diff --git a/protobuf/items.proto b/protobuf/items.proto
index 7e3d165..d4fbdbe 100644
--- a/protobuf/items.proto
+++ b/protobuf/items.proto
@@ -26,4 +26,41 @@ enum Source {
   ROBLOX = 1;
 }
 
-message PersonList { repeated Person person = 1; }
\ No newline at end of file
+message PersonList { repeated Person person = 1; }
+// Authentication messages
+message LoginRequest {
+  string username = 1;
+  string password = 2;
+}
+
+message LoginResponse {
+  string token = 1;
+  bool success = 2;
+  string message = 3;
+}
+
+message LogoutRequest {
+  string token = 1;
+}
+
+message LogoutResponse {
+  bool success = 1;
+  string message = 2;
+}
+
+message AuthStatusRequest {
+  string token = 1;
+}
+
+message AuthStatusResponse {
+  bool authenticated = 1;
+  string username = 2;
+  string message = 3;
+}
+
+// Authentication service
+service AuthService {
+  rpc Login (LoginRequest) returns (LoginResponse);
+  rpc Logout (LogoutRequest) returns (LogoutResponse);
+  rpc GetAuthStatus (AuthStatusRequest) returns (AuthStatusResponse);
+}
\ No newline at end of file