Skip to main content
Legacy: Tyk Classic PortalYou’re viewing documentation for the Tyk Classic Portal, which is no longer actively maintained.If you’re looking for the latest API documentation for the new Tyk Developer Portal, please refer to the Postman collection or visit the Tyk Developer Portal section.The Classic Portal is in maintenance mode and will be deprecated soon. For questions or support, contact us at support@tyk.io.

​
Description

You get following errors in the browser console: 
Access to fetch at 'https://<Your Gateway URL>/<Your API>/' from origin 'https://<Your Dashboard URL>' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

POST https://<Your Gateway URL>/<Your API>/ net::ERR_FAILED

​
Cause

The CORS middleware in the Gateway is blocking this request. This can happen when the CORS settings of the API are not enabled or misconfigured for the developer portal.

​
Solution

Make sure that your CORS in the Advanced Options of the API is enabled and the settings are correct. This means:
  • Allowed Origins should allow the developer portal domain
  • Allowed Methods should allow all methods needed for API documentation (at least GET and POST)
  • Allowed Headers should allow at least Origin, Content-Type and for authenticated requests the authorization header (e.g. Authorization)
Note: When creating a new API with Dashboard v3.1 and higher the CORS settings will be prefilled with some default values (but disabled by default).
You can learn more about CORS on this pages: