diff --git a/README.md b/README.md
index 6c12b7d..d536047 100644
--- a/README.md
+++ b/README.md
@@ -10,11 +10,11 @@ BeamingDrive Multiplayer (BeamMP) server compatible with BeamMP clients.
   - [ ] TCP Server part:
     - [x] Handle code
     - [x] Understanding beamp header
-    - [ ] Authorization
+    - [X] Authorization
     - [ ] Upload mods
-  - [ ] UDP Server part:
     - [ ] Connecting to the world
-    - [ ] Any....
+  - [ ] UDP Server part:
+    - [ ] Players synchronizations
   - [x] Additional:
     - [x] Events System
     - [x] Plugins support
diff --git a/src/core/tcp_server.py b/src/core/tcp_server.py
index 5f7ba90..9dc725e 100644
--- a/src/core/tcp_server.py
+++ b/src/core/tcp_server.py
@@ -5,9 +5,10 @@
 # Licence: FPA
 # (c) kuitoi.su 2023
 import asyncio
-import socket
 import traceback
 
+import aiohttp
+
 from core import utils
 
 
@@ -52,30 +53,57 @@ class TCPServer:
             # return DeComp(Data);
         return data
 
-    async def auth_client(self, sock):
+    async def auth_client(self, reader, writer):
         # TODO: Authentication
-        client = self.Core.create_client(sock)
-        self.log.debug(f"Client: \"IP: {client.addr!r}; ID: {client.cid}\" - Authentication!")
+        client = self.Core.create_client(reader, writer)
+        self.log.info(f"Identifying new ClientConnection...")
         data = await self.recv(client)
         self.log.debug(f"recv1 data: {data}")
         if len(data) > 50:
-            client.kick("Too long data")
+            await client.kick("Too long data")
             return
         if "VC2.0" not in data.decode("utf-8"):
-            client.kick("Outdated Version.")
+            await client.kick("Outdated Version.")
             return
         else:
-            pass
-            # self.log.debug('tcp_send(b"A")')
-            # client.tcp_send(b"A")
+            await client.tcp_send(b"A")  # Accepted client version
+            # await client.tcp_send(b"S")  # Ask client key
 
-        # data = await self.recv(client)
-        # self.log.debug(f"recv2 data: {data}")
+        data = await self.recv(client)
+        self.log.debug(f"recv2 data: {data}")
+        if len(data) > 50:
+            await client.kick("Invalid Key (too long)!")
+            return
+        client.key = data.decode("utf-8")
+        async with aiohttp.ClientSession() as session:
+            url = 'https://auth.beammp.com/pkToUser'
+            async with session.post(url, data={'key': client.key}) as response:
+                res = await response.json()
+        self.log.debug(f"res: {res}")
+        try:
+            if res.get("error"):
+                await client.kick('Invalid key! Please restart your game.')
+                return
+            client.nick = res["username"]
+            client.roles = res["roles"]
+            client.guest = res["guest"]
+        except Exception as e:
+            self.log.error(f"Auth error: {e}")
+            await client.kick('Invalid authentication data! Try to econnect in 5 minutes.')
 
-        client.kick("TODO Authentication")
-        return False
+        # TODO: Password party
 
-    async def handle_download(self, sock):
+        ev.call_event("on_auth", client)
+
+        if len(self.Core.clients) > config.Game["players"]:
+            await client.kick("Server full!")
+        else:
+            self.log.info("Identification success")
+            self.Core.insert_client(client)
+
+        return True, client
+
+    async def handle_download(self, writer):
         # TODO: HandleDownload
         self.log.debug(f"Client: \"IP: {0!r}; ID: {0}\" - HandleDownload!")
         return False
diff --git a/src/core/tcp_server.pyi b/src/core/tcp_server.pyi
index 10c00c7..967e5a9 100644
--- a/src/core/tcp_server.pyi
+++ b/src/core/tcp_server.pyi
@@ -4,8 +4,10 @@
 # Version 0.1.2
 # Licence: FPA
 # (c) kuitoi.su 2023
+import asyncio
 from asyncio import StreamWriter, StreamReader
 import socket
+from typing import Tuple
 
 from core import utils, Core
 from core.core import Client
@@ -17,11 +19,12 @@ class TCPServer:
         self.Core = core
         self.host = host
         self.port = port
+        self.loop = asyncio.get_event_loop()
     async def recv(self, client: Client) -> bytes: ...
-    async def auth_client(self, sock: socket.socket) -> None: ...
-    async def handle_download(self, sock: socket.socket) -> None: ...
-    async def handle_code(self, code: str, sock: socket.socket) -> None: ...
-    async def handle_client(self, sock: socket.socket) -> None: ...
+    async def auth_client(self, reader: StreamReader, writer: StreamWriter) -> Tuple[bool, Client]: ...
+    async def handle_download(self, writer: StreamWriter) -> bool: ...
+    async def handle_code(self, code: str, reader: StreamReader, writer: StreamWriter) -> bool: ...
+    async def handle_client(self, reader: StreamReader, writer: StreamWriter) -> None: ...
     async def start(self) -> None: ...
     async def stop(self) -> None: ...