diff --git a/api/v3/apps-script-client/ProjectService.js b/api/v3/apps-script-client/ProjectService.js
new file mode 100644
index 0000000..1487a53
--- /dev/null
+++ b/api/v3/apps-script-client/ProjectService.js
@@ -0,0 +1,52 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/* eslint-disable no-unused-vars */
+
+/**
+ * Creates a ComponentDef.
+ * @param {string} projectName The resource name of the parent project.
+ * @param {string} value The name of the component
+ *     e.g. "Triage" or "Triage>Security".
+ * @param {string=} docstring Short description of the ComponentDef.
+ * @param {Array<string>=} admins Array of User resource names to set as admins.
+ * @param {Array<string>=} ccs Array of User resources names to set as auto-ccs.
+ * @param {Array<string>=} labels Array of labels.
+ * @return {ComponentDef}
+ */
+function createComponentDef(
+    projectName, value, docstring, admins, ccs, labels) {
+  const componentDef = {
+    'value': value,
+    'docstring': docstring,
+  };
+  if (admins) {
+    componentDef['admins'] = admins;
+  }
+  if (ccs) {
+    componentDef['ccs'] = ccs;
+  }
+  if (labels) {
+    componentDef['labels'] = labels;
+  }
+  const message = {
+    'parent': projectName,
+    'componentDef': componentDef,
+  };
+  const url = URL + 'monorail.v3.Projects/CreateComponentDef';
+  return run_(url, message);
+}
+
+/**
+ * Deletes a ComponentDef.
+ * @param {string} componentName Resource name of the ComponentDef to delete.
+ * @return {EmptyProto}
+ */
+function deleteComponentDef(componentName) {
+  const message = {
+    'name': componentName,
+  };
+  const url = URL + 'monorail.v3.Projects/DeleteComponentDef';
+  return run_(url, message);
+}