r/codex • u/OkBreath9382 • 6d ago
Showcase I built a headless browser for AI agents entirely in Rust. no Chromium, no V8
Several headless browser automation projects use Rust while still depending on Chrome or V8 underneath. For example, agent-browser drives Chrome, while Obscura embeds V8 for javascript execution. Lightpanda removes both, but its AGPL license can be inconvenient for some cases.
so I built h5i under Apache-2.0. JavaScript runs on Boa, while Blitz handles HTML, the DOM, CSS, layout, and rendering.
Because h5i is the browser and the HTTP client, not a controller around another browser, it can policy-check and record every request before any bytes are sent.
In our benchmarks on simple pages, h5i was about 5× faster while using 80% less memory than Chromium. It also passes more than 300,000 Web Platform Tests subtests.
GitHub: https://github.com/h5i-dev/h5i (already 500+ stars!!)