I've not looked into it, but I certainly will. Thanks for the link. And if anyone else has a chance to look into it more deeply, please do share your info here.

From what I can tell from a brief skim of the docs, it uses the GApple API, so that makes it a prime candidate for implementation. It also appears to use Google's Exposure Notification Reference Server for the backend, which is also a good reason to look at it further.

It would be useful to know the server addresses in actual use, and also the method for uploading test results..

The news reported that the german app will also work in other countries.

Does this have any impact on this issue?

EDIT translation by google of the linked article:

This means that contacts with users of the official Corona apps from other countries can now also be determined when determining the risk.

With the update, the apps from Germany, Ireland and Italy exchange warnings in the first step. Other countries, including Denmark, Latvia and Spain, are to follow shortly afterwards, with countries such as the Netherlands, Austria, Poland and the Czech Republic expected in November. Up to 16 national apps could be linked to one another by the end of the year. France will not be there for technical reasons.

Thanks for this, it's an excellent observation. The current version of Contrac collects its downloaded files from the German Corona-Warn-App servers using a URL like this: https://svc90.main.px.t-online.de/version/v1/diagnosis-keys/country/DE. A recent change is the addition of an EUR folder, as can be seen here https://svc90.main.px.t-online.de/version/v1/diagnosis-keys/country.

This is new. I'll need to investigate further, but it's likely that this is sharing the diagnosis keys from the other collaborating countries (just Ireland and Italy right now, but it seems more later).

Although this will help with downloads, it won't help with uploading a diagnosis result though. That will require other changes.

So it's a small step forward, but it won't automagically make the app work fully for Austria, right?