CORS

Cross-origin resource sharing (CORS) is a browser security mechanism which allows a server to control which origins can request resources.

Tip

CORS is enforced on the browser, not the server. Request that violate the CORS policy will still have responses returned, but the browser will reject them. As such, usage of tools like curl with cors can be confusing, as curl does not respect CORS headers.

Example:

cors:
  allowOrigins:
  - "*"
  allowHeaders:
  - mcp-protocol-version
  - content-type
  allowCredentials: true
  exposeHeaders:
  - x-my-header
  maxAge: 100s