# fourzerotwo

> 400+ data APIs for agents: UK companies, property, trade, tenders, recalls, sanctions. Free tier

- name: si.fourzerotwo/data
- version: 1.2.1
- connection class: R0 (autonomous)
- trust: 82/100 flags: no-repository
- quality: 80/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/si.fourzerotwo%2Fdata
- tools: https://api.protogrid.dev/v1/servers/si.fourzerotwo%2Fdata/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

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

Placeholders to fill: `${X_API_KEY}`.

## Trust

- hygiene: 80
- liveness: 99
- freshness: 100
- provenance: 55
- drivers: +dns-namespace +website +reachable +uptime-97% +updated-9d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 80/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 3 of 3 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 655 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 50 (weight 15)

- pass `stability.changes`: 5 tool changes in 30 days
- fail `stability.rug_pull`: 2 tools kept their name but changed most of their description in 30 days; review before trusting them

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 3, about 655 tokens to load them all
- tool set hash: 3f66373228d1207e3f26a934d6aedda2
- tools last changed: 2026-10-11T23:42:26.578Z
- badge: [![protogrid quality](https://protogrid.dev/badge/si.fourzerotwo/data.svg)](https://protogrid.dev/servers/si.fourzerotwo/data)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

- 2026-10-11 `call_api` changed (description)
  - 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: 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.
- 2026-10-11 `search_apis` changed (description)
  - 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: 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.
- 2026-10-11 `call_api` changed (title, description, inputSchema, outputSchema, annotations) **meaning 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: 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.
- 2026-10-11 `list_apis` added
  - 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.
- 2026-10-11 `search_apis` changed (title, description, inputSchema, outputSchema, annotations) **meaning changed**
  - before: Free. Search the fourzerotwo catalog of data APIs by keyword; returns tool names, prices, free_tier (free/sample/null) and parameters.
  - after: 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: https://api.protogrid.dev/v1/servers/si.fourzerotwo%2Fdata/changes

## Remotes

- https://fourzerotwo.si/mcp (streamable-http, auth none, reachable true, uptime30d 0.9714286)

## Packages

_none_

## Tools (3)

- `call_api`: 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`: 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`: 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.