Intercepting requests and responses From Angualr Docs "With interception, you declare interceptors that inspect and transform HTTP requests from your application to a server. The same interceptors can also inspect and transform a server's responses on their way back to the application. Multiple interceptors form a forward-and-backward chain of request/response handlers. Interceptors can perform a variety of implicit tasks, from authentication to logging, in a routine, standard way, for every HTTP request/response. Without interception, developers would have to implement these tasks explicitly for each HttpClient method call." Multiple interceptors Example : Adding custom headers in all http request. Example code on github Run the code in stackblitz File Structure: Code: Output: The header will be added in all http request.