Cloudflare 推出 Kitesurf：一款为 AI Agent 打造的云端浏览器

Cloudflare 成为最新一家加入新一代浏览器竞赛的公司。但这家互联网基础设施提供商并非向消费者推销 Chrome 替代品，而是推出了 Kitesurf——一款专门为 AI Agent 设计、托管于云端的浏览器。

AI 软件正在从能够回答问题的聊天机器人，演进为能够代表用户完成任务的 Agent。浏览器是这一转变的关键组成部分，因为这些 Agent 需要像人类一样浏览互联网并使用网站。

Cloudflare 在其公告中解释称，与为人类设计的传统网页浏览器不同，为 AI Agent 打造的浏览器并不关注主题、标签页或浏览器扩展等视觉元素。面向 AI Agent 的浏览器需要管理上下文窗口、性能、Token 成本和可扩展性。该公司指出，它还面临不同的威胁模型，因为 AI 浏览器可能遭受提示词注入攻击等漏洞的影响。

借助 Kitesurf，AI 开发者将能够构建可浏览网站、填写表单及完成其他基于浏览器任务的软件，而无需自行开发浏览器软件。

Cloudflare 表示，公司仅在 12 周前决定开发 Kitesurf，该浏览器完全构建于其名为 Workers 的无服务器平台之上。Kitesurf 目前在测试阶段可通过 Browser Run 免费使用；Browser Run 允许开发者以编程方式控制并与 Cloudflare 网络上的无头浏览器实例交互。

对于开发者而言，Cloudflare 的核心卖点是：这使 AI Agent 能够以更高效率使用互联网，同时比 Chromium 消耗更少的计算资源，从而降低成本。

“在截图和 HTML 提取等常见 Agent 任务中，Kitesurf 的 CPU 和内存消耗显著低于 Chromium。”该公司表示。

图片来源： Cloudflare

该浏览器本身基于多项其他技术构建，包括来自 Blitz 的模块化渲染引擎、Firefox 的 CSS 解析器 Stylo，以及 Rust ECMAScript 引擎 Boa JS。其余所有组件均运行在 Cloudflare Workers 内部。尽管仍处于早期阶段，Cloudflare 表示，Kitesurf 已通过约 215,000 多项 Web 平台测试，并且每周都会新增通过数百项测试。

Cloudflare 还表示，开源 Rust 无头引擎 Obscura 为其开发 Kitesurf 提供了灵感；该项目最初的概念验证版本，是将 Obscura 移植到 Workers 上。

该公司称，该浏览器能够正确渲染 TodoMVC 等页面。TodoMVC 是用于比较 JavaScript 框架的热门基准应用。此外，Kitesurf 还能够正确渲染 Wikipedia、Hacker News、Cloudflare Blog，以及 Cloudflare 控制面板的大部分内容。

Cloudflare is the latest company to join the race to build a new web browser. But instead of pitching a Chrome alternative to consumers, the internet infrastructure provider launched Kitesurf, a cloud-hosted browser designed specifically for AI agents.

AI software is evolving from chatbots that answer questions to agents that can complete tasks on users’ behalf. Browsers are a critical part of this transition, as they’ll need to navigate the web and use websites, as humans do.

Unlike traditional web browsers built for humans, a browser built for AI agents doesn’t care about visual elements, like themes, tabs, or browser extensions, Cloudflare explained in its announcement. A browser designed for AI agents needs to manage context windows, performance, token costs, and scalability. It also faces a different threat model because an AI browser could be subject to vulnerabilities like prompt injection attacks and more, the company noted.

With Kitesurf, AI developers will be able to build software that can navigate websites, fill out forms, and complete other browser-based tasks, without having to build their own browser software.

Cloudflare says it decided to build Kitesurf just 12 weeks ago, and it runs entirely on top of the company’s serverless platform, called Workers. Kitesurf is available for free while in beta in Browser Run, which lets developers programmatically control and interact with headless browser instances on Cloudflare’s network.

For developers, Cloudflare’s pitch is that this enables AI agents to use the web more efficiently while using less computing power than Chromium, which keeps costs down.

“Kitesurf is significantly more efficient in CPU and memory consumption than Chromium for common agentic tasks like screenshots and HTML extraction,” according to the company.

Image Credits: Cloudflare

The browser itself was built from other technologies, including a modular rendering engine from Blitz; Firefox’s CSS parser, Stylo; and Boa JS, a Rust ECMAScript engine. Everything else runs inside Cloudflare Workers. Although still new, Cloudflare says Kitesurf already passes around 215,000+ web platform tests, and it’s adding hundreds more, passing tests every week.

Cloudflare also credited the open source Rust headless engine, Obscura, for inspiring it to develop Kitesurf, noting that the first proof of concept was a port of Obscura to Workers.

The company said the browser correctly renders pages like TodoMVC, a popular benchmark application for comparing JavaScript frameworks, along with Wikipedia, Hacker News, the Cloudflare Blog, and much of the Cloudflare dashboard.