diff --git a/ryu/app/ofctl/__init__.py b/ryu/app/ofctl/__init__.py
new file mode 100644
index 00000000..bd6808cb
--- /dev/null
+++ b/ryu/app/ofctl/__init__.py
@@ -0,0 +1,15 @@
+# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/ryu/app/ofctl/api.py b/ryu/app/ofctl/api.py
new file mode 100644
index 00000000..a3d0a332
--- /dev/null
+++ b/ryu/app/ofctl/api.py
@@ -0,0 +1,35 @@
+# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# client for ryu.app.ofctl.service
+
+import event
+
+
+def get_datapath(app, dpid):
+    """
+    Get datapath object by dpid.
+    Returns None on error.
+    """
+    assert isinstance(dpid, (int, long))
+    return app.send_request(event.GetDatapathRequest(dpid=dpid))()
+
+
+def send_msg(app, msg):
+    """
+    Send an openflow message.
+    """
+    return app.send_request(event.SendMsgRequest(msg=msg))()
diff --git a/ryu/app/ofctl/event.py b/ryu/app/ofctl/event.py
new file mode 100644
index 00000000..99208337
--- /dev/null
+++ b/ryu/app/ofctl/event.py
@@ -0,0 +1,55 @@
+# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ryu.controller import event
+
+
+# base classes
+
+class _RequestBase(event.EventRequestBase):
+    def __init__(self):
+        self.dst = 'ofctl_service'
+
+
+class _ReplyBase(event.EventReplyBase):
+    pass
+
+
+# get datapath
+
+class GetDatapathRequest(_RequestBase):
+    def __init__(self, dpid):
+        assert isinstance(dpid, (int, long))
+        super(GetDatapathRequest, self).__init__()
+        self.dpid = dpid
+
+
+# send msg
+
+class SendMsgRequest(_RequestBase):
+    def __init__(self, msg):
+        super(SendMsgRequest, self).__init__()
+        self.msg = msg
+
+
+# generic reply
+
+class Reply(_ReplyBase):
+    def __init__(self, result=None):
+        self.result = result
+
+    def __call__(self):
+        return self.result
diff --git a/ryu/app/ofctl/service.py b/ryu/app/ofctl/service.py
new file mode 100644
index 00000000..eac8d681
--- /dev/null
+++ b/ryu/app/ofctl/service.py
@@ -0,0 +1,117 @@
+# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+# Copyright (C) 2014 YAMAMOTO Takashi <yamamoto at valinux co jp>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# ofctl service
+
+from ryu.base import app_manager
+
+from ryu.controller import ofp_event
+from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER,\
+    DEAD_DISPATCHER
+from ryu.controller.handler import set_ev_cls
+
+import event
+
+
+class _SwitchInfo(object):
+    def __init__(self, datapath):
+        self.datapath = datapath
+        self.xids = {}
+        self.barriers = {}
+        self.results = {}
+
+
+class OfctlService(app_manager.RyuApp):
+    def __init__(self, *args, **kwargs):
+        super(OfctlService, self).__init__(*args, **kwargs)
+        self.name = 'ofctl_service'
+        self._switches = {}
+
+    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
+    def _switch_features_handler(self, ev):
+        datapath = ev.msg.datapath
+        id = datapath.id
+        assert isinstance(id, (int, long))
+        self.logger.info('add dpid %s datapath %s' % (id, datapath))
+        self._switches[datapath.id] = _SwitchInfo(datapath=datapath)
+
+    @set_ev_cls(ofp_event.EventOFPStateChange, DEAD_DISPATCHER)
+    def _handle_dead(self, ev):
+        datapath = ev.datapath
+        id = datapath.id
+        self.logger.info('del dpid %s datapath %s' % (id, datapath))
+        datapath2 = self._switches.pop(id)
+        assert datapath2 == datapath
+
+    @set_ev_cls(event.GetDatapathRequest, MAIN_DISPATCHER)
+    def _handle_get_datapath(self, req):
+        id = req.dpid
+        assert isinstance(id, (int, long))
+        try:
+            datapath = self._switches[id].datapath
+        except KeyError:
+            datapath = None
+        self.logger.info('dpid %s -> datapath %s' % (id, datapath))
+        rep = event.Reply(result=datapath)
+        self.reply_to_request(req, rep)
+
+    @set_ev_cls(event.SendMsgRequest, MAIN_DISPATCHER)
+    def _handle_send_msg(self, req):
+        msg = req.msg
+        datapath = msg.datapath
+        datapath.set_xid(msg)
+        xid = msg.xid
+        datapath.send_msg(msg)
+        barrier = datapath.ofproto_parser.OFPBarrierRequest(datapath)
+        datapath.set_xid(barrier)
+        barrier_xid = barrier.xid
+        datapath.send_msg(barrier)
+        si = self._switches[datapath.id]
+        si.xids[xid] = req
+        si.barriers[barrier_xid] = xid
+
+    @set_ev_cls(ofp_event.EventOFPBarrierReply, MAIN_DISPATCHER)
+    def _handle_barrier(self, ev):
+        msg = ev.msg
+        datapath = msg.datapath
+        try:
+            si = self._switches[datapath.id]
+        except KeyError:
+            self.logger.error('unknown dpid %s' % (datapath.id,))
+            return
+        try:
+            xid = si.barriers[msg.xid]
+        except KeyError:
+            self.logger.error('unknown barrier xid %s' % (msg.xid,))
+            return
+        try:
+            result = si.results.pop(xid)
+        except KeyError:
+            result = None
+        req = si.xids.pop(xid)
+        rep = event.Reply(result=result)
+        self.reply_to_request(req, rep)
+
+    @set_ev_cls(ofp_event.EventOFPErrorMsg, MAIN_DISPATCHER)
+    def _handle_error(self, ev):
+        msg = ev.msg
+        datapath = msg.datapath
+        try:
+            si = self._switches[datapath.id]
+        except KeyError:
+            self.logger.error('unknown dpid %s' % (datapath.id,))
+            return
+        si.results[xid] = ev.msg