> Portal Navigation:
> 
> - Append `.md` to any URL under `https://dev.wix.com/docs/` to get its markdown version.
> - Pages are either content pages (article or reference text) or menu pages (a list of links to child pages).
> - To get a menu page, truncate any URL to a parent path and append `.md` (e.g. `https://dev.wix.com/docs/sdk.md`, `https://dev.wix.com/docs/sdk/core-modules.md`).
> - Top-level index of all portals: https://dev.wix.com/docs/llms.txt
> - Full concatenated docs: https://dev.wix.com/docs/llms-full.txt

## Resource: Introduction

## Article: Introduction

## Article Link: https://dev.wix.com/docs/api-reference/business-solutions/stores/service-plugins/product-restrictions-v3/introduction.md

## Article Content:

# About the Product Restrictions Service Plugin

The Product Restrictions service plugin (formerly SPI) allows 3rd-party fulfillment apps, such as dropshipping and print-on-demand, to implement editing restrictions on product fields within the Wix ecosystem.
This ensures consistent business rules and data integrity.

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).

## Before you begin
It’s important to note the following points before starting to code:

* The Product Restrictions service plugin only works with sites that support Wix Stores [Catalog V3](https://dev.wix.com/docs/api-reference/business-solutions/stores/catalog-v3/introduction.md).
* This service plugin only works for products created by a fulfillment provider app.
* When creating a new product for a new fulfiller, you must pass the `fulfillerId` (app ID) under the `product.physicalProperties` field.
* If you update a restriction after it's defined, the change will affect all existing products from the same fulfiller.

## Use cases
* [Configure custom restrictions for editing your products](https://dev.wix.com/docs/api-reference/business-solutions/stores/service-plugins/product-restrictions-v3/sample-flows.md).

## Terminology
* **Fulfiller**: A 3rd-party app that provides fulfillment services, such as dropshipping or print-on-demand.
* **Dashboard**: The Wix Studio dashboard where you can manage your products.