WSO2 Identity Server supports Oauth2 authorization code grant type with basic authentication OOTB. But basic authentication is done only with WSO2 user store. So there could be use cases that basic authentication has to be done against some other system. In this case you follow below steps to achieve your requirement. First you need to create an class which extends AbstractApplicationAuthenticator and implements LocalApplicationAuthenticator. Because this class is going to act as your application authenticator so it needs to be an implementation of application authenticator interface and to achieve this it needs to be a local authenticator as well. [2] public class CustomBasicAuthenticator extends AbstractApplicationAuthenticator implements LocalApplicationAuthenticator { Then you need to override the initiateAuthenticationRequest method so you can redirect to the page to enter user and password. In my sample I redirected to the page that is used by our default basic au