English Français العربية

W3c

Registre officiel Outils de développement

W3C MCP — web-standards lookup over w3c/browser-specs (GitHub, CF-reachable).

Code source Site web Documentation

Installation

Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http w3c 'https://gateway.pipeworx.io/w3c/mcp'
Configuration JSON (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "w3c": {
            "type": "http",
            "url": "https://gateway.pipeworx.io/w3c/mcp"
        }
    }
}

Documentation

Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.

Sommaire
  1. mcp-w3c
  2. Tools
  3. Quick Start
  4. No MCP client? Call it over HTTP
  5. Standalone (no gateway account)
  6. Using with ask_pipeworx
  7. More
  8. License

mcp-w3c

W3C MCP — web-standards lookup over w3c/browser-specs (GitHub, CF-reachable).

Part of Pipeworx — an MCP gateway connecting AI agents to 1679+ live data sources.

Tools

ToolDescription
w3c_searchFind 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" }).
w3c_specDetail 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.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "w3c": {
      "url": "https://gateway.pipeworx.io/w3c/mcp"
    }
  }
}
What this endpoint actually serves

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 1679+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/w3c_search \
  -H 'Content-Type: application/json' \
  -d '{"query":"flexbox"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/w3c_search. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "w3c": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-w3c"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-w3c

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

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.

More

License

MIT

Questions fréquentes

Qu'est-ce que W3c ?

W3C MCP — web-standards lookup over w3c/browser-specs (GitHub, CF-reachable).

Comment installer W3c ?

Il fonctionne comme serveur distant. Dans Claude Code : claude mcp add --transport http w3c 'https://gateway.pipeworx.io/w3c/mcp'. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.

Faut-il une clé API pour W3c ?

Son entrée au registre n'indique aucune clé ni secret obligatoire. Certaines fonctions peuvent tout de même demander un compte auprès du service auquel il se connecte.

W3c est-il open source ?

Oui. Son code est sur GitHub sous licence MIT.

Qui maintient W3c ?

Il est publié par pipeworx-io. AI.tn le référence sans le maintenir ni le recommander.

Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.