diff --git a/tests/src/receive_spec.cpp b/tests/src/receive_spec.cpp
new file mode 100644
index 0000000..71906e3
--- /dev/null
+++ b/tests/src/receive_spec.cpp
@@ -0,0 +1,143 @@
+#include "PubSubClient.h"
+#include "ShimClient.h"
+#include "Buffer.h"
+#include "BDDTest.h"
+#include "trace.h"
+
+
+byte server[] = { 172, 16, 0, 2 };
+
+bool callback_called = false;
+char lastTopic[1024];
+char lastPayload[1024];
+unsigned int lastLength;
+
+void reset_callback() {
+    callback_called = false;
+    lastTopic[0] = '\0';
+    lastPayload[0] = '\0';
+    lastLength = 0;
+}
+
+void callback(char* topic, byte* payload, unsigned int length) {
+    callback_called = true;
+    strcpy(lastTopic,topic);
+    memcpy(lastPayload,payload,length);
+    lastLength = length;
+}
+
+int test_receive_callback() {
+    IT("receives a callback message");
+    reset_callback();
+    
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+    
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+    
+    byte publish[] = {0x30,0xe,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
+    shimClient.respond(publish,16);
+    
+    rc = client.loop();
+    
+    IS_TRUE(rc);
+    
+    IS_TRUE(callback_called);
+    IS_TRUE(strcmp(lastTopic,"topic")==0);
+    IS_TRUE(memcmp(lastPayload,"payload",7)==0);
+    IS_TRUE(lastLength == 7);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_receive_stream() {
+    IT("receives a stream payload");
+    // TODO
+    IS_FALSE(true);
+    END_IT
+}
+
+int test_receive_max_sized_message() {
+    IT("receives an max-sized message");
+    reset_callback();
+    
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+    
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+    
+    byte length = MQTT_MAX_PACKET_SIZE;
+    byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
+    byte bigPublish[length];
+    memset(bigPublish,'A',length);
+    memcpy(bigPublish,publish,16);
+    shimClient.respond(bigPublish,length);
+    
+    rc = client.loop();
+    
+    IS_TRUE(rc);
+    
+    IS_TRUE(callback_called);
+    IS_TRUE(strcmp(lastTopic,"topic")==0);
+    IS_TRUE(lastLength == length-9);
+    IS_TRUE(memcmp(lastPayload,bigPublish+9,lastLength)==0);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_receive_oversized_message() {
+    IT("drops an oversized message");
+    reset_callback();
+    
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+    
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+    
+    byte length = MQTT_MAX_PACKET_SIZE+1;
+    byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
+    byte bigPublish[length];
+    memset(bigPublish,'A',length);
+    memcpy(bigPublish,publish,16);
+    shimClient.respond(publish,length);
+    
+    rc = client.loop();
+    
+    IS_TRUE(rc);
+    
+    IS_FALSE(callback_called);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+
+int main()
+{
+    test_receive_callback();
+    test_receive_stream();
+    test_receive_max_sized_message();
+    test_receive_oversized_message();
+    
+    FINISH
+}
diff --git a/tests/src/subscribe_spec.cpp b/tests/src/subscribe_spec.cpp
new file mode 100644
index 0000000..b682f48
--- /dev/null
+++ b/tests/src/subscribe_spec.cpp
@@ -0,0 +1,150 @@
+#include "PubSubClient.h"
+#include "ShimClient.h"
+#include "Buffer.h"
+#include "BDDTest.h"
+#include "trace.h"
+
+
+byte server[] = { 172, 16, 0, 2 };
+
+void callback(char* topic, byte* payload, unsigned int length) {
+  // handle message arrived
+}
+
+
+
+int test_subscribe_no_qos() {
+    IT("subscribe without qos defaults to 0");
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+
+    byte subscribe[] = { 0x82,0xa,0x0,0x2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x0 };
+    shimClient.expect(subscribe,12);
+    byte suback[] = { 0x90,0x3,0x0,0x2,0x0 };
+    shimClient.respond(suback,5);
+    
+    rc = client.subscribe((char*)"topic");
+    IS_TRUE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_subscribe_qos_1() {
+    IT("subscribes qos 1");
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+
+    byte subscribe[] = { 0x82,0xa,0x0,0x2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x1 };
+    shimClient.expect(subscribe,12);
+    byte suback[] = { 0x90,0x3,0x0,0x2,0x1 };
+    shimClient.respond(suback,5);
+    
+    rc = client.subscribe((char*)"topic",1);
+    IS_TRUE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_subscribe_not_connected() {
+    IT("subscribe fails when not connected");
+    ShimClient shimClient;
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    
+    int rc = client.subscribe((char*)"topic");
+    IS_FALSE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_subscribe_invalid_qos() {
+    IT("subscribe fails when not connected");
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+    
+    rc = client.subscribe((char*)"topic",2);
+    IS_FALSE(rc);
+    rc = client.subscribe((char*)"topic",254);
+    IS_FALSE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_unsubscribe() {
+    IT("unsubscribes");
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+
+    byte unsubscribe[] = { 0xA2,0x9,0x0,0x2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63 };
+    shimClient.expect(unsubscribe,12);
+    byte unsuback[] = { 0xB0,0x2,0x0,0x2 };
+    shimClient.respond(unsuback,4);
+    
+    rc = client.unsubscribe((char*)"topic");
+    IS_TRUE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int test_unsubscribe_not_connected() {
+    IT("unsubscribe fails when not connected");
+    ShimClient shimClient;
+    
+    PubSubClient client(server, 1883, callback, shimClient);
+    
+    int rc = client.unsubscribe((char*)"topic");
+    IS_FALSE(rc);
+    
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
+int main()
+{
+    test_subscribe_no_qos();
+    test_subscribe_qos_1();
+    test_subscribe_not_connected();
+    test_subscribe_invalid_qos();
+    test_unsubscribe();
+    test_unsubscribe_not_connected();
+    FINISH
+}