Browser model requests are blocked cross-origin: how do you distinguish CORS from authentication?
For cross-origin blocking, inspect browser CORS rules separately from authentication instead of calling every console warning a key error. Check preflight and actual requests for permitted origins, methods and headers.
Start troubleshooting here
For cross-origin blocking, inspect browser CORS rules separately from authentication instead of calling every console warning a key error. Check preflight and actual requests for permitted origins, methods and headers. Do not disable browser safeguards or expose long-lived keys in public frontend code for direct-call convenience.
Separate browser blocking from service error responses
This applies when command-line calls work but the page fails, OPTIONS is rejected or an error response lacks readable CORS headers. Record page origin, destination and credential-free request data. Command-line clients do not enforce browser same-origin restrictions, so their success does not establish web configuration. Browser blocking also does not establish successful authentication.
Inspect preflight, origins and allowed headers
Check preflight arrival and permitted origin, methods and headers before actual service status. Credentialed requests impose additional origin constraints, and wildcards are not a universal solution. CORS principally controls script access to responses, not account authorization. An allowed origin does not authorize every user to access business resources.
Handle secret-bearing calls through a controlled backend
Configure precise origin scope only on services you own and are authorized to manage. Use a controlled backend for model calls and secret protection where the architecture requires it. Disabling browser security or using no-cors to obtain an unreadable response does not repair the application. Keep authentication and permissions independent and avoid arbitrary-origin or arbitrary-action expansion.
Test both permitted and rejected origins
Test preflight and actual responses from the real page origin and confirm readable results while unauthorized origins remain rejected. Verify useful non-secret authentication errors and absence of keys from frontend bundles and URLs. Acceptance means a functional browser path with intended restrictions, not a quiet console or successful command-line call.
This article changed no server security settings or read keys. Follow actual browser rules and service support for headers and credentials. Some third-party APIs are not intended for direct webpage calls. Network, authentication and CORS problems can coexist, requiring full-path checks after each repair. CORS is not a general resource permission mechanism.
Checked sources
These sources support the concepts and methods described here. Examples and test scope are labeled separately; check the version of the tools you use.