TFS 2015 lets you define build and release workflows comprised of discrete tasks. Although it provides a handful to you (build-specific, release-specific, general utility, etc..), you can also write your own “Extension Tasks” and upload them. I previously described how to use Microsoft’s tfx tool to upload a single task from the command-line.

You might also need to upload one or more tasks that have been packaged into a VSIX file (Microsoft’s Visual Studio Extension packaging format). These are essentially zip-files that have a manifest and one or more directories. In this case, those directories represent tasks (they each have a task.json file). Although you can probably do this from the command-line using the tfx tool, you can also use your TFS’s web UI to do it. Note that this process will need to be repeated for each collection that you’ll want the extension to be available in.

Click the “Shop” icon to open the corresponding menu and then click on “Browse of Extensions”:

Click on the “Manage extensions” button in the middle of the page. It’s not the same link/button as the previous one even if they have the same text:

Click on “Upload New Extension”. Browse to the VSIX file and upload it.

After, you’re presented with a list of installed extensions:

Observe that the extension populated on to the previous local-management screen. Click on it:

Now, click on “Install”:

After installation, the new tasks will be available within the lists of available tasks.