Every single record (e.g. a product, cms page etc.) sent to Klevu servers is managed in a dedicated index of the respective store. The Indexing API is useful for adding, updateing and/or deleting records from this index.
The Indexing API requires that you first authenticate yourself to the Klevu servers. As a result, you are provided a sessionId, that you can use for all you subsequent requests to the Klevu servers.
Indexing API Methods