Square Payments Sync for Shopify is a build-to-order integration for omnichannel retailers who already run Square POS in-store and want Shopify to behave as one connected system instead of a second silo. This is not an instant App Store install — ECOSIRE builds, configures, installs and supports the app for your store, then hands you a tested, production-ready integration scoped to your catalog and locations.

The app authenticates to Square via OAuth and to your store through a custom Shopify app using the Admin GraphQL API. It reconciles online checkout charges and in-store Square POS sales into one unified ledger, so a single sale never gets double-counted and refunds resolve to the right transaction. Inventory stays honest through webhook-driven multi-location sync: when a register sells the last unit, Shopify's multi-location inventory levels update before the next online shopper can oversell it, and vice versa.

Because every retailer's Square setup differs — multiple locations, taxonomy quirks, partial-refund rules, gift-card handling — we map your Square catalog to Shopify products and variants during the build, store linkage in metafields, and confirm edge cases with you before go-live. Apple Pay and Google Pay are enabled through Square's wallet support at checkout. Staff can issue refunds and voids straight from the Shopify admin, and customer profiles sync so a shopper recognized at the register is the same record online.

You get unified omnichannel reporting, a documented architecture, and a real human to call when Square or Shopify ships an API change. Honest delivery: typical build and installation runs 2–4 weeks depending on catalog size and the number of locations.