googleapis
diff --git a/bigtable/CMakeLists.txt b/bigtable/CMakeLists.txt
@@ -128,6 +128,8 @@ enable_testing()
 
 # the client library
 add_library(bigtable_data_api
+  client/client_options.h
+  client/client_options.cc
   client/data.h
   client/data.cc
   client/rpc_retry_policy.h
@@ -141,6 +143,7 @@ target_link_libraries(bigtable_data_api googleapis ${GRPCPP_LIBRARIES}
 
 # List the unit tests, then setup the targets and dependencies.
 set(all_unit_tests
+        bigtable_client_client_options_test
         bigtable_client_mutations_test
         bigtable_client_table_apply_test
         bigtable_client_rpc_retry_policy_test)

diff --git a/bigtable/client/client_options.cc b/bigtable/client/client_options.cc
@@ -0,0 +1,32 @@
+// Copyright 2017 Google 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
+
+#include "bigtable/client/client_options.h"
+
+namespace bigtable {
+inline namespace BIGTABLE_CLIENT_NS {
+// TODO() resolve issue #52
+ClientOptions::ClientOptions() {
+  char const* emulator = std::getenv("BIGTABLE_EMULATOR_HOST");
+  if (emulator != nullptr) {
+    endpoint_ = emulator;
+    credentials_ = grpc::InsecureChannelCredentials();
+  } else {
+    endpoint_ = "bigtable.googleapis.com";
+    credentials_ = grpc::GoogleDefaultCredentials();
+  }
+  channel_arguments_ = grpc::ChannelArguments();
+}
+
+}  // namespace BIGTABLE_CLIENT_NS
+}  // namespace bigtable
diff --git a/bigtable/client/client_options.h b/bigtable/client/client_options.h
@@ -0,0 +1,65 @@
+// Copyright 2017 Google 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.
+
+#ifndef BIGTABLE_CLIENT_CLIENTOPTIONS_H_
+#define BIGTABLE_CLIENT_CLIENTOPTIONS_H_
+
+#include <grpc++/grpc++.h>
+
+namespace bigtable {
+inline namespace BIGTABLE_CLIENT_NS {
+/**
+ * Configuration options for the Bigtable Client.
+ *
+ * Applications typically configure the client class using:
+ * @code
+ * auto client =
+ *   bigtable::Client(bigtable::ClientOptions().SetCredentials(...));
+ * @endcode
+ */
+class ClientOptions {
+ public:
+  ClientOptions();
+  const std::string& endpoint() const { return endpoint_; }
+  ClientOptions& SetEndpoint(const std::string& endpoint) {
+    endpoint_ = endpoint;
+    return *this;
+  }
+  std::shared_ptr<grpc::ChannelCredentials> credentials() const {
+    return credentials_;
+  }
+  ClientOptions& SetCredentials(
+      std::shared_ptr<grpc::ChannelCredentials> credentials) {
+    credentials_ = credentials;
+    return *this;
+  }
+  // TODO() create setter/getter for each channel argument. Issue #53
+  const grpc::ChannelArguments channel_arguments() const {
+    return channel_arguments_;
+  }
+  ClientOptions& SetChannelArguments(grpc::ChannelArguments channel_arguments) {
+    channel_arguments_ = channel_arguments;
+    return *this;
+  }
+
+ private:
+  // Endpoint here stands for data endpoint for fetching data.
+  std::string endpoint_;
+  std::shared_ptr<grpc::ChannelCredentials> credentials_;
+  grpc::ChannelArguments channel_arguments_;
+};
+}  // namespace BIGTABLE_CLIENT_NS
+}  // namespace bigtable
+
+#endif  // BIGTABLE_CLIENT_CLIENTOPTIONS_H_
diff --git a/bigtable/client/client_options_test.cc b/bigtable/client/client_options_test.cc
@@ -0,0 +1,48 @@
+// Copyright 2017 Google 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.
+
+#include "bigtable/client/client_options.h"
+
+#include <gmock/gmock.h>
+
+TEST(ClientOptionsTest, ClientOptionsDefaultSettings) {
+  bigtable::ClientOptions client_options_object = bigtable::ClientOptions();
+  EXPECT_EQ("bigtable.googleapis.com", client_options_object.endpoint());
+  EXPECT_EQ(typeid(grpc::GoogleDefaultCredentials()),
+            typeid(client_options_object.credentials()));
+}
+
+TEST(ClientOptionsTest, ClientOptionsCustomEndpoint) {
+  setenv("BIGTABLE_EMULATOR_HOST", "testendpoint.googleapis.com", 1);
+  bigtable::ClientOptions client_options_object = bigtable::ClientOptions();
+  EXPECT_EQ("testendpoint.googleapis.com", client_options_object.endpoint());
+  EXPECT_EQ(typeid(grpc::InsecureChannelCredentials()),
+            typeid(client_options_object.credentials()));
+  unsetenv("BIGTABLE_EMULATOR_HOST");
+}
+
+TEST(ClientOptionsTest, EditEndpoint) {
+  bigtable::ClientOptions client_options_object = bigtable::ClientOptions();
+  client_options_object =
+      client_options_object.SetEndpoint("customendpoint.com");
+  EXPECT_EQ("customendpoint.com", client_options_object.endpoint());
+}
+
+TEST(ClientOptionsTest, EditCredentials) {
+  bigtable::ClientOptions client_options_object = bigtable::ClientOptions();
+  client_options_object =
+      client_options_object.SetCredentials(grpc::InsecureChannelCredentials());
+  EXPECT_EQ(typeid(grpc::InsecureChannelCredentials()),
+            typeid(client_options_object.credentials()));
+}
diff --git a/bigtable/client/data.cc b/bigtable/client/data.cc
@@ -24,17 +24,6 @@ namespace btproto = ::google::bigtable::v2;
 
 namespace bigtable {
 inline namespace BIGTABLE_CLIENT_NS {
-ClientOptions::ClientOptions() {
-  char* emulator = std::getenv("BIGTABLE_EMULATOR_HOST");
-  if (emulator != nullptr) {
-    endpoint_ = emulator;
-    credentials_ = grpc::InsecureChannelCredentials();
-  } else {
-    endpoint_ = "bigtable.googleapis.com";
-    credentials_ = grpc::GoogleDefaultCredentials();
-  }
-}
-
 std::unique_ptr<Table> Client::Open(const std::string& table_id) {
   std::string table_name = std::string("projects/") + project_ + "/instances/" +
                            instance_ + "/tables/" + table_id;

diff --git a/bigtable/client/data.h b/bigtable/client/data.h
@@ -15,6 +15,7 @@
 #ifndef BIGTABLE_CLIENT_DATA_H_
 #define BIGTABLE_CLIENT_DATA_H_
 
+#include <bigtable/client/client_options.h>
 #include <bigtable/client/mutations.h>
 #include <bigtable/client/rpc_retry_policy.h>
 
@@ -24,30 +25,6 @@ namespace bigtable {
 inline namespace BIGTABLE_CLIENT_NS {
 class Table;
 
-class ClientOptions {
- public:
-  ClientOptions();
-
-  const std::string& endpoint() const { return endpoint_; }
-  ClientOptions& SetEndpoint(const std::string& endpoint) {
-    endpoint_ = endpoint;
-    return *this;
-  }
-
-  std::shared_ptr<grpc::ChannelCredentials> credentials() const {
-    return credentials_;
-  }
-  ClientOptions& SetCredentials(
-      std::shared_ptr<grpc::ChannelCredentials> credentials) {
-    credentials_ = credentials;
-    return *this;
-  }
-
- private:
-  std::string endpoint_;
-  std::shared_ptr<grpc::ChannelCredentials> credentials_;
-};
-
 class ClientInterface {
  public:
   virtual ~ClientInterface() = default;