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
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+++ 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
+}