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:

### NoChange 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.

### NoCharge users to install

We don't provide a way to charge users for installing add-ons, and add-ons
[can't include ads](https://developers.google.com/apps-script/terms). 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.

### NoDetect many events

Except for [certain triggers](https://developers.google.com/workspace/add-ons/concepts/workspace-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.

## Google Workspace add-ons

The following restrictions only apply to
Google Workspace add-ons and the use of the
[Card service](https://developers.google.com/apps-script/reference/card-service/card-service). Don't do the following:

### No Extend all Google Workspace apps

Google Workspace add-ons can only extend Gmail,
Calendar, Drive, Meet, Docs, Sheets, and Slides. Eventually Google Workspace add-ons will be able to extend other Google Workspace
applications.

### No Document context in editors

Google Workspace add-ons don't yet support the use of
document context in editors. That is, you can't use methods such as
[`SpreadsheetApp.getActiveSpreadsheet()`](https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet-app#getactivespreadsheet)
to acquire the current document.

### No Use HTML/CSS or client-side scripting

Google Workspace add-ons must use card-based
interfaces. The HTML/CSS interfaces supported by Editor add-ons can't be used.
Google Workspace add-ons use a
[widget-based](https://developers.google.com/workspace/add-ons/concepts/widgets) approach to building user
interfaces. This lets the add-on work well on desktop and mobile platforms
without requiring you to build an interface for each.

### No Full mobile support

For the time being, Google Workspace add-ons function
on desktop web clients. Contextual triggering (that is, Gmail message reading)
is also supported from within the Gmail mobile app. Non-contextual homepages
are not yet available from the Gmail, Calendar, or Drive mobile apps.
Google Workspace add-ons are not
available from mobile web browsers.

### NoUse Apps Script triggers

You can't create or use Apps Script
[simple triggers](https://developers.google.com/apps-script/guides/triggers) in a
Google Workspace add-on.

### NoUse SVG Images

You can't currently use SVG images with
[Card service](https://developers.google.com/apps-script/reference/card-service/card-service) cards and widgets.

### NoHave more than 100 widgets

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