Add custom button to Rich Text Editor (RTE) toolbar

Learn how to add a custom button to Rich Text Editor (RTE) toolbar in the AEM Content Fragment Editor.

Custom buttons can be added to the RTE toolbar in the Content Fragment Editor using the rte extension point. This example shows how to add a custom button called Add Tip to the RTE toolbar and modify the content within the RTE.

Using rte extension point’s getCustomButtons() method one or many custom buttons can be added to the RTE toolbar. It is also possible to add or remove standard RTE buttons like Copy, Paste, Bold, and Italic using getCoreButtons() and removeButtons) methods respectively.

This example shows how to insert a highlighted note or tip using custom Add Tip toolbar button. The highlighted note or tip content has a special formatting applied via HTML elements, and the associated CSS classes. The placeholder content and HTML code are inserted using the onClick() callback method of the getCustomButtons().

Extension point

This example extends to extension point rte to add custom button to RTE toolbar in the Content Fragment Editor.

AEM UI extended
Extension point
Content Fragment Editor
Rich Text Editor Toolbar

Example extension

The following example creates an Add Tip custom button in the RTE toolbar. The click action inserts the placeholder text at the current caret position in the RTE.

The code shows how to add the custom button with an icon and register the click handler function.

Extension registration

ExtensionRegistration.js, mapped to the index.html route, is the entry point for the AEM extension and defines:

  • The RTE toolbar button’s definition in getCustomButtons() function with id, tooltip and icon attributes.
  • The click handler for the button, in the onClick() function.
  • The click handler function receives the state object as an argument to get the RTE’s content in HTML or text format. However in this example it’s not used.
  • The click handler function returns an instructions array. This array has an object with type and value attributes. To insert the content, the value attributes HTML code snippet, the type attribute uses the insertContent. If there is a use case to replace the content, use case the replaceContent instruction type.

The insertContent value is a HTML string, <div class=\"cmp-contentfragment__element-tip\"><div>TIP</div><div>Add your tip text here...</div></div>. The CSS classes cmp-contentfragment__element-tip used to display the value are not defined in the widget, but rather implemented on the web experience this Content Fragment field is displayed on.


import React from "react";
import { Text } from "@adobe/react-spectrum";
import { register } from "@adobe/uix-guest";
import { extensionId } from "./Constants";

// This function is called when the extension is registered with the host and runs in an iframe in the Content Fragment Editor browser window.
function ExtensionRegistration() {
  const init = async () => {
    const guestConnection = await register({
      id: extensionId,
      methods: {
        rte: {
          // RTE Toolbar custom button
          getCustomButtons: () => [
              id: "wknd-cf-tip", // Provide a unique ID for the custom button
              tooltip: "Add Tip", // Provide a label for the custom button
              icon: "Note", // Provide an icon for the button (see for a list of available icons)
              onClick: (state) => {
                // Provide a click handler function that returns the instructions array with type and value. This example inserts the HTML snippet for TIP content.
                return [
                    type: "insertContent",
                      '<div class="cmp-contentfragment__element-tip"><div>TIP</div><div>Add your tip text here...</div></div>',


  return <Text>IFrame for integration with Host (AEM)...</Text>;

export default ExtensionRegistration;