I'm using PHP curl to achieve this. I know you provide an example where you get this done just writing your own multipart form. I'm trying to let curl do it for me. The problem is that the "attachments" array you are expecting isn't a true array, so it won't accept files in a structure like attachments nor attachments. I can't pass an array to curl with 2 different values in the same index of an array (attachments). So, my question is, how can this be done without having to manage the multipart form myself.