---
title: Changing Configuration Values Using the Server‑to‑Server API
framework: exposurenotification
role: article
role_heading: Article
path: exposurenotification/changing-configuration-values-using-the-server-to-server-api
---

# Changing Configuration Values Using the Server‑to‑Server API

Update Exposure Notifications configuration values from a Public Health Authority’s server.

## Overview

Overview The Exposure Notifications feature reads configuration values to customize behavior for each region based on values provided by that region’s Public Health Authority (PHA). PHAs can push changes to these configuration values from their servers using the Exposure Notifications server-to-server API. A PHA might use the server-to-server API, for example, to automate changes under certain conditions, such as changing the polling interval when experiencing unusually high activity, or providing a configuration portal hosted on their own servers. Exposure Notifications server-to-server API is located at the following URL: https://gateway.icloud.com/enservice/v2/update/app/config This API expects a POST request with a content-type of application/json. Requests must include both of the custom headers listed below to authenticate the request. The server rejects requests that the API can’t authenticate, and doesn’t make any changes to the existing configuration values. The body of the POST request contains a JSON dictionary that uses the following keys: This API responds with an HTTP response code, but won’t send a response body or any custom headers. If the API can make the requested changes, the API returns an HTTP 200 response code. If the API can’t change the values, it returns one of the following codes:

## See Also

### Essentials

- [Supporting Exposure Notifications Express](exposurenotification/supporting-exposure-notifications-express.md)
- [Building an App to Notify Users of COVID-19 Exposure](exposurenotification/building-an-app-to-notify-users-of-covid-19-exposure.md)
- [Setting Up a Key Server](exposurenotification/setting-up-a-key-server.md)
- [ENManager](exposurenotification/enmanager.md)
- [ENDeveloperRegion](bundleresources/information-property-list/endeveloperregion.md)
- [ENAPIVersion](bundleresources/information-property-list/enapiversion.md)
- [Testing Exposure Notifications Apps in iOS 13.7 and Later](exposurenotification/testing-exposure-notifications-apps-in-ios-13-7-and-later.md)
- [Supporting Exposure Notifications in iOS 12.5](exposurenotification/supporting-exposure-notifications-in-ios-12-5.md)