If you sell 1P (wholesale) to Amazon through Vendor Central, the transaction flow is EDI-driven and unforgiving: Amazon drops purchase orders you must acknowledge, ship against with a compliant ASN (856), and invoice electronically (810) — all inside tight windows, or you eat chargebacks for late ASNs, ASN accuracy defects, and PO non-compliance. ERPNext gives you clean Purchase Order, Delivery Note, and Sales Invoice DocTypes, but out of the box it has no idea Vendor Central exists. Teams end up rekeying POs from the Vendor Central portal or a spreadsheet, hand-building ASNs, and reconciling deductions after the money is already gone. That manual bridge is exactly where margin leaks.

ECOSIRE builds a dedicated Frappe app — its own module with purpose-built DocTypes such as Amazon Vendor PO, Vendor Central ASN, Vendor Central Invoice, and Vendor Chargeback — that sits natively inside your ERPNext instance rather than as a bolt-on middleware. The connector ingests inbound EDI 850 purchase orders (via your EDI/VAN or Amazon's SP-API/EDI gateway, whichever your account uses), maps ASINs and vendor SKUs to ERPNext Item records, and creates linked Sales Order documents so your fulfillment team works in the UI they already know. hooks.py doc events fire on Delivery Note submit to assemble a compliant 856 ASN — carton/pallet hierarchy, SSCC labels, ship-from/ship-to party codes — and on Sales Invoice submit to emit the 810 with the correct PO reference, allowances, and terms. Whitelisted server-side methods exposed over the Frappe REST API handle the outbound transmission and acknowledgement (997/functional acks), and scheduler events poll for new POs and status updates on the interval your SLA needs.

Under the hood it is standard, maintainable Frappe engineering: server scripts and Python controller logic for the EDI mapping and validation, client scripts for the operator workflow (PO acknowledge, ASN build, exception review), custom Role and role-profile permissions so warehouse, finance, and admin users see only what they should, and structured logging plus an Error Log-backed retry queue so a dropped transmission is visible and recoverable rather than silent. Chargeback and shortage records are captured against the originating PO so finance can dispute deductions with the shipment and invoice evidence attached, and catalog/cost updates can be pushed back to Vendor Central from your ERPNext Item and price data. The app targets Frappe/ERPNext v15 and v16 and is delivered as versioned source you own.

Because this is build-to-order, nothing ships as a one-click download. We start with a short scoping call to confirm your Vendor Central setup (EDI vs SP-API, VAN provider, document set, label spec, and which regions/marketplaces), then build against your real requirements, prove it on a staging bench with UAT, and only then install on production. Typical delivery is 2–4 weeks from confirmed scope depending on the document set and edge cases. You receive the installable source, technical and user documentation, a training session, a git repo handover, and a post-go-live support window — so the connector is yours to run and extend, not a black box.