Use the item spec

The recommended usage of the different operations mentioned above is as follows:

For initial insertion, use the MPItem object with item details and item listing/offer.
Once the item has been set up and the status is PUBLISHED, use the Offer Only object item for non-item edits, such as price changes.
Use the Product only item object for item edits.** Note: You should not use an MPItem object because any price change included in the MPItem object is effective only when the entire object is processed.**

The published status of an item describes where the item is in the submission process.

PUBLISHED: The item is visible on Walmart.com and available for sale.
READY_TO_PUBLISH: The item is in the final staging process and is ready to be published.
IN_PROGRESS: The item is processing. An error could still occur at this point.
UNPUBLISHED: The item has been made unavailable on Walmart.com because of backend rules, such as not having inventory for too long or problems with images.
STAGE: The item is in the final staging process but has not been published because the seller has not gone live.
SYSTEM_PROBLEM: The item cannot be published. Contact Partner Support.

The lifecycle status of an item describes where the item listing is in the overall lifecycle.

ACTIVE: The item’s offer is current.
RETIRED: The offer has moved past its expiration date (as set in the EndDate field). The item is not visible on Walmart.com. It can be made ACTIVE again by extending the expiration date into the future.
ARCHIVED: The offer has been in RETIRED status for over a year. To return the listing to the ACTIVE status, contact Partner Support.