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8 clients · secrets stay placeholders

JSON (mcpServers)Claude CodeCodexOpenCodeCursorVS CodeGemini CLIGoose

{
  "mcpServers": {
    "data": {
      "type": "http",
      "url": "https://fourzerotwo.si/mcp",
      "headers": {
        "X-API-Key": "${X_API_KEY}"
      }
    }
  }
}

claude mcp add --transport http data https://fourzerotwo.si/mcp --header "X-API-Key: ${X_API_KEY}"

[mcp_servers.data]
url = "https://fourzerotwo.si/mcp"
env_http_headers = { "X-API-Key" = "X_API_KEY" }

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "data": {
      "type": "remote",
      "url": "https://fourzerotwo.si/mcp",
      "enabled": true,
      "headers": {
        "X-API-Key": "{env:X_API_KEY}"
      }
    }
  }
}

{
  "mcpServers": {
    "data": {
      "type": "http",
      "url": "https://fourzerotwo.si/mcp",
      "headers": {
        "X-API-Key": "${X_API_KEY}"
      }
    }
  },
  "deeplink": "cursor://anysphere.cursor-deeplink/mcp/install?name=data&config=eyJ0eXBlIjoiaHR0cCIsInVybCI6Imh0dHBzOi8vZm91cnplcm90d28uc2kvbWNwIiwiaGVhZGVycyI6eyJYLUFQSS1LZXkiOiIke1hfQVBJX0tFWX0ifX0%3D"
}

{
  "servers": {
    "data": {
      "type": "http",
      "url": "https://fourzerotwo.si/mcp",
      "headers": {
        "X-API-Key": "${X_API_KEY}"
      }
    }
  }
}

{
  "mcpServers": {
    "data": {
      "httpUrl": "https://fourzerotwo.si/mcp",
      "headers": {
        "X-API-Key": "${X_API_KEY}"
      }
    }
  }
}

extensions:
  "data":
    enabled: true
    name: "data"
    type: streamable_http
    uri: "https://fourzerotwo.si/mcp"
    headers:
      "X-API-Key": "${X_API_KEY}"
    timeout: 300

Placeholders to fill from your own secret store: ${X_API_KEY}. The registry never accepts secret values.

Quality 80 / 100good

protocol75 · weight 25

warn
protocol.modernnewest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
n/a
protocol.statelessonly applies to 2026-07-28 servers
pass
protocol.transportstreamable HTTP
n/a
protocol.list_ttlonly applies to 2026-07-28 servers

authorizationn/a · weight 15

n/a
auth.prm, auth.as_metadata, auth.cimdno remote uses OAuth
n/a
auth.secret_in_urlno templated URL

tool hygiene100 · weight 30

pass
tools.descriptionsevery tool has a description
pass
tools.description_lengthdescriptions are concise
pass
tools.schemasevery tool has an object input schema
pass
tools.annotations3 of 3 tools declare readOnlyHint or destructiveHint
pass
tools.directory_hintsevery tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
pass
tools.token_costabout 655 tokens to load every tool
pass
tools.api_dumptools are not a one-to-one API dump

stability50 · weight 15

pass
stability.changes5 tool changes in 30 days
fail
stability.rug_pull2 tools kept their name but changed most of their description in 30 days; review before trusting them

dependenciesn/a · weight 15

n/a
deps.known_vulns, deps.mcp_sdk_version, deps.resolvableno npm or PyPI package

3 tools, about 655 tokens to load them all · tool set 3f66373228d1 · tools last changed 2026-10-11 · checked 2026-10-19 10:20 UTC

Tool changes

2026-10-11call_apichangeddescription
before
Run one endpoint by the tool name that search_apis returned, with that endpoint's parameters, and get its data back as JSON (with source and licence attribution). Endpoints with free_tier "free" or "sample" cost nothing within the daily allowance (50 calls/day anonymously, 500 with a free key). Otherwise the result is a payment request: pay in USDC via x402 and retry with _meta["x402/payment"]. Invalid arguments are rejected before any charge, and failed upstream calls are never charged.
after · 97% of words in common
Run one endpoint by the tool name that search_apis returned, with that endpoint's parameters, and get its data back as JSON (with source and licence attribution). Endpoints with free_tier "free" or "sample" cost nothing within the daily allowance (100 calls/day anonymously, 500 with a free key). Otherwise the result is a payment request: pay in USDC via x402 and retry with _meta["x402/payment"]. Invalid arguments are rejected before any charge, and failed upstream calls are never charged.
2026-10-11search_apischangeddescription
before
Find the right data endpoint for a task. Searches 350+ endpoints (UK legislation, Companies House, property prices, sanctions lists, vehicle tax, weather, earthquakes, arXiv/PubMed/Crossref papers, IP geolocation, GB electricity, ONS/World Bank/ECB economics, and more) by keyword and returns each match's tool name, parameters, price and free_tier. Always free to call. Next step: pass a returned tool name to call_api.
after · 97% of words in common
Find the right data endpoint for a task. Searches 500+ endpoints (UK legislation, Companies House, property prices, sanctions lists, vehicle tax, weather, earthquakes, arXiv/PubMed/Crossref papers, IP geolocation, GB electricity, ONS/World Bank/ECB economics, and more) by keyword and returns each match's tool name, parameters, price and free_tier. Always free to call. Next step: pass a returned tool name to call_api.
2026-10-11call_apichangedtitle, description, input schema, output schema, annotationsmeaning changed
before
Call any fourzerotwo endpoint by its tool name (from search_apis). free_tier endpoints work free up to a daily allowance; otherwise paid via x402: the call returns payment requirements, retry with _meta["x402/payment"].
after · 30% of words in common
Run one endpoint by the tool name that search_apis returned, with that endpoint's parameters, and get its data back as JSON (with source and licence attribution). Endpoints with free_tier "free" or "sample" cost nothing within the daily allowance (50 calls/day anonymously, 500 with a free key). Otherwise the result is a payment request: pay in USDC via x402 and retry with _meta["x402/payment"]. Invalid arguments are rejected before any charge, and failed upstream calls are never charged.
2026-10-11list_apisadded
Overview of every API group in the catalog: name, category, summary, number of endpoints and whether it has a free tier. Always free to call. Use it to browse; use search_apis to find a specific endpoint.
2026-10-11search_apischangedtitle, description, input schema, output schema, annotationsmeaning changed
before
Free. Search the fourzerotwo catalog of data APIs by keyword; returns tool names, prices, free_tier (free/sample/null) and parameters.
after · 17% of words in common
Find the right data endpoint for a task. Searches 350+ endpoints (UK legislation, Companies House, property prices, sanctions lists, vehicle tax, weather, earthquakes, arXiv/PubMed/Crossref papers, IP geolocation, GB electricity, ONS/World Bank/ECB economics, and more) by keyword and returns each match's tool name, parameters, price and free_tier. Always free to call. Next step: pass a returned tool name to call_api.

Full history: list_changes · trend: quality JSON.

Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed. How it is computed.

Trust 82 / 100

no-repository

provenance55

liveness99

freshness100

hygiene80

+dns-namespace +website +reachable +uptime-97% +updated-8d-ago -no-repository

Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed. How it is computed.

Endpoints

remote	auth	reachable	uptime 30d	p50	protocol	last ok
`https://fourzerotwo.si/mcp` streamable-http	none	yes	97%	447 ms	2025-11-25	2026-10-19

Tools (3)

`call_api`read-only	Run one endpoint by the tool name that search_apis returned, with that endpoint's parameters, and get its data back as JSON (with source and licence attribution). Endpoints with free_tier "free" or "sample" cost nothing within the daily allowance (100 calls/day anonymously, 500 with a free key). Otherwise the result is a payment request: pay in USDC via x402 and retry with _meta["x402/payment"]. Invalid arguments are rejected before any charge, and failed upstream calls are never charged.
`list_apis`read-only	Overview of every API group in the catalog: name, category, summary, number of endpoints and whether it has a free tier. Always free to call. Use it to browse; use search_apis to find a specific endpoint.
`search_apis`read-only	Find the right data endpoint for a task. Searches 500+ endpoints (UK legislation, Companies House, property prices, sanctions lists, vehicle tax, weather, earthquakes, arXiv/PubMed/Crossref papers, IP geolocation, GB electricity, ONS/World Bank/ECB economics, and more) by keyword and returns each match's tool name, parameters, price and free_tier. Always free to call. Next step: pass a returned tool name to call_api.

Schemas: list_tools.

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Official server.json

{
  "name": "si.fourzerotwo/data",
  "title": "fourzerotwo",
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "remotes": [
    {
      "url": "https://fourzerotwo.si/mcp",
      "type": "streamable-http",
      "headers": [
        {
          "name": "X-API-Key",
          "isSecret": true,
          "description": "Optional free key from https://fourzerotwo.si/free (raises the free allowance from 100 to 500 calls/day)"
        }
      ]
    }
  ],
  "version": "1.2.1",
  "websiteUrl": "https://fourzerotwo.si",
  "description": "400+ data APIs for agents: UK companies, property, trade, tenders, recalls, sanctions. Free tier"
}