Explore the development of a Python client for HTTP/3 proxies in this 27-minute conference talk from EuroPython 2022. Dive into the MASQUE protocol, which enables proxy and VPN services to operate indistinguishably from HTTPS servers. Learn about Akamai's implementation of MASQUE for iCloud Private Relay's egress proxy service. Discover the challenges of creating a Python client for testing proxy services, given the limitations of common Python libraries in supporting HTTP/3 and HTTP/2. Gain insights into the complexities of client implementations despite the simplicity of MASQUE proxy design. Review HTTP proxy operations and the differences between HTTP versions. Uncover valuable lessons from designing a low-level HTTP client using Python asyncio.