This page provides a general overview of the main add-on categories. These add-on types differ in what applications they extend, how they are created, what restrictions they have, and how they are published.
For more information about add-ons for specific G Suite applications, see the links provided in the below sections.
G Suite add-ons
G Suite add-ons are the newest generation of add-ons, and provide many new capabilities:
Build just one add-on for multiple G Suite apps: Instead of separate add-ons for Gmail, Calendar, and Drive, you can build and manage a single G Suite add-on to extend multiple G Suite apps.
Build homepage experiences: Show a non-contextual card for an easy entry point into your add-on. You can create individual homepages for each G Suite app your add-on extends, or use the same homepage for multiple apps. You can design your G Suite add-on to use only non-contextual cards, only contextual cards, or a combination of both.
Reflect the user's context in your add-on: For example, your add-on can display info from an email or calendar event in your add-on, or suggest an action based on the current G Suite app page.
Use standardized interfaces: Construct user interfaces from built-in widget elements provided by the Apps Script
Cardservice. This simplifies development and allows your add-on function in mobile environments. You don't need any expertise with HTML or CSS when defining these interfaces.
Extend desktop and mobile clients for Gmail: If a G Suite add-on extends Gmail, you can use it in both the desktop and mobile versions of Gmail. If you build a G Suite add-on that extends Gmail, you don't need to design a separate mobile version of the add-on—the same add-on interface used everywhere.
Publish your add-ons: You can publish G Suite add-ons to the G Suite Marketplace where others can find and install them. When you publish, you can restrict the availability of your add-on to only your organization's domain or make the add-on available to millions of business users and domain administrators.
Gmail add-ons were launched in 2017 to provide a way for developers to extend Gmail. These add-ons introduced card-based interface development, as well as other features now used by G Suite add-ons. In effect, the Gmail add-on framework was a prototype for the infrastructure that now supports G Suite add-ons.
Today, Gmail add-ons are simply a sub-type of G Suite add-ons that only extend Gmail. Gmail add-ons that were previously published still function, but you should upgrade your Gmail add-ons to take advantage of the new capabilities provided by G Suite add-ons.
Calendar conferencing add-ons
Calendar conferencing add-ons allow conferencing providers to insert their conference solutions in Google Calendar. After a user installs a Calendar conferencing add-on, that user can select that conference solution when creating or editing events in Calendar.
These add-ons require a well-developed third-party conferencing solution for the add-on to connect to. Because of this requirement, Calendar conferencing add-ons were kept in an extended beta phase and not documented publicly for some time. Most developers don't have any need to ever develop a conferencing add-on.
Like Gmail add-ons, Calendar conferencing add-ons can be upgraded into a full G Suite add-on, retaining the conferencing features and adding new features such as homepages. See Upgrade your add-on for more details.
Editor add-ons extend one of the Google Drive editor applications. Each editor add-on type (for example, Sheets add-ons) can have its own set of type-specific capabilities, restrictions, and special considerations. When building editor add-ons, it's important to understand these editor-specific details. For more details on add-ons for specific editors, see the corresponding sections:
Editor add-ons are generally used to improve productivity when working with G Suite. For example, editor add-ons can automate common editor tasks such as file creation, editing, formatting, and moving data between applications. Editor add-on interfaces are highly-customizable for the tasks at hand.
Editor add-ons behave differently from G Suite add-ons in the following ways:
- Editor add-ons can create interfaces consisting of menu items, dialogs, and sidebars. Add-on dialogs and sidebars are defined using standard HTML and CSS.
- Editor add-ons have special authorization rules because they create, modify, or otherwise interact with files within Google Drive. It is important to understand the editor add-on authorization lifecycle while developing an editor add-on.
- Files created and updated in each editor have specific structures. For example, Google Slides presentations are composed of pages which can be slides, masters, or layouts. You should understand these file structures, as add-ons often interact with them when reading or editing files.
- Editor add-ons only function in desktop clients, not Android or iOS.
Android add-ons are a different experience from the other add-on types. Android add-ons are components of an existing Android app (or a full Android app by itself), that extend Google Docs or Google Sheets Android app. When a user starts an Android add-on they have installed from one of these apps, it can receive context information from the Google Docs or Google Sheets app, present a customized Android interface using that data, take actions the user specifies, and then send information back to the calling app to update the file being worked on.
Android add-ons have the following properties:
- Android add-ons are Android applications and use the Android development platform to control behavior and define the user interface. They are published to the Google Play Store like any other Android app.
- These add-ons only extend the Google Docs and Google Sheets mobile experience. Other G Suite applications can't be extended this way.
- Android add-ons are usually designed as components of a larger, existing Android app. They don't change the Google Docs or Sheets app interface, except to provide a set of menu items that launch the Android add-on from different contexts.
- Android add-ons can receive context information from the calling Google Docs or Google Sheet app. The add-on can use the Apps Script API to call functions in separate Apps Script projects to manipulate this data and construct an appropriate response to send back to the calling app.
- Android add-ons can't create or modify Apps Script triggers.