Custom deployment phase implementation (for programmatic endpoints in this case)

CustomServerAppConfigProvider.java

public class CustomServerAppConfigProvider implements ServerApplicationConfig {

    @Override
    public Set<ServerEndpointConfig> getEndpointConfigs(Set<Class<? extends Endpoint>> endpointClasses) {
        Set<ServerEndpointConfig> result = new HashSet<>();
        for (Class epClass : endpointClasses) {
            //need to ignore Client endpoint class
            if (epClass.equals(ProgrammaticChatEndpoint.class)) {
                ServerEndpointConfig sec = ServerEndpointConfig.Builder.create(epClass, "/letschat").build();
                result.add(sec);
            }
        }
        return result;
    }

    @Override
    public Set<Class<?>> getAnnotatedEndpointClasses(Set<Class<?>> scanned) {
        return Collections.emptySet();
    }
}