> Markdown version of [Vaadin Service Interfaces as CDI Beans](https://vaadin.com/docs/v23/integrations/cdi/service-beans). Section index: [llms.txt](https://vaadin.com/docs/v23/integrations/llms.txt)

# Vaadin Service Interfaces as CDI Beans

Some Vaadin service interfaces can be implemented as CDI beans. If you do this, the service interface becomes a managed bean with CDI features. In which case, there is no need to register the implementation in Vaadin.

The [Vaadin CDI](https://vaadin.com/directory/component/vaadin-cdi/) add-on references the following interfaces:

- `I18NProvider`

- `InstantiatorFactory`

- `SystemMessagesProvider`

- `ErrorHandler`

To ensure the beans are recognized, they should be qualified by the `@VaadinServiceEnabled` annotation. This is required because it marks a bean which is used as an `I18NProvider` by the service. If there are any other `I18NProvider` beans, the one that’s also used by the service is used.

An example of this is using the `@VaadinServiceEnabled` annotation to qualify `TestSystemMessagesProvider`.

```java
@VaadinServiceEnabled
@VaadinServiceScoped
public class TestSystemMessagesProvider
        implements SystemMessagesProvider {

    @Override
    public SystemMessages getSystemMessages(
            SystemMessagesInfo systemMessagesInfo) {
        CustomizedSystemMessages messages =
                new CustomizedSystemMessages();
        messages.setInternalErrorMessage(
                "Sorry, something went wrong :(");
        return messages;
    }
}

@Route
 public class SampleView extends Div {

     @VaadinServiceEnabled
     @Inject
     private TestSystemMessagesProvider messageProvider;

 }
```

The purpose of `@VaadinServiceScoped` is to define a context of the lifespan of the Vaadin service. It isn’t necessary for this kind of bean, but it’s recommended because other Vaadin contexts can be problematic.

For example, there’s no guarantee that an active Vaadin session or UI context exists when the add-on looks for any of these beans. It’s safe, though, to use standard CDI `@Dependent` and `@ApplicationScoped` contexts.

`A55D3416-D5B7-40B9-8C4A-1454E97C92F1`