If you want to, you can specify that only certain IP addresses can access the API via your account.
​
You can find the corresponding setting option in the webapp under the menu item Developer, if you click on the blue cogs in the upper right corner of the field API Key.

In the following field you can create a whitelist. It is possible to enter IP addresses and hostnames here. Please enter only one address/only one hostname per line. If you are connecting via IPv6, please also specify the IPv6 address.
​
If you leave the field blank, access to the API will be allowed from any IP addresses.
​
After saving your whitelist, if you try to access the API from an IP address that is not noted in this whitelist, the API will give back error 903.
​
​
​
Do you have any further questions? Our support will be happy to help you.
​