diff --git a/protocols/gnmi/BUILD b/protocols/gnmi/BUILD
index 8a3510d..0b6b6e6 100644
--- a/protocols/gnmi/BUILD
+++ b/protocols/gnmi/BUILD
@@ -1,11 +1,13 @@
 BUNDLES = [
     "//protocols/gnmi/stub:onos-protocols-gnmi-stub",
+    "//protocols/gnmi/ctl:onos-protocols-gnmi-ctl",
+    "//protocols/gnmi/api:onos-protocols-gnmi-api",
 ]
 
 onos_app(
     app_name = "org.onosproject.protocols.gnmi",
     category = "Protocol",
-    description = "ONOS gNMI protocol subsystem",
+    description = "gNMI protocol subsystem",
     included_bundles = BUNDLES,
     required_apps = [
         "org.onosproject.protocols.grpc",
diff --git a/protocols/gnmi/api/BUILD b/protocols/gnmi/api/BUILD
new file mode 100644
index 0000000..1cf1a3d
--- /dev/null
+++ b/protocols/gnmi/api/BUILD
@@ -0,0 +1,8 @@
+COMPILE_DEPS = CORE_DEPS + [
+    "//protocols/grpc/api:onos-protocols-grpc-api",
+    "//protocols/gnmi/stub:onos-protocols-gnmi-stub",
+]
+
+osgi_jar(
+    deps = COMPILE_DEPS,
+)
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClient.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClient.java
new file mode 100644
index 0000000..7f43d1f
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClient.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+
+import gnmi.Gnmi.CapabilityResponse;
+import gnmi.Gnmi.GetResponse;
+import gnmi.Gnmi.GetRequest;
+import gnmi.Gnmi.SetRequest;
+import gnmi.Gnmi.SetResponse;
+import org.onosproject.grpc.api.GrpcClient;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Client to control a gNMI server.
+ */
+@Beta
+public interface GnmiClient extends GrpcClient {
+
+    /**
+     * Gets capability from a target. This allows device driver behavior
+     * to validate the service version and models which gNMI device supported.
+     *
+     * @return the capability response
+     */
+    CompletableFuture<CapabilityResponse> capability();
+
+    /**
+     * Retrieve a snapshot of data from the device.
+     *
+     * @param request the get request
+     * @return the snapshot of data from the device
+     */
+    CompletableFuture<GetResponse> get(GetRequest request);
+
+    /**
+     * Modifies the state of data on the device.
+     *
+     * @param request the set request
+     * @return the set result
+     */
+    CompletableFuture<SetResponse> set(SetRequest request);
+
+    // TODO: Support gNMI subscription
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClientKey.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClientKey.java
new file mode 100644
index 0000000..26ce113
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiClientKey.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.grpc.api.GrpcClientKey;
+import org.onosproject.net.DeviceId;
+
+/**
+ * Key that uniquely identifies a gNMI client.
+ */
+@Beta
+public class GnmiClientKey extends GrpcClientKey {
+
+    /**
+     * Creates a new gNMI client key.
+     *
+     * @param serviceName gNMI service name of the client
+     * @param deviceId    ONOS device ID
+     * @param serverAddr  gNMI server address
+     * @param serverPort  gNMI server port
+     */
+    public GnmiClientKey(String serviceName, DeviceId deviceId, String serverAddr, int serverPort) {
+        super(serviceName, deviceId, serverAddr, serverPort);
+    }
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiController.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiController.java
new file mode 100644
index 0000000..f4964ed
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiController.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.grpc.api.GrpcClientController;
+
+/**
+ * Controller of gNMI devices.
+ */
+@Beta
+public interface GnmiController
+        extends GrpcClientController<GnmiClientKey, GnmiClient> {
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEvent.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEvent.java
new file mode 100644
index 0000000..5129926
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEvent.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Representation of an event received from a gNMI device.
+ */
+@Beta
+public final class GnmiEvent extends AbstractEvent<GnmiEvent.Type, GnmiEventSubject> {
+
+    /**
+     * Type of gNMI event.
+     */
+    public enum Type {
+        /**
+         * Update.
+         */
+        UPDATE,
+
+        /**
+         * Sync response.
+         */
+        SYNC_RESPONSE
+    }
+
+    protected GnmiEvent(Type type, GnmiEventSubject subject) {
+        super(type, subject);
+    }
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventListener.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventListener.java
new file mode 100644
index 0000000..0fe2fd3
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventListener.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.EventListener;
+
+/**
+ * A listener of events received from gNMI devices.
+ */
+@Beta
+public interface GnmiEventListener extends EventListener<GnmiEvent> {
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventSubject.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventSubject.java
new file mode 100644
index 0000000..d1563ed
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/GnmiEventSubject.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.gnmi.api;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.net.DeviceId;
+
+/**
+ * Information about an event generated by a gNMI device .
+ */
+@Beta
+public interface GnmiEventSubject {
+
+    /**
+     * Returns the deviceId associated to this subject.
+     *
+     * @return the device ID
+     */
+    DeviceId deviceId();
+}
diff --git a/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/package-info.java b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/package-info.java
new file mode 100644
index 0000000..5f07b46
--- /dev/null
+++ b/protocols/gnmi/api/src/main/java/org/onosproject/gnmi/api/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.
+ */
+
+/**
+ * gNMI protocol API.
+ */
+package org.onosproject.gnmi.api;
\ No newline at end of file
diff --git a/protocols/gnmi/ctl/BUILD b/protocols/gnmi/ctl/BUILD
new file mode 100644
index 0000000..db4cd44
--- /dev/null
+++ b/protocols/gnmi/ctl/BUILD
@@ -0,0 +1,23 @@
+COMPILE_DEPS = CORE_DEPS + KRYO + [
+    "//protocols/gnmi/api:onos-protocols-gnmi-api",
+    "//protocols/gnmi/stub:onos-protocols-gnmi-stub",
+    "//protocols/grpc/api:onos-protocols-grpc-api",
+    "//protocols/grpc/ctl:onos-protocols-grpc-ctl",
+    "//protocols/grpc:grpc-core-repkg",
+    "@com_google_protobuf//:protobuf_java",
+    "@io_grpc_grpc_java//netty",
+    "@io_grpc_grpc_java//protobuf-lite",
+    "@io_grpc_grpc_java//stub",
+    "@com_google_api_grpc_proto_google_common_protos//jar",
+]
+
+TEST_DEPS = TEST + [
+    "@minimal_json//jar",
+    "@io_grpc_grpc_java//core:inprocess",
+    "@io_grpc_grpc_java//protobuf-lite",
+]
+
+osgi_jar_with_tests(
+    test_deps = TEST_DEPS,
+    deps = COMPILE_DEPS,
+)
diff --git a/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiClientImpl.java b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiClientImpl.java
new file mode 100644
index 0000000..74a9ec0
--- /dev/null
+++ b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiClientImpl.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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 protocols.gnmi.ctl.java.org.onosproject.gnmi.ctl;
+
+import gnmi.Gnmi.CapabilityRequest;
+import gnmi.Gnmi.CapabilityResponse;
+import gnmi.Gnmi.GetRequest;
+import gnmi.Gnmi.GetResponse;
+import gnmi.Gnmi.SetRequest;
+import gnmi.Gnmi.SetResponse;
+import gnmi.gNMIGrpc;
+import io.grpc.ManagedChannel;
+import io.grpc.StatusRuntimeException;
+import org.onosproject.gnmi.api.GnmiClientKey;
+import org.onosproject.grpc.ctl.AbstractGrpcClient;
+import org.slf4j.Logger;
+import org.onosproject.gnmi.api.GnmiClient;
+
+import java.util.concurrent.CompletableFuture;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Implementation of gNMI client.
+ */
+public class GnmiClientImpl extends AbstractGrpcClient implements GnmiClient {
+    private final Logger log = getLogger(getClass());
+    private final gNMIGrpc.gNMIBlockingStub blockingStub;
+
+    public GnmiClientImpl(GnmiClientKey clientKey, ManagedChannel managedChannel) {
+        super(clientKey, managedChannel);
+        this.blockingStub = gNMIGrpc.newBlockingStub(managedChannel);
+    }
+
+    @Override
+    public CompletableFuture<CapabilityResponse> capability() {
+        return supplyInContext(this::doCapability, "capability");
+    }
+
+    @Override
+    public CompletableFuture<GetResponse> get(GetRequest request) {
+        return supplyInContext(() -> doGet(request), "get");
+    }
+
+    @Override
+    public CompletableFuture<SetResponse> set(SetRequest request) {
+        return supplyInContext(() -> doSet(request), "set");
+    }
+
+    private CapabilityResponse doCapability() {
+        CapabilityRequest request = CapabilityRequest.newBuilder().build();
+        try {
+            return blockingStub.capabilities(request);
+        } catch (StatusRuntimeException e) {
+            log.warn("Unable to get capability from {}: {}", deviceId, e.getMessage());
+            return null;
+        }
+    }
+
+    private GetResponse doGet(GetRequest request) {
+        try {
+            return blockingStub.get(request);
+        } catch (StatusRuntimeException e) {
+            log.warn("Unable to get data from {}: {}", deviceId, e.getMessage());
+            return null;
+        }
+    }
+
+    private SetResponse doSet(SetRequest request) {
+        try {
+            return blockingStub.set(request);
+        } catch (StatusRuntimeException e) {
+            log.warn("Unable to set data to {}: {}", deviceId, e.getMessage());
+            return null;
+        }
+    }
+}
diff --git a/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiControllerImpl.java b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiControllerImpl.java
new file mode 100644
index 0000000..7ddc3f0
--- /dev/null
+++ b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/GnmiControllerImpl.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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 protocols.gnmi.ctl.java.org.onosproject.gnmi.ctl;
+
+import io.grpc.ManagedChannel;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onosproject.gnmi.api.GnmiEvent;
+import org.onosproject.gnmi.api.GnmiEventListener;
+import org.onosproject.grpc.ctl.AbstractGrpcClientController;
+import org.onosproject.gnmi.api.GnmiClient;
+import org.onosproject.gnmi.api.GnmiClientKey;
+import org.onosproject.gnmi.api.GnmiController;
+import org.slf4j.Logger;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Implementation of gNMI controller.
+ */
+@Component(immediate = true)
+@Service
+public class GnmiControllerImpl
+        extends AbstractGrpcClientController<GnmiClientKey, GnmiClient, GnmiEvent, GnmiEventListener>
+        implements GnmiController {
+    private final Logger log = getLogger(getClass());
+
+    @Activate
+    public void activate() {
+        super.activate();
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        super.deactivate();
+        log.info("Stopped");
+    }
+
+    @Override
+    protected GnmiClient createClientInstance(GnmiClientKey clientKey, ManagedChannel channel) {
+        return new GnmiClientImpl(clientKey, channel);
+    }
+}
diff --git a/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/package-info.java b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/package-info.java
new file mode 100644
index 0000000..ae46aa4
--- /dev/null
+++ b/protocols/gnmi/ctl/src/main/java/org/onosproject/gnmi/ctl/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.
+ */
+
+/**
+ * Implementation classes of the gNMI protocol subsystem.
+ */
+package protocols.gnmi.ctl.java.org.onosproject.gnmi.ctl;
\ No newline at end of file