Retailers and restaurants in low-connectivity regions lose revenue every time the line drops. ERPNext's stock POS relies on a live connection to the server for pricing, item lookups and POS Invoice submission; when the network flaps, the till stalls, queues back up, and staff resort to paper slips that never make it back into the system. The native POS Profile and offline mode buffer some transactions in the browser, but they do not survive a full page reload or device restart, do not cache full item and pricing catalogs reliably, and give you no conflict-safe reconciliation when several offline terminals reconnect at once. That is exactly where ERPNext out of the box runs out of road for a shop that simply cannot stop selling.

ECOSIRE builds Offline-First POS for ERPNext as a proper Frappe app installed on your bench (bench get-app / bench install-app), not a fragile browser hack. The checkout screen runs against a durable local store (IndexedDB) so billing, item search, price and tax lookup, and receipt generation all work with zero connectivity. Every sale is written locally first as a queued transaction with a client-generated idempotency key, then replayed to ERPNext through whitelisted server methods and the Frappe REST API when the link returns. On the server side we add custom DocTypes for the offline queue and sync ledger, hooks.py doc events to validate and post each POS Invoice/Sales Invoice, and a scheduler event that sweeps for stragglers so nothing is silently lost.

The sync engine is conflict-safe by design. Each terminal caches item prices, Price List rates, stock levels and customer records, and stamps every offline invoice with device id, sequence number and timestamp. On reconnect, the server-side handler deduplicates on the idempotency key (so a double-tap or a retry never creates two invoices), validates stock and pricing against current ERPNext state, and flags genuine conflicts — for example an item that went out of stock while the terminal was offline — into a review queue instead of guessing. ESC/POS receipt printing runs entirely offline over USB or network printers, and cash, card and mobile-wallet tenders are captured against the correct Mode of Payment and reconciled into the ERPNext POS Closing Entry at end of shift. Role profiles and permissions gate who can void, discount, reopen a shift or resolve a sync conflict.

Because this is build-to-order, we start from your real scope: your ERPNext version (v15 or v16), your item and pricing structure, tender types, printer models, and how many terminals need to run dark. ECOSIRE writes the app, adapts DocTypes, server scripts, client scripts and permissions to fit your workflow, tests it on a staging bench, and installs it on your production instance. Typical delivery is 2 to 4 weeks from confirmed scope — there is no instant download, and we do not resell a generic marketplace listing. You get the installable source for your version, documentation, training, a post-go-live support window and the git repository so your team is never locked in.