Kitesurf is now open source

Cloudflare has published the source of Kitesurf, its browser engine for AI agents, under the Apache 2.0 license. Kitesurf launched in August as part of Browser Run, Cloudflare's managed browser-automation service (earlier Intel on the launch), and Cloudflare had promised to open it. With the code on GitHub, developers can now read it, change it, and run their own copy instead of calling Cloudflare's managed API.

Kitesurf is a browser that runs inside Workers, Cloudflare's serverless platform, with no Chromium container behind it. It parses HTML, applies CSS, runs a page's JavaScript and renders screenshots, and it speaks the Chrome DevTools Protocol, the interface that automation tools such as Puppeteer and many agent harnesses already use to drive Chrome. Cloudflare's case for building it, set out at launch, is that full browsers carry features agents do not need and cost too much memory and compute to give every agent its own instance. The engine is assembled largely from open-source Rust projects compiled to WebAssembly, including Stylo for CSS and Blitz for HTML layout and painting, with Boa running JavaScript only as a fallback.

Self-hosting still means Cloudflare's platform. Local development runs through Cloudflare's wrangler tool, and deployment goes to your own Cloudflare account on the Workers Paid plan, because Kitesurf uses Dynamic Workers to give each page its own isolated Worker. The repository's README calls Kitesurf experimental and describes it as a DevTools Protocol endpoint, not a full Chrome implementation, so some DevTools features do not work yet. It also has no authentication of its own, and a deployed Worker's URL is public by default, so the README tells users to put Cloudflare Access or another authentication layer in front of it straight away.

For teams already automating the web with agents, the release removes the managed API as the only way to use the engine and makes its behavior inspectable, but it does not make Kitesurf a drop-in Chrome replacement. Cloudflare says it is concentrating on compatibility, reliability and efficiency, and publishes its progress on Web Platform Tests, the shared browser conformance suite. That page is the place to check whether the sites an agent depends on are likely to work.