diff --git a/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/MappingCodecRegistrator.java b/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/MappingCodecRegistrator.java
index 7bebe43..0621e19 100644
--- a/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/MappingCodecRegistrator.java
+++ b/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/MappingCodecRegistrator.java
@@ -21,6 +21,7 @@
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onosproject.codec.CodecService;
+import org.onosproject.mapping.MappingKey;
 import org.onosproject.mapping.MappingTreatment;
 import org.onosproject.mapping.actions.MappingAction;
 import org.onosproject.mapping.addresses.MappingAddress;
@@ -28,6 +29,7 @@
 import org.onosproject.mapping.web.codec.MappingActionCodec;
 import org.onosproject.mapping.web.codec.MappingAddressCodec;
 import org.onosproject.mapping.web.codec.MappingInstructionCodec;
+import org.onosproject.mapping.web.codec.MappingKeyCodec;
 import org.onosproject.mapping.web.codec.MappingTreatmentCodec;
 import org.slf4j.Logger;
 
@@ -50,6 +52,7 @@
         codecService.registerCodec(MappingInstruction.class, new MappingInstructionCodec());
         codecService.registerCodec(MappingAction.class, new MappingActionCodec());
         codecService.registerCodec(MappingTreatment.class, new MappingTreatmentCodec());
+        codecService.registerCodec(MappingKey.class, new MappingKeyCodec());
 
         log.info("Started");
     }
@@ -60,6 +63,7 @@
         codecService.unregisterCodec(MappingInstruction.class);
         codecService.unregisterCodec(MappingAction.class);
         codecService.unregisterCodec(MappingTreatment.class);
+        codecService.unregisterCodec(MappingKey.class);
 
         log.info("Stopped");
     }
diff --git a/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/codec/MappingKeyCodec.java b/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/codec/MappingKeyCodec.java
new file mode 100644
index 0000000..93dd106
--- /dev/null
+++ b/apps/mappingmanagement/web/src/main/java/org/onosproject/mapping/web/codec/MappingKeyCodec.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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 org.onosproject.mapping.web.codec;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.mapping.DefaultMappingKey;
+import org.onosproject.mapping.MappingKey;
+import org.onosproject.mapping.addresses.MappingAddress;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Mapping key codec.
+ */
+public final class MappingKeyCodec extends JsonCodec<MappingKey> {
+
+    protected static final String ADDRESS = "address";
+
+    @Override
+    public ObjectNode encode(MappingKey key, CodecContext context) {
+        checkNotNull(key, "Mapping key cannot be null");
+
+        final ObjectNode result = context.mapper().createObjectNode();
+        final JsonCodec<MappingAddress> addressCodec =
+                context.codec(MappingAddress.class);
+
+        result.set(ADDRESS, addressCodec.encode(key.address(), context));
+
+        return result;
+    }
+
+    @Override
+    public MappingKey decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        MappingKey.Builder builder = DefaultMappingKey.builder();
+
+        ObjectNode addressJson = get(json, ADDRESS);
+        if (addressJson != null) {
+            final JsonCodec<MappingAddress> addressCodec =
+                    context.codec(MappingAddress.class);
+            builder.withAddress(addressCodec.decode(addressJson, context));
+        }
+
+        return builder.build();
+    }
+}
diff --git a/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingKeyCodecTest.java b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingKeyCodecTest.java
new file mode 100644
index 0000000..39f43d4
--- /dev/null
+++ b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingKeyCodecTest.java
@@ -0,0 +1,198 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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 org.onosproject.mapping.web.codec;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeDiagnosingMatcher;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.packet.IpPrefix;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.codec.impl.CodecManager;
+import org.onosproject.mapping.DefaultMappingKey;
+import org.onosproject.mapping.MappingKey;
+import org.onosproject.mapping.addresses.MappingAddress;
+import org.onosproject.mapping.addresses.MappingAddresses;
+import org.onosproject.mapping.web.MappingCodecRegistrator;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+
+/**
+ * Unit tests for MappingKeyCodec.
+ */
+public class MappingKeyCodecTest {
+
+    private static final String IPV4_STRING = "1.2.3.4";
+    private static final String PORT_STRING = "32";
+    private static final IpPrefix IPV4_PREFIX =
+                         IpPrefix.valueOf(IPV4_STRING + "/" + PORT_STRING);
+
+    private CodecContext context;
+    private JsonCodec<MappingKey> keyCodec;
+    private MappingCodecRegistrator registrator;
+
+    /**
+     * Sets up for each test.
+     * Creates a context and fetches the mapping key codec.
+     */
+    @Before
+    public void setUp() {
+        CodecManager manager = new CodecManager();
+        registrator = new MappingCodecRegistrator();
+        registrator.codecService = manager;
+        registrator.activate();
+
+        context = new MappingKeyCodecTest.MappingTestContext(registrator.codecService);
+        keyCodec = context.codec(MappingKey.class);
+        assertThat(keyCodec, notNullValue());
+    }
+
+    /**
+     * Deactivates the codec registrator.
+     */
+    @After
+    public void tearDown() {
+        registrator.deactivate();
+    }
+
+    /**
+     * Tests encoding of a mapping key object.
+     */
+    @Test
+    public void testMappingKeyEncode() {
+
+        MappingAddress address = MappingAddresses.ipv4MappingAddress(IPV4_PREFIX);
+
+        MappingKey key = DefaultMappingKey.builder()
+                                .withAddress(address)
+                                .build();
+
+        ObjectNode keyJson = keyCodec.encode(key, context);
+        assertThat(keyJson, MappingKeyJsonMatcher.matchesMappingKey(key));
+    }
+
+    /**
+     * Tests decoding of a mapping key JSON object.
+     */
+    @Test
+    public void testMappingKeyDecode() throws IOException {
+        MappingKey key = getKey("MappingKey.json");
+        assertThat(key.address().toString(),
+                            is("IPV4:" + IPV4_STRING + "/" + PORT_STRING));
+    }
+
+    /**
+     * Hamcrest matcher for mapping key.
+     */
+    public static final class MappingKeyJsonMatcher
+            extends TypeSafeDiagnosingMatcher<JsonNode> {
+
+        private final MappingKey mappingKey;
+
+        /**
+         * A default constructor.
+         *
+         * @param mappingKey mapping key
+         */
+        private MappingKeyJsonMatcher(MappingKey mappingKey) {
+            this.mappingKey = mappingKey;
+        }
+
+        @Override
+        protected boolean matchesSafely(JsonNode jsonNode, Description description) {
+
+            // check address
+            final JsonNode jsonAddressNode = jsonNode.get(MappingKeyCodec.ADDRESS);
+
+            assertThat(jsonAddressNode,
+                    MappingAddressJsonMatcher.matchesMappingAddress(mappingKey.address()));
+
+            return true;
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText(mappingKey.toString());
+        }
+
+        /**
+         * Factory to allocate a mapping treatment.
+         *
+         * @param mappingKey mapping treatment object we are looking for
+         * @return matcher
+         */
+        static MappingKeyJsonMatcher matchesMappingKey(MappingKey mappingKey) {
+            return new MappingKeyJsonMatcher(mappingKey);
+        }
+    }
+
+    /**
+     * Test mapping codec context.
+     */
+    private class MappingTestContext implements CodecContext {
+        private final ObjectMapper mapper = new ObjectMapper();
+        private final CodecService manager;
+
+        /**
+         * Constructs a new mock codec context.
+         */
+        public MappingTestContext(CodecService manager) {
+            this.manager = manager;
+        }
+
+        @Override
+        public ObjectMapper mapper() {
+            return mapper;
+        }
+
+        @Override
+        public <T> JsonCodec<T> codec(Class<T> entityClass) {
+            return manager.getCodec(entityClass);
+        }
+
+        @Override
+        public <T> T getService(Class<T> serviceClass) {
+            return null;
+        }
+    }
+
+    /**
+     * Reads in a mapping key from the given resource and decodes it.
+     *
+     * @param resourceName resource to use to read the JSON for the rule
+     * @return decoded mappingKey
+     * @throws IOException if processing the resource fails
+     */
+    private MappingKey getKey(String resourceName) throws IOException {
+        InputStream jsonStream = MappingKeyCodecTest.class.getResourceAsStream(resourceName);
+        JsonNode json = context.mapper().readTree(jsonStream);
+        assertThat(json, notNullValue());
+        MappingKey key = keyCodec.decode((ObjectNode) json, context);
+        assertThat(key, notNullValue());
+        return key;
+    }
+}
diff --git a/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingTreatmentCodecTest.java b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingTreatmentCodecTest.java
index ca8b2df..6a17502 100644
--- a/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingTreatmentCodecTest.java
+++ b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/codec/MappingTreatmentCodecTest.java
@@ -170,6 +170,12 @@
                 }
             }
 
+            // check address
+            final JsonNode jsonAddressNode = jsonNode.get(MappingKeyCodec.ADDRESS);
+
+            assertThat(jsonAddressNode,
+                    MappingAddressJsonMatcher.matchesMappingAddress(mappingTreatment.address()));
+
             return true;
         }
 
diff --git a/apps/mappingmanagement/web/src/test/resources/org/onosproject/mapping/web/codec/MappingKey.json b/apps/mappingmanagement/web/src/test/resources/org/onosproject/mapping/web/codec/MappingKey.json
new file mode 100644
index 0000000..aac8c5e
--- /dev/null
+++ b/apps/mappingmanagement/web/src/test/resources/org/onosproject/mapping/web/codec/MappingKey.json
@@ -0,0 +1,6 @@
+{
+  "address": {
+    "type": "IPV4",
+    "ipv4": "1.2.3.4/32"
+  }
+}