diff --git a/device.go b/device.go
index 4d54ad91..8ee0e443 100644
--- a/device.go
+++ b/device.go
@@ -34,6 +34,10 @@ const (
 	subscribeChCap    = 100
 )
 
+// DeviceClient inplements mqtt.Client interface.
+// Publishing messages and subscribing topics are queued in the DeviceClient if
+// the network connection is lost. They are re-tried after the connection is
+// resumed.
 type DeviceClient struct {
 	opt             *Options
 	mqttOpt         *mqtt.ClientOptions
@@ -92,12 +96,15 @@ func New(opt *Options) *DeviceClient {
 	d.mqttOpt.SetAutoReconnect(false) // MQTT AutoReconnect doesn't work well for mqtts
 	d.mqttOpt.SetConnectTimeout(time.Second * 5)
 
-	d.connect()
-	go connectionHandler(d)
-
 	return d
 }
 
+func (s *DeviceClient) Connect() mqtt.Token {
+	s.connect()
+	go connectionHandler(s)
+	return &mqtt.DummyToken{}
+}
+
 func (s *DeviceClient) connect() {
 	s.cli = mqtt.NewClient(s.mqttOpt)
 
@@ -111,17 +118,46 @@ func (s *DeviceClient) connect() {
 	}()
 }
 
-func (s *DeviceClient) Disconnect() {
+func (s *DeviceClient) Disconnect(quiesce uint) {
 	s.stateUpdateCh <- terminating
 }
 
-func (s *DeviceClient) Publish(topic string, payload interface{}) {
+func (s *DeviceClient) Publish(topic string, qos byte, retained bool, payload interface{}) mqtt.Token {
 	s.publishCh <- &pubqueue.Data{Topic: topic, Payload: payload}
+	return &mqtt.DummyToken{}
 }
 
-func (s *DeviceClient) Subscribe(topic string, cb mqtt.MessageHandler) {
+func (s *DeviceClient) Subscribe(topic string, qos byte, cb mqtt.MessageHandler) mqtt.Token {
 	s.subscribeCh <- &subqueue.Subscription{Type: subqueue.Subscribe, Topic: topic, Cb: cb}
+	return &mqtt.DummyToken{}
+}
+
+func (s *DeviceClient) SubscribeMultiple(filters map[string]byte, callback mqtt.MessageHandler) mqtt.Token {
+	for topic, qos := range filters {
+		s.Subscribe(topic, qos, callback)
+	}
+	return &mqtt.DummyToken{}
+}
+
+func (s *DeviceClient) Unsubscribe(topics ...string) mqtt.Token {
+	for _, topic := range topics {
+		s.subscribeCh <- &subqueue.Subscription{Type: subqueue.Unsubscribe, Topic: topic, Cb: nil}
+	}
+	return &mqtt.DummyToken{}
+}
+
+func (s *DeviceClient) AddRoute(topic string, callback mqtt.MessageHandler) {
+	panic("awsiotdev doesn't support AddRoute")
+}
+
+func (s *DeviceClient) IsConnected() bool {
+	return s.cli.IsConnected()
+}
+func (s *DeviceClient) IsConnectionOpen() bool {
+	// paho.mqtt.golang v1.1.1 don't have it.
+	// this will be added in the next version.
+	return true // since offline queued
 }
-func (s *DeviceClient) Unsubscribe(topic string) {
-	s.subscribeCh <- &subqueue.Subscription{Type: subqueue.Unsubscribe, Topic: topic, Cb: nil}
+func (s *DeviceClient) OptionsReader() mqtt.ClientOptionsReader {
+	return s.cli.OptionsReader()
 }
diff --git a/device_test.go b/device_test.go
new file mode 100644
index 00000000..f84d8f24
--- /dev/null
+++ b/device_test.go
@@ -0,0 +1,27 @@
+// Copyright 2018 SEQSENSE, Inc.
+//
+// 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.
+
+package awsiotdev
+
+import (
+	"testing"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+)
+
+func TestClientInterface(t *testing.T) {
+	var cli mqtt.Client
+	cli = &DeviceClient{}
+	_ = cli
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 00000000..3ecb5e44
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,6 @@
+module github.com/seqsense/aws-iot-device-sdk-go
+
+require (
+	github.com/eclipse/paho.mqtt.golang v1.1.1
+	golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 00000000..2a39bb98
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,4 @@
+github.com/eclipse/paho.mqtt.golang v1.1.1 h1:iPJYXJLaViCshRTW/PSqImSS6HJ2Rf671WR0bXZ2GIU=
+github.com/eclipse/paho.mqtt.golang v1.1.1/go.mod h1:H9keYFcgq3Qr5OUJm/JZI/i6U7joQ8SYLhZwfeOo6Ts=
+golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc h1:ZMCWScCvS2fUVFw8LOpxyUUW5qiviqr4Dg5NdjLeiLU=
+golang.org/x/net v0.0.0-20181102091132-c10e9556a7bc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
diff --git a/sample/main.go b/sample/main.go
index 4581dd7a..38ed4f9e 100644
--- a/sample/main.go
+++ b/sample/main.go
@@ -73,7 +73,8 @@ func main() {
 		AutoResubscribe:          true,
 	}
 	cli := awsiot.New(o)
-	cli.Subscribe("test", messageHandler)
+	cli.Connect()
+	cli.Subscribe("test", 1, messageHandler)
 
 	sig := make(chan os.Signal, 1)
 	signal.Notify(sig, os.Interrupt, syscall.SIGTERM)
@@ -85,7 +86,7 @@ func main() {
 		case <-sig:
 			return
 		case <-tick.C:
-			cli.Publish("notification", "{\"status\": \"tick\"}")
+			cli.Publish("notification", 1, false, "{\"status\": \"tick\"}")
 		}
 	}
 }