Drop-ship from Ashley, Coaster, Sunbrella, Yeti, how does PO orchestration work?

Each manufacturer has a slightly different protocol. The Magento pattern is the same: order placed → split by vendor → auto-PO per vendor → ingest ASN + tracking → sync to customer.

• Ashley HomeStore, EDI 850 PO via VAN (SPS Commerce / TrueCommerce / B2BGateway). Ashley sends 855 PO ack + 856 ASN + 810 invoice. Real-time inventory feed via daily 846. Cost: ~$300, $800/mo VAN fee + $5, $15k integration.
• Coaster Furniture, EDI 850 via SPS Commerce. Similar pattern to Ashley. Lead time on bedroom sets typically 3-5 business days from PO.
• Sunbrella (Glen Raven), REST API with OAuth. Per-yard cut-to-order for upholstery fabric, finished cushion drop-ship for outdoor. Daily inventory pull.
• Yeti, REST API + branded packaging option. Tight MAP enforcement, underpricing gets you de-listed. Inventory feed every 4 hours.
• John Deere, dealer-network integration via Deere’s Operations Center API. Dealers (not Deere directly) drop-ship; you become a referral partner with margin share.

Architecture: Magento has the order-of-record. On checkout, a custom observer splits the order into per-vendor sub-orders, fires the PO (EDI or REST), tracks the shipment via the vendor’s ASN webhook, and updates the customer-facing order status. The hard part is the inventory-of-truth question: pull every 4 hours and accept some oversells, or pull at add-to-cart and accept slower checkout. I default to the former + a 6-hour cart timeout that re-validates inventory before payment capture.