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The road to the agentic browser: Kitesurf gets WebMCP, terminal rendering, and 730,000+ passing tests

Cloudflare Blog ★★★★ View Markdown
#cloudflare#ai#serverless

Hi everyone, Shii-chan here! Today's news is a big step forward for browsers built for agents.

Cloudflare Blog blog.cloudflare.com

What was announced?

The Cloudflare Blog covers an update to Kitesurf, Cloudflare's Workers-based browser for AI agents. The highlights are WebMCP support, improved DOM performance, and terminal-based rendering.

Why it matters

For agents to handle complex sites, the browser has to support enough web standards. Kitesurf now passes over 730,000 Web Platform Tests subtests, up by 500,000 since launch.

What changes

  • Sites can expose their functionality directly to agents, so agents don't need to click pixels
  • More web standards are supported, so complex sites are easier to handle
  • You can browse pages without leaving your terminal

Dive Deep

Let's break it down:

  • WebMCP: sites can turn it on with a single switch. In the Cloudflare Radar example, tools like navigate-to and set-location let agents drive the page
  • More web standards: CSS Layout, CSSOM, CSS Typed OM, and custom elements. It also handles URL-based module resolution, JSON modules, and import maps, which matter for sites that load JavaScript in chunks. Iframe timing, isolation, and multilingual text rendering improved too
  • Performance: fewer trips across the Boa-to-DOM boundary, streamlined timer handling, and font loading that fetches only the characters and language-specific files it needs cut latency in the agent loop. Wall-clock time and CPU usage stay in line with launch benchmarks despite the added capability
  • Browser Run integration: full Browser Run API coverage, including CDP, Playwright, Puppeteer, and MCP. Quick Actions can be called from a Worker binding with env.BROWSER.quickAction()
  • Terminal rendering: PageRenderer is decoupled, so pages can render via the Kitty graphics protocol or ANSI text mode. You can install it with Homebrew:
brew install cloudflare/cloudflare/kitesurf

Kitesurf is free during the beta, with per-account limits. You can use it through the kitesurf.dev playground and Browser Run, and open sourcing is planned soon.

Wrap-up

  • WebMCP support lets sites expose functionality directly to agents
  • Passes over 730,000 Web Platform Tests subtests
  • Renders in the terminal and installs with Homebrew
  • Free in beta, with open sourcing planned

This one is for people building browser agents, and for terminal lovers!

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