The “viral” part of AGPL comes from the GPL itself. If I write, say, a Java servlet that relies on an AGPL library, then by the same mechanics as effect GPL so

The “viral” part of AGPL comes from the GPL itself. If I write, say, a Java servlet that relies on an AGPL library, then by the same mechanics as effect GPL software, my servlet must now also be AGPL. Now I host my service and the servlet runs, sending content to whoever made the request. Whoever made that request to the servlet over the network is now entitled to the source code of the servlet. This is what the AGPL does. That whole effect stems from the original GPL, the AGPL just mucks with the new concept of network access being akin to the GPLs original use of distribution. If the library was just a GPL library, now even though the servlet is, now too, GPLd, there’s no obligation for source code release because the servlet was not “distributed”. Simply used on site of the servlet developer. Now if the original request is routed through a proxy, does the AGPL apply? Does the AGPL somehow “infect” the proxy? If not then a proxy is a simple AGPL firewall. If it does, let’s host some AGPL services and start make requests of AWS and Cloudflare for some of their source code. Which sounds pretty silly.