When I first started working with #ActivityPub, before #Fedify existed, it felt like writing web apps in Perl and CGI in the late '90s. Interesting, even exciting—but never comfortable. That era where your business logic and your protocol plumbing were just… the same thing:
print "HTTP/1.1 200 OK"
print "Content-Type: text/html"
print
print "Hello, world!"Decades of web development have given us layers of abstraction we now take for granted. Nobody hand-parses application/x-www-form-urlencoded query strings anymore. Nobody writes their own JSON codec, or manually constructs HTTP request/response messages. These things just aren't your problem when you're building an app.
ActivityPub development still feels like they are your problem. What do you do when the https://www.w3.org/ns/activitystreams#actor property comes in as a string instead of an array? What about when https://www.w3.org/ns/activitystreams#object is an embedded entity rather than a URI? How exactly do you implement HTTP Signatures? And wait—what's Linked Data Signatures, and do you need that too?
The real issue isn't that ActivityPub is complicated per se. It's that you can't get away with understanding it at a high level. You have to know it the way an implementor knows it—every edge case, every inconsistency in how different servers serialize JSON-LD, every signature scheme that exists in the wild. That's a lot to learn before you can even start thinking about your actual app. And when developers understandably cut corners on the protocol to focus on their product, it quietly becomes an interoperability problem for the whole ecosystem.
What I want ActivityPub development to feel like: you spend a day understanding the big picture, and then you just… build your app. That was the goal when I started Fedify, and honestly, we're not fully there yet. But it's where I want to get.
