When your beans are annotated with a scope type, the server recognizes the application as a bean archive and no additional configuration is required. The possible scope types for CDI beans are listed in Using Scopes.

CDI uses an optional deployment descriptor named beans.xml. Like other Java EE deployment descriptors, the configuration settings in beans.xml are used in addition to annotation settings in CDI classes. The settings in beans.xml override the annotation settings if there is a conflict. An archive must contain the beans.xml deployment descriptor only in certain limited situations, described in Chapter 27, "Contexts and Dependency Injection for Java EE: Advanced Topics".

For a web application, the beans.xml deployment descriptor, if present, must be in the WEB-INF directory. For EJB modules or JAR files, the beans.xml deployment descriptor, if present, must be in the META-INF directory.