Cloudflare Makes Open-Source h3i For HTTP/3 Testing & Debugging

Cloudflare is ending 2024 by announcing a new open-source project: h3i for low-level HTTP/3 testing and debugging.

Cloudflare's newly open-sourced h3i project is a command line tool and Rust library for low-level testing and debugging of HTTP/3. The h3i free software is part of Cloudflare's larger Quiche project.

The h3i tool allows for quick low-level debugging and exploratory testing around HTTP/3. The h3i tool in simple forms is akin to the curl command line tool but with extra HTTP/3 parameters. With h3i there is record and replay support, the ability to send intentionally malformed requests with Rust, built-in test automation, and other capabilities.

"Cloudflare takes testing very seriously. While h3i has a limited feature set as a test HTTP/3 client, we believe it provides a strong framework that can be extended to a wider range of different cases and different protocols. For example, we'd like to add support for low-level HTTP/2.

We've designed h3i to integrate into a wide range of testing methodologies, from manual ad-hoc testing, to native Rust tests, to conformance testbenches built with scripting languages. We've had great success migrating our existing zoo of test tools to a single one that is more accessible and easier to maintain."

Those wishing to learn more about the h3i open-source project can do so via the Cloudflare Blog. The code can be found via the Quiche GitHub repository.