API to add and read attachments?

I'm writing an application that works with Zoho CRM. I'd like to be able to query for the attachments on a Potential, and then be able to query for the attachment files to get at the bytes of the files. I'd also like add attachments to a Potential via the API. Is this possible?

I believe such a call to query attachments would be something like:

https://crm.zoho.com/crm/private/xml/ Attachments/getRelatedRecords?newFormat=1&apikey=<my api key>&ticket=<my ticket>&parentModule=Potentials&id=<my potential id>

as this works for other related records, such as Cases.

Is this already possible? If not, is it coming in the future?