diff --git a/y2023/constants.cc b/y2023/constants.cc
new file mode 100644
index 0000000..843af2b
--- /dev/null
+++ b/y2023/constants.cc
@@ -0,0 +1,49 @@
+#include "y2023/constants.h"
+
+#include <cinttypes>
+#include <map>
+
+#if __has_feature(address_sanitizer)
+#include "sanitizer/lsan_interface.h"
+#endif
+
+#include "absl/base/call_once.h"
+#include "aos/mutex/mutex.h"
+#include "aos/network/team_number.h"
+#include "glog/logging.h"
+
+namespace y2023 {
+namespace constants {
+
+const int Values::kZeroingSampleSize;
+
+Values MakeValues(uint16_t team) {
+  LOG(INFO) << "creating a Constants for team: " << team;
+
+  Values r;
+
+  switch (team) {
+    // A set of constants for tests.
+    case 1:
+      break;
+
+    case kCompTeamNumber:
+      break;
+
+    case kPracticeTeamNumber:
+      break;
+
+    case kCodingRobotTeamNumber:
+      break;
+
+    default:
+      LOG(FATAL) << "unknown team: " << team;
+  }
+
+  return r;
+}
+
+Values MakeValues() { return MakeValues(aos::network::GetTeamNumber()); }
+
+}  // namespace constants
+}  // namespace y2023