Category Supplementary Resource Organisation World Health Organization (WHO) Type Standard Access Open Status Active An ICD API allows programmatic access to the International Classification of Diseases (ICD). It is an HTTP based REST API. This resource lays out the steps to follow so that you can use the ICD APIs. ICD APIs use OAUTH2 authentication with client credentials grant type, which makes use of the Client Id and Client Secret for authentication. The details on how to register and use them are presented here. Access ICD API Authentication By accessing this content, you are leaving this website. The Agency takes no responsibility for the accuracy of content on the destination page.