Adding items to Walmart works similarly to adding items to any other channel using bulk using the headers you mapped to your Walmart Category Fields. Attached is an example of bulk add headers (see Example Bulk Add Headers.csv). Headers that start with "wm" indicate default Walmart fields (i.e. wmcategory, wmtaxcode, etc).  

Once an item has been submitted it will be added to the SureDone queue and sent to Walmart to be created. Once Walmart has finished processing the item, any subsequent price and inventory updates that have been made during that time will be sent. If multiple price and / or inventory changes have been made, only the latest price and inventory information will be sent.

Note: Walmart requires all submitted products to have a valid 12-digit UPC or GTIN-14.