Hi Marc, Officially, EAP 7.x is supported only with the version of RESTEasy 3.x that shipped with it. Unofficially, EAP 7.x *should* work with RESTEasy 4.x. The easiest thing to do is to download a distribution zip file from https://resteasy.github.io/downloads/ (e.g., resteasy-jaxrs-4.5.9.Final-all.zip <http://download.jboss.org/resteasy/resteasy-jaxrs-4.5.9.Final-all.zip>) and unzip it in directory modules//system/layers/base. It will replace all of the relevant jars. To answer your specific questions, org.jboss.resteasy:jaxrs-api is now             <dependency> <groupId>org.jboss.spec.javax.ws.rs</groupId> <artifactId>jboss-jaxrs-api_2.1_spec</artifactId>                 <version>2.0.1.Final</version>             </dependency> and org.jboss.resteasy:resteasy-jaxrs is now         <dependency>             <groupId>org.jboss.resteasy</groupId>             <artifactId>resteasy-core-api</artifactId>             <version>...</version>         </dependency> and         <dependency>             <groupId>org.jboss.resteasy</groupId>             <artifactId>resteasy-core</artifactId>             <version>...</version>         </dependency> -Ron On 5/22/21 9:18 AM, Marc Steiner wrote: