diff --git a/Cargo.toml b/Cargo.toml
index edca595..7f2e570 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+clap = "4.5.4"
 serde_json = "1.0.117"
 tokio = { version = "1.37.0", features = ["full"] }
 tracing = "0.1.40"
diff --git a/src/handler/mod.rs b/src/handler/mod.rs
index 8685fd6..4221f87 100644
--- a/src/handler/mod.rs
+++ b/src/handler/mod.rs
@@ -17,8 +17,11 @@ pub fn handle(json: &str) {
     println!("{}: {:?}", "val", val["method"]);
 
     match method {
+        "enter" => {
+            enter::handle(&val);
+        }
         "login" => {
-            login_handler::handle(&val);
+            login::handle(&val);
         }
         _ => {
             tracing::error!("Unkown method request: {:?}", method);
@@ -26,7 +29,13 @@ pub fn handle(json: &str) {
     }
 }
 
-mod login_handler {
+mod enter {
+    pub fn handle(json: &serde_json::Value) {
+        tracing::trace!("method: {:?}", json["method"]);
+    }
+}
+
+mod login {
     pub fn handle(json: &serde_json::Value) {
         tracing::trace!("method: {:?}", json["method"]);
     }
diff --git a/src/main.rs b/src/main.rs
index ed6f2d0..0e92bfc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,14 +1,17 @@
 #![allow(dead_code)]
+#![allow(unused_imports)]
 
-mod server;
 mod handler;
 mod packet;
+mod server;
 
 use server::Server;
 
 use std::io;
 use tracing_subscriber::{fmt, layer::SubscriberExt};
 
+use clap::{arg, Command};
+
 /// Setup logger rotator.
 ///
 /// https://docs.rs/tracing-appender/0.2.3/tracing_appender/non_blocking/struct.WorkerGuard.html
@@ -26,6 +29,20 @@ pub fn setup_logger() -> tracing_appender::non_blocking::WorkerGuard {
 #[tokio::main]
 async fn main() {
     let _guard = setup_logger();
-    let mut server = Server::new("127.0.0.1".to_string(), 8080);
+
+    let matches = Command::new("Cogru")
+        .version("0.1.0")
+        .about("Where the collaboration start!?")
+        .arg(
+            arg!(--port <VALUE>)
+                .required(false)
+                .help("Port number")
+                .default_value("8786"),
+        )
+        .get_matches();
+
+    let port = matches.get_one::<String>("port").unwrap().parse::<u16>().unwrap();
+
+    let mut server = Server::new("127.0.0.1".to_string(), port);
     let _ = server.start().await;
 }
diff --git a/src/server.rs b/src/server.rs
index c28c8fd..7c7cc2b 100644
--- a/src/server.rs
+++ b/src/server.rs
@@ -13,7 +13,7 @@ use tokio::net::TcpListener;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
 const SEPARATOR_LEN: usize = "\r\n".len();
-const BUF_SIZE: usize = 1024;
+const BUF_SIZE: usize = 1024 * 1;
 
 fn get_content_len(line: &str) -> usize {
     if !line.starts_with("Content-Length: ") {