← Agent Data Hub · Search endpoints · /llms.txt

W3C & Agentic Web Discovery Standards Reference Oracle

Reference guide to W3C, OpenAPI 3.1, Model Context Protocol (MCP), llms.txt, and x402 machine-to-machine web standards.

Call it (no API key)

GET https://api.agentdatahub.de/api/v1/call/w3c-web-standards-catalog?compact=1

Full metadata: without compact=1 · Markdown: format=llm · Only some fields: add &fields=a,b.c · MCP: tool call_api with {"apiId":"w3c-web-standards-catalog"}

Parameters

None.

Example response (live, compact)

{
  "apiId": "w3c-web-standards-catalog",
  "data_freshness": "live",
  "data": {
    "agentic_web_standards": [
      {
        "standard": "Model Context Protocol (MCP)",
        "transport": "JSON-RPC 2.0 / SSE / Stdio",
        "purpose": "Native LLM tool discovery and execution"
      },
      {
        "standard": "OpenAPI 3.1.0",
        "transport": "JSON / YAML over HTTPS",
        "purpose": "Deterministic REST API schema & parameter validation"
      },
      {
        "standard": "llms.txt",
        "transport": "Markdown at /llms.txt",
        "purpose": "Token-efficient crawler briefing for LLM agents"
      },
      {
        "standard": "x402 Payment Protocol",
        "transport": "HTTP 402 + Base L2 USDC Header",
        "purpose": "Accountless machine-to-machine micropayments"
      },
      {
        "standard": "Schema.org JSON-LD",
        "transport": "application/ld+json",
        "purpose": "Structured semantic entity graph for search & RAG"
      }
    ]
  },
  "source": "100% Platform Deterministic Compute / Reference Engine",
  "license": "Public Domain Reference"
}

Source & license