Has something changed over the last two days and what should be done to avoid this error.
It looks like you have to set the Access-Control-Allow-Origin header in the response.
Yes, on Monday the CORS configurations were changed on our servers to comply with stricter security requirements. The access to API endpoints form localhost is no longer supported.
This is very inconvenient, because a lot of mobile apps are web based apps making request from localhost.
What security problem are we trying to solve here?
Due to the new CORS policy, you cannot call the API endpoints directly from your web application.
A possible solution would be by proxying the request.
You can proxy the request through your own server. Their server can make the request to ‘https://api.nuki.io’ on behalf of your web application. If the request comes from your server, CORS won’t be an issue.