diff --git a/test_cli/CMakeLists.txt b/test_cli/CMakeLists.txt
new file mode 100644
index 00000000..e37acb97
--- /dev/null
+++ b/test_cli/CMakeLists.txt
@@ -0,0 +1,35 @@
+cmake_minimum_required(VERSION 3.5)
+
+project(test_cli)
+
+find_package(ament_cmake_auto REQUIRED)
+
+if(BUILD_TESTING)
+  # Default to C++14
+  if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 14)
+  endif()
+
+  find_package(ament_cmake REQUIRED)
+  find_package(ament_lint_auto REQUIRED)
+  find_package(ament_cmake_pytest REQUIRED)
+  find_package(rclcpp REQUIRED)
+
+  ament_lint_auto_find_test_dependencies()
+
+  add_executable(initial_params_rclcpp
+    test/initial_params.cpp)
+  ament_target_dependencies(initial_params_rclcpp
+    "rclcpp")
+
+  ament_add_pytest_test(test_params_yaml
+    test/test_params_yaml.py
+    ENV
+      INITIAL_PARAMS_RCLCPP=$<TARGET_FILE:initial_params_rclcpp>
+  )
+  set_tests_properties(test_params_yaml
+    PROPERTIES DEPENDS
+      initial_params_rclcpp)
+endif()
+
+ament_auto_package()
diff --git a/test_cli/package.xml b/test_cli/package.xml
new file mode 100644
index 00000000..a1901a62
--- /dev/null
+++ b/test_cli/package.xml
@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format2.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="2">
+  <name>test_cli</name>
+  <version>0.4.0</version>
+  <description>
+    Test command line arguments passed to ros2 executables.
+  </description>
+  <maintainer email="sloretz@openrobotics.org">Shane Loretz</maintainer>
+  <license>Apache License 2.0</license>
+
+  <buildtool_depend>ament_cmake_auto</buildtool_depend>
+
+  <build_depend>ament_cmake</build_depend>
+
+  <test_depend>ament_cmake_pytest</test_depend>
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+  <test_depend>launch</test_depend>
+  <test_depend>rcl_interfaces</test_depend>
+  <test_depend>rclcpp</test_depend>
+  <test_depend>rclpy</test_depend>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>
diff --git a/test_cli/test/__init__.py b/test_cli/test/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/test_cli/test/initial_params.cpp b/test_cli/test/initial_params.cpp
new file mode 100644
index 00000000..7a2c5694
--- /dev/null
+++ b/test_cli/test/initial_params.cpp
@@ -0,0 +1,31 @@
+// Copyright 2018 Open Source Robotics Foundation, 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 <string>
+
+#include "rclcpp/rclcpp.hpp"
+
+int main(int argc, char ** argv)
+{
+  rclcpp::init(argc, argv);
+
+  std::string node_name = "initial_params_node";
+  std::string namespace_ = "/";
+  auto node = rclcpp::Node::make_shared(node_name, namespace_);
+
+  rclcpp::spin(node);
+
+  rclcpp::shutdown();
+  return 0;
+}
diff --git a/test_cli/test/test_params_yaml.py b/test_cli/test/test_params_yaml.py
new file mode 100644
index 00000000..3936d99d
--- /dev/null
+++ b/test_cli/test/test_params_yaml.py
@@ -0,0 +1,254 @@
+# Copyright 2018 Open Source Robotics Foundation, 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.
+
+import pytest
+from rcl_interfaces.msg import ParameterType
+from rcl_interfaces.srv import GetParameters
+import rclpy
+
+from .utils import BackgroundExecutor
+from .utils import HelperCommand
+from .utils import require_environment_variable
+from .utils import TemporaryFileWithContent
+
+
+CLIENT_LIBRARY_EXECUTABLES = (
+    require_environment_variable('INITIAL_PARAMS_RCLCPP'),
+)
+
+
+@pytest.fixture(scope='module', params=CLIENT_LIBRARY_EXECUTABLES)
+def node_fixture(request):
+    """Create a fixture with a node and helper executable."""
+    rclpy.init()
+    node = rclpy.create_node('tests_yaml')
+    try:
+        yield {
+            'node': node,
+            'executable': request.param,
+        }
+    finally:
+        node.destroy_node()
+        rclpy.shutdown()
+
+
+def get_params(node, node_name, param_names, wfs_timeout=5.0):
+    client = node.create_client(GetParameters, '/{name}/get_parameters'.format(name=node_name))
+    resp = None
+    with BackgroundExecutor(node):
+        assert client.wait_for_service(timeout_sec=wfs_timeout)
+        request = GetParameters.Request()
+        request.names = param_names
+        resp = client.call(request)
+
+    # Don't destroy client while spinning ros2/rmw_fastrtps#205
+    node.destroy_client(client)
+    return resp
+
+
+def test_bool_params(node_fixture):
+    param_file_content = """
+bool_params:
+    ros__parameters:
+        b1: False
+        b2: True
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=bool_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'bool_params', ['b1', 'b2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_BOOL == resp.values[0].type
+        assert ParameterType.PARAMETER_BOOL == resp.values[1].type
+        assert not resp.values[0].bool_value
+        assert resp.values[1].bool_value
+
+
+def test_integer_params(node_fixture):
+    param_file_content = """
+int_params:
+    ros__parameters:
+        i1: 42
+        i2: -27
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=int_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'int_params', ['i1', 'i2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_INTEGER == resp.values[0].type
+        assert ParameterType.PARAMETER_INTEGER == resp.values[1].type
+        assert 42 == resp.values[0].integer_value
+        assert -27 == resp.values[1].integer_value
+
+
+def test_double_params(node_fixture):
+    param_file_content = """
+double_params:
+    ros__parameters:
+        d1: 3.14
+        d2: -2.718
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=double_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'double_params', ['d1', 'd2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_DOUBLE == resp.values[0].type
+        assert ParameterType.PARAMETER_DOUBLE == resp.values[1].type
+        assert pytest.approx(3.14) == resp.values[0].double_value
+        assert pytest.approx(-2.718) == resp.values[1].double_value
+
+
+def test_string_params(node_fixture):
+    param_file_content = """
+str_params:
+    ros__parameters:
+        s1: hello
+        s2: world
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=str_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'str_params', ['s1', 's2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_STRING == resp.values[0].type
+        assert ParameterType.PARAMETER_STRING == resp.values[1].type
+        assert resp.values[0].string_value == 'hello'
+        assert resp.values[1].string_value == 'world'
+
+
+# TODO(sloretz) PARAMETER_BYTE_ARRAY when rcl_yaml_param_parser supports it
+
+
+def test_bool_array_params(node_fixture):
+    param_file_content = """
+ba_params:
+    ros__parameters:
+        ba1: [true, false]
+        ba2: [false, true]
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=ba_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'ba_params', ['ba1', 'ba2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_BOOL_ARRAY == resp.values[0].type
+        assert ParameterType.PARAMETER_BOOL_ARRAY == resp.values[1].type
+        assert resp.values[0].bool_array_value == [True, False]
+        assert resp.values[1].bool_array_value == [False, True]
+
+
+def test_integer_array_params(node_fixture):
+    param_file_content = """
+ia_params:
+    ros__parameters:
+        ia1: [42, -27]
+        ia2: [1234, 5678]
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=ia_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'ia_params', ['ia1', 'ia2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_INTEGER_ARRAY == resp.values[0].type
+        assert ParameterType.PARAMETER_INTEGER_ARRAY == resp.values[1].type
+        assert resp.values[0].integer_array_value == [42, -27]
+        assert resp.values[1].integer_array_value == [1234, 5678]
+
+
+def test_double_array_params(node_fixture):
+    param_file_content = """
+da_params:
+    ros__parameters:
+        da1: [3.14, -2.718]
+        da2: [1234.5, -9999.0]
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=da_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'da_params', ['da1', 'da2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_DOUBLE_ARRAY == resp.values[0].type
+        assert ParameterType.PARAMETER_DOUBLE_ARRAY == resp.values[1].type
+        assert resp.values[0].double_array_value == pytest.approx([3.14, -2.718])
+        assert resp.values[1].double_array_value == pytest.approx([1234.5, -9999.0])
+
+
+def test_string_array_params(node_fixture):
+    param_file_content = """
+sa_params:
+    ros__parameters:
+        sa1: ['Four', 'score']
+        sa2: ['and', 'seven']
+"""
+    with TemporaryFileWithContent(param_file_content) as yaml_file:
+        command = (node_fixture['executable'], '__params:=' + yaml_file, '__node:=sa_params')
+
+        with HelperCommand(command):
+            resp = get_params(node_fixture['node'], 'sa_params', ['sa1', 'sa2'])
+
+        assert 2 == len(resp.values)
+        assert ParameterType.PARAMETER_STRING_ARRAY == resp.values[0].type
+        assert ParameterType.PARAMETER_STRING_ARRAY == resp.values[1].type
+        assert resp.values[0].string_array_value == ['Four', 'score']
+        assert resp.values[1].string_array_value == ['and', 'seven']
+
+
+def test_multiple_parameter_files(node_fixture):
+    first_yaml_content = """
+multi_params:
+    ros__parameters:
+        i1: 42
+        i2: -27
+"""
+    second_yaml_content = """
+multi_params:
+    ros__parameters:
+        i2: 12345
+        i3: -27
+"""
+
+    with TemporaryFileWithContent(first_yaml_content) as first_yaml_file:
+        with TemporaryFileWithContent(second_yaml_content) as second_yaml_file:
+            command = (
+                node_fixture['executable'],
+                '__params:=' + first_yaml_file,
+                '__params:=' + second_yaml_file,
+                '__node:=multi_params'
+            )
+            with HelperCommand(command):
+                resp = get_params(node_fixture['node'], 'multi_params', ['i1', 'i2', 'i3'])
+
+            assert 3 == len(resp.values)
+            assert ParameterType.PARAMETER_INTEGER == resp.values[0].type
+            assert ParameterType.PARAMETER_INTEGER == resp.values[1].type
+            assert ParameterType.PARAMETER_INTEGER == resp.values[2].type
+            assert 42 == resp.values[0].integer_value
+            assert 12345 == resp.values[1].integer_value
+            assert -27 == resp.values[2].integer_value
diff --git a/test_cli/test/utils.py b/test_cli/test/utils.py
new file mode 100644
index 00000000..55345b02
--- /dev/null
+++ b/test_cli/test/utils.py
@@ -0,0 +1,94 @@
+# Copyright 2018 Open Source Robotics Foundation, 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.
+
+import copy
+import os
+import random
+import subprocess
+import sys
+import tempfile
+import threading
+
+import rclpy
+
+
+def require_environment_variable(name):
+    """Get environment variable or raise if it does not exist."""
+    env = os.getenv(name)
+    if env is None:
+        raise EnvironmentError('Missing environment variable "%s"' % name)
+    return env
+
+
+class HelperCommand:
+    """Execute a command in the background."""
+
+    def __init__(self, command):
+        self._env = dict(os.environ)
+        self._command = copy.deepcopy(command)
+
+        # Execute python files using same python used to start this test
+        if command[0][-3:] == '.py':
+            self._command.insert(0, sys.executable)
+            self._env['PYTHONUNBUFFERED'] = '1'
+
+    def __enter__(self):
+        self._proc = subprocess.Popen(self._command, env=self._env)
+        return self
+
+    def __exit__(self, t, v, tb):
+        self._proc.kill()
+
+
+class TemporaryFileWithContent:
+    """Create a named temporary file with content."""
+
+    def __init__(self, content):
+        self._tempdir = tempfile.TemporaryDirectory(prefix='test_cli_')
+        self._content = content
+
+    def __enter__(self):
+        directory = self._tempdir.__enter__()
+        name = ''.join(random.choice('abcdefghijklmnopqrstuvwxyz') for _ in range(10))
+        self._filename = os.path.join(directory, name)
+        self._file = open(self._filename, mode='w')
+        self._file.write(self._content)
+        self._file.flush()
+        # close so it can be opened again on windows
+        self._file.close()
+        return self._file.name
+
+    def __exit__(self, t, v, tb):
+        self._tempdir.__exit__(t, v, tb)
+
+
+class BackgroundExecutor:
+    """Spin an executor in the background."""
+
+    def __init__(self, node, time_between_spins=0.25):
+        self._node = node
+        self._time_between_spins = time_between_spins
+
+    def __enter__(self):
+        self._stop = threading.Event()
+        self._thr = threading.Thread(target=self._run, daemon=True)
+        self._thr.start()
+
+    def _run(self):
+        while not self._stop.is_set():
+            rclpy.spin_once(self._node, timeout_sec=self._time_between_spins)
+
+    def __exit__(self, t, v, tb):
+        self._stop.set()
+        self._thr.join()