In this section we look at the most common technical problems and solutions


CORS error (widget isn’t loading)

Access to manifest at https://sandbox-widget.mrcr.io/img/favicon/light/site.webmanifest' from origin https://sandbox-exchange.mrcr.io has been blocked by CORS policy: No Access-Control-Allow-Origin header is present on the requested resource.

  • Solution #1: You are trying to run the widget in another iFrame? Opening Mercuryo widget in another iFrame isn’t possible.

  • Solution #2: You have to change the Domain in the widget settings. Open the dashboard and go to "My Widgets":

- Sandbox: https://sandbox-exchange.mrcr.io

- Production: https://exchange.mercuryo.io


Error 403. What does this mean?

sandbox-partners.mrcr.io, sandbox-exchange.mrcr.io and api-sandbox.mrcr.io are only available if your IP address has been added to a whitelist. This is done for greater security.


What is the request limit?

Usually no more than 5000 requests in 5 minutes.

Contact us if you need to increase the number of requests per minute.


What should I enter in the Domain field when I set up my first widget?


Do you have any recommendations for the frame size in which the widget will open?

It is designed so that all the information you need is always in view for all screen sizes. Outside the screen is usually the footer. That's why we don't have size recommendations, because we think it should be ok for all screen sizes.


Buy button is not available

In most cases, the wrong address is predefined/entered or the user has not agreed to the terms and conditions


Signature is invalid error

To protect a crypto-wallet address against forgery, we use signature for wallet addresses. Signature is calculated using the following algorithm:

  • signature = sha512(address+secret), where + concatenation operation.

  • Take the address to which we will buy cryptocurrency (thisismyaddress).

  • In the partners' admin panel search for secret (123123123).

  • Open SHA512 hash calculator, paste thisismyaddress123123123 in the field and get crypto-wallet address signature (helloworld).

  • In the partners’ widget URL add signature https://exchange.mercuryo.io?signature=helloworld

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