Look up HTTP status codes, MIME types, periodic table elements, and convert units via @cyanheads/reference-data-mcp-server (npx)

{
  "server": "@cyanheads/[email protected]",
  "transport": "stdio",
  "launch": "npx -y @cyanheads/reference-data-mcp-server",
  "tools_count": 10,
  "tools": ["ref_geo_lookup", "ref_geo_search", "ref_timezone_lookup", "ref_timezone_convert", "ref_element_lookup", "ref_element_search", "ref_constant_lookup", "ref_unit_convert", "ref_http_status", "ref_mime_type"],
  "total_calls": 34,
  "success_rate": "30/34 (88% — 4 correct rejections)",
  "p50_ms": 1,
  "gotchas": ["Country 'Turkey' not found — use alpha-2 'TR' (dataset uses 'Türkiye')", "ref_timezone_lookup by param: only 'iana'/'country'/'auto' — no 'city'", "GB→MB returns 1024 (binary prefix)", "Temperature units: single letter C/F/K", "Fuzzy constant matching warns about imprecise queries", "Output is formatted Markdown with emoji flags, not raw JSON"],
  "sample_calls": [
    {
      "tool": "ref_geo_lookup",
      "input": {
        "query": "JP",
        "by": "alpha2"
      },
      "output_summary": "Japan, Tokyo, JPY, .jp",
      "ms": 1,
      "success": true
    },
    {
      "tool": "ref_element_lookup",
      "input": {
        "query": "118",
        "by": "number"
      },
      "output_summary": "Oganesson Og, noble gas, radioactive",
      "ms": 1,
      "success": true
    },
    {
      "tool": "ref_constant_lookup",
      "input": {
        "query": "speed of light"
      },
      "output_summary": "c = 299792458 m/s, exact",
      "ms": 0,
      "success": true
    },
    {
      "tool": "ref_unit_convert",
      "input": {
        "value": 42.195,
        "from": "km",
        "to": "mi"
      },
      "output_summary": "26.2189 mi",
      "ms": 0,
      "success": true
    },
    {
      "tool": "ref_http_status",
      "input": {
        "query": "teapot"
      },
      "output_summary": "418 I'm a Teapot, RFC 2324",
      "ms": 1,
      "success": true
    },
    {
      "tool": "ref_mime_type",
      "input": {
        "query": "pdf"
      },
      "output_summary": "application/pdf, not compressible",
      "ms": 1,
      "success": true
    },
    {
      "tool": "ref_timezone_convert",
      "input": {
        "datetime": "2026-06-22T10:00:00",
        "from_tz": "America/New_York",
        "to_tz": "Asia/Tokyo"
      },
      "output_summary": "23:00 Tokyo (+9), correct 13h offset",
      "ms": 1,
      "success": true
    },
    {
      "tool": "ref_constant_lookup",
      "input": {
        "query": "Boltzmann"
      },
      "output_summary": "k_B = 1.381e-23 J/K, exact",
      "ms": 2,
      "success": true
    }
  ]
}

{
  "server": "@cyanheads/[email protected]",
  "transport": "stdio",
  "launch": "MCP_TRANSPORT_TYPE=stdio npx -y @cyanheads/[email protected]",
  "tools_count": 10,
  "calls": [
    {
      "tool": "ref_http_status",
      "input": {
        "query": "418"
      },
      "output": {
        "code": 418,
        "reason_phrase": "I'm a Teapot",
        "category": "4xx Client Error",
        "rfc": "RFC 2324",
        "rfc_section": "2.3.2"
      },
      "success": true
    },
    {
      "tool": "ref_element_lookup",
      "input": {
        "query": "gold"
      },
      "output": {
        "number": 79,
        "symbol": "Au",
        "name": "Gold",
        "atomic_mass": 196.97,
        "category": "transition metal",
        "density_g_per_cm3": 19.3,
        "melting_point_k": 1337.33
      },
      "success": true
    },
    {
      "tool": "ref_mime_type",
      "input": {
        "query": ".json"
      },
      "output": {
        "type": "application/json",
        "extensions": ["json", "map"],
        "compressible": true,
        "source": "iana"
      },
      "success": true
    },
    {
      "tool": "ref_unit_convert",
      "input": {
        "value": 100,
        "from": "km",
        "to": "mi"
      },
      "output": {
        "result": 62.137121212121215,
        "result_precision": "62.1371",
        "measure": "length"
      },
      "success": true
    }
  ],
  "success_rate": "4/4 (100%)"
}