Offline-First POS for WooCommerce

Key Features

Local order queue: sales are written to a browser-side IndexedDB store and replayed against the WooCommerce REST API (POST /wp-json/wc/v3/orders) automatically on reconnect

Cached product catalog, prices, and tax classes synced to the device so cashiers can search and build carts with no connection

Inventory conflict resolution on re-sync — reconciles _stock meta across registers and flags oversells for manual review instead of silently overwriting

Installable PWA (manifest.json + service worker with a cache-first strategy) so a tablet or desktop runs the register full-screen, even after a reboot offline

Offline receipt generation from a cached HTML/ESC-POS template, printable to thermal printers via the browser or a local print bridge

HPOS-aware order creation — writes to WooCommerce High-Performance Order Storage custom tables when enabled, or the legacy shop_order post type when not

Background sync driven by the Service Worker Background Sync API with a WP-Cron fallback to retry queued orders if a tab is closed

Per-register device identity and a local session log so each terminal's queued sales are auditable after sync

Hooks into your existing payment methods and fires woocommerce_thankyou / order-status transitions so downstream automations (email, invoicing, fulfillment) still run

Configurable sync conflict policy (last-write-wins, server-authoritative, or hold-for-review) set from a wp-admin settings panel under WooCommerce

Optional WPML and WooCommerce multisite compatibility so multi-store / multi-language catalogs cache and sync correctly per site

Connection-state UI: a live online/offline indicator and a pending-queue counter so staff always know what has and hasn't synced

Built to order, done for you

No DIY setup — a working app, built, installed and supported by ECOSIRE.

You order

Start with a one-time build price. We scope it with you at kickoff.

We build & install

ECOSIRE builds, configures and installs it on your WooCommerce.

Go live + support

You go live in about 2–4 weeks, with a post-launch support window.

About this Product

Offline-First POS for WooCommerce is a custom POS layer that ECOSIRE builds, installs, and supports directly on your existing WordPress + WooCommerce site — not an instant marketplace download. We engineer it around your catalog, tax rules, and hardware, then deliver a working register on your domain.

The core problem it solves: a standard WooCommerce checkout dies the instant connectivity drops, because every "place order" call hits the WooCommerce REST API (/wp-json/wc/v3/orders) live. This plugin flips that. Sales are written to a local IndexedDB queue inside a PWA (installable via a manifest.json + service worker) so cashiers keep ringing up customers with zero network. When the connection returns, a background sync worker replays the queue against the REST API and creates the real WooCommerce orders — into HPOS / custom order tables when enabled, or the legacy shop_order post type otherwise.

The browser caches your product catalog, prices, and tax classes so staff can search and add line items fully offline. On reconnect, an inventory conflict-resolution pass reconciles _stock meta against sales made on other registers, surfacing oversells for review rather than silently corrupting stock. Receipts render and print offline from a cached template.

Because we build to order, the POS is wired into your WooCommerce: your payment methods, your woocommerce_thankyou and order-status hooks, your tax setup, and optionally WPML or multisite. Typical delivery is a few weeks, after which ECOSIRE provides updates and support. You own the code on your server.

What you get

A custom Offline-First POS plugin built for and installed on your WordPress + WooCommerce site, with source code you own

PWA configuration (manifest.json + service worker) so the POS installs to tablet/desktop and launches full-screen

wp-admin settings panel under WooCommerce for sync policy, cached-catalog scope, receipt template, and per-register setup

Integration of the POS with your existing payment methods, tax classes, and order-status / woocommerce_thankyou hooks

HPOS and (optionally) WPML / multisite compatibility configured and tested against your store

A staging-environment deployment plus a guided go-live on your production site

Offline receipt template styled to your branding and tested against your printer

Setup documentation, a cashier quick-start guide, and a post-launch support window with updates

Who this is for

Brick-and-mortar retailer with patchy connectivity

Runs one or more counters in an area where the broadband or mobile signal drops several times a day. Needs the register to keep taking sales and printing receipts through every outage, then reconcile cleanly once the line is back.

WooCommerce store owner unifying online and in-store sales

Already sells online with WooCommerce and wants the physical till to write into the same orders, stock, and customer records — without a separate, siloed POS system that double-counts inventory.

Multi-register shop or pop-up operator

Operates several tills, market stalls, or event booths on the same WooCommerce catalog and needs each terminal to queue independently offline, then merge sales and resolve stock conflicts without overselling.

How Offline-First POS for WooCommerce Compares

Criterion	ECOSIRE	Custom Build	Competitor
Keeps selling and printing receipts with no internet connection	Included	Partial support	Partial support
Local order queue with automatic replay to the WooCommerce REST API on reconnect	Included	Partial support	Not included
Inventory conflict resolution across multiple registers after re-sync	Included	Partial support	Not included
Built, installed, and configured on your existing WooCommerce site by the vendor	Included	Included	Not included
HPOS / custom order tables and WPML / multisite compatibility tested for your store	Included	Partial support	Partial support
Instant self-service download from a public marketplace	Not included	Not included	Included
Fixed low one-time price with no per-register or per-seat license	Included	Not included	Partial support
Source code you own on your own server	Included	Included	Not included

Frequently Asked Questions about Offline-First POS for WooCommerce

How long until the POS is live on my site, and is this an instant download?

This is build-to-order, not a marketplace download. After we confirm scope — your catalog size, payment methods, tax rules, printer, and whether you use HPOS, WPML, or multisite — ECOSIRE builds and configures the plugin, tests it on a staging copy of your site, then deploys to production with you. Typical delivery is a few weeks depending on complexity. You get a working register installed on your own WordPress, not a ZIP you have to wire up yourself.

What exactly happens to a sale made while the internet is down?

The sale is written immediately to a local IndexedDB queue in the browser and a receipt prints offline from a cached template, so the customer is served with zero delay. Nothing is lost if the tab closes or the device reboots — the queue persists on disk. When connectivity returns, a background sync worker replays each queued sale against the WooCommerce REST API to create the real order (into HPOS tables or the legacy shop_order type), and a WP-Cron fallback retries anything still pending.

How do you stop overselling when two registers sell the last item offline?

On reconnect the plugin runs an inventory conflict-resolution pass that compares queued sales against current _stock meta and against what other registers synced. Instead of silently overwriting stock, conflicts (such as the same last unit sold twice) are surfaced for review according to the policy you choose in the WooCommerce settings panel — server-authoritative, last-write-wins, or hold-for-review. You decide how aggressive reconciliation is for your business.

Will it work with my existing WooCommerce setup — HPOS, WPML, my payment methods?

Yes, that's the point of building to order. We wire the POS into your live store: it creates orders through your configured payment methods, respects your tax classes, fires your woocommerce_thankyou and order-status hooks so email/invoicing/fulfillment automations keep running, and writes to HPOS custom order tables when you have them enabled. WPML and WooCommerce multisite compatibility are supported as optional scope and tested against your specific configuration.

What ongoing support and updates do I get after launch?

Every build includes a post-launch support window during which ECOSIRE fixes issues, tunes the sync and conflict behavior to your real-world usage, and keeps the plugin compatible with WordPress and WooCommerce core updates. Because you own the source on your server, there's no per-seat license lock-in. Extended support and maintenance can be arranged after the initial window, and we can add registers, printers, or new sync rules as your operation grows.