diff --git a/source/client/src/clientmain.c b/source/client/src/clientmain.c
new file mode 100644
index 0000000000..7dac304c58
--- /dev/null
+++ b/source/client/src/clientmain.c
@@ -0,0 +1,86 @@
+#include "clientInt.h"
+#include "trpc.h"
+#include "os.h"
+#include "taosmsg.h"
+#include "tcache.h"
+#include "tconfig.h"
+#include "tglobal.h"
+#include "tnote.h"
+#include "tref.h"
+#include "tscLog.h"
+#include "tsched.h"
+#include "ttime.h"
+#include "ttimezone.h"
+
+#define TSC_VAR_NOT_RELEASE 1
+#define TSC_VAR_RELEASED    0
+
+static int32_t sentinel = TSC_VAR_NOT_RELEASE;
+static pthread_once_t tscinit = PTHREAD_ONCE_INIT;
+
+extern int32_t tscInitRes;
+
+int taos_options(TSDB_OPTION option, const void *arg, ...) {
+  static int32_t lock = 0;
+
+  for (int i = 1; atomic_val_compare_exchange_32(&lock, 0, 1) != 0; ++i) {
+    if (i % 1000 == 0) {
+      tscInfo("haven't acquire lock after spin %d times.", i);
+      sched_yield();
+    }
+  }
+
+  int ret = taos_options_imp(option, (const char*)arg);
+
+  atomic_store_32(&lock, 0);
+  return ret;
+}
+
+int taos_init() {
+  pthread_once(&tscinit, taos_init_imp);
+  return tscInitRes;
+}
+
+// this function may be called by user or system, or by both simultaneously.
+void taos_cleanup(void) {
+  tscDebug("start to cleanup client environment");
+
+  if (atomic_val_compare_exchange_32(&sentinel, TSC_VAR_NOT_RELEASE, TSC_VAR_RELEASED) != TSC_VAR_NOT_RELEASE) {
+    return;
+  }
+
+  int32_t id = tscReqRef;
+  tscReqRef = -1;
+  taosCloseRef(id);
+
+  void* p = tscQhandle;
+  tscQhandle = NULL;
+  taosCleanUpScheduler(p);
+
+  id = tscConnRef;
+  tscConnRef = -1;
+  taosCloseRef(id);
+
+  p = tscRpcCache;
+  tscRpcCache = NULL;
+
+  if (p != NULL) {
+    taosCacheCleanup(p);
+    pthread_mutex_destroy(&rpcObjMutex);
+  }
+
+  rpcCleanup();
+  taosCloseLog();
+}
+
+void taos_close(TAOS* taos) {
+
+}
+
+const char *taos_errstr(TAOS_RES *res) {
+
+}
+
+void taos_free_result(TAOS_RES *res) {
+
+}
\ No newline at end of file
diff --git a/source/client/test/CMakeLists.txt b/source/client/test/CMakeLists.txt
new file mode 100644
index 0000000000..a3f2ad88bb
--- /dev/null
+++ b/source/client/test/CMakeLists.txt
@@ -0,0 +1,18 @@
+
+MESSAGE(STATUS "build parser unit test")
+
+# GoogleTest requires at least C++11
+SET(CMAKE_CXX_STANDARD 11)
+AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
+
+ADD_EXECUTABLE(clientTest ${SOURCE_LIST})
+TARGET_LINK_LIBRARIES(
+        clientTest
+        PUBLIC os util common transport gtest taos
+)
+
+TARGET_INCLUDE_DIRECTORIES(
+        clientTest
+        PUBLIC "${CMAKE_SOURCE_DIR}/include/libs/client/"
+        PRIVATE "${CMAKE_SOURCE_DIR}/source/libs/client/inc"
+)