npx diagnose-endpoint@1.0.12 --endpoint=https://endpoint-you-want-to-hit --origin=https://origin-of-page-that-makes-the-request
This package was created to help Apollo Studio users more definitively diagnose why their endpoint might not work with Studio's Explorer (in particular via Sandbox)
Browsers don't expose why a network request failed, so applications aren't able to tell whether a request failed because of missing CORS headers or if there's just nothing being served from the endpoint (server offline or typo in URL)
Certain security software can cause browsers network requests to break in opaque ways that this script won't be able to diagnose