---
title: Breaking changes for Optimizely Search & Navigation 16
slug: cms-12/docs/breaking-changes-for-optimizely-search-navigation-16
docTags: 
createdAt: 2026-08-10T15:55:59.000Z
---

Optimizely Search & Navigation 16 uses the `HttpClient` library instead of the obsolete `HttpWebRequest` to send requests to the search service. As a result, Optimizely Search & Navigation extends the public constructors in the client class with a parameter of type `IHttpClientFactory`.

If you are currently creating instances of the client class using this constructor, you must provide an instance of `IHttpClientFactory`. However, extensions in the Search & Navigation package are automatically registering an `HttpClient`so if you are using Dependency Injection (DI), you do not need to take further action.