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Specify Office applications and API requirements

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Your Office Add-in might depend on a specific Office application (also called an Office host) or on specific members of the Office JavaScript API (office.js). For example, your add-in might:

  • Run in a single Office application (e.g., Word or Excel), or several applications.
  • Make use of Office JavaScript APIs that are only available in some versions of Office. For example, the volume-licensed perpetual version of Excel 2016 doesn't support all Excel-related APIs in the Office JavaScript library.

In these situations, you need to ensure that your add-in is never installed on Office applications or Office versions in which it cannot run.

There are also scenarios in which you want to control which features of your add-in are visible to users based on their Office application and Office version. Two examples are:

  • Your add-in has features that are useful in both Word and PowerPoint, such as text manipulation, but it has some additional features that only make sense in PowerPoint, such as slide management features. You need to hide the PowerPoint-only features when the add-in is running in Word.
  • Your add-in has a feature that requires an Office JavaScript API method that is supported in some versions of an Office application, such as Microsoft 365 subscription Excel, but is not supported in others, such as volume-licensed perpetual Excel 2016. But your add-in has other features that require only Office JavaScript API methods that are supported in volume-licensed perpetual Excel 2016. In this scenario, you need the add-in to be installable on that version of Excel 2016, but the feature that requires the unsupported method should be hidden from those users.

This article helps you understand which options you should choose to ensure that your add-in works as expected and reaches the broadest audience possible.

Note

For a high-level view of where Office Add-ins are currently supported, see the Office client application and platform availability for Office Add-ins page.

Tip

Many of the tasks described in this article are done for you, in whole or in part, when you create your add-in project with a tool, such as the Yeoman generator for Office Add-ins or one of the Office Add-in templates in Visual Studio. In such cases, please interpret the task as meaning that you should verify that it has been done.

Use the latest Office JavaScript API library

Your add-in should load the most current version of the Office JavaScript API library from the content delivery network (CDN). To do this, be sure you have the following script tag in the first HTML file your add-in opens. Using /1/ in the CDN URL ensures that you reference the most recent version of Office.js.

<script src="https://appsforoffice.microsoft.com/lib/1.1/hosted/office.js" type="text/javascript"></script>

Specify which Office applications can host your add-in

By default, an add-in is installable in all Office applications supported by the specified add-in type (that is, Mail, Task pane, or Content). For example, a task pane add-in is installable by default on Access, Excel, OneNote, PowerPoint, Project, and Word.

To ensure that your add-in is installable in a subset of Office applications, use the Hosts and Host elements in the manifest.

For example, the following <Hosts> and <Host> declaration specifies that the add-in can install on any release of Excel, which includes Excel on the web, Windows, and iPad, but cannot be installed on any other Office application.

<Hosts>
  <Host Name="Workbook" />
</Hosts>

The <Hosts> element can contain one or more <Host> elements. There should be a separate <Host> element for each Office application on which the add-in should be installable. The Name attribute is required and can be set to one of the following values.

Name Office client applications Available add-in types
Document Word on the web, Windows, Mac, iPad Task pane
Mailbox Outlook on the web, Windows (new and classic), Mac, Android, iOS Mail
Notebook OneNote on the web Task pane, Content
Presentation PowerPoint on the web, Windows, Mac, iPad Task pane, Content
Project Project on Windows Task pane
Workbook Excel on the web, Windows, Mac, iPad Task pane, Content
Database Access (obsolete) Task pane

Note

Office applications are supported on different platforms and run on desktops, web browsers, tablets, and mobile devices. You usually can't specify which platform can be used to run your add-in. For example, if you specify Workbook, both Excel on the web and on Windows can be used to run your add-in. However, if you specify Mailbox, your add-in won't run on Outlook mobile clients unless you define the mobile extension point.

Note

It isn't possible for an add-in manifest to apply to more than one type: Mail, Task pane, or Content. This means that if you want your add-in to be installable on Outlook and on one of the other Office applications, you must create two add-ins, one with a Mail type manifest and the other with a Task pane or Content type manifest.

Specify which Office versions and platforms can host your add-in

You can't explicitly specify the Office versions and builds or the platforms on which your add-in should be installable, and you wouldn't want to because you would have to revise your manifest whenever support for the add-in features that your add-in uses is extended to a new version or platform. Instead, specify in the manifest the APIs that your add-in needs. Office prevents the add-in from being installed on combinations of Office version and platform that don't support the APIs and ensures that the add-in won't appear in My Add-ins.

Important

Only use the base manifest to specify the API members that your add-in must have to be of any significant value at all. If your add-in uses an API for some features but has other useful features that don't require the API, you should design the add-in so that it's installable on platform and Office version combinations that don't support the API but provides a diminished experience on those combinations. For more information, see Design for alternate experiences.

Requirement sets

To simplify the process of specifying the APIs that your add-in needs, Office groups most APIs together in requirement sets. The APIs in the Common API Object Model are grouped by the development feature that they support. For example, all the APIs connected to table bindings are in the requirement set called "TableBindings 1.1". The APIs in the Application specific object models are grouped by when they were released for use in production add-ins.

Requirement sets are versioned. For example, the APIs that support Dialog Boxes are in the requirement set DialogApi 1.1. When additional APIs that enable messaging from a task pane to a dialog were released, they were grouped into DialogApi 1.2, along with all the APIs in DialogApi 1.1. Each version of a requirement set is a superset of all earlier versions.

Requirement set support varies by Office application, the version of the Office application, and the platform on which it is running. For example, DialogApi 1.2 isn't supported on volume-licensed perpetual versions of Office before Office 2021, but DialogApi 1.1 is supported on all perpetual versions back to Office 2016. You want your add-in to be installable on every combination of platform and Office version that supports the APIs that it uses, so you should always specify in the manifest the minimum version of each requirement set that your add-in requires. Details about how to do this are later in this article.

Tip

For more information about requirement set versioning, see Office requirement sets availability, and for the complete lists of requirement sets and information about the APIs in each, start with Office Add-in requirement sets. The reference topics for most Office.js APIs also specify the requirement set they belong to (if any).

Note

Some requirement sets also have manifest elements associated with them. See Specifying requirements in a VersionOverrides element for information about when this fact is relevant to your add-in design.

APIs not in a requirement set

All APIs in the application specific models are in requirement sets, but some of those in the Common API model are not. There is also a way that you can specify one of these setless APIs in the manifest when your add-in requires one. Details are later in this article.

Requirements element

Use the Requirements element and its child elements Sets and Methods to specify the minimum requirement sets or API members that must be supported by the Office application to install your add-in.

If the Office application or platform doesn't support the requirement sets or API members specified in the <Requirements> element, the add-in won't run in that application or platform, and won't display in My Add-ins.

Note

The <Requirements> element is optional for all add-ins, except for Outlook add-ins. When the xsi:type attribute of the root OfficeApp element is MailApp, there must be a <Requirements> element that specifies the minimum version of the Mailbox requirement set that the add-in requires. For more information, see Outlook JavaScript API requirement sets.

The following code example shows how to configure an add-in that is installable in all Office applications that support the following:

  • TableBindings requirement set, which has a minimum version of "1.1".
  • OOXML requirement set, which has a minimum version of "1.1".
  • Document.getSelectedDataAsync method.
<OfficeApp ... >
  ...
  <Requirements>
     <Sets DefaultMinVersion="1.1">
        <Set Name="TableBindings" MinVersion="1.1"/>
        <Set Name="OOXML" MinVersion="1.1"/>
     </Sets>
     <Methods>
        <Method Name="Document.getSelectedDataAsync"/>
     </Methods>
  </Requirements>
    ...
</OfficeApp>

Note the following about this example.

  • The <Requirements> element contains the <Sets> and <Methods> child elements.
  • The <Sets> element can contain one or more <Set> elements. DefaultMinVersion specifies the default MinVersion value of all child <Set> elements.
  • A Set element specifies a requirement set that the Office application must support to make the add-in installable. The Name attribute specifies the name of the requirement set. The MinVersion specifies the minimum version of the requirement set. MinVersion overrides the value of the DefaultMinVersion attribute in the parent <Sets>.
  • The <Methods> element can contain one or more Method elements. You can't use the <Methods> element with Outlook add-ins.
  • The <Method> element specifies an individual method that the Office application must support to make the add-in installable. The Name attribute is required and specifies the name of the method qualified with its parent object.

Design for alternate experiences

The extensibility features that the Office Add-in platform provides can be usefully divided into three kinds:

  • Extensibility features that are available immediately after the add-in is installed. You can make use of this kind of feature by configuring a VersionOverrides element in the manifest. An example of this kind of feature is Add-in Commands, which are custom ribbon buttons and menus.
  • Extensibility features that are available only when the add-in is running and that are implemented with Office.js JavaScript APIs; for example, Dialog Boxes.
  • Extensibility features that are available only at runtime but are implemented with a combination of Office.js JavaScript and configuration in a <VersionOverrides> element. Examples of these are Excel custom functions, single sign-on, and custom contextual tabs.

If your add-in uses a specific extensibility feature for some of its functionality but has other useful functionality that doesn't require the extensibility feature, you should design the add-in so that it's installable on platform and Office version combinations that don't support the extensibility feature. It can provide a valuable, albeit diminished, experience on those combinations.

You implement this design differently depending on how the extensibility feature is implemented:

Runtime checks for method and requirement set support

You test at runtime to discover whether the user's Office supports a requirement set with the isSetSupported method. Pass the requirement set's name and the minimum version as parameters. If the requirement set is supported, isSetSupported returns true. The following code shows an example.

if (Office.context.requirements.isSetSupported('WordApi', '1.2'))
{
   // Code that uses API members from the WordApi 1.2 requirement set.
} else {
   // Provide diminished experience here. E.g., run alternate code when the user's Word is volume-licensed perpetual Word 2016 (which doesn't support WordApi 1.2).
}

About this code, note:

  • The first parameter is required. It's a string that represents the name of the requirement set. For more information about available requirement sets, see Office Add-in requirement sets.
  • The second parameter is optional. It's a string that specifies the minimum requirement set version that the Office application must support in order for the code within the if statement to run (e.g., "1.9"). If not used, version "1.1" is assumed.

Warning

When calling the isSetSupported method, the value of the second parameter (if specified) should be a string not a number. The JavaScript parser cannot differentiate between numeric values such as 1.1 and 1.10, whereas it can for string values such as "1.1" and "1.10".

The following table shows the requirement set names for the application specific API models.

Office application RequirementSetName
Excel ExcelApi
OneNote OneNoteApi
Outlook Mailbox
PowerPoint PowerPointApi
Word WordApi

The following is an example of using the method with one of the Common API model requirement sets.

if (Office.context.requirements.isSetSupported('CustomXmlParts'))
{
    // Run code that uses API members from the CustomXmlParts requirement set.
}
else
{
    // Run alternate code when the user's Office application doesn't support the CustomXmlParts requirement set.
}

Note

The isSetSupported method and the requirement sets for these applications are available in the latest Office.js file on the CDN. If you don't use Office.js from the CDN, your add-in might generate exceptions if you are using an old version of the library in which isSetSupported is undefined. For more information, see Use the latest Office JavaScript API library.

When your add-in depends on a method that isn't part of a requirement set, use the runtime check to determine whether the method is supported by the Office application, as shown in the following code example. For a complete list of methods that don't belong to a requirement set, see Office Add-in requirement sets.

Note

We recommend that you limit the use of this type of runtime check in your add-in's code.

The following code example checks whether the Office application supports document.setSelectedDataAsync.

if (Office.context.document.setSelectedDataAsync)
{
    // Run code that uses `document.setSelectedDataAsync`.
}

Specify requirements in a VersionOverrides element

The VersionOverrides element was added to the manifest schema primarily, but not exclusively, to support features that must be available immediately after an add-in is installed, such as add-in commands (custom ribbon buttons and menus). Office must know about these features when it parses the add-in manifest.

Suppose your add-in uses one of these features, but the add-in is valuable, and should be installable, even on Office versions that don't support the feature. In this scenario, identify the feature using a Requirements element (and its child Sets and Methods elements) that you include as a child of the <VersionOverrides> element itself instead of as a child of the base OfficeApp element. The effect of doing this is that Office will allow the add-in to be installed, but Office will ignore certain of the child elements of the <VersionOverrides> element on Office versions where the feature isn't supported.

Specifically, the child elements of the <VersionOverrides> that override elements in the base manifest, such as a <Hosts> element, are ignored and the corresponding elements of the base manifest are used instead. However, there can be child elements in a <VersionOverrides> that actually implement additional features rather than override settings in the base manifest. Two examples are the WebApplicationInfo and EquivalentAddins. These parts of the <VersionOverrides> will not be ignored, assuming the platform and version of Office support the corresponding feature.

For information about the descendent elements of the <Requirements> element, see Requirements element earlier in this article.

The following is an example.

<VersionOverrides ... >
   ...
   <Requirements>
      <Sets DefaultMinVersion="1.1">
         <Set Name="WordApi" MinVersion="1.2"/>
      </Sets>
   </Requirements>
   <Hosts>

      <!-- ALL MARKUP INSIDE THE HOSTS ELEMENT IS IGNORED WHEREVER WordApi 1.2 IS NOT SUPPORTED -->

      <Host xsi:type="Workbook">
         <!-- markup for custom add-in commands -->
      </Host>
   </Hosts>
</VersionOverrides>

Warning

Use great care before including a <Requirements> element in a <VersionOverrides>, because on platform and version combinations that don't support the requirement, none of the add-in commands will be installed, even those that invoke functionality that doesn't need the requirement. Consider, for example, an add-in that has two custom ribbon buttons. One of them calls Office JavaScript APIs that are available in requirement set ExcelApi 1.4 (and later). The other calls APIs that are only available in ExcelApi 1.9 (and later). If you put a requirement for ExcelApi 1.9 in the <VersionOverrides>, then when 1.9 is not supported neither button will appear on the ribbon. A better strategy in this scenario would be to use the technique described in Runtime checks for method and requirement set support. The code invoked by the second button first uses isSetSupported to check for support of ExcelApi 1.9. If it isn't supported, the code gives the user a message saying that this feature of the add-in is not available on their version of Office.

Tip

There's no point to repeating a Requirement element in a <VersionOverrides> that already appears in the base manifest. If the requirement is specified in the base manifest, then the add-in can't install where the requirement isn't supported so Office doesn't even parse the <VersionOverrides> element.

See also