An incomplete HTTP(S) man-in-the-middle library akin to Fiddler.
Hence, the goal is to intercept HTTP(S) requests via an HTTP(S) proxy. HTTPS is the hard part, as it requires a man-in-the-middle attack to accomplish. Like Fiddler, this attack is facilitated by creating a local CA Certificate trust. The code relies "github.com/smallstep/truststore" to reg for Java, Firefox, and the local operatings system.
This is a work in progress, and doesn't fully function yet If you're looking for working software, check out goproxy.
It's worth noting that setting the proxy in MacOS requires permissions, with code signing.
It seems that building the solution doesn't work, but running it as go run . does!