If you sell on Coupang, Korea's largest marketplace, and run ERPNext for your back office, you are almost certainly re-keying data by hand. Coupang orders live in Coupang WING while your stock, pricing, invoices, and financials live in ERPNext — and there is no native bridge between them. ERPNext core ships integrations for a handful of Western channels, but nothing that speaks the Coupang OpenAPI, understands Rocket Growth (마켓플레이스) versus Rocket-fulfilled listings, or reconciles Coupang's settlement statements against your Sales Invoice and Payment Entry records. The result is oversells when stock drifts, late shipments that hurt your seller score, and month-end settlement math done in spreadsheets.

ECOSIRE builds the ERPNext Coupang Connector to close that gap. It is delivered as a proper Frappe app (erpnext_coupang) with its own module, versioned migrations via patches.txt, and a clean uninstall — not a pile of loose customizations scattered across your site. We add DocTypes such as Coupang Settings (encrypted access-key and secret-key fields with HMAC-signed request headers), Coupang Order, and Coupang Settlement, plus a mapping child table that links each ERPNext Item to its Coupang seller product ID, option ID, and vendor item ID. A whitelisted method registered against scheduler_events polls the Coupang OpenAPI on a cron interval, pulls new orders, and converts them into ERPNext Sales Order and Delivery Note documents with Korean-market customer, address, and tax handling built in.

Technically, the flow is event-driven where it matters. Inventory and price sync run two-way: an ERPNext Stock Ledger Entry change fires a hooks.py doc event that debounces and pushes the new available quantity to Coupang, while inbound polling keeps ERPNext aware of channel-side changes — with a configurable source-of-truth rule so you decide who wins on conflict. When you dispatch, an on_submit handler on Delivery Note writes the carrier and tracking number back to Coupang to close the shipment, and invoice creation is mirrored to the channel. Listing pushes for Rocket Growth / Marketplace go through a queued background job (frappe.enqueue) so a slow API call never blocks your desk. Every API call, retry, and failure is written to an audit log DocType, and all endpoints respect ERPNext role permissions and a dedicated Coupang Manager role profile.

Because this is build-to-order, nothing ships until we have agreed your exact scope. We start with a short scoping call, confirm which Coupang account model you run (seller-fulfilled vs Rocket), map your ERPNext version (v15 or v16) and item structure, and write a fixed scope document. We then build against a staging copy of your site, run UAT with your team, and only cut over to production once you sign off. Typical delivery is one working week from confirmed scope, and you receive the full source repository so you are never locked in.