fourzerotwo

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.

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "description": "Keywords describing the data you need; every word must match. Examples: \"postcode\", \"sanctions screen\", \"sold prices\", \"earthquake\", \"bank holiday\"."
    },
    "category": {
      "type": "string",
      "description": "Optional category filter, e.g. \"legal\", \"property\", \"finance\", \"research\", \"energy\", \"network\". See list_apis for all categories."
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 50,
      "default": 20,
      "description": "Maximum results (default 20)."
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "total": {
      "type": "integer"
    },
    "results": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "tool": {
            "type": "string"
          },
          "api": {
            "type": "string"
          },
          "endpoint": {
            "type": "string"
          },
          "description": {
            "type": "string"
          },
          "category": {
            "type": "string"
          },
          "price_usd": {
            "type": "string"
          },
          "free_tier": {
            "type": [
              "string",
              "null"
            ],
            "enum": [
              "free",
              "sample",
              null
            ]
          },
          "params": {
            "type": "array"
          }
        },
        "required": [
          "tool",
          "api",
          "endpoint",
          "price_usd"
        ]
      }
    }
  },
  "required": [
    "total",
    "results"
  ]
}

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.

{
  "type": "object",
  "properties": {
    "category": {
      "type": "string",
      "description": "Optional category filter, e.g. \"property\"."
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "categories": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "apis": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "slug": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "category": {
            "type": "string"
          },
          "summary": {
            "type": "string"
          },
          "endpoints": {
            "type": "integer"
          },
          "free_tier": {
            "type": "boolean"
          }
        },
        "required": [
          "slug",
          "name",
          "category",
          "endpoints"
        ]
      }
    }
  },
  "required": [
    "categories",
    "apis"
  ]
}

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.

{
  "type": "object",
  "properties": {
    "tool": {
      "type": "string",
      "pattern": "^[a-z0-9-]+__[a-z0-9-]+$",
      "description": "Endpoint tool name from search_apis, e.g. \"uk-postcodes__lookup\" or \"sanctions__screen\"."
    },
    "arguments": {
      "type": "object",
      "description": "The endpoint's parameters as listed in search_apis results, e.g. {\"postcode\": \"SW1A 1AA\"}.",
      "additionalProperties": true
    }
  },
  "required": [
    "tool"
  ],
  "additionalProperties": false
}

{
  "type": "object",
  "description": "The endpoint's JSON response. Proxied sources return {data, source{name, licence, attribution}}; first-party endpoints return their own documented object. List responses are wrapped as {result: [...]}.",
  "additionalProperties": true
}