Shared inventory pools with Shopify inventory webhooks (Recount Kit)
Some products are one pile of stock wearing several variant names. Shopify will happily track each variant on its own. Sell one, and the siblings still say they have the old count. Recount Kit treats those variants as a pool and lets Shopify stay the source of truth. The webhook Shopify sends inventory_levels/update when available quantity changes at a location. The handler turns the numeric ids into inventory-item and location gids, then looks for a pool member at that shop and location. ...