I'm trying to develop MVP version of a HTTP proxy app, like Charles or Burp Suite. To do so, I need to intercept, read and write HTTP and HTTPS requests. I’m reading about the possibilities that Network Extensions give me but I’m very confused about all types of extensions (App Proxy, Content Filter) and which one of them can supply my necessities. I was thinking about recent Content Filter using System Extensions (the one of SimpleFirewall WWDC 2019 video), but it doesn’t seem to help me because I can only access source and destination IP addresses, and I need to read the HTTPrequest data, something like NEFilterBrowserFlow, but it seems to be available only for iOS platform.
The ContentFilter was built to perform a tunneling with a server, and since I need to perform everything local, it doesn't seem that it should be used in my scenario.
I found some amazing open-source frameworks built in Node.JS to perform this proxy behavior, like Hoxy, and that's that I'm trying to find using Apple's framworks.