Currently custom HTTP headers are configured on CustomMediaTypeResponder which is nice, but on the other hand would be great if we could move it to controller. Maybe creating something like a CustomHttpHeaderProducer (or whatever name) using the same approach done for CorsConfigProducer. For example (just an example):

    public CustomHttpHeaderConfiguration demoConfig() {
        return HttpConfig.enableCustomHttpSupport()
                .addHeader("Auth-Token","xxxx")
                .addHeader("AG-X", "xxxx")
                .build();
    }