diff --git a/proto/sharing_enums.proto b/proto/sharing_enums.proto
index 709295a7ee..ffb4883542 100644
--- a/proto/sharing_enums.proto
+++ b/proto/sharing_enums.proto
@@ -32,7 +32,7 @@ option objc_class_prefix = "GNSHP";
 // in NearbyClearcutLogger (for android, or clearcut_event_logger as the
 // equivalence for Windows) for all events (may exclude settings), and
 // session_id for a pair of events (start and end of a session).
-// Next id: 72
+// Next id: 73
 enum EventType {
   UNKNOWN_EVENT_TYPE = 0;
 
@@ -310,6 +310,9 @@ enum EventType {
   // native Quick Share app.
   QR_CODE_OPENED_IN_WEB_CLIENT = 71;
 
+  // A HaTS survey session id has been joined with Quick Share flow id.
+  HATS_JOINT_EVENT = 72;
+
   // LINT.ThenChange(//depot/google3/location/nearby/proto/nearby_event_codes.proto:SharingEventCode)
 }
 
diff --git a/sharing/proto/analytics/nearby_sharing_log.proto b/sharing/proto/analytics/nearby_sharing_log.proto
index 811761c84c..f5641035f1 100644
--- a/sharing/proto/analytics/nearby_sharing_log.proto
+++ b/sharing/proto/analytics/nearby_sharing_log.proto
@@ -31,7 +31,7 @@ option objc_class_prefix = "GNCP";
 
 // Top-level log proto for all NearbySharing logging.
 // Each log contains a key (event_type), value (a verb-noun event) pair.
-// Next Tag: 81
+// Next Tag: 82
 // LINT.IfChange
 message SharingLog {
   /* collection_basis = {
@@ -218,6 +218,8 @@ message SharingLog {
 
   optional QrCodeOpenedInWebClient qr_code_opened_in_web_client = 80;
 
+  optional HatsJointEvent hats_joint_event = 81;
+
   // Used only for Nearby Share Windows app now.
   message AppInfo {
     // e.g. "1.0.408"
@@ -953,5 +955,11 @@ message SharingLog {
     }
     optional ClientPlatform client_platform = 1;
   }
+  // EventType: HATS_JOINT_EVENT
+  message HatsJointEvent {
+    optional int64 flow_id = 1 /* type = ST_SESSION_ID */;
+    optional string hats_session_id = 2
+        /* type = ST_SESSION_ID */;
+  }
 }
 // LINT.ThenChange(//depot/google3/logs/proto/location/nearby/nearby_client_log.proto)