diff --git a/codexcrawler/config.nim b/codexcrawler/config.nim
index 5506407..1fa4328 100644
--- a/codexcrawler/config.nim
+++ b/codexcrawler/config.nim
@@ -10,7 +10,7 @@ Usage:
 
 Options:
   --logLevel=<l>          Sets log level [default: TRACE]
-  --metricsAddress=<ip>   Listen address of the metrics server [default: 127.0.0.1]
+  --metricsAddress=<ip>   Listen address of the metrics server [default: 0.0.0.0]
   --metricsPort=<p>       Listen HTTP port of the metrics server [default: 8008]
   --dataDir=<dir>         Directory for storing data [default: crawler_data]
   --discoveryPort=<p>     Port used for DHT [default: 8090]
diff --git a/codexcrawler/list.nim b/codexcrawler/list.nim
new file mode 100644
index 0000000..591ba21
--- /dev/null
+++ b/codexcrawler/list.nim
@@ -0,0 +1,20 @@
+import pkg/metrics
+
+type
+  OnUpdateMetric = proc(value: int64): void {.gcsafe, raises:[].}
+  List*[T] = ref object
+    items: seq[T]
+    onMetric: OnUpdateMetric
+
+proc new*[T](
+  _: type List[T],
+  onMetric: OnUpdateMetric
+): List[T] =
+  List[T](
+    items: newSeq[T](),
+    onMetric: onMetric
+  )
+
+proc add*[T](this: List[T], item: T) =
+  this.items.add(item)
+  this.onMetric(this.items.len.int64)
diff --git a/codexcrawler/main.nim b/codexcrawler/main.nim
index e3e8748..5fb488a 100644
--- a/codexcrawler/main.nim
+++ b/codexcrawler/main.nim
@@ -1,14 +1,26 @@
 import pkg/chronicles
 import pkg/chronos
 
+import pkg/metrics
+
+import ./list
+
 logScope:
   topics = "main"
 
+declareGauge(example, "testing")
+
 proc startApplication*() {.async.} =
+  proc onExampleMetric(value: int64) =
+    example.set(value)
+  var exampleList = List[string].new(onExampleMetric)
+
   proc aaa() {.async.} =
     while true:
       notice "a"
       await sleepAsync(1000)
+      exampleList.add("str!")
+
 
   asyncSpawn aaa()
 
diff --git a/config.nims b/config.nims
new file mode 100644
index 0000000..d8bdeee
--- /dev/null
+++ b/config.nims
@@ -0,0 +1 @@
+--define:metrics