diff --git a/visualdl/logic/sdk_test.cc b/visualdl/logic/sdk_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5f204095320e8a7377d325faeaf033a01b4df339
--- /dev/null
+++ b/visualdl/logic/sdk_test.cc
@@ -0,0 +1,78 @@
+#include "visualdl/logic/sdk.h"
+
+#include <gtest/gtest.h>
+
+namespace visualdl {
+
+struct ScalarTestHelper {
+  ImHelper rim;
+  ImHelper wim;
+  const std::string dir = "./tmp/1.test";
+
+  void operator()(std::function<void()> read, std::function<void()> write) {
+    wim.StartWriteSerice(dir, 200);
+    write();
+
+    rim.StartReadService(dir, 200);
+    std::this_thread::sleep_for(std::chrono::milliseconds(600));
+    read();
+  }
+};
+
+TEST(Scalar, set_caption) {
+  ScalarTestHelper helper;
+
+  const std::vector<std::string> captions({"train", "test"});
+
+  auto write = [&] {
+    auto tablet = helper.wim.AddTablet("tag0", -1);
+    components::ScalarHelper<float> scalar(tablet, &helper.wim.handler());
+
+    scalar.SetCaptions(captions);
+  };
+
+  auto read = [&] {
+    auto mytablet = helper.rim.tablet("tag0");
+    components::ScalarHelper<float> myscalar(mytablet, &helper.rim.handler());
+    auto mycaptions = myscalar.GetCaptions();
+
+    ASSERT_EQ(captions, mycaptions);
+  };
+
+  helper(read, write);
+}
+
+TEST(Scalar, add_records) {
+  ScalarTestHelper helper;
+
+  const std::vector<std::string> captions({"train", "test"});
+
+  const size_t nsteps = 100;
+
+  auto write = [&] {
+    auto tablet = helper.wim.AddTablet("tag0", -1);
+    components::ScalarHelper<float> scalar(tablet, &helper.wim.handler());
+
+    scalar.SetCaptions(captions);
+
+    for (int i = 0; i < nsteps; i++) {
+      scalar.AddRecord(i * 10, std::vector<float>({(float)i, (float)i + 1}));
+    }
+  };
+
+  auto read = [&] {
+    auto mytablet = helper.rim.tablet("tag0");
+    components::ScalarHelper<float> myscalar(mytablet, &helper.rim.handler());
+
+    auto records = myscalar.GetRecords();
+    ASSERT_EQ(records.size(), nsteps);
+
+    for (int i = 0; i < nsteps; i++) {
+      ASSERT_EQ(records[i], std::vector<float>({(float)i, (float)i + 1}));
+    }
+  };
+
+  helper(read, write);
+}
+
+}  // namespace visualdl