diff --git a/backend/mpc-system/services/account/adapters/input/http/co_managed_handler.go b/backend/mpc-system/services/account/adapters/input/http/co_managed_handler.go
index 2f092a86..9a34bd22 100644
--- a/backend/mpc-system/services/account/adapters/input/http/co_managed_handler.go
+++ b/backend/mpc-system/services/account/adapters/input/http/co_managed_handler.go
@@ -647,6 +647,12 @@ func (h *CoManagedHTTPHandler) GetSignSessionByInviteCode(c *gin.Context) {
 		return
 	}
 
+	// Convert message_hash to hex string (for fallback response too)
+	messageHashHex := ""
+	if len(messageHash) > 0 {
+		messageHashHex = hex.EncodeToString(messageHash)
+	}
+
 	// Get session status from coordinator
 	statusResp, err := h.sessionCoordinatorClient.GetSessionStatus(ctx, sessionID)
 	if err != nil {
@@ -658,6 +664,7 @@ func (h *CoManagedHTTPHandler) GetSignSessionByInviteCode(c *gin.Context) {
 			"session_id":        sessionID,
 			"keygen_session_id": keygenSessionID,
 			"wallet_name":       walletName,
+			"message_hash":      messageHashHex,
 			"threshold_n":       thresholdN,
 			"threshold_t":       thresholdT,
 			"status":            status,
@@ -696,12 +703,6 @@ func (h *CoManagedHTTPHandler) GetSignSessionByInviteCode(c *gin.Context) {
 		}
 	}
 
-	// Convert message_hash to hex string
-	messageHashHex := ""
-	if len(messageHash) > 0 {
-		messageHashHex = hex.EncodeToString(messageHash)
-	}
-
 	logger.Info("Found sign session for invite_code",
 		zap.String("invite_code", inviteCode),
 		zap.String("session_id", sessionID),