Teams JavaScript client library

Article
05/18/2023

The Microsoft Teams JavaScript client library (TeamsJS) can help you create hosted experiences in Teams, Microsoft 365 app, and Outlook, where your app content is hosted in an iFrame. The library is helpful for developing apps with the following Teams capabilities:

Starting with version 2.0.0, the existing TeamsJS library (@microsoft/teams-js, or simply TeamsJS) has been refactored to enable Teams apps to run in Outlook and Microsoft 365 app, in addition to Microsoft Teams. From a functional perspective, the latest version of TeamsJS supports all existing (v.1.x.x) Teams app functionality while adding the optional ability to host Teams apps in Outlook and Microsoft 365 app.

Here's the current versioning guidance for various app scenarios:

	TeamsJS version	App manifest version	Next steps
Teams apps extended to Microsoft 365 / Outlook	TeamsJS v.2.0 or later	1.13 or later	Extend a Teams app to run across Microsoft 365 or Create a new Microsoft 365 app
Existing Teams-only apps	Update to TeamsJS v.2.0 when possible (v.1.12 is still supported*)	1.12	Understand TeamsJS backwards compatibility and Update to TeamsJS v.2.0
New Teams-only apps	TeamsJS v.2.0 or later	1.12	Create a new Teams app using Teams Toolkit

*Use the latest TeamsJS (v.2.0 or later) whenever possible, in order to leverage from the latest improvements and new feature support including Teams-only apps. TeamsJS v.1.12 continue to be supported, however, no new features or improvements will be added. The 1.12 and 1.13 schemas are otherwise the same. For more information, see TeamsJS library.

The remainder of this article will walk you through the structure and latest updates to the TeamsJS library.

Microsoft 365 support (running Teams apps in Microsoft 365 and Outlook)

TeamsJS v.2.0 introduces the ability for certain types of Teams apps to run across the Microsoft 365 ecosystem. Currently, other Microsoft 365 application hosts (including Microsoft 365 app and Outlook) for Teams apps support a subset of the application types and capabilities you can build for the Teams platform. This support will expand over time. For a summary of host support for Teams apps, see TeamsJS capability support across Microsoft 365.

What's new in TeamsJS version 2.x.x

There are two significant changes between TeamsJS 1.x.x versions and v.2.0.0 and later:

Callback functions now return Promise objects. Most functions with callback parameters in TeamsJS v.1.12 have been modernized to return a JavaScript Promise object for improved handling of asynchronous operations and code readability.
APIs are now organized into capabilities. You can think of capabilities as logical groupings of APIs that provide similar functionality, such as authentication, dialog, chat, and calendar. Each namespace represents a separate capability.

Tip

You can use the Teams Toolkit extension for Microsoft Visual Studio Code to simplify the TeamsJS v.2.0 update process for an existing Teams app.

Backwards compatibility

Once you start referencing @microsoft/teams-js@2.0.0 (or later) from an existing Teams app, you'll see deprecation warnings for any code calling APIs that have changed.

An API translation layer (mapping v.1 to v.2 TeamsJS API calls) is provided to enable existing Teams apps to continue working in Teams until they're able to update application code to use the TeamsJS v.2 API patterns.

Teams-only apps

Even if you intend your app to only run in Teams (and not Microsoft 365 app and Outlook), best practice is to start referencing the latest TeamsJS (v.2.0 or later) as soon as convenient, in order to benefit from the latest improvements, new features, and support (even for Teams-only apps). TeamsJS v.1.12 will continue to be supported, but no new features or improvements will be added.

Once you're able, the next step is to update existing application code with the changes described in this article. In the meantime, the v.1 to v.2 API translation layer provides backwards compatibility, ensuring your existing Teams app continues to work in TeamsJS version 2.0.

Teams apps running across Microsoft 365

Enabling an existing Teams app to run in Outlook and Microsoft 365 requires all of the following:

Dependency on TeamsJS version 2.x.x ( @microsoft/teams-js@2.0.0) or later,
Modifying existing application code according to the required changes described in this article, and
Updating your app manifest (previously called Teams app manifest) to version 1.13 or later.

For more info, see Extend Teams apps across Microsoft 365.

Callbacks converted to promises

Note

The getTabInstances API isn't implemented on Teams mobile.

Teams APIs that previously took a callback parameter have been updated to return a JavaScript Promise object. These include the following APIs:

app.getContext, app.initialize, appInstallDialog.openAppInstallDialog, app.openLink, authentication.authenticate, authentication.getAuthToken, authentication.getUser, authentication.registerAuthenticationHandlers was removed to support using Promises, calendar.openCalendarItem, calendar.composeMeeting, call.startCall, chat.getChatMembers, conversations.openConversation, location.getLocation, location.showLocation, mail.openMailItem, mail.composeMail, pages.backStack.navigateBack, pages.navigateCrossDomain, pages.navigateToTab, pages.tabs.getMruTabInstances, pages.tabs.getTabInstances, pages.getConfig, pages.config.setConfig, pages.backStack.navigateBack, people.selectPeople, teams.fullTrust.getConfigSetting, teams.fullTrust.joinedTeams.getUserJoinedTeams

You'll need to update the way your code calls any of these APIs to use Promises. For example, if your code is calling a Teams API like this:

JavaScript
TypeScript

This code:

import microsoftTeams from "@microsoft/teams-js";

microsoftTeams.getContext((context) => { /* ... */ });

Needs to be updated to:

import { app, Context } from "@microsoft/teams-js";

app.getContext().then((context) => {
    /*...*/
});

...or the equivalent async/await pattern:

import { app, Context } from "@microsoft/teams-js";

async function example() {
  const context = await app.getContext();
  /*...*/
}

This code:

import * as microsoftTeams from "@microsoft/teams-js";
microsoftTeams.app.getContext().then((context:  microsoftTeams.app.Context) => { 
/* ... */ 
});

Needs to be updated to:

import { app, Context } from "@microsoft/teams-js"; 

app.getContext().then((context: app.Context) => { 
/*...*/
});

...or the equivalent async/await pattern:

import { app, Context } from "@microsoft/teams-js"; 

async function example() {
            const context: app.Context = await app.getContext();
            /*...*/
          }

Tip

When you use Teams Toolkit to update to TeamsJS v.2.0, the required updates are flagged for you with TODO comments in your client code.

APIs organized into capabilities

A capability is a logical grouping (via namespace) of APIs that provide similar functionality. You can think of Microsoft Teams, Outlook, and Microsoft 365 app, as hosts to your tab app. A host supports a given capability if it supports all the APIs defined within that capability. A host can't partially implement a capability. Capabilities can be feature- or content-based, such as authentication, or dialog. There are also capabilities for application types such as pages, and other groupings.

Starting with TeamsJS v.2.0, APIs are defined as functions in a JavaScript namespace whose name matches their required capability. For example, if an app is running in a host that supports the dialog capability, then the app can safely call APIs such as dialog.open (in addition to other dialog-related APIs defined in the namespace). If an app attempts to call an API that's not supported in that host, the API generates an exception.

Tip

Check for host support of a given capability at runtime by calling the isSupported() function on that capability (namespace).

Differentiate your app experience

You can check for host support of a given capability at runtime by calling the isSupported() function on that capability (namespace). It will return true if it's supported and false if not, and you can adjust app behavior as appropriate. This allows your app to light up UI and functionality in hosts that support it, while continuing to run for hosts that don't.

The name of the host your app is running in is exposed as a hostName property on the Context interface (app.Context.app.host.name), which can be queried at runtime by calling getContext. It's also available as a {hostName} URL placeholder value. Best practice is to use the hostName mechanism sparingly:

Don't assume certain functionality is or isn't available in a host based on the hostName property value. Instead, check for capability support (isSupported).
Don't use hostName to gate API calls. Instead, check for capability support (isSupported).
Do use hostName to differentiate the theme of your application based on the host it's running in. For example, you can use Microsoft Teams purple as the main accent color when running in Teams, and Outlook blue when running in Outlook.
Do use hostName to differentiate messages shown to the user based on which host it's running in. For example, show Manage your tasks in Microsoft 365 when running in Microsoft 365 on the web, and Manage your tasks in Teams when running in Teams.

Namespaces

Starting with TeamsJS v.2.0, APIs are organized into capabilities by way of namespaces. Several new namespaces of particular importance are app, pages, dialog, and teamsCore.

app namespace

The app namespace contains top-level APIs required for overall app usage, across Teams, Microsoft 365 app, and Outlook. All the APIs from various other TeamsJS namespaces have been moved to the app namespace as of TeamsJS v.2.0:

Original namespace `global (window)`	New namespace `app`
`executeDeepLink`	`app.openLink` (renamed)
`initialize`	`app.initialize`
`getContext`	`app.getContext`
`registerOnThemeChangeHandler`	`app.registerOnThemeChangeHandler`

Original namespace `appInitialization`	New namespace `app`
`appInitialization.notifyAppLoaded`	`app.notifyAppLoaded`
`appInitialization.notifySuccess`	`app.notifySuccess`
`appInitialization.notifyFailure`	`app.notifyFailure`
`appInitialization.notifyExpectedFailure`	`app.notifyExpectedFailure`
`appInitialization.FailedReason` enum	`app.FailedReason`
`appInitialization.ExpectedFailureReason` enum	`app.ExpectedFailureReason`
`appInitialization.IFailedRequest` enum	`app.IFailedRequest`
`appInitialization.IExpectedFailureRequest` enum	`app.IExpectedFailureRequest`

pages namespace

The pages namespace includes functionality for running and navigating webpages within various Microsoft 365 hosts, including Teams, Microsoft 365 app, and Outlook. It also includes several subcapabilities, implemented as subnamespaces.

Original namespace `global (window)`	New namespace `pages`
`setFrameContext`	`pages.setCurrentFrame` (renamed)
`initializeWithFrameContext`	`pages.initializeWithFrameContext`
`registerFocusEnterHandler`	`pages.registerFocusEnterHandler`
`registerFullScreenHandler`	`pages.registerFullScreenHandler`
`navigateCrossDomain`	`pages.navigateCrossDomain`
`returnFocus`	`pages.returnFocus`
`shareDeepLink`	`pages.shareDeepLink`

Original namespace `settings`	New namespace `pages`
`settings.getSettings`	`pages.getConfig` (renamed)

pages.tabs

Original namespace `global (window)`	New namespace `pages.tabs`
`getTabInstances`	`pages.tabs.getTabInstances`
`getMruTabInstances`	`pages.tabs.getMruTabInstances`

Original namespace `navigation`	New namespace `pages.tabs`
`navigation.navigateToTab`	`pages.tabs.navigateToTab`

pages.config

Original namespace `settings`	New namespace `pages.config`
`settings.setSettings`	`pages.config.setConfig` (renamed)
`settings.setValidityState`	`pages.config.setValidityState`
`settings.initialize`	`pages.config.initialize`
`settings.registerOnSaveHandler`	`pages.config.registerOnSaveHandler`
`settings.registerOnRemoveHandler`	`pages.config.registerOnRemoveHandler`
`settings.Settings` interface	`pages.config.Config` (renamed)
`settings.SaveEvent` interface	`pages.config.SaveEvent` (renamed)
`settings.RemoveEvent` interface	`pages.config.RemoveEvent` (renamed)
`settings.SaveParameters` interface	`pages.config.SaveParameters` (renamed)
`settings.SaveEventImpl` interface	`pages.config.SaveEventImpl` (renamed)

Original namespace `global (window)`	New namespace `pages.config`
`registerChangeConfigHandler`	`pages.config.registerChangeConfigHandler` (renamed)

pages.backStack

Original namespace `navigation`	New namespace `pages.backStack`
`navigation.navigateBack`	`pages.backStack.navigateBack`

Original namespace `global (window)`	New namespace `pages.backStack`
`registerBackButtonHandler`	`pages.backStack.registerBackButtonHandler`

pages.appButton

Original namespace `global (window)`	New namespace `pages.appButton`
`registerAppButtonClickHandler`	`pages.appButton.onClick` (renamed)
`registerAppButtonHoverEnterHandler`	`pages.appButton.onHoverEnter` (renamed)
`registerAppButtonHoverLeaveEnter`	`pages.appButton.onHoverLeave` (renamed)
`FrameContext` interface	`pages.appButton.FrameInfo` (renamed))

dialog namespace

The TeamsJS tasks namespace has been renamed to dialog, and the following APIs have been renamed:

Original namespace `tasks`	New namespace `dialog`
`tasks.startTask`	`dialog.open` (renamed)
`tasks.submitTasks`	`dialog.submit` (renamed)
`tasks.updateTasks`	`dialog.update.resize` (renamed)
`tasks.TaskModuleDimension` enum	`dialog.DialogDimension` (renamed)
`tasks.TaskInfo` interface	`dialog.DialogInfo` (renamed)

Additionally, this capability has been split into a main capability (dialog) for supporting HTML-based dialogs, and a subcapability for bot-based dialogs, dialog.bot.

teamsCore namespace

To generalize the TeamsJS library to run other Microsoft 365 hosts such as Microsoft 365 app and Outlook, Teams-specific functionality (originally in the global namespace) has been moved to a teamsCore namespace:

Original namespace `global (window)`	New namespace `teamsCore`
`enablePrintCapability`	`teamsCore.enablePrintCapability`
`print`	`teamsCore.print`
`registerOnLoadHandler`	`teamsCore.registerOnLoadHandler`
`registerBeforeUnloadHandler`	`teamsCore.registerBeforeUnloadHandler`

Updates to the Context interface

The Context interface has been moved to the app namespace and updated to group similar properties for better scalability as it runs in Outlook and Microsoft 365 app, in addition to Teams.

A new property app.Context.app.host.name has been added to enable tabs to differentiate user experience depending on the host application.

You can also visualize the changes by reviewing the transformLegacyContextToAppContext function in the TeamsJS version 2.x.x source (app.ts file).

Original name in `Context` interface	New location in `app.Context`
`appIconPosition`	`app.Context.app.iconPositionVertical`
`appLaunchId`	NOT IN TeamsJS v.2.0
`appSessionId`	`app.Context.app.sessionId`
`channelId`	`app.Context.channel.id`
`channelName`	`app.Context.channel.displayName`
`channelRelativeUrl`	`app.Context.channel.relativeUrl`
`channelType`	`app.Context.channel.membershipType`
`chatId`	`app.Context.chat.id`
`defaultOneNoteSectionId`	`app.Context.channel.defaultOneNoteSectionId`
`entityId`	`app.Context.page.id`
`frameContext`	`app.Context.page.frameContext`
`groupId`	`app.Context.team.groupId`
`hostClientType`	`app.Context.app.host.clientType`
`hostTeamGroupId`	`app.Context.channel.ownerGroupId`
`hostTeamTenantId`	`app.Context.channel.ownerTenantId`
`isCallingAllowed`	`app.Context.user.isCallingAllowed`
`isFullScreen`	`app.Context.page.isFullScreen`
`isMultiWindow`	`app.Context.page.isMultiWindow`
`isPSTNCallingAllowed`	`app.Context.user.isPSTNCallingAllowed`
`isTeamArchived`	`app.Context.team.isArchived`
`locale`	`app.Context.app.locale`
`loginHint`	`app.Context.user.loginHint`
`meetingId`	`app.Context.meeting.id`
`osLocaleInfo`	`app.Context.app.osLocaleInfo`
`parentMessageId`	`app.Context.app.parentMessageId`
`ringId`	`app.Context.app.host.ringId`
`sessionId`	`app.Context.app.host.sessionId`
`sourceOrigin`	`app.Context.page.sourceOrigin`
`subEntityId`	`app.Context.page.subPageId`
`teamId`	`app.Context.team.internalId`
`teamSiteDomain`	`app.Context.sharepointSite.domain`
`teamSitePath`	`app.Context.sharepointSite.path`
`teamSiteUrl`	`app.Context.sharepointSite.url`
`teamTemplateId`	`app.Context.team.templateId`
`teamType`	`app.Context.team.type`
`tenantSKU`	`app.Context.user.tenant.teamsSku`
`tid`	`app.Context.user.tenant.id`
`upn`	`app.Context.user.userPrincipalName`
`userClickTime`	`app.Context.app.userClickTime`
`userFileOpenPreference`	`app.Context.app.userFileOpenPreference`
`userLicenseType`	`app.Context.user.licenseType`
`userObjectId`	`app.Context.user.id`
`userTeamRole`	`app.Context.team.userRole`
NA	`app.Context.app.host.name`

Updating to TeamsJS version 2.0

The easiest way to update your Teams app with TeamsJS version 2.0.x is to use the Teams Toolkit extension for Visual Studio Code. This section will walk you through the steps to do that. If you prefer to manually update your code, see the Callbacks converted to promises and APIs organized into capabilities sections for more details on required API changes.

1. Install the latest Teams Toolkit Visual Studio Code extension

In the Visual Studio Code Extensions Marketplace, search for Teams Toolkit and install the latest version.

2. Update TeamsJS references

To run in Outlook and Microsoft 365 app, your app will need to depend on the npm package @microsoft/teams-js@2.0.0 (or later). To perform these steps manually, and for more information on the API changes, see the following sections on Callbacks converted to promises and APIs organized into capabilities.

Ensure you have the latest Teams Toolkit (version 2.10.0 or later)
Open the Command palette: Ctrl+Shift+P
Run the command Teams: Upgrade Teams JS SDK references to support Outlook and Microsoft 365 apps

After completion, the utility will have updated your package.json file with the TeamsJS version 2.x.x (@microsoft/teams-js@2.0.0 or later) dependency, and your *.js/.ts and *.jsx/.tsx files will be updated with:

package.json references to TeamsJS version 2.x.x
Import statements for TeamsJS version 2.x.x
Function, Enum, and Interface calls to TeamsJS version 2.x.x
TODO comment reminders to review areas that might be impacted by Context interface changes
TODO comment reminders to convert callback functions to promises

Important

Code inside html files is not supported by the upgrade tooling and will require manual changes.

3. Update the app manifest (optional)

If you're updating a Teams app to run in Microsoft 365 app and Outlook, you'll also need to update the app manifest to version 1.13 or later. You can do this easily with Teams Toolkit, or manually.

Teams Toolkit
Manual steps

Open the Command palette: Ctrl+Shift+P
Run Teams: Upgrade Teams manifest to support Outlook and Microsoft 365 apps command and select your app manifest file. Changes will be made in place.

Open your app manifest and update the $schema and manifestVersion with the following values:

{
    "$schema" : "https://developer.microsoft.com/json-schemas/teams/v1.13/MicrosoftTeams.schema.json",
    "manifestVersion" : "1.13"
}

If you used Teams Toolkit to create your personal app, you can also use it to validate the changes to your app manifest file and identify any errors. Open the command palette Ctrl+Shift+P and find Teams: Validate manifest file or select the option from the Deployment menu of the Teams Toolkit (look for the Teams icon on the left side of Visual Studio Code).

Teams Toolkit 'Validate manifest file' option under 'Deployment' menu

Next steps

Use the TeamsJS library reference to get started with the TeamsJS library.
Review the changelog for latest updates to TeamsJS.