# Architecture

This page explains the technical architecture of WCPOS for developers and advanced users.

## Two-Part System[​](#two-part-system "Direct link to Two-Part System")

WCPOS is designed as a two-part system:

1. **PHP Plugin:** Hosted on your server, this is a relatively small plugin which extends the [WooCommerce REST API](/reference/wc-rest-api.md).

2. **JavaScript Client:** This runs locally in your browser or the desktop app, and later on iOS and Android apps.

You can think of it as two separate worlds:

* The *PHP world* is where data management happens using WordPress and WooCommerce.
* The *JavaScript world* replicates your WooCommerce store locally, optimised for fast searching and offline use.

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)

## Data Synchronization[​](#data-synchronization "Direct link to Data Synchronization")

Data is fetched from WooCommerce using the [WooCommerce REST API](https://woocommerce.github.io/woocommerce-rest-api-docs/). This means the POS has to download every product, variation, product category, customer, tax rate, and more to store them locally.

Although this can be time-consuming initially, once downloaded, they're available instantly without the need to continually fetch from the server.

### What Gets Synced?[​](#what-gets-synced "Direct link to What Gets Synced?")

* Products and variations
* Product categories and tags
* Customers
* Tax rates and tax classes
* Payment gateways (for checkout)
* Orders (for order history in Pro)

### Sync Strategy[​](#sync-strategy "Direct link to Sync Strategy")

WCPOS uses an incremental sync strategy:

1. **Initial sync:** Downloads all data on first load
2. **Incremental updates:** Only fetches changes since the last sync
3. **Background sync:** Periodically checks for updates
4. **Manual sync:** User can trigger a sync at any time

## Architecture Pros and Cons[​](#architecture-pros-and-cons "Direct link to Architecture Pros and Cons")

| Good 😊                                                            | Bad 😟                                                  |
| ------------------------------------------------------------------ | ------------------------------------------------------- |
| Searching local data is instant                                    | Keeping data in sync is challenging                     |
| Cached data available offline                                      | Limited by the WooCommerce REST API                     |
| Ability to create better native apps for desktop, iOS, and Android | WordPress themes and hooks cannot customise the POS app |

## Local Database[​](#local-database "Direct link to Local Database")

The JavaScript client stores data in IndexedDB, a browser-based database. This provides:

* **Persistence:** Data survives browser restarts
* **Performance:** Fast queries without network latency
* **Offline browsing:** Cached data remains accessible without internet

## Checkout Architecture[​](#checkout-architecture "Direct link to Checkout Architecture")

The checkout process uses an iframe/webview that loads the WooCommerce Order Pay page. This approach:

* **Leverages existing payment gateways:** Any WooCommerce payment gateway can work in the POS
* **Maintains security:** Payment processing happens through WooCommerce's secure infrastructure
* **Reduces complexity:** No need to re-implement payment gateway integrations

## API Extensions[​](#api-extensions "Direct link to API Extensions")

The PHP plugin extends the WooCommerce REST API with additional endpoints for POS-specific functionality. See [WooCommerce REST API](/reference/wc-rest-api.md) for details.