How to: Building an iOS App to Notify Users of COVID-19 Exposure

Building an App to Notify Users of COVID-19 Exposure

Inform people when they may have been exposed to COVID-19.



    • iOS 13.5+
    • Xcode 11.5+


    • ExposureNotification

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This code project uses the ExposureNotification framework to build a sample app that lets people know when they have come into contact with someone who meets a set of criteria for a case of COVID-19. When using the project as a reference for designing a notification app, you can define the criteria for how the framework determines whether the risk is high enough to report to the user.

The sample app includes code to simulate server responses. When building an exposure notification app based on this project, create a server environment to provide diagnosis keys and exposure criteria, and add code to your app to communicate with this server. If the app you build operates in a country that authenticates medical tests for COVID-19, you may need to include additional network code to communicate with those authentication services.

For more information on the architecture and security of the ExposureNotification service, see Privacy-Preserving Contact Tracing.

Configure the Sample Code Project

Before you run the sample code project in Xcode, make sure:

Your iOS device is running iOS 13.5 or later.

You are running Xcode 11.5 or later.

You configure the project with a provisioning profile that includes the Exposure Notification entitlement. To get permission to use this 

Setting Up an Exposure Notification Server

Ensure that your exposure notification server meets the requirements for handling COVID-19 exposure notifications.

class ENManager

A class that manages exposure notifications.