Rest API for CSI on Multi Tenant?

What are the different ways to extract data (say customer orders, items, vendors etc) from the Multi tenant cloud version of CSI v10 via an external app?

The documentations I have come across seems to be mostly relevant for single tenant. Is this feasible on the Multi Tenant environment?

Can this be done via ION? I have had a look at the Infor Provisioned APIs on ION, but I can't establish which one is suitable for this job? For example, when I look at 'Infor Document Management' API it's clear I ran tests via the IDM Rest API's documentation tab, works all well. Is there an equivalent CSI Rest API to try/test?