Detect if web app is running as PWA through the Microsoft Store

Question

I submitted a PWA to the Microsoft Store and got the following notes on my submission:

10.8.5 Your app or app metadata includes links that promote installation or purchase of software outside the Store. Your app may promote or distribute software only through the Microsoft Store.

The reason for this is that my web app has a products page with links to the various platforms the app is available on. This is so that users visiting my web app using a browser get the ability to install it as "native" app on their platform rather.

How can I detect if my web app is running as PWA through the Microsoft Store, so that I can render a trimmed version of my app without the products page?

My first idea would be to check the navigator.userAgent, but this seems ambiguous, since the user agent will be Microsoft Edge whether the app is running "natively" or is visited manually in the browser.

I'd prefer solutions for distinguishing these use cases in JavaScript, but I'm also open for completely different approaches.

Answer 1

The correct official way is to check for window.Windows. The whole WinRT API surface is injected when running as a Store app. So, you can (and should) do the following rather than user-agent sniffing:

if (window.Windows) {
  // running as a Windows app
}
else {
  // running in browser
}

Answer 2

I realized that the user agent wasn't so ambiguous after all.

Microsoft Edge does indicate when it is running as an app host by adding MSAppHost/<WebView Rev> to its user agent.

Example:

On my machine, the user agent of my hosted PWA lists "MSAppHost/3.0":

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; MSAppHost/3.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36 Edge/15.15063

Solution:

Testing navigator.userAgent for the string MSAppHost/ discloses if the web app is running as an hosted app.

I'm using this check now for my server-side and client-side rendering to strip any content linking to external stores.