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 Google Workspace
The add-ons framework is designed to enhance Google Workspace applications—not to add limits. Consequently, you can't alter existing features or lock down the Google Workspace 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.
Editor Add-ons
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.