diff --git a/plugin/api/alerting/api.go b/plugin/api/alerting/api.go
index ba31bd0e..8bcb55da 100644
--- a/plugin/api/alerting/api.go
+++ b/plugin/api/alerting/api.go
@@ -25,6 +25,7 @@ func (alert *AlertAPI) Init() {
 	api.HandleAPIMethod(api.GET, "/alerting/rule/_search", alert.RequirePermission(alert.searchRule, enum.PermissionAlertRuleRead))
 	api.HandleAPIMethod(api.GET, "/alerting/stats", alert.getAlertStats)
 	api.HandleAPIMethod(api.POST, "/alerting/rule/info", alert.fetchAlertInfos)
+	api.HandleAPIMethod(api.POST, "/alerting/rule/preview_metric", alert.getPreviewMetricData)
 	api.HandleAPIMethod(api.POST, "/alerting/rule/:rule_id/_enable", alert.RequirePermission(alert.enableRule, enum.PermissionAlertRuleWrite))
 	api.HandleAPIMethod(api.GET, "/alerting/rule/:rule_id/metric", alert.RequirePermission(alert.getMetricData, enum.PermissionAlertRuleRead))
 	api.HandleAPIMethod(api.GET, "/alerting/rule/:rule_id/info", alert.RequirePermission(alert.getRuleDetail, enum.PermissionAlertRuleRead, enum.PermissionAlertMessageRead))
diff --git a/plugin/api/alerting/rule.go b/plugin/api/alerting/rule.go
index a7d0031d..536b6db0 100644
--- a/plugin/api/alerting/rule.go
+++ b/plugin/api/alerting/rule.go
@@ -672,6 +672,7 @@ func (alertAPI *AlertAPI) getPreviewMetricData(w http.ResponseWriter, req *http.
 		minStr = alertAPI.Get(req, "min", "")
 		maxStr = alertAPI.Get(req, "max", "")
 	)
+
 	bucketSize, min, max, err := api.GetMetricRangeAndBucketSize(minStr, maxStr, 60, 15)
 	filterParam := &alerting.FilterParam{
 		Start: min,