There are a few restrictions on what add-ons can do. Improve your users' overall experience by avoiding these pitfalls.
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 host application 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.
The following restrictions only apply to editor add-ons. Don't do the following:
Define UIs with the Card service
Editor add-ons can currently only define a UI using HTML and CSS, not the Card service.
Use editor add-ons on mobile
Editor add-ons are only available on desktop clients, not the mobile apps for the editors.