This is a follow-up to the feature that adds CSV support to the data mapper.
It seems that we are missing a section on how a user can define input/output types (data shapes). Currently, this is barely mentioned in the section on HTTP (Integration Applications guides, section 6.2. Creating an integration that an HTTP request can trigger). However, I asked Zoran and his reply is:

It is something that I think deserves a separate chapter. It is not tied only to HTTP use cases, many connectors (those with kind=any) support user defined data shapes. And specifying data shapes is required & essential for using the mapping steps.