If you want to use API's you'll need either an OAuth Client (for OAuth) or an Integration ID (for Basic Auth).
Follow these steps to request an Integration ID for use with Basic Authentication.
Basic Authentication (also known as Basic Auth) involves sending the credentials of a user account (username and password) with every API request. Org Admins can also assign permissions to allow users to create, view, update and deactivate integration IDs within your organization.
An Integration ID can only be used on the Aconex instance it was created on. You must create a separate Integration ID for each instance of Aconex you want to integrate with.