diff --git a/src/judas_server/backend/backend_server.py b/src/judas_server/backend/backend_server.py
index 3d45dd9..d9d18ec 100644
--- a/src/judas_server/backend/backend_server.py
+++ b/src/judas_server/backend/backend_server.py
@@ -6,12 +6,13 @@ import selectors
 import socket
 import threading
 import time
+import yaml
 
 from typing import Any
 
 from judas_protocol import Category, ControlAction, Message
 
-from judas_server.backend.client import Client
+from judas_server.backend.client import Client, ClientStatus
 
 
 class BackendServer:
@@ -27,6 +28,27 @@ class BackendServer:
         )
         self.logger.debug("Initializing Server...")
 
+        self.known_clients: dict[str, dict[str, str | float]] = {}
+        try:
+            with open("cache/known_clients.yaml", "r") as f:
+                self.known_clients = (
+                    yaml.safe_load(f).get("known_clients", {}) or {}
+                )
+                self.logger.debug(
+                    f"Loaded known clients: {self.known_clients}"
+                )
+                self.logger.info(
+                    f"Loaded {len(self.known_clients)} known clients"
+                )
+        except FileNotFoundError:
+            self.logger.warning(
+                "known_clients.yaml not found, creating empty known clients list"
+            )
+            with open("cache/known_clients.yaml", "w") as f:
+                yaml.safe_dump({"known_clients": {}}, f)
+        except Exception as e:
+            self.logger.error(f"Error loading known clients: {e}")
+
         self.selector = selectors.DefaultSelector()
         self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.server_socket.setsockopt(
@@ -41,8 +63,23 @@ class BackendServer:
 
         self.clients: dict[str, Client] = {}
 
+        if self.known_clients:
+            for client_id in self.known_clients:
+                client = Client(id=client_id, addr=None, socket=None)
+                client.status = ClientStatus.OFFLINE
+                client.last_seen = float(
+                    self.known_clients[client_id].get("last_seen", 0.0)
+                )
+                self.clients[client_id] = client
+
         self.running: bool = False
 
+    def _save_known_clients(self) -> None:
+        """Save the list of known clients to a YAML file."""
+        with open("cache/known_clients.yaml", "w") as f:
+            yaml.safe_dump({"known_clients": self.known_clients}, f)
+        self.logger.debug("Saved known clients")
+
     def _bind_socket(self, host: str, port: int) -> None:
         """Bind the server socket to the specified host and port.
 
@@ -113,6 +150,7 @@ class BackendServer:
             self.logger.error(f"Error unregistering client {client}: {e}")
 
         client.disconnect()
+        self._save_known_clients()
 
     def _send_outbound(self, sock: socket.socket, client: Client) -> None:
         """Queue data to be sent to a client.
@@ -194,9 +232,14 @@ class BackendServer:
                                 f"Client {client.id} is already connected from {old_client.addr}, disconnecting old client..."
                             )
                             self.send_close(old_client)
-                            # self._disconnect(old_client)
-                            # TODO: tell client not to reconnect
+
                         self.clients[client.id] = client
+                        self.known_clients[client.id] = {
+                            "last_seen": client.last_seen
+                        }
+                        self._save_known_clients()
+                        client.status = ClientStatus.ONLINE
+
                         self.logger.info(f"[+] Registered new client {client}")
                     else:
                         self.logger.error(