private String getType(IVersionedApimanEvent event) {
        String currentValue = event.getHeaders().getType();
        if (StringUtils.isEmpty(currentValue)) {
            if (event.getClass().isAnnotationPresent(ApimanEvent.class)) {
                ApimanEvent ev = event.getClass().getAnnotation(ApimanEvent.class);
                currentValue = ev.name();
            }
        }
        return Optional.ofNullable(currentValue)
                       .filter(s -> !s.isBlank())
                       .orElse(event.getClass().getCanonicalName());
    }
Use version number in priority: (1) provided in headers, (2) in @ApimanEvent annotation.
manager/api/rest-impl/src/main/java/io/apiman/manager/api/events/EventService.java