Submit product listings and update inventory on Walmart Marketplace via the Walmart Seller API

Steps

1. Authenticate using your Walmart Client ID and Client Secret via the token endpoint to obtain a bearer token; include WM_SVC.NAME and WM_QOS.CORRELATION_ID headers on every request
2. Prepare a product feed in the Walmart MP_ITEM feed type format (JSON or XML) containing items with each item's SKU, product identifiers (UPC/GTIN), pricing, inventory, and rich media content
3. Submit the feed via POST /v3/feeds?feedType=MP_ITEM with the feed payload as multipart/form-data; receive a feedId in the response
4. Poll feed status via GET /v3/feeds/{feedId}?includeDetails=true until ingestionStatus is PROCESSED, then inspect itemDetails for per-item errors
5. Update inventory separately using the INVENTORY feed type or the single-item PUT /v3/inventory?sku={sku} endpoint with quantity and fulfillmentLagTime
6. Update pricing via PUT /v3/price with a Price feed or the single-item endpoint specifying currency, amount, and optionally comparisonPrice for strike-through pricing