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## Resource: Introduction

## Article: Introduction

## Article Link: https://dev.wix.com/docs/api-reference/business-solutions/e-commerce/catalogs/inventory-service-plugin/introduction.md

## Article Content:

# About the Inventory Service Plugin

The Inventory Service Plugin enables any business vertical or catalog implementor to integrate with a unified inventory system. It supports inventory business logic without requiring implementors to acquire deep knowledge of purchase or post-purchase events. It keeps inventory in sync with order flows and prevents orders for unavailable items—whether physical, digital, or time-based.

The integration is done via an app in the Wix App Market (created in the Wix Studio workspace), and the Wix Inventory service plugin.

Learn more about [implementing a service plugin with Wix](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/backend-extensions/service-plugins/about-service-plugin-extensions.md).

With the Inventory Service Plugin, you can:
+ Decrement availability when items are ordered, paid for, or allocated.
+ Increment availability when orders are canceled, refunded, or edited.
+ Manage inventory across multiple locations.
+ Handle both regular and subscription items.
+ Control inventory validation behavior for different order flows.

## Use cases

+ [Decrement inventory as part of order placed flow](https://dev.wix.com/docs/rest/business-solutions/e-commerce/catalogs/inventory-service-plugin/sample-flows.md)
+ [Update inventory as part of order edit flow](https://dev.wix.com/docs/rest/business-solutions/e-commerce/catalogs/inventory-service-plugin/sample-flows.md)

Both operations work with the same `item` object, which includes catalog references, quantities, location information, and subscription details.

## Key service plugin behavior

### Inventory validation control

The `restrictInventoryValue` parameter in decrement requests controls critical validation behavior:

+ **When `true`**: The operation validates available stock and fails if decrementing would result in negative inventory.
+ **When `false`**: The operation proceeds regardless of current stock levels, allowing negative inventory.

This distinction is crucial for different order flows - strict validation for customer-initiated orders versus flexible handling for merchant-initiated changes.

### Location-based inventory

Inventory can be managed per location using the optional `locationId` field:

+ **When provided**: Inventory changes apply to the specific location.
+ **When omitted**: Changes apply to the default location.

### Quantity limits

The service plugin has different quantity limits for operations:

+ **Decrement operations**: Support up to 300 items per request.
+ **Increment operations**: Support up to 300 items per request.

## Before you begin

It's important to note the following points before starting to code:

+ You can configure your inventory update preference with the [Orders Settings API](https://dev.wix.com/docs/rest/business-solutions/e-commerce/orders/orders-settings/introduction.md):
  + **Order placed (default)**: This will fail the order creation if items aren't available.
  + **Order paid**: An order will always be created and inventory will update upon successful payment. If items are no longer available at that moment, the merchant will be responsible for resolving the issue.
+ Your service must handle both increment and decrement operations.

## Terminology

+ **Inventory integration**: A 3rd-party app that implements custom logic to manage inventory.
+ **Inventory item**: Identify an item with quantity in the inventory system that needs to be updated.
+ **Catalog reference**: The unique identifier of an item in the platform managed by the catalog owner.
+ **Subscription item**: Describes if the current item is part of a recurring subscription. Inventory systems can decide to handle those items differently.
+ **Restrict inventory**: A flag passed on the decrement API. When set to true, the implementer should fail the request if inventory is not available.