diff --git a/apps/emqttd/src/emqttd_acl.erl b/apps/emqttd/src/emqttd_acl.erl
index 7cd57efcf..fc8d6dc49 100644
--- a/apps/emqttd/src/emqttd_acl.erl
+++ b/apps/emqttd/src/emqttd_acl.erl
@@ -27,3 +27,61 @@
 -module(emqttd_acl).
 
 %%TODO: 0.6.0...
+
+% Three types of authorization
+% 
+% 1. connection from
+% 2. subscribe topic
+% 3. publish to topic
+%
+
+-behaviour(gen_server).
+
+-define(SERVER, ?MODULE).
+
+%% ------------------------------------------------------------------
+%% API Function Exports
+%% ------------------------------------------------------------------
+
+-export([start_link/0]).
+
+%% ------------------------------------------------------------------
+%% gen_server Function Exports
+%% ------------------------------------------------------------------
+
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+         terminate/2, code_change/3]).
+
+%% ------------------------------------------------------------------
+%% API Function Definitions
+%% ------------------------------------------------------------------
+
+start_link() ->
+    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+
+%% ------------------------------------------------------------------
+%% gen_server Function Definitions
+%% ------------------------------------------------------------------
+
+init(Args) ->
+    {ok, Args}.
+
+handle_call(_Request, _From, State) ->
+    {reply, ok, State}.
+
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%% ------------------------------------------------------------------
+%% Internal Function Definitions
+%% ------------------------------------------------------------------
+