---
category: [Administration & Integrations, Platform and Product Extensions, Platform and Product Extensions/Integration, Administration & Integrations/Custom Integrations & Apps, Platform and Product Extensions/Workday Extend]
keyword: Extend
nav: wcp_docs
parent_url: /wcp_docs/
title: >- 
  Concept: Cross Origin Resource Sharing (CORS)
layout: subsection
---

Cross Origin Resource Sharing (CORS) is a standard mechanism to enable browsers to make cross-domain requests. A cross origin request occurs when an app hosted on 1 domain can initiate a request for resources located on a target domain. The browser enables the request only if the target domain has specified that it will accept a cross origin request from the initiating domain.

When you develop a Workday Extend browser-based app that requires access to Workday Extend or Workday REST API resources, you must specify 1 or more valid CORS domains when you register your client. Workday will then accept cross origin requests from those domains.

### Related Information

[Cross-Origin Resource Sharing (CORS)](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS)