mitmproxy.org
mitmproxy is a free and open source interactive HTTPS proxy. It can be used to intercept, inspect, modify and replay web traffic, including HTTP/1, HTTP/2, HTTP/3, WebSockets and other SSL/TLS-protected protocols. It offers a command line interface, a graphical web interface, and a Python API for writing addons and scripts. Downloads are available for Windows, Linux, macOS and Docker.