Modern Web Guidance, an open-source set of skills for AI coding agents, has been published under the GoogleChrome organization on GitHub. The project's README says it is stewarded by the Google Chrome, Microsoft Edge, Mozilla Firefox and MDN teams, alongside the web development community. It drew wide attention on Hacker News on November 10.
The project describes itself as "a set of skills that embed web platform expertise, best practices, and browser compatibility data" into agents, so they use features that browsers support today instead of older patterns common in their training data. It covers 250 modern web features: 140 in CSS and layout, 36 in HTML and DOM, and 74 in JavaScript and APIs. It also covers 203 real-world use cases across areas including accessibility, forms, performance, security, privacy, built-in AI and UI components. The guides are written to be token-efficient, with content trimmed using evals.
Installation runs through an interactive wizard started with npx modern-web-guidance@latest install. The repository includes plugin manifests for Claude Code, Codex, Cursor, Gemini CLI, Grok and Kimi. A command-line tool can also search the guides, fetch a guide by ID, and run a legacy scan that finds outdated patterns in an existing codebase.
The project is released under the Apache-2.0 license and needs no API key. For teams using agents to write front-end code, it is a ready-made fix for a common complaint: agents reaching for polyfills, heavy libraries or deprecated APIs where a native browser feature would do. The legacy scan gives teams a way to find code that agents have already written that way.