diff --git a/src/structs.rs b/src/structs.rs
index 3f56f4a..b480f3a 100644
--- a/src/structs.rs
+++ b/src/structs.rs
@@ -1,25 +1,28 @@
 // use std::collections::HashMap;
 use serde::{Serialize, Deserialize};
 use serde_json::Value;
+use std::borrow::Cow;
 // use anyhow::Result;
 // use std::sync::Arc;
 
 pub mod v3 {
     pub use super::*;
     // to prometheus and nmns
-    #[derive(Serialize, Deserialize, Debug)]
-    pub struct MetricOutput {
+    #[derive(Serialize, Deserialize, Debug, Clone)]
+    pub struct MetricOutput<'a> {
         pub id : String,
         #[serde(rename = "type")]
         json_type : String,
         addr : String,
         pub value : Value,
+        #[serde(rename = "description")]
+        pub desc : Option<Cow<'a, String>>,
     }
 
     #[derive(Serialize, Deserialize, Debug)]
-    pub struct PrometheusMetrics {
+    pub struct PrometheusMetrics<'a> {
         pub service_name: String,
         pub endpoint_name: String,
-        pub metrics: Vec<MetricOutput>,
+        pub metrics: Vec<MetricOutput<'a>>,
     }
 }
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