Jb Mdn

jb-mdn

Use the official MDN MCP server through a persistent mcporter server config for current web platform docs and browser compatibility, while avoiding a direct MCP connection in the agent harness.

Server URL: https://mcp.mdn.mozilla.net/ Configured name: mdn

When to use

• Questions about CSS, HTML, JavaScript, DOM, Web APIs, browser features, or web standards.
• Browser compatibility, Baseline, or “can I use this?” checks.
• New or recently shipped platform features where model memory may be stale.
• Implementation work where exact MDN examples, syntax, or compatibility tables matter.

Setup

Persist the official MDN MCP server in mcporter once per project or machine:

# Project-local config, preferred for repo-specific agent workflows
mcporter config add mdn https://mcp.mdn.mozilla.net/ --description "Official MDN Web Docs MCP server"

# Or global/home config when you want it everywhere
mcporter config add mdn https://mcp.mdn.mozilla.net/ --scope home --description "Official MDN Web Docs MCP server"

Verify:

mcporter config get mdn
mcporter list mdn --schema

Quick commands

# Inspect available MDN MCP tools
mcporter list mdn --schema

# Search MDN
mcporter call mdn.search query="view transition"

# Fetch an MDN documentation page as markdown
mcporter call mdn.get-doc path="/en-US/docs/Web/CSS/Reference/At-rules/@view-transition"

# Fetch browser compatibility data by BCD key
mcporter call mdn.get-compat key="css.at-rules.view-transition"

Prefer --output json when parsing results programmatically:

mcporter call mdn.search query="popover attribute" --output json

Workflow

1. Search first when you do not know the exact MDN path or BCD key.
2. Fetch docs with get-doc for syntax, examples, notes, and links.
3. Fetch compatibility with get-compat for support tables and Baseline claims.
4. Cite what you used in the final answer: MDN page path/URL and compatibility key when relevant.

Tool names

The server currently exposes:

• search — search MDN documentation by query.
• get-doc — retrieve an MDN page as markdown. Takes a docs path or full URL.
• get-compat — retrieve MDN Browser Compatibility Data. Takes a BCD feature key like api.fetch, javascript.builtins.Promise, or css.properties.display.

Guardrails

• Do not rely on memory for current browser support when MDN MCP can answer it.
• Treat the MDN MCP server as experimental; if a call fails, retry once, then fall back to fetch_content or web search and mention the fallback.
• Use the official remote HTTP server above, not an unofficial local MDN package, unless the user explicitly asks.
• Prefer a persistent mcporter config named mdn; do not wire MDN directly into Claude, Codex, Pi, Cursor, or other harness MCP configs unless the user explicitly asks.