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Exposure Notification

Implement a COVID-19 exposure notification system that protects user privacy.

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Overview

Use the Exposure Notification framework to inform people of potential exposure to COVID-19, the disease caused by the SARS-CoV-2 virus. You can build a notification system that employs random, rotating keys and identifiers to convey positive diagnoses in addition to data such as associated symptoms, proximity, and duration.

Establish User Roles

The ExposureNotification framework defines two user roles:

Affected user

When a user has a confirmed or probable diagnosis of COVID-19 (as defined by the Health Authority), the framework identifies them as affected and shares their diagnosis keys to alert other users to potential exposure.

Potentially exposed user

To assign a user the potentially exposed role, use the framework to determine whether a set of temporary exposure keys indicate proximity to an affected user. If so, the app can retrieve additional information such as date and duration from the framework.

Identify Your App’s Region

All EN apps must specify the region for which they work by adding a key called ENDeveloperRegion to the app’s Info.plist file. The value for ENDeveloperRegion is set to a string that represents the app’s region. This value can be an ISO 3166-1 country code (for example, “CA” for Canada), or the ISO 3166-1/3166-2 country code plus subdivision code (“US-CA” for California).

Explicitly set the associated domain link to your region code. Avoid using wildcards because they can impact system operations. See Associated Domains Entitlement for more information.

Specify Exposure Notification API Version

iOS 13.7 introduces a new method of calculating the user’s Exposure Risk Value, described in ENExposureConfiguration. Apps can implement this new method, or continue to use the calculation method introduced in earlier versions of iOS. To choose your app’s approach, add an entry to your app’s Info.plist file with a key of ENAPIVersion. To use the new approach, specify a value of 2. To use the original approach, specify a value of 1.

Support Exposure Notification Express

Starting with iOS 13.7, Health Authorities can inform users of potential exposure to COVID-19 without a dedicated Exposure Notification app. This feature is called Exposure Notification Express and must be enabled by a Health Authority. For more information, see Supporting Exposure Notifications Express.

Topics

Essentials

Exposures

Summaries

Status

Errors

Variables

Type Aliases