Allows looking up CSS specifications (e.g., css-grid-1) and provides details such as status, working groups, and official URLs.
Allows looking up SVG specifications and provides details such as status, working groups, and official URLs.
Allows looking up WebAuthn specifications and provides details such as status, working groups, and official URLs.
Click on "Install Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@mcp-w3c What spec defines the CSS grid layout?"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
W3C MCP — web-standards lookup over w3c/browser-specs (GitHub, CF-reachable).
Part of Pipeworx — an MCP gateway connecting AI agents to 1476+ live data sources.
Tool | Description |
| Find W3C / web-standards specifications by keyword or topic — HTML, CSS, WCAG accessibility, DOM, SVG, WAI-ARIA, WebAuthn, Fetch, and 800+ others. Answers "what W3C spec defines X", "the CSS grid specification", "web accessibility standard", "which spec covers custom elements". Returns specs with shortname, title, status (Recommendation / Working Draft / Living Standard), organization, and official URL. Example: w3c_search({ query: "flexbox" }). |
| Detail for one web-standards spec by shortname ("WCAG21", "css-grid-1", "html") or title fragment ("web content accessibility"). Returns title, status, organization (W3C/WHATWG), working groups, series, official URL, editor's-draft URL. Example: w3c_spec({ spec: "WCAG21" }). Accepts shortname/name/title too. |
Related MCP server: w3c-mcp
Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):
{
"mcpServers": {
"w3c": {
"url": "https://gateway.pipeworx.io/w3c/mcp"
}
}
}tools/list at https://gateway.pipeworx.io/w3c/mcp returns the tools in the table
above plus the shared Pipeworx meta-tools — ask_pipeworx,
discover_tools, search_within, remember/recall and the rest of the
gateway-wide set. So the tool count you see is larger than this table: a
single-pack endpoint currently lists roughly 30 shared tools alongside the
pack's own. The connection's initialize response states its exact scope, and
is the authoritative answer for a given day.
This is deliberate, not multiplexing by accident. The meta-tools are what let a
scoped connection answer a question this pack does not cover — via
ask_pipeworx, which routes across the whole catalog — without you adding a
second MCP server. There is currently no way to mount a pack endpoint without
them; if the extra schemas cost you more context than the routing is worth,
connect to the full gateway once rather than to several pack endpoints.
Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:
{
"mcpServers": {
"pipeworx": {
"url": "https://gateway.pipeworx.io/mcp"
}
}
}Both URLs reach the same gateway and the same 1476+ data sources. The
only difference is which pack's tools are listed directly; ask_pipeworx
reaches all of them from either one.
Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:
ask_pipeworx({ question: "your question about W3c data" })The gateway picks the right tool and fills the arguments automatically.
MIT
This server cannot be installed
Unclaimed servers have limited discoverability.
If you are the server author, to access and configure the admin panel.
Web search, fetch, extract, and research for AI agents. Markdown output + AI-synthesized answers.
Provides AI assistants with access to Seltz's powerful Web Search capabilities.
Web data tools for AI agents: pages as markdown, search, maps, commerce, jobs, AI answers.
The best web search for your AI Agent
