartbeatThrottleInterval;
@@ -39,14 +39,14 @@ public class ActivityExecutionContextFactoryImpl implements ActivityExecutionCon
   private final ManualActivityCompletionClientFactory manualCompletionClientFactory;
 
   public ActivityExecutionContextFactoryImpl(
-      WorkflowServiceStubs service,
+      WorkflowClient client,
       String identity,
       String namespace,
       Duration maxHeartbeatThrottleInterval,
       Duration defaultHeartbeatThrottleInterval,
       DataConverter dataConverter,
       ScheduledExecutorService heartbeatExecutor) {
-    this.service = Objects.requireNonNull(service);
+    this.client = Objects.requireNonNull(client);
     this.identity = identity;
     this.namespace = Objects.requireNonNull(namespace);
     this.maxHeartbeatThrottleInterval = Objects.requireNonNull(maxHeartbeatThrottleInterval);
@@ -56,14 +56,14 @@ public ActivityExecutionContextFactoryImpl(
     this.heartbeatExecutor = Objects.requireNonNull(heartbeatExecutor);
     this.manualCompletionClientFactory =
         ManualActivityCompletionClientFactory.newFactory(
-            service, namespace, identity, dataConverter);
+            client.getWorkflowServiceStubs(), namespace, identity, dataConverter);
   }
 
   @Override
   public InternalActivityExecutionContext createContext(
       ActivityInfoInternal info, Scope metricsScope) {
     return new ActivityExecutionContextImpl(
-        service,
+        client,
         namespace,
         info,
         dataConverter,
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextImpl.java b/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextImpl.java
index f21a8df88..bd065a86f 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextImpl.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/activity/ActivityExecutionContextImpl.java
@@ -25,10 +25,10 @@
 import io.temporal.activity.ActivityInfo;
 import io.temporal.activity.ManualActivityCompletionClient;
 import io.temporal.client.ActivityCompletionException;
+import io.temporal.client.WorkflowClient;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.internal.client.external.ManualActivityCompletionClientFactory;
 import io.temporal.payload.context.ActivitySerializationContext;
-import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.workflow.Functions;
 import java.lang.reflect.Type;
 import java.time.Duration;
@@ -47,6 +47,7 @@
 @ThreadSafe
 class ActivityExecutionContextImpl implements InternalActivityExecutionContext {
   private final Lock lock = new ReentrantLock();
+  private final WorkflowClient client;
   private final ManualActivityCompletionClientFactory manualCompletionClientFactory;
   private final Functions.Proc completionHandle;
   private final HeartbeatContext heartbeatContext;
@@ -58,7 +59,7 @@ class ActivityExecutionContextImpl implements InternalActivityExecutionContext {
 
   /** Create an ActivityExecutionContextImpl with the given attributes. */
   ActivityExecutionContextImpl(
-      WorkflowServiceStubs service,
+      WorkflowClient client,
       String namespace,
       ActivityInfo info,
       DataConverter dataConverter,
@@ -69,13 +70,14 @@ class ActivityExecutionContextImpl implements InternalActivityExecutionContext {
       String identity,
       Duration maxHeartbeatThrottleInterval,
       Duration defaultHeartbeatThrottleInterval) {
+    this.client = client;
     this.metricsScope = metricsScope;
     this.info = info;
     this.completionHandle = completionHandle;
     this.manualCompletionClientFactory = manualCompletionClientFactory;
     this.heartbeatContext =
         new HeartbeatContextImpl(
-            service,
+            client.getWorkflowServiceStubs(),
             namespace,
             info,
             dataConverter,
@@ -170,4 +172,9 @@ public ActivityInfo getInfo() {
   public Object getLastHeartbeatValue() {
     return heartbeatContext.getLastHeartbeatDetails();
   }
+
+  @Override
+  public WorkflowClient getWorkflowClient() {
+    return client;
+  }
 }
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextFactoryImpl.java b/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextFactoryImpl.java
index 3305b635a..e569c48fb 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextFactoryImpl.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextFactoryImpl.java
@@ -21,14 +21,18 @@
 package io.temporal.internal.activity;
 
 import com.uber.m3.tally.Scope;
+import io.temporal.client.WorkflowClient;
 
 public class LocalActivityExecutionContextFactoryImpl implements ActivityExecutionContextFactory {
+  private final WorkflowClient client;
 
-  public LocalActivityExecutionContextFactoryImpl() {}
+  public LocalActivityExecutionContextFactoryImpl(WorkflowClient client) {
+    this.client = client;
+  }
 
   @Override
   public InternalActivityExecutionContext createContext(
       ActivityInfoInternal info, Scope metricsScope) {
-    return new LocalActivityExecutionContextImpl(info, metricsScope);
+    return new LocalActivityExecutionContextImpl(client, info, metricsScope);
   }
 }
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextImpl.java b/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextImpl.java
index ad9c2a9d1..006c0cfe9 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextImpl.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/activity/LocalActivityExecutionContextImpl.java
@@ -24,14 +24,17 @@
 import io.temporal.activity.ActivityInfo;
 import io.temporal.activity.ManualActivityCompletionClient;
 import io.temporal.client.ActivityCompletionException;
+import io.temporal.client.WorkflowClient;
 import java.lang.reflect.Type;
 import java.util.Optional;
 
 class LocalActivityExecutionContextImpl implements InternalActivityExecutionContext {
+  private final WorkflowClient client;
   private final ActivityInfo info;
   private final Scope metricsScope;
 
-  LocalActivityExecutionContextImpl(ActivityInfo info, Scope metricsScope) {
+  LocalActivityExecutionContextImpl(WorkflowClient client, ActivityInfo info, Scope metricsScope) {
+    this.client = client;
     this.info = info;
     this.metricsScope = metricsScope;
   }
@@ -92,4 +95,9 @@ public Scope getMetricsScope() {
   public Object getLastHeartbeatValue() {
     return null;
   }
+
+  @Override
+  public WorkflowClient getWorkflowClient() {
+    return client;
+  }
 }
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncActivityWorker.java b/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncActivityWorker.java
index 5fd7a96e7..6a3225ecc 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncActivityWorker.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncActivityWorker.java
@@ -20,10 +20,10 @@
 
 package io.temporal.internal.worker;
 
+import io.temporal.client.WorkflowClient;
 import io.temporal.internal.activity.ActivityExecutionContextFactory;
 import io.temporal.internal.activity.ActivityExecutionContextFactoryImpl;
 import io.temporal.internal.activity.ActivityTaskHandlerImpl;
-import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.worker.tuning.ActivitySlotInfo;
 import io.temporal.worker.tuning.SlotSupplier;
 import java.time.Duration;
@@ -47,7 +47,7 @@ public class SyncActivityWorker implements SuspendableWorker {
   private final ActivityWorker worker;
 
   public SyncActivityWorker(
-      WorkflowServiceStubs service,
+      WorkflowClient client,
       String namespace,
       String taskQueue,
       double taskQueueActivitiesPerSecond,
@@ -69,7 +69,7 @@ public SyncActivityWorker(
                 null));
     ActivityExecutionContextFactory activityExecutionContextFactory =
         new ActivityExecutionContextFactoryImpl(
-            service,
+            client,
             identity,
             namespace,
             options.getMaxHeartbeatThrottleInterval(),
@@ -86,7 +86,7 @@ public SyncActivityWorker(
             options.getContextPropagators());
     this.worker =
         new ActivityWorker(
-            service,
+            client.getWorkflowServiceStubs(),
             namespace,
             taskQueue,
             taskQueueActivitiesPerSecond,
diff --git a/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncWorkflowWorker.java b/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncWorkflowWorker.java
index feb1aa1ab..ff33427e4 100644
--- a/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncWorkflowWorker.java
+++ b/temporal-sdk/src/main/java/io/temporal/internal/worker/SyncWorkflowWorker.java
@@ -24,6 +24,7 @@
 
 import io.temporal.api.common.v1.Payloads;
 import io.temporal.api.taskqueue.v1.TaskQueue;
+import io.temporal.client.WorkflowClient;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.internal.activity.ActivityExecutionContextFactory;
 import io.temporal.internal.activity.ActivityTaskHandlerImpl;
@@ -31,7 +32,6 @@
 import io.temporal.internal.replay.ReplayWorkflowTaskHandler;
 import io.temporal.internal.sync.POJOWorkflowImplementationFactory;
 import io.temporal.internal.sync.WorkflowThreadExecutor;
-import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.worker.WorkflowImplementationOptions;
 import io.temporal.worker.WorkflowTaskDispatchHandle;
 import io.temporal.worker.tuning.LocalActivitySlotInfo;
@@ -75,7 +75,7 @@ public class SyncWorkflowWorker implements SuspendableWorker {
   private boolean runningLocalActivityWorker;
 
   public SyncWorkflowWorker(
-      @Nonnull WorkflowServiceStubs service,
+      @Nonnull WorkflowClient client,
       @Nonnull String namespace,
       @Nonnull String taskQueue,
       @Nonnull SingleWorkerOptions singleWorkerOptions,
@@ -101,7 +101,7 @@ public SyncWorkflowWorker(
             namespace);
 
     ActivityExecutionContextFactory laActivityExecutionContextFactory =
-        new LocalActivityExecutionContextFactoryImpl();
+        new LocalActivityExecutionContextFactoryImpl(client);
     laTaskHandler =
         new ActivityTaskHandlerImpl(
             namespace,
@@ -126,12 +126,12 @@ public SyncWorkflowWorker(
             singleWorkerOptions,
             stickyTaskQueue,
             singleWorkerOptions.getStickyQueueScheduleToStartTimeout(),
-            service,
+            client.getWorkflowServiceStubs(),
             laWorker.getLocalActivityScheduler());
 
     workflowWorker =
         new WorkflowWorker(
-            service,
+            client.getWorkflowServiceStubs(),
             namespace,
             taskQueue,
             stickyTaskQueueName,
@@ -152,7 +152,7 @@ public SyncWorkflowWorker(
             singleWorkerOptions,
             null,
             Duration.ZERO,
-            service,
+            client.getWorkflowServiceStubs(),
             laWorker.getLocalActivityScheduler());
 
     queryReplayHelper = new QueryReplayHelper(nonStickyReplayTaskHandler);
diff --git a/temporal-sdk/src/main/java/io/temporal/worker/Worker.java b/temporal-sdk/src/main/java/io/temporal/worker/Worker.java
index 1e1f8a42d..61f522495 100644
--- a/temporal-sdk/src/main/java/io/temporal/worker/Worker.java
+++ b/temporal-sdk/src/main/java/io/temporal/worker/Worker.java
@@ -36,7 +36,6 @@
 import io.temporal.internal.sync.WorkflowThreadExecutor;
 import io.temporal.internal.worker.*;
 import io.temporal.serviceclient.MetricsTag;
-import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.worker.tuning.*;
 import io.temporal.workflow.Functions.Func;
 import io.temporal.workflow.WorkflowMethod;
@@ -94,7 +93,6 @@ public final class Worker {
     this.taskQueue = taskQueue;
     this.options = WorkerOptions.newBuilder(options).validateAndBuildWithDefaults();
     factoryOptions = WorkerFactoryOptions.newBuilder(factoryOptions).validateAndBuildWithDefaults();
-    WorkflowServiceStubs service = client.getWorkflowServiceStubs();
     WorkflowClientOptions clientOptions = client.getOptions();
     String namespace = clientOptions.getNamespace();
     Map<String, String> tags =
@@ -114,7 +112,7 @@ public final class Worker {
 
       activityWorker =
           new SyncActivityWorker(
-              service,
+              client,
               namespace,
               taskQueue,
               this.options.getMaxTaskQueueActivitiesPerSecond(),
@@ -161,9 +159,10 @@ public final class Worker {
             ? new FixedSizeSlotSupplier<>(this.options.getMaxConcurrentLocalActivityExecutionSize())
             : this.options.getWorkerTuner().getLocalActivitySlotSupplier();
     attachMetricsToResourceController(taggedScope, localActivitySlotSupplier);
+
     workflowWorker =
         new SyncWorkflowWorker(
-            service,
+            client,
             namespace,
             taskQueue,
             singleWorkerOptions,
diff --git a/temporal-sdk/src/test/java/io/temporal/workflow/activityTests/ActivityClientTest.java b/temporal-sdk/src/test/java/io/temporal/workflow/activityTests/ActivityClientTest.java
new file mode 100644
index 000000000..47a4f0adb
--- /dev/null
+++ b/temporal-sdk/src/test/java/io/temporal/workflow/activityTests/ActivityClientTest.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2022 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ * Copyright (C) 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this material 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.
+ */
+
+package io.temporal.workflow.activityTests;
+
+import io.temporal.activity.Activity;
+import io.temporal.activity.ActivityInterface;
+import io.temporal.activity.ActivityOptions;
+import io.temporal.activity.LocalActivityOptions;
+import io.temporal.testing.internal.SDKTestWorkflowRule;
+import io.temporal.workflow.Workflow;
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+import java.time.Duration;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+
+public class ActivityClientTest {
+
+  @Rule
+  public SDKTestWorkflowRule testWorkflowRule =
+      SDKTestWorkflowRule.newBuilder()
+          .setWorkflowTypes(TestWorkflowImpl.class)
+          .setActivityImplementations(new ActivityClientTestActivitiesImpl())
+          .build();
+
+  @Test
+  public void testActivityGetWorkflowClient() {
+    TestWorkflow stub = testWorkflowRule.newWorkflowStubTimeoutOptions(TestWorkflow.class);
+    Assert.assertEquals("from activity of TestWorkflow", stub.execute(false));
+  }
+
+  @Test
+  public void testLocalActivityGetWorkflowClient() {
+    TestWorkflow stub = testWorkflowRule.newWorkflowStubTimeoutOptions(TestWorkflow.class);
+    Assert.assertEquals("from local activity of TestWorkflow", stub.execute(true));
+  }
+
+  @ActivityInterface
+  public interface ActivityClientTestActivities {
+    String query(String workflowId);
+  }
+
+  public static class ActivityClientTestActivitiesImpl implements ActivityClientTestActivities {
+    @Override
+    public String query(String workflowId) {
+      String workflowType =
+          Activity.getExecutionContext()
+              .getWorkflowClient()
+              .newUntypedWorkflowStub(workflowId)
+              .describe()
+              .getWorkflowType();
+      if (Activity.getExecutionContext().getInfo().isLocal()) {
+        return "from local activity of " + workflowType;
+      } else {
+        return "from activity of " + workflowType;
+      }
+    }
+  }
+
+  @WorkflowInterface
+  public interface TestWorkflow {
+
+    @WorkflowMethod
+    String execute(boolean local);
+  }
+
+  public static class TestWorkflowImpl implements TestWorkflow {
+
+    private final ActivityClientTestActivities activities =
+        Workflow.newActivityStub(
+            ActivityClientTestActivities.class,
+            ActivityOptions.newBuilder().setStartToCloseTimeout(Duration.ofSeconds(5)).build());
+
+    private final ActivityClientTestActivities localActivities =
+        Workflow.newLocalActivityStub(
+            ActivityClientTestActivities.class,
+            LocalActivityOptions.newBuilder()
+                .setStartToCloseTimeout(Duration.ofSeconds(5))
+                .build());
+
+    @Override
+    public String execute(boolean local) {
+      if (local) {
+        return localActivities.query(Workflow.getInfo().getWorkflowId());
+      } else {
+        return activities.query(Workflow.getInfo().getWorkflowId());
+      }
+    }
+  }
+}
diff --git a/temporal-testing/src/main/java/io/temporal/testing/TestActivityEnvironmentInternal.java b/temporal-testing/src/main/java/io/temporal/testing/TestActivityEnvironmentInternal.java
index 1f13e16e8..2f9c2087f 100644
--- a/temporal-testing/src/main/java/io/temporal/testing/TestActivityEnvironmentInternal.java
+++ b/temporal-testing/src/main/java/io/temporal/testing/TestActivityEnvironmentInternal.java
@@ -39,6 +39,7 @@
 import io.temporal.api.workflowservice.v1.RespondActivityTaskCompletedRequest;
 import io.temporal.api.workflowservice.v1.RespondActivityTaskFailedRequest;
 import io.temporal.api.workflowservice.v1.WorkflowServiceGrpc;
+import io.temporal.client.WorkflowClient;
 import io.temporal.common.SearchAttributeUpdate;
 import io.temporal.common.converter.DataConverter;
 import io.temporal.common.converter.EncodedValues;
@@ -123,7 +124,8 @@ public TestActivityEnvironmentInternal(@Nullable TestEnvironmentOptions options)
 
     ActivityExecutionContextFactory activityExecutionContextFactory =
         new ActivityExecutionContextFactoryImpl(
-            workflowServiceStubs,
+            WorkflowClient.newInstance(
+                this.workflowServiceStubs, testEnvironmentOptions.getWorkflowClientOptions()),
             testEnvironmentOptions.getWorkflowClientOptions().getIdentity(),
             testEnvironmentOptions.getWorkflowClientOptions().getNamespace(),
             WorkerOptions.getDefaultInstance().getMaxHeartbeatThrottleInterval(),