If you are experiencing connection problems and want to verify whether the API is up and running you can use the ping endpoint. Open your browser and go to: 

https://<tenant>.xill.io/v2/system/ping

where you replace <tenant> with your tenant id. The ping endpoint is unauthorized so you don't need an authentication token. This is a fast and easy way to verify if the API is up and running and to verify if you can access the tenant from your network.