Set up your dev environment for extending Teams apps across Microsoft 365

The development environment for extending Teams apps across Microsoft 365 is similar to Microsoft Teams development. This article discusses specific configurations required to run preview builds of Microsoft Teams and Microsoft Office applications in order to preview Teams apps running in Outlook and Office.

To set up your development environment:

Prepare a Developer Tenant for testing

You need a Microsoft 365 developer subscription sandbox tenant to set up your dev environment. If you don't already have one, create a sandbox tenant or get a test tenant through your organization.

You also need to enable sideloading for your tenant:

  1. Sign in to Teams admin center with your test tenant credentials.

  2. Go to Teams apps > Manage apps.

  3. At the top right, select Org-wide app settings.

  4. Under Custom apps, turn on the Interaction with custom app toggle and Save.

    The screenshot is an example that enables sideloading for custom apps from the Teams Admin Center

  5. Apart from Org-wide app settings, custom app policy settings also allow users to upload custom apps to Teams. For more information, see manage custom app policies and settings.

  6. In the Teams admin center, go to Teams apps > Setup policies, and then select Global (Org-wide default) policy.

  7. Turn on Upload custom apps, and select Save.

Enroll your developer tenant for Office 365 Targeted releases

Important

It can take up to five days after creating a Microsoft 365 developer sandbox tenant and enrolling in Office 365 Targeted releases for sideloaded Teams apps to appear in Outlook and Office.

To enroll your test tenant for Office 365 targeted releases:

  1. Sign in to Microsoft 365 admin center with your test tenant credentials.

  2. Go to Settings > Org Settings > Organization profile.

  3. Select Release preferences.

  4. Select any Targeted release preference:

    1. Target release for everyone
    2. Target release for select users

    The screenshot is an example that shows the Microsoft 365 admin center 'Release preferences' menu with Targeted release option selected.

  5. Select Save.

For more information on Office 365 release options, see set up the Standard or Targeted release options in Microsoft 365 admin center help.

Install Office apps in your test environment

Desktop

You can preview Teams apps running in Outlook on Windows desktop by using a recent Beta Channel build. Check if you have to change the Microsoft 365 Apps update channel for your test tenant to install an Office 365 Beta Channel build.

To install Office 365 Beta Channel applications in your test environment:

  1. Sign in to your test environment with your test tenant credentials.

  2. Download the Office Deployment Tool and extract to a local folder.

  3. Go to the local folder and open configuration-Office365-x86.xml (or *x64.xml, depending on your environment) in a text editor and update the Channel value to BetaChannel.

  4. Open Command Prompt and go to the local folder path.

  5. Run setup.exe /configure configuration-Office365-x86.xml (or use the *x64.xml file, depending on your setup).

  6. Open Outlook (desktop client) and set up the mail account using your test tenant credentials.

  7. Open File > Office Account > About Outlook to confirm you're running a Microsoft 365 Beta Channel build of Outlook.

    The screenshot is an example that shows about Outlook to verify that you're running a Beta Channel build.

  8. Verify that Microsoft Edge WebView2 Runtime is installed. Open Windows Start > Apps & features, and search for webview:

    The screenshot is an example that shows the search field in your Windows settings.

    If it's not listed, install Microsoft Edge WebView2 to your test environment.

Mobile

You can preview Teams personal tabs running in Office app for Android by joining the beta program.

To install the latest Office app beta, build to your physical Android device or Android emulator:

  1. Ensure you use a Google Play supported Android device.

  2. Launch the Play Store on your Android device.

  3. Search for office and select Microsoft Office: Edit & Share.

  4. Select the Install button.

    The screenshot is an example that shows the install button for the Microsoft Office: Edit & Share app in Google Play Store.

  5. Select Join under Join the beta section after the installation completes.

    The screenshot is an example that shows the Join the beta screen.

  6. Launch the Office app and sign in with your test tenant credentials.

  7. Open your profile (Me) > Settings and scroll to the bottom of the menu.

  8. Ensure you use Office app version 16.0.15726.20000 or higher for Android.

Switch to the Developer Preview version of Teams

Ensure that you switch to the Public Developer Preview from your Microsoft Teams client.

  1. Sign in to Teams with your sandbox tenant credentials.

  2. From the ellipsis (...) menu next to your user profile, select About > Developer preview. A dialog appears, select Switch to developer preview.

  3. After the Teams app restarts, go to the ellipsis (...) menu next to your user profile and check if Developer Preview is selected.

    The screenshot is an example that shows the public developer preview option in Teams.

Install Visual Studio Code and Teams Toolkit extension

Optionally, you can use Visual Studio Code to extend Teams apps into Office and Outlook.

The extension Teams Toolkit for Visual Studio Code (v2.10.0 or later) provides commands that can help modify your existing Teams code to be compatible with Outlook and Office. For more information, see enable Teams personal tab for Office and Outlook.

Next step

Create or update a Teams app to run across Microsoft 365: