diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..c690720
--- /dev/null
+++ b/.env.example
@@ -0,0 +1 @@
+PROMETHEUS_EXPORTER_PORT = 9100 
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index bd08195..e64fef2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,4 +13,5 @@ tracing = "0.1.41"
 tracing-subscriber = "0.3.19"
 serde = { version = "1.0.217", features = ["derive"] }
 serde_json = "1.0.138"
+dotenv = "0.15.0"
 
diff --git a/src/endpoints.rs b/src/endpoints.rs
index f1538eb..d3d1525 100644
--- a/src/endpoints.rs
+++ b/src/endpoints.rs
@@ -7,9 +7,20 @@ use crate::structs::v3::PrometheusMetrics;
 use prometheus::{ Encoder, Gauge, Registry, TextEncoder};
 use std::sync::{ Arc, MutexGuard };
 use crate::AppState;
-use tracing::{ error, info, warn };
+use tracing::{ debug, error, info, warn };
 use crate::metrics::{MetricsProcesser, MetricsValueType};
 
+/// An `Update` endpoint
+/// 
+/// Used to registrate new metrics and to update already 
+/// existing in local metrics `Registry`
+/// 
+/// # Usage
+/// 
+/// ``` bash
+/// curl -X POST -d '"id" : ...' 'http::/localhost:9100/update'
+/// ```
+/// 
 pub async fn update_metrics(
     State(state): State<Arc<AppState>>,
     Json(request) : Json<PrometheusMetrics<'_>>
@@ -19,6 +30,7 @@ pub async fn update_metrics(
     let endpoint = &request.endpoint_name;
 
     for i in request.metrics {
+        debug!("Processing metric: {:?}", &i);
         let metric_name = format!("{}_{}_{}", service, endpoint, &i.id);
         match MetricsProcesser::get_type_of_value(&i) {
             MetricsValueType::Array | 
@@ -59,6 +71,17 @@ pub async fn update_metrics(
     (http::StatusCode::ACCEPTED, "Ok")
 }
 
+/// An `Metrics` endpoint
+/// 
+/// Needed in sharing current local metrics `Registry` state
+/// and all stored metrics  
+/// 
+/// # Usage
+/// 
+/// ``` bash
+/// curl -X GET 'http::/localhost:9100/metrics'
+/// ```
+/// 
 pub async fn metrics_handler(State(state): State<Arc<AppState>>) -> String {
     let registry = state.registry.lock();
     
@@ -76,6 +99,11 @@ pub async fn metrics_handler(State(state): State<Arc<AppState>>) -> String {
     }
 }
 
+/// A function-registrator 
+/// 
+/// Registrates or updates metrics state in local 
+/// `Registry`
+/// 
 pub fn update_or_insert_metric<'a>(
     metric: Gauge, 
     registry: MutexGuard<'a, Registry>,
diff --git a/src/main.rs b/src/main.rs
index f7ee7bb..e691d1f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,12 @@
+/// Prometheus-exporter - a Rust binary crate to provide functional 
+/// of the metrics Exporter.
+/// 
+/// It handles metrics list in it's own local `Registry`
+
 mod endpoints;
-// mod logger;
 mod metrics;
 mod structs;
 
-// use logger::setup_logger;
 use axum::{
     routing::{get, post}, 
     Router};
@@ -11,72 +14,44 @@ use prometheus::Registry;
 use std::sync::{Arc, Mutex};
 use endpoints::*;
 use tokio::net::TcpListener;
-// use log::{warn, info, error};
 use tracing::info;
+use dotenv::dotenv;
 
+/// Shared state of the Web-server 
+/// 
+/// Used to store and share state of the metrics `Registry`
+/// 
 struct AppState {
     registry: Mutex<Registry>,
-    // counter: Mutex<Counter>,
-    // sum : Mutex<Summary>,
 }
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    // let _ = setup_logger().await;
-
     tracing_subscriber::fmt()
         .with_max_level(tracing::Level::DEBUG)
         .init();
 
+    info!("Loading env vars from .env if exists ...");
+    dotenv().ok();
+
     info!("Initializing local Prometehus metrics registry ...");
-
     let registry = Registry::new();
-    // let counter_opts = Opts::new("example_counter", "Пример счётчика");
-    // let histogram_opts = Opts::new("example_histogram", "Пример histogram");
-
-    // use prometheus::proto::{Summary, Quantile};
-    // use prometheus::proto::
-
-    // let guage = prometheus::ProtobufEncoder::new();
-
-
-
-    // let mut sunops = Summary::new();
-    // let mut q1 = Quantile::new();
-    // let mut q2 = Quantile::new();
-
-    // q1.set_quantile(25.0);
-    // q2.set_quantile(75.0);
-    // // prometheus::proto::Metric::
-
-    // let vq = vec![q1, q2];
-    // sunops.set_quantile(vq.into());
-
-    // let counter = Counter::with_opts(counter_opts).unwrap();
-    // // counter.desc()
-    // registry.register(Box::new(counter.clone())).unwrap();
-    // registry.register(Box::new(prometheus::proto::MetricFamily::));
-    // registry.register(Box::new(sunops.clone())).unwrap();
-    
 
     info!("Initializing shared state for Prometheus Exporter web-server ...");
-
     let state = Arc::new(AppState {
         registry: Mutex::new(registry),
-        // counter: Mutex::new(counter),
-        // sum : Mutex::new(sunops)
     });
 
-    // info!("Configurating Web-Server...");
 
     info!("Configurating internals of Prometheus Exporter web-server...");
-
     let app = Router::new()
         .route("/metrics", get(metrics_handler))
         .route("/update", post(update_metrics))
         .with_state(state.clone());
 
-    let listener = TcpListener::bind("0.0.0.0:9100").await.unwrap();
+    let bind_address = format!("0.0.0.0:{}", std::env::var("PROMETHEUS_EXPORTER_PORT").unwrap_or_else(|_| "9100".to_owned()));
+    let listener = TcpListener::bind(bind_address).await.unwrap();
+    
     info!("Serving on ...:9100");
     axum::serve(listener, app).await?;
     Ok(())