subscan api

[Gintma]

I encountered a CORS issue when calling Subscan's API from the frontend website. I would like to confirm whether this is due to your API policy restrictions or if there is an issue with my calling method.

My calling scenario is as follows:

• Frontend site domain: demo.lunolab.xyz

• Requested API endpoint: polkadot.api.subscan.io/api/scan/account/tokens

• Calling method: The request is initiated directly from the browser frontend

The browser error message is as follows:

Access to fetch at 'polkadot.api.subscan.io/api/scan/account/tokens' from origin 'demo.lunolab.xyz' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I would like to confirm the following questions:

1. Is this API not originally supporting direct calls from the browser frontend? I previously called it without any issues.

2. Is it mandatory to call through a server-side proxy?

3. Is there an API or access method that supports frontend calls and has CORS enabled?

4. If frontend calls are supported, is it necessary to apply for a whitelist domain, or use specific request headers/configurations?

[freehere107]

Hey @Gintma

Currently, Subscan has updated its API usage rules.All requests to Subscan API must now include an API key.

For more details, please refer to the official documentation:https://support.subscan.io/

This is likely the cause of your CORS issue. You may need to:

1. Obtain a valid API key
2. Include it in your request headers
3. If issues persist, you may still need to use a server-side proxy to avoid browser CORS restrictions