Dear developers, we are happy to welcome you to our developer portal. Please be aware that we offer the API only for Account Information Service (AIS) and that there will be already some changes coming within the next weeks for new version 6 in order to be more in line with the OAuth 2.0 standards. We will provide description of version 6 on the developer portal and accordingly upgrade the sandbox. If you have any questions about our current sandbox or our APIs don't hesitate to contact us. You will find our contact details in the footer of this website. Have fun testing! Your onvista xs2a-team