OPTIONS
CORS preflight and capability discovery.
What it does
OPTIONS is used for two things: (1) CORS preflight—browsers send it before cross-origin requests to check if the server allows the real request; (2) discovering what methods a server supports (via Allow header).
CORS and proxy mode
When you call an API from a different origin (e.g. your app from localhost calling api.example.com), the browser blocks it unless the server sends proper CORS headers. Our proxy mode bypasses this by sending the request from our server, so you can test any API without CORS issues.