Hi, I do not know your exact project setup but you have to declare any dependencies as wildfly isolates classloaders. As AbstractIdpAuthenticator is included in the keycloak-services module, you can use this In the jar's META-INF/MANIFEST.MF: Dependencies: org.keycloak.keycloak-services Maybe additional Modules have to be included as well. See appropriate documentation of how to do this in your favourite build tool. See http://docs.wildfly.org/17/Developer_Guide.html#ear-class-loading (applies to keycloak's jar mechanism as well) Best Daniel -----Ursprüngliche Nachricht----- Von: keycloak-user-bounces(a)lists.jboss.org <keycloak-user-bounces(a)lists.jboss.org&gt; Im Auftrag von Christophe de Vienne Gesendet: Mittwoch, 4. September 2019 11:32 An: keycloak-user(a)lists.jboss.org Betreff: [keycloak-user] Use keycloak classes from a custom Authenticator: NoClassDefFoundError Hi everyone, I want to write a custom Authenticator that borrow code from AbstractIdpAuthenticator (or better, extends it). However, as soon as my authenticator attempts to load a class from the keycloak-services package, I get a NoClassDefFoundError. For example: 08:24:53,608 ERROR [org.keycloak.services.error.KeycloakErrorHandler] (default task-6) Uncaught server error: java.lang.NoClassDefFoundError: org/keycloak/authentication/authenticators/broker/util/SerializedBrokeredIdentityContext I used the authenticator example provided in the examples directory as a base for writing the pom.xml file. Should I be able to use or extend keycloak classes from within my provider (packaged as a jar, I also tried wildfly:deploy)? If so, what am I missing? I also posted a question on stackoverflow, you may find some relevant detail in it: https://stackoverflow.com/questions/57778240/noclassdeffounderror-in-a-pr... Thanks, Christophe _______________________________________________ keycloak-user mailing list keycloak-user(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/keycloak-user _______________________________________________ keycloak-user mailing list keycloak-user(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/keycloak-user