@hongminhee I haven't reached that point in GoActivityPub development to really think about it.

Currently for binary uploads I use world's hackiest hack™️, where I encode the media as a base64 media URI and set it as the Content of a Image/Audio/Video object that I send through client to server.

So far this has worked well enough between the clients and servers *I* developed, but I can't really ask anyone else to support that.