Open-sourcing a privacy proxy CLI

The privacy-protecting protocol Oblivious HTTP (OHTTP) involves multiple complex steps and binary encoding, making it very difficult to debug. In particular, separating the 'who' sent a request from the 'what' of the request content requires complex interaction between a Relay and a Gateway.

Based on the know-how gained from handling millions of requests per second, Cloudflare has open-sourced pvcli (privacy-client) under the Apache-2.0 license to address this complexity.

The main features of pvcli are as follows:

• Intuitive interface: Complex OHTTP requests can be executed with a single line command.
• Step-by-step debugging: Displays every step of the protocol in order, making it easy to quickly identify where problems occur.
• Binary data handling: Efficiently handles binary HTTP encoding that is hard for humans to read, reducing human error during debugging.
• Extensibility: Designed to support new privacy protocols and architectures.

This tool was created to reduce friction in development and incident response encountered while operating various privacy product lines, including Apple's Private Relay and Microsoft Edge Secure Network.