OpenAPI invocations are now done, if codegen maven step is enabled, through https://github.com/quarkiverse/quarkus-openapi-generator This is a breaking compatibility change, you need to 1) Ensure maven codegen build step is enabled Your pom has this execution plugin <plugin>         <groupId>${quarkus.platform.group-id}</groupId>         <artifactId>quarkus-maven-plugin</artifactId>         <version>${quarkus-plugin.version}</version>         <extensions>true</extensions>         <executions>           <execution>             <goals>               <goal>build</goal>               <goal>generate-code</goal>               <goal>generate-code-tests</goal>             </goals>           </execution>         </executions>       </plugin> 2) Modify properties of the form org.kogito.openapi.client.<service_name>.<property name> to quarkus.rest-client."<fqcn generated class name>".<new property name For example org.kogito.openapi.client.queryservice.base_path to quarkus.rest-client."org.openapi.quarkus.api.DefaultApi".url