CORS error when running Polar locally for contributing

[Manas-Kenge]

Hi,

I’m running Polar locally for contributing and I’m hitting CORS errors when trying to create products or discounts from the frontend.

What I see

When creating a product (src/hooks/queries/products.ts):

Access to fetch at 'http://127.0.0.1:8000/v1/products/' 
from origin 'http://127.0.0.1:3000' has been blocked by CORS policy: 
No 'Access-Control-Allow-Origin' header is present on the requested resource.

POST http://127.0.0.1:8000/v1/products/ net::ERR_FAILED 500 (Internal Server Error)
Uncaught (in promise) TypeError: Failed to fetch
    at Object.mutationFn (products.ts:105:18)
    ...

When creating a discount (src/hooks/queries/discounts.ts):

Access to fetch at 'http://127.0.0.1:8000/v1/discounts/' 
from origin 'http://127.0.0.1:3000' has been blocked by CORS policy: 
No 'Access-Control-Allow-Origin' header is present on the requested resource.

POST http://127.0.0.1:8000/v1/discounts/ net::ERR_FAILED 500 (Internal Server Error)
Uncaught (in promise) TypeError: Failed to fetch
    ...

Debugging done

• Tried sending the same request via Postman → still fails.
• Tried setting CORS_ORIGINS to "*" → still blocked by the browser.

Additional notes

• Already asked for help on Discord but didn’t get a response.
• This happens only on POST requests (/v1/products/, /v1/discounts/).
• Running frontend on 127.0.0.1:3000 and backend on 127.0.0.1:8000.

Could you clarify if this is a misconfiguration on my side, or if there’s an issue with how CORS is applied on POST endpoints locally?

Thanks!

[frankie567]

This is not a direct CORS issue. We clearly see the server returned an error 500, which in turn makes the browser unhappy.

Check the logs in the terminal running the API backend to learn more about the error happening.