diff --git a/apps/efka/src/iot/efka_iot_client.erl b/apps/efka/src/iot/efka_iot_client.erl
index 565632b..958e9ed 100644
--- a/apps/efka/src/iot/efka_iot_client.erl
+++ b/apps/efka/src/iot/efka_iot_client.erl
@@ -452,11 +452,11 @@ handle_container_command(Ref, Request, Socket) ->
     ok.
 
 -spec handle_stream_frame(term(), term(), #state{}) -> gen_statem:event_handler_result(atom(), #state{}).
-handle_stream_frame(StreamId, {<<"open">>, Params}, State = #state{streams = Streams})
-    when is_integer(StreamId), StreamId > 0, is_map(Params) ->
+handle_stream_frame(StreamId, <<"open">>, State = #state{streams = Streams})
+    when is_integer(StreamId), StreamId > 0 ->
     case valid_iot_stream_id(StreamId) andalso not maps:is_key(StreamId, Streams) of
         true ->
-            {ok, {WorkerPid, MonitorRef}} = efka_iot_stream:start_stream(StreamId, Params),
+            {ok, {WorkerPid, MonitorRef}} = efka_iot_stream:start_stream(StreamId),
             StreamState = #stream_state{worker_pid = WorkerPid, monitor_ref = MonitorRef},
             {keep_state, State#state{streams = maps:put(StreamId, StreamState, Streams)}};
         false ->
diff --git a/apps/efka/src/iot/efka_iot_stream.erl b/apps/efka/src/iot/efka_iot_stream.erl
index af8dbed..1d7f768 100644
--- a/apps/efka/src/iot/efka_iot_stream.erl
+++ b/apps/efka/src/iot/efka_iot_stream.erl
@@ -6,28 +6,21 @@
 %%%-------------------------------------------------------------------
 -module(efka_iot_stream).
 
--export([start_stream/2]).
--export([run/2]).
+-export([start_stream/1]).
+-export([run/1]).
 
 -define(DEFAULT_CONNECT_TIMEOUT, 3000).
 -define(DEFAULT_IDLE_TIMEOUT, 120000).
 
 -type stream_id() :: pos_integer().
 
--record(options, {
-    host :: inet:hostname() | inet:ip_address(),
-    port :: inet:port_number(),
-    connect_timeout = 0 :: timeout(),
-    idle_timeout = 0 :: timeout()
-}).
+-spec start_stream(StreamId :: integer()) -> {ok, {pid(), reference()}}.
+start_stream(StreamId) when is_integer(StreamId), StreamId > 0 ->
+    {ok, spawn_monitor(?MODULE, run, [StreamId])}.
 
--spec start_stream(StreamId :: integer(), Params :: map()) -> {ok, {pid(), reference()}}.
-start_stream(StreamId, Params) when is_integer(StreamId), StreamId > 0, is_map(Params) ->
-    {ok, spawn_monitor(?MODULE, run, [StreamId, Params])}.
-
--spec run(StreamId :: stream_id(), Params :: map()) -> ok.
-run(StreamId, Params) when is_integer(StreamId), StreamId > 0, is_map(Params) ->
-    try run0(StreamId, Params) of
+-spec run(StreamId :: stream_id()) -> ok.
+run(StreamId) when is_integer(StreamId), StreamId > 0 ->
+    try run0(StreamId) of
         ok ->
             ok
     catch
@@ -40,9 +33,9 @@ run(StreamId, Params) when is_integer(StreamId), StreamId > 0, is_map(Params) ->
         efka_iot_client:stream_done(StreamId)
     end.
 
--spec run0(stream_id(), map()) -> ok.
-run0(StreamId, Params) ->
-    case open_target_socket(Params) of
+-spec run0(stream_id()) -> ok.
+run0(StreamId) ->
+    case open_target_socket() of
         {ok, Socket, IdleTimeout} ->
             efka_iot_client:send_stream(StreamId, <<"opened">>),
             ok = inet:setopts(Socket, [{active, once}]),
@@ -52,46 +45,26 @@ run0(StreamId, Params) ->
             ok
     end.
 
--spec open_target_socket(map()) -> {ok, gen_tcp:socket(), timeout()} | {error, term()}.
-open_target_socket(Params) when is_map(Params) ->
-    case stream_target_options(Params) of
-        error ->
-            {error, <<"invalid_target">>};
-        {ok, #options{host = Host, port = Port, connect_timeout = ConnectTimeout, idle_timeout = IdleTimeout}} ->
-            SocketOpts = [
-                binary,
-                {packet, raw},
-                {active, false},
-                {nodelay, true}
-            ],
-            case gen_tcp:connect(Host, Port, SocketOpts, ConnectTimeout) of
-                {ok, Socket} ->
-                    {ok, Socket, IdleTimeout};
-                {error, Reason} ->
-                    {error, Reason}
-            end
-    end.
+-spec open_target_socket() -> {ok, gen_tcp:socket(), timeout()} | {error, term()}.
+open_target_socket() ->
+    {ok, Props} = application:get_env(efka, stream_target),
+    Host = proplists:get_value(host, Props),
+    Port = proplists:get_value(port, Props),
+    ConnectTimeout = proplists:get_value(connect_timeout, Props, ?DEFAULT_CONNECT_TIMEOUT),
+    IdleTimeout = proplists:get_value(idle_timeout, Props, ?DEFAULT_IDLE_TIMEOUT),
 
--spec stream_target_options(map()) -> error | {ok, #options{}}.
-stream_target_options(Params = #{<<"target">> := Target}) when is_binary(Target) ->
-    {ok, StreamTargets} = application:get_env(efka, stream_targets),
-    case proplists:get_value(Target, StreamTargets, undefined) of
-        undefined ->
-            error;
-        Props ->
-            Host = proplists:get_value(host, Props),
-            Port = proplists:get_value(port, Props),
-            ConnectTimeout0 = proplists:get_value(connect_timeout, Props, ?DEFAULT_CONNECT_TIMEOUT),
-            IdleTimeout0 = proplists:get_value(idle_timeout, Props, ?DEFAULT_IDLE_TIMEOUT),
-            {ok, #options{
-                host = Host,
-                port = Port,
-                connect_timeout = maps:get(<<"connect_timeout">>, Params, ConnectTimeout0),
-                idle_timeout = maps:get(<<"idle_timeout">>, Params, IdleTimeout0)
-            }}
-    end;
-stream_target_options(_Params) ->
-    error.
+    SocketOpts = [
+        binary,
+        {packet, raw},
+        {active, false},
+        {nodelay, true}
+    ],
+    case gen_tcp:connect(Host, Port, SocketOpts, ConnectTimeout) of
+        {ok, Socket} ->
+            {ok, Socket, IdleTimeout};
+        {error, Reason} ->
+            {error, Reason}
+    end.
 
 -spec loop(stream_id(), gen_tcp:socket(), timeout()) -> ok.
 loop(StreamId, Socket, IdleTimeout) ->
diff --git a/config/sys.config.src b/config/sys.config.src
index 2ddbf85..372313c 100644
--- a/config/sys.config.src
+++ b/config/sys.config.src
@@ -15,13 +15,11 @@
       {udp_port, 24000}
     ]},
 
-    {stream_targets, [
-        {<<"manager">>, [
-            {host, "127.0.0.1"},
-            {port, 18091},
-            {connect_timeout, 3000},
-            {idle_timeout, 120000}
-        ]}
+    {stream_target, [
+        {host, "127.0.0.1"},
+        {port, 18091},
+        {connect_timeout, 3000},
+        {idle_timeout, 120000}
     ]},
 
     {heartbeat, [
diff --git a/docs/efka_iot_protocol.md b/docs/efka_iot_protocol.md
index d7d5845..07c0990 100644
--- a/docs/efka_iot_protocol.md
+++ b/docs/efka_iot_protocol.md
@@ -53,7 +53,7 @@
 `Body` 取值：
 
 ```erlang
-{<<"open">>, #{<<"target">> => <<"manager">>}}
+<<"open">>
 <<"opened">>
 {<<"open_error">>, Reason}
 {<<"data">>, Chunk}
@@ -63,7 +63,7 @@
 
 语义：
 
-- `open`：发起方请求打开一个透明 TCP stream。当前 `efka` 端支持 `target = <<"manager">>`，由本地配置决定实际本机管理程序地址。
+- `open`：发起方请求打开一个透明 TCP stream。`open` 不携带参数；`efka` 端固定连接本机 `stream_target`，通常指向本机 manager/nginx 入口。
 - `opened`：本地 TCP 连接建立成功。
 - `open_error`：本地 TCP 连接建立失败，stream 结束。
 - `data`：透明字节数据，`Chunk` 是 binary。HTTP 请求头、请求体、响应头、响应体都只是该 binary 的内容，iot/efka 中间协议不解析 HTTP。
@@ -73,7 +73,7 @@
 典型 iot 发起访问 efka 本机监控服务的流程：
 
 ```erlang
-iot  -> efka: {<<"stream">>, 1, {<<"open">>, #{<<"target">> => <<"manager">>}}}
+iot  -> efka: {<<"stream">>, 1, <<"open">>}
 efka -> iot:  {<<"stream">>, 1, <<"opened">>}
 
 iot  -> efka: {<<"stream">>, 1, {<<"data">>, RawHttpRequestBytes}}