{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "ErrorResponse",
  "description": "Standard error envelope returned by ExchangeRate-API.",
  "type": "object",
  "properties": {
    "result": {
      "type": "string",
      "description": "Status indicator (error).",
      "const": "error"
    },
    "documentation": {
      "type": "string",
      "format": "uri",
      "description": "Link to API documentation."
    },
    "terms_of_use": {
      "type": "string",
      "format": "uri",
      "description": "Link to terms of use."
    },
    "error-type": {
      "type": "string",
      "description": "Machine-readable error code.",
      "enum": [
        "unsupported-code",
        "malformed-request",
        "invalid-key",
        "inactive-account",
        "quota-reached",
        "plan-upgrade-required",
        "no-data-available"
      ]
    }
  },
  "required": ["result", "error-type"]
}