For whatever it is worth the post specifically calls out the desire to not use a proxy:
There’s a bunch of nice tools such as Fiddler2, OWASP ZAP, mitmproxy, that can proxy HTTPS, and they can decrypt the traffic by impersonating the site being connected to and taking the traffic.
However, in order to use any of these proxies, one needs to execute an active woman-in-the-middle attack, which has Consequences:
Proxy support is required
Support for adding trusted CAs is required
Key pinning must be disabled
It’s possible that certain HTTP library compatibility bugs may be concealed by virtue of the proxy decoding and re-encoding the data.
I would like to look at the actual traffic and not put anything relevant in the data plane to the greatest extent possible.
This is built on a really fascinating binary instrumentation tool, which is new to me: https://frida.re/
Unfortunate name is unfortunate: https://en.wikipedia.org/wiki/Clipper_chip
It’s intentional, the author mentioned the Clipper chip explicitly in the post :)
In that case, bravo!
Or you could use Charles Proxy, which has been around for a long time.
Or on MacOS, the excellent Paw app (recently renamed RapidAPI).
For whatever it is worth the post specifically calls out the desire to not use a proxy:
Charles proxy doesn’t seem to be foss and it looks like Clipper is. That’s an advantage for me.