Agents and WebMCP

▶ Watch (9:41)

WebMCP transforms HTML forms and JavaScript functions into tools that agents can call. Developers add tool-description attributes to forms or use navigator.modelcontext.registerTool. The agent matches user intent with available tools. Expedia integrated WebMCP for hotel search. Chrome 149 origin trial begins June 2. Paul ran a demo where an agent turned off lights and rebooted a computer. WebMCP runs inside the browser, preserving sign-in state and cookies.

Modern Web Guidance

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Modern web guidance is a skills pack that injects validated, evergreen platform knowledge into AI coding tools. Install with mpx modern-web-guidance install. It includes skills for performance, identity, security, and over 100 common use cases. The guidance respects baseline, suggesting fallbacks and progressive enhancements when a feature isn’t widely available. A new Google Analytics integration lets you compute your user-specific baseline target at baseline-checker.chrome.dev.

DevTools for Agents

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DevTools for agents is an MCP server that gives AI tools access to console logs, network traffic, memory traces, the accessibility tree, and Lighthouse audits. New features include skills for complex tasks like heap snapshots, a CLI version for token efficiency, a TypeScript API for CI, multi-instance support for multi-user testing, and automatic Chrome extension debugging. Agents can connect to a running instance and pick up where you left off.

Platform Features: 52 New Baseline APIs

▶ Watch (26:03)

55 features became baseline widely available since last year; 52 more are baseline newly available as of this morning. View transitions, the navigation API, and cross-browser Core Web Vitals (LCP, INP) are among them. View transitions replace JavaScript animation libraries for smooth page transitions. The navigation API unifies history management into one event. Core Web Vitals now work on iOS. Use baseline alerts at web-status.dev to track features entering browsers.

New Rendering Capabilities

▶ Watch (34:27)

Declarative partial updates let HTML be rendered out of order without JavaScript. A clock demo updates every second using only this API. Critical content renders first; menus can be patched in later. The streaming API for dynamic markup, available in Chrome 148, injects HTML directly from fetch responses — no JSON transform needed. HTML and canvas renders standard DOM into a canvas element, enabling 3D experiences with full accessibility, translation, and search. It integrates with Three.js and PlayCanvas.

Notable Quotes

I actually nearly quit programming before I even started because I didn’t realize American English was a thing and that you spelled color incorrectly without a U. Paul Kinlan · ▶ Watch (3:49)

This to me marks one of the most significant shifts in computing since the invention of the web. Paul Kinlan · ▶ Watch (5:30)

I think it’s one of the biggest changes to HTML in a decade. Paul Kinlan · ▶ Watch (34:27)

I would like to make HTML the new JSON. Paul Kinlan · ▶ Watch (35:51)

You can probably tell I’m quite excited for the future of the web platform. Paul Kinlan · ▶ Watch (40:56)

Key Takeaways

  • WebMCP turns HTML forms and JS functions into agent tools; origin trial starts June 2.
  • Modern web guidance gives AI coding tools validated, evergreen platform knowledge.
  • 52 new baseline APIs include view transitions and cross-browser Core Web Vitals.