diff --git a/src/common/task.cc b/src/common/task.cc
index 9b4969618482..e60aa8865958 100644
--- a/src/common/task.cc
+++ b/src/common/task.cc
@@ -324,7 +324,11 @@ int TaskSpec_arg_id_count(TaskSpec *spec, int64_t arg_index) {
   RAY_CHECK(spec);
   auto message = flatbuffers::GetRoot<TaskInfo>(spec);
   auto ids = message->args()->Get(arg_index)->object_ids();
-  return ids->size();
+  if (ids == nullptr) {
+    return 0;
+  } else {
+    return ids->size();
+  }
 }
 
 ObjectID TaskSpec_arg_id(TaskSpec *spec, int64_t arg_index, int64_t id_index) {
diff --git a/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.cc b/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.cc
new file mode 100644
index 000000000000..d5cd92eb5dfe
--- /dev/null
+++ b/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.cc
@@ -0,0 +1,229 @@
+#include <jni.h>
+
+#include "local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.h"
+#include "local_scheduler_client.h"
+#include "logging.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+class UniqueIdFromJByteArray {
+ private:
+  JNIEnv *_env;
+  jbyteArray _bytes;
+
+ public:
+  UniqueID *PID;
+
+  UniqueIdFromJByteArray(JNIEnv *env, jbyteArray wid) {
+    _env = env;
+    _bytes = wid;
+
+    jbyte *b =
+        reinterpret_cast<jbyte *>(_env->GetByteArrayElements(_bytes, nullptr));
+    PID = reinterpret_cast<UniqueID *>(b);
+  }
+
+  ~UniqueIdFromJByteArray() {
+    _env->ReleaseByteArrayElements(_bytes, reinterpret_cast<jbyte *>(PID), 0);
+  }
+};
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _init
+ * Signature: (Ljava/lang/String;[B[BZJ)J
+ */
+JNIEXPORT jlong JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1init(JNIEnv *env,
+                                                         jclass,
+                                                         jstring sockName,
+                                                         jbyteArray wid,
+                                                         jbyteArray actorId,
+                                                         jboolean isWorker,
+                                                         jlong numGpus) {
+  // 	native private static long _init(String localSchedulerSocket,
+  //     byte[] workerId, byte[] actorId, boolean isWorker, long numGpus);
+  UniqueIdFromJByteArray worker_id(env, wid);
+  const char *nativeString = env->GetStringUTFChars(sockName, JNI_FALSE);
+  auto client =
+      LocalSchedulerConnection_init(nativeString, *worker_id.PID, isWorker);
+  env->ReleaseStringUTFChars(sockName, nativeString);
+  return reinterpret_cast<jlong>(client);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _submitTask
+ * Signature: (JLjava/nio/ByteBuffer;II)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1submitTask(
+    JNIEnv *env,
+    jclass,
+    jlong c,
+    jbyteArray cursorId,
+    jobject buff,
+    jint pos,
+    jint sz) {
+  // task -> TaskInfo (with FlatBuffer)
+  // native private static void _submitTask(long client, /*Direct*/ByteBuffer
+  // task);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  TaskSpec *task =
+      reinterpret_cast<char *>(env->GetDirectBufferAddress(buff)) + pos;
+  std::vector<ObjectID> execution_dependencies;
+  if (cursorId != nullptr) {
+    UniqueIdFromJByteArray cursor_id(env, cursorId);
+    execution_dependencies.push_back(*cursor_id.PID);
+  }
+  TaskExecutionSpec taskExecutionSpec =
+      TaskExecutionSpec(execution_dependencies, task, sz);
+  local_scheduler_submit(client, taskExecutionSpec);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _getTaskTodo
+ * Signature: (J)[B
+ */
+JNIEXPORT jbyteArray JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1getTaskTodo(JNIEnv *env,
+                                                                jclass,
+                                                                jlong c) {
+  // native private static ByteBuffer _getTaskTodo(long client);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  int64_t task_size = 0;
+
+  // TODO: handle actor failure later
+  TaskSpec *spec = local_scheduler_get_task(client, &task_size);
+
+  jbyteArray result;
+  result = env->NewByteArray(task_size);
+  if (result == nullptr) {
+    return nullptr; /* out of memory error thrown */
+  }
+
+  // move from task spec structure to the java structure
+  env->SetByteArrayRegion(result, 0, task_size,
+                          reinterpret_cast<jbyte *>(spec));
+
+  TaskSpec_free(spec);
+  return result;
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _computePutId
+ * Signature: (J[BI)[B
+ */
+JNIEXPORT jbyteArray JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1computePutId(JNIEnv *env,
+                                                                 jclass,
+                                                                 jlong c,
+                                                                 jbyteArray tid,
+                                                                 jint index) {
+  // native private static byte[] _computePutId(long client, byte[] taskId, int
+  // putIndex);
+  UniqueIdFromJByteArray task(env, tid);
+
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  ObjectID putId = task_compute_put_id(*task.PID, index);
+  local_scheduler_put_object(client, *task.PID, putId);
+
+  jbyteArray result;
+  result = env->NewByteArray(sizeof(ObjectID));
+  if (result == nullptr) {
+    return nullptr; /* out of memory error thrown */
+  }
+
+  // move from task spec structure to the java structure
+  env->SetByteArrayRegion(result, 0, sizeof(ObjectID),
+                          reinterpret_cast<jbyte *>(&putId));
+  return result;
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _destroy
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1destroy(JNIEnv *,
+                                                            jclass,
+                                                            jlong c) {
+  // native private static void _destroy(long client);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  local_scheduler_disconnect_client(client);
+  LocalSchedulerConnection_free(client);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _task_done
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1task_1done(JNIEnv *,
+                                                               jclass,
+                                                               jlong c) {
+  // native private static void _task_done(long client);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  local_scheduler_task_done(client);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _reconstruct_object
+ * Signature: (J[B)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1reconstruct_1object(
+    JNIEnv *env,
+    jclass,
+    jlong c,
+    jbyteArray oid) {
+  // native private static void _reconstruct_object(long client, byte[]
+  // objectId);
+  UniqueIdFromJByteArray o(env, oid);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  local_scheduler_reconstruct_object(client, *o.PID);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _notify_unblocked
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1notify_1unblocked(JNIEnv *,
+                                                                      jclass,
+                                                                      jlong c) {
+  // native private static void _notify_unblocked(long client);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  local_scheduler_notify_unblocked(client);
+}
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _put_object
+ * Signature: (J[B[B)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1put_1object(
+    JNIEnv *env,
+    jclass,
+    jlong c,
+    jbyteArray tid,
+    jbyteArray oid) {
+  // native private static void _put_object(long client, byte[] taskId, byte[]
+  // objectId);
+  UniqueIdFromJByteArray o(env, oid), t(env, tid);
+  auto client = reinterpret_cast<LocalSchedulerConnection *>(c);
+  local_scheduler_put_object(client, *t.PID, *o.PID);
+}
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.h b/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.h
new file mode 100644
index 000000000000..dfcafd607a45
--- /dev/null
+++ b/src/local_scheduler/lib/java/org_ray_spi_impl_DefaultLocalSchedulerClient.h
@@ -0,0 +1,117 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class org_ray_spi_impl_DefaultLocalSchedulerClient */
+
+#ifndef _Included_org_ray_spi_impl_DefaultLocalSchedulerClient
+#define _Included_org_ray_spi_impl_DefaultLocalSchedulerClient
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _init
+ * Signature: (Ljava/lang/String;[B[BZJ)J
+ */
+JNIEXPORT jlong JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1init(JNIEnv *,
+                                                         jclass,
+                                                         jstring,
+                                                         jbyteArray,
+                                                         jbyteArray,
+                                                         jboolean,
+                                                         jlong);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _submitTask
+ * Signature: (JLjava/nio/ByteBuffer;II)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1submitTask(JNIEnv *,
+                                                               jclass,
+                                                               jlong,
+                                                               jbyteArray,
+                                                               jobject,
+                                                               jint,
+                                                               jint);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _getTaskTodo
+ * Signature: (J)[B
+ */
+JNIEXPORT jbyteArray JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1getTaskTodo(JNIEnv *,
+                                                                jclass,
+                                                                jlong);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _computePutId
+ * Signature: (J[BI)[B
+ */
+JNIEXPORT jbyteArray JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1computePutId(JNIEnv *,
+                                                                 jclass,
+                                                                 jlong,
+                                                                 jbyteArray,
+                                                                 jint);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _destroy
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1destroy(JNIEnv *,
+                                                            jclass,
+                                                            jlong);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _task_done
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1task_1done(JNIEnv *,
+                                                               jclass,
+                                                               jlong);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _reconstruct_object
+ * Signature: (J[B)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1reconstruct_1object(
+    JNIEnv *,
+    jclass,
+    jlong,
+    jbyteArray);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _notify_unblocked
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1notify_1unblocked(JNIEnv *,
+                                                                      jclass,
+                                                                      jlong);
+
+/*
+ * Class:     org_ray_spi_impl_DefaultLocalSchedulerClient
+ * Method:    _put_object
+ * Signature: (J[B[B)V
+ */
+JNIEXPORT void JNICALL
+Java_org_ray_spi_impl_DefaultLocalSchedulerClient__1put_1object(JNIEnv *,
+                                                                jclass,
+                                                                jlong,
+                                                                jbyteArray,
+                                                                jbyteArray);
+
+#ifdef __cplusplus
+}
+#endif
+#endif