There are a few restrictions on what add-ons can do. Improve your users' overall experience by avoiding these pitfalls.

General restrictions

The following restrictions apply to all add-ons. Don't do the following:

Change features in G Suite

The Add-ons framework is designed to enhance G Suite applications—not to add limits. Consequently, you can't alter existing features or lock down the G Suite document sharing model.

Charge users to install

We don't provide a way to charge users for installing add-ons, and add-ons can't include ads. However, you can roll your own payment system or call into an existing billing database. Your add-on can connect to non-Google services that bill users.

Detect many events

Except for certain triggers, add-ons can't tell what a user does outside the add-on itself. For example, you can't detect when the user clicks on the Google Docs toolbar. It is possible to poll for changes in a file's contents from a sidebar's client-side code, although you'll always have a slight delay.

Gmail add-ons

The following restrictions only apply to Gmail add-ons and the use of the Card service. Don't do the following:

Develop Gmail add-ons for iOS

Gmail add-ons have not yet been added to the iOS version of the Gmail app.

Change features in Gmail

The add-ons framework is designed to enhance Gmail—not to add limits. Consequently, you can't alter existing features or the Gmail user interface.

Use client-side scripting

You can't design a custom UI for your add-on using HTML, CSS and JavaScript. Gmail add-ons use a widget-based approach to building user interfaces. This lets the add-on to work well on desktop and mobile platforms without requiring you to build an interface for each.

Use Apps Script triggers

You can't create or use Apps Script simple or installable triggers in a Gmail add-on.

Use SVG Images

You can't currently use SVG images with Card service widgets.

Have more than 100 widgets

For performance reasons, you can't add more than 100 widgets to a card section.