Read our Planning Document with more details about how Exposure Notifications work
Apple and Google are both creating API’s for a compatible BLE based Contact Tracing implementation which relies heavily on generating and storing rolling unique identifiers on a device, which are broadcast to nearby devices. Devices which detect nearby identifiers then store these identifiers as they come into range (or contact) with for up to 14 days.
When a person has confirmed a diagnosis, they tell their device which then submits the locally stored, self-generated rolling unique identifiers from the last 14 days to a back end service provided by the app implementing the API.
Devices continually request the keys submitted by diagnosed people from the backend server. The device then compares these keys to the unique identifiers of other devices it has been near in the last 14 days.
This project contains the cross platform wrapper API around the native Android and iOS API's. The sample app uses this library to implement the exposure notification code one time for both platforms.
We also have NuGet packages available with bindings to the native Android and iOS Exposure Notifaction API's
- iOS: Xamarin.iOS.ExposureNotification (Requires XCode 11.5 beta1 or newer)
- Android: Xamarin.GooglePlayServices.Nearby.ExposureNotification
A sample mobile app written using C# and Xamarin.Forms which accesses the native iOS and Android Exposure Notification API's and communicates with the sample server backend.
NOTE: There is a Xamarin.iOS fix pending release which is required to use
BGTaskrelated API's on iOS. This means in order for the periodic background fetching task to be invoked, the fix is required. Until the fix is available in a soon to be released stable version you can install these builds to test with on macOS:See Issue #44 for more details.
A sample backend to handle diagnosis submissions. This sample consists of Azure Functions, a EF Core Compatible Database, Azure Blob Storage, and Azure Key Vault. You can read more about the Server Architecture and Configuration in the Wiki
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