diff --git a/src/fields/mod.rs b/src/fields/mod.rs
new file mode 100644
index 0000000..fa25bde
--- /dev/null
+++ b/src/fields/mod.rs
@@ -0,0 +1,32 @@
+use std::fmt;
+use uuid::Uuid;
+
+struct ID {
+    data: Uuid,
+}
+
+impl ID {
+    fn new(id: Uuid) -> Self {
+        Self {
+            data: id,
+        }
+    }
+}
+
+impl fmt::Display for ID {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.data)
+    }
+}
+
+#[cfg(test)]
+mod id {
+    use super::*;
+
+    #[test]
+    fn id_new() {
+        let data = Uuid::new_v4();
+        let id = ID::new(data.clone());
+        assert_eq!(id.to_string(), data.to_string());
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 915b039..86d1293 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 mod client;
+mod fields;
 mod message;
 mod router;
 mod session;