{
  "openapi": "3.1.0",
  "info": {
    "title": "EPC Rating Lookup by Postcode API",
    "description": "Returns the registered Energy Performance Certificate for a single address, looked up by postcode or certificate number. Pre-launch design; endpoints are not live yet.",
    "version": "0.1.0",
    "x-planned-pricing": {
      "model": "free tier for evaluation, paid tiers by volume",
      "status": "planned; nothing charged before launch"
    }
  },
  "servers": [
    {
      "url": "https://openapiregistry.com/api/v1/epc-rating-lookup",
      "description": "Pre-launch: endpoints are not live yet and answer 503."
    }
  ],
  "security": [
    {
      "ApiKeyAuth": []
    }
  ],
  "paths": {
    "/ratings": {
      "get": {
        "summary": "Look up an EPC rating",
        "description": "Returns the registered energy certificate for a property matched by postcode or certificate number.",
        "tags": [
          "climate/energy"
        ],
        "operationId": "epc-rating-lookup-get-ratings",
        "parameters": [
          {
            "name": "postcode",
            "in": "query",
            "required": false,
            "description": "Property postcode used to find the registered certificate.",
            "schema": {
              "type": "string"
            }
          },
          {
            "name": "certificateNumber",
            "in": "query",
            "required": false,
            "description": "The EPC certificate number used to look up a specific record.",
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Certificate details returned.",
            "content": {
              "application/json": {
                "example": {
                  "rating": "C",
                  "score": 68,
                  "certificateNumber": "1234-5678-9012-3456-7890",
                  "address": "1 High Street, Bristol"
                },
                "schema": {
                  "type": "object",
                  "properties": {
                    "rating": {
                      "type": "string",
                      "description": "The energy rating band (A to G)."
                    },
                    "score": {
                      "type": "number",
                      "description": "The energy efficiency score."
                    },
                    "certificateNumber": {
                      "type": "string",
                      "description": "The registered certificate number."
                    },
                    "address": {
                      "type": "string",
                      "description": "The address the certificate is registered to."
                    }
                  }
                }
              }
            }
          },
          "404": {
            "description": "No certificate found for the supplied postcode or certificate number."
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "ApiKeyAuth": {
        "type": "apiKey",
        "in": "header",
        "name": "X-API-Key",
        "description": "Planned for launch: an API key issued on request. Free tier for evaluation, paid tiers by volume; nothing is charged before launch."
      }
    }
  }
}