Cloudflare’s Kitesurf agent browser adds WebMCP support, passes 730,000+ WPT subtests
Cloudflare's Kitesurf agent browser now supports WebMCP and passes 730,000+ Web Platform Tests subtests, up 500,000 since launch, the company says.
Cloudflare’s Kitesurf, the browser for AI agents that runs entirely on Cloudflare Workers, now supports WebMCP, the company announced in a September 28 update. The project was introduced in August as a browser built around what agents need from the web rather than the features of a browser designed for humans.
WebMCP lets developers expose site functionality directly to agents, so an agent can call a function like searchFlights() instead of simulating clicks. Cloudflare says it has supported WebMCP since its early days, and that site owners can now turn it on with one switch, letting browser agents discover and use tools on their sites without changing the site’s code.
You can try it in Cloudflare’s public Kitesurf playground: open Cloudflare Radar and go to WebMCP on the Application tab in the DevTools panel. According to Cloudflare, Radar exposes WebMCP tools such as navigate-to and set-location that let clients interact with the page programmatically.
More browser standards, more tests passing
Since launch, Cloudflare says it has added browser standards so agents can render more sophisticated pages. The supported API list now includes WebMCP, CSS Layout, CSS Object Model (CSSOM), CSS Typed OM and custom elements. The company also added URL-based module resolution, JSON modules and import map handling — useful for sites that load JavaScript in chunks — and is using the new Cloudflare Workers module registry to support imports from URLs.
Iframe behavior has improved too: Cloudflare says iframes now load at the right time, stay better isolated, and display text correctly across more languages and encodings.
On quality, Cloudflare reports that Kitesurf now passes more than 730,000 Web Platform Tests (WPT) subtests, up 500,000 from when it launched. WPT is a shared, open-source suite that checks whether browsers implement web standards consistently.
What Cloudflare says comes next
The post, written by Celso Martinho, says the team has put Kitesurf through increasingly realistic tasks and used internal and external customer feedback to make it more capable and more efficient, and that the next focus is efficiency optimized for agents — measured by the latency of the agentic loop rather than page load speed. The announcement stops short of detailing those changes.
To point an AI agent at Kitesurf, Cloudflare shows a configuration using the Chrome DevTools MCP package with a WebSocket endpoint at wss://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/browser-run/devtools/browser?browser=kitesurf, a bearer token header and the --category-experimental-webmcp flag. Cloudflare says documentation on using WebMCP with Kitesurf and Browser Run is available, and the playground is open for testing today.
Related reading
Sources
- The road to the agentic browser: A Kitesurf update — Cloudflare Blog
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