diff --git a/README.md b/README.md
index 020d0648e..de4686df3 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 
 eMQTT is a scalable, fault-tolerant and extensible mqtt broker written in Erlang/OTP.
 
+eMQTT support MQTT V3.1 Protocol Specification.
+
 eMQTT requires Erlang R17+.
 
 ## Startup in Five Minutes
diff --git a/apps/emqtt/include/emqtt_frame.hrl b/apps/emqtt/include/emqtt_frame.hrl
index 1aca3243c..bdaa087b7 100644
--- a/apps/emqtt/include/emqtt_frame.hrl
+++ b/apps/emqtt/include/emqtt_frame.hrl
@@ -18,6 +18,8 @@
 %% Copyright (c) 2007-2012 VMware, Inc.  All rights reserved.
 %%
 
+-define(CLIENT_ID_MAXLEN, 1024).
+
 -define(PROTOCOL_NAMES,  [{3, <<"MQIsdp">>}, {4, <<"MQTT">>}]).
 
 -define(MQTT_PROTO_MAJOR, 3).
diff --git a/apps/emqtt/src/emqtt_client.erl b/apps/emqtt/src/emqtt_client.erl
index 500c66d6b..ef7a01d2d 100644
--- a/apps/emqtt/src/emqtt_client.erl
+++ b/apps/emqtt/src/emqtt_client.erl
@@ -43,6 +43,22 @@
 
 -include("emqtt_frame.hrl").
 
+-record(state, {socket,
+				conn_name,
+				await_recv,
+				connection_state,
+				conserve,
+				parse_state,
+                message_id,
+                client_id,
+                clean_sess,
+                will_msg,
+				keep_alive, 
+				awaiting_ack,
+                subtopics,
+				awaiting_rel}).
+
+
 -define(FRAME_TYPE(Frame, Type),
         Frame = #mqtt_frame{ fixed = #mqtt_frame_fixed{ type = Type }}).