Build apps with the Microsoft Teams Toolkit and Visual Studio Code

The Microsoft Teams Toolkit enables you to create custom Teams apps directly within the Visual Studio Code environment. The toolkit guides you through the process and provides everything you need to build, debug, and launch your Teams app.

Installing the Teams Toolkit

The Microsoft Teams Toolkit for Visual Studio Code is available for download from the Visual Studio Marketplace or directly as an extension within Visual Studio Code.


After installation, you should see the Teams Toolkit in the Visual Studio Code activity bar. If not, right-click within the activity bar and select Microsoft Teams to pin the toolkit for easy access.

Using the toolkit

Set up a new Teams project

  1. Create a workspace/folder for your project in your local environment.
  2. In Visual Studio Code, select the Teams icon Teams icon from the activity bar on the left side of the window.
  3. Select Open the Microsoft Teams Toolkit from the command menu.
  4. Select Create a new Teams app from the command menu.
  5. When prompted, enter the name of the workspace . This will be used as both the name of the folder where your project will reside, and the default name of your app.
  6. Press Enter and you will arrive at the Add capabilities screen configure the properties for your new app.
  7. Select the Finish button to complete the configuration process.

Import an existing Teams app project

  1. In Visual Studio Code, select the Teams icon Teams icon from the activity bar on the left side of the window.
  2. Select Import app package from the command menu.
  3. Choose your existing Teams app package zip file.
  4. Choose the Select publishing package button. The configuration tab of the toolkit should now be populated with your app's details.
  5. In Visual Studio Code, select File -> Add Folder to Workspace to add your source code directory to the Visual Studio Code workspace.

Configure your app

At its core, the Teams app embraces three components:

  1. The Microsoft Teams client (web, desktop or mobile) where users interact with your app.
  2. A server that responds to requests for content that will be displayed in Teams, e.g., HTML tab content or a bot adaptive card .
  3. A Teams app package consisting of three files:
  • The manifest.json
  • A color icon for your app to display in the public or organization app catalog
  • An outline icon for display on the Teams activity bar.

When an app is installed, the Teams client parses the manifest file to determine needed information like the name of your app and the URL where the services are located.

  1. To configure your app, navigate to the Microsoft Teams Toolkit tab in Visual Studio Code.
  2. Select Edit app package to view the App details page.
  3. Editing the fields in the App details page updates the contents of the manifest.json file that will ultimately ship as part of the app package. Learn more

Package your app

Modifying your the app details page or updating the manifest, or .env files in your app's .publish folder will automatically generate your file. You'll need to include two icons in that same folder.

Install and run your app locally

Refer to the *Build and Run content in your project homepage for detailed instructions for packaging and testing your app. In general, you need to install your app's server, get it running, then setup a tunneling solution so that Teams can access content running from localhost.

Add a trusted certificate for localhost

If you wish to debug your tab based app on localhost using https, you will need to add a certificate for localhost to Trusted Root Certification Authorities catalog. You only need to complete this step once per machine.

Create and install a trusted certificate:

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  • Build and run your app

    • Follow the instuctions in the Build and Run section of your project Readme so that it's being served from https://localhost:3000/tab. Generally, this will involve executing npm install then npm start
    • Navigate to https://localhost:3000/tab from Google Chrome or Edge Chromium.
  • Acquire the SSL certificate:

    • Open the Chrome Developer Tools window (ctrl + shift + i / cmd + option + i).
    • Click on the Security tab
    • Click on View certificate and you’ll have the option to download the certificate — either by dragging it to your desktop in OS X, or by clicking on the Details tab in Windows and clicking Copy to File…
    • Name the file <anything>.cer and save it to a folder that doesn't require admin consent to perform a write action.
  • Install the certificate on Windows

    • Choose the DER encoded binary X.509 (.CER) option (the first one) and save it.
    • Double click on the certificate and install it.
    • Choose Local Machine
    • Select Place all certificates in the following store
    • Choose Trusted Root Certification Authorities
    • Confirm your installation
  • Install the certificate Mac OS X

    • On OS X, open the Keychain Access utility and select System from the menu on the left. Click the lock icon to enable changes.
    • Click the plus button near the bottom to add a new certificate, and select the localhost.cer file you dragged to the desktop. Click Always Trust in the dialog that appears.
    • After adding the certificate to the system keychain, double-click the certificate and expand the Trust section of the certificate details. Select Always Trust for every option.


If you receive a security certificate warning, navigate to https://localhost:3000/tab. If the site is still not trusted, reboot your machine and localhost should be accepted as trusted.

Run your app in Teams

  1. Navigate to the activity bar on the left side of the Visual Studio Code window.
  2. Select the Run icon to display the Run and Debug view.
  3. You can also use the keyboard shortcut Ctrl+Shift+D.

Validate your app

The Validate page allows you to check your app package before submitting your app to AppSource. Simply upload the manifest package and the validation tool will check your app against all manifest related test cases. For each failed tests, the description provides a documentation link to help you fix the error. For the tests that are hard to automate, the Preliminary checklist details 7 of the most common failed test cases as well as link to a complete submission checklist.

Publish your app to Teams

On your project home page, you can upload your app to a team, submit your app to your company custom app store for users in your organization, or submit your app to App Source for all Teams users. Your IT admin will review these submissions. You can return to the Publish page to check on your submission status and learn if your app was approved or rejected by your IT admin. This is also where you'll come to submit updates to your app or cancel any currently active submissions.