There're 2 version related attributes for a daynamic ESDL service, version and default_client_version:
The default_client_version will be used for API requests in SOAP format if the client doesn't specify the version. The "version" will be used for requests coming from a web browser. default_client_version is normally lower than version. The reason for this behavior is for better API backward compatibility, and in the mean time allowing users to see the latest interface from the browser. If default_client_version is higher than version (which is rarely the case), the service will use default_client_version for all requests that don't specify a version.