fluxzy is a fully managed and fully streamed MITM engine and a CLI app to intercept, record and alter HTTP/1.1, H2, websocket traffic over plain or secure channels. It provides core features such as intercepting traffic, acting as a system proxy, managing certificates, exporting as HTTP Archive, using custom root certificate authority, capturing raw packets, and more. It also offers alteration and traffic management features through Fluxzy actions, including modifying headers and mocking or substituting request and response body.