Authenticating a user for testing purposes. A web server receives a request from a client that includes an authentication credential and that is formatted to be handled by a particular authentication module. The authentication module is configured to obtain authentication tokens based on authentication credentials included in requests, while refraining from generating any interactive authentication dialog. Based on the request, the web server passes at least a portion of the request, including the authentication credential, to the authentication module. The authentication module determines that the request is formatted in a manner that triggers the authentication module. The authentication module obtains an authentication token from an identity provider based on the authentication credential, while refraining from generating any interactive authentication dialog. The authentication module returns the authentication token to the web server. The web server returns the authentication token to the client.