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Sergey Tregub edited this page Sep 30, 2018 · 23 revisions

Welcome to the AspNet-WebApi wiki!

Cross-Origin Resource Sharing (CORS)

Quote from an MDN article:

Cross-Origin Resource Sharing (CORS) is a mechanism that uses additional HTTP headers to tell a browser to let a web application running at one origin (domain) have permission to access selected resources from a server at a different origin. A web application makes a cross-origin HTTP request when it requests a resource that has a different origin (domain, protocol, and port) than its own origin.

By default, all origins are allowed. You can set up origin by uncommenting this line in web.config. To specify more than one origin split them by semicolon.

For example:

  <appSettings>
    <add key="allowed-origins" value="http://localhost:5000; https://api.some-domain.com"/>
  </appSettings>

If you want more control you can adjust CORS-policy in App_Start/CorsConfig.cs.