Software & DevOpsDone with Claude Code Oct 9, 2025
Write better CSS with an MDN-aware helper
An MCP server that consults MDN docs, reports browser compatibility, and analyzes your CSS for the agent.
- What They Did
- You add the server to Claude Code, VS Code or another MCP client with an npx command. The agent can then call tools to fetch MDN docs for a CSS feature, pull browser compatibility data, and analyze pasted CSS or a project's built CSS files. Analysis returns a short summary by default, and you ask in plain language.
- How It Went
- The README gives no real-world results. It lists first fetches at about 400-500ms and cached ones at about 100ms. Summary analysis costs roughly 1-2k tokens.
- Worth Knowing
- Full 150+ metric analysis uses about 10k+ tokens, so keep the default summary mode. It needs Node 20+ and native build tools for the SQLite cache.
Try it yourself with Claude Code
Review the CSS in [path to stylesheet or project] and check each questionable property or feature against MDN docs for browser support in [browsers, e.g. the last 2 versions of Safari and Chrome]. Fix issues you find, like unsupported properties or redundant rules, and explain each change. Finish with a short compatibility report listing what's safe to ship and what needs a fallback.