There are four available options for the action column.
inventory
Updates a listing's inventory. You need to provide the listing_id, sku, and new quantity.
update
If no listing_id is given this creates a new listing
If a listing_id is given this updates and overwrites a listing's information.
delete
Deletes the listing. You need to provide the listing's listing_id.
state_change
Turns a draft listing into a published listing. You need to provide the listing's listing_id.
Do not use this when creating new listings.
How the action column interacts with the listing_state column
