The ONTAPI API (ZAPI) is the original set of proprietary calls included with the NetApp ONTAP software to support the automation of data storage administration and management tasks. The ONTAPI interface will be disabled in future versions of ONTAP. If you are using ONTAPI, you should plan your migration to the ONTAP REST API.
NetApp first introduced the REST API with ONTAP 9.6. Since then the REST API has continued to expand and mature. It now provides the preferred and strategic option when automating the administration of your ONTAP deployments. There are many helpful resources and tools available to support your migration.