List HIP-4 questions

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "listHip4Questions query parameters",
  "type": "object",
  "properties": {
    "cursor": {
      "description": "Question ID cursor for pagination.",
      "type": "integer",
      "format": "int64",
      "x-parameter-location": "query"
    },
    "limit": {
      "description": "Maximum number of results (default: 100, max: 1000)",
      "type": "integer",
      "default": 100,
      "maximum": 1000,
      "x-parameter-location": "query"
    }
  }
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "listHip4Questions response 200",
  "description": "API response containing HIP-4 questions.",
  "type": "object",
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "description": "HIP-4 question grouping for one or more outcome markets.",
        "type": "object",
        "properties": {
          "class": {
            "description": "Question class.",
            "type": "string",
            "nullable": true,
            "example": "priceBinary"
          },
          "created_at": {
            "type": "string",
            "format": "date-time",
            "nullable": true
          },
          "display_title": {
            "description": "Display title for UIs and generated clients.",
            "type": "string",
            "nullable": true
          },
          "outcome_ids": {
            "description": "Outcome IDs grouped by this question.",
            "type": "array",
            "items": {
              "type": "integer",
              "format": "int64"
            }
          },
          "question_id": {
            "description": "Question identifier.",
            "type": "integer",
            "format": "int64",
            "example": 0
          },
          "slug": {
            "description": "Question slug when available.",
            "type": "string",
            "nullable": true,
            "example": "btc-above-78213-may-04-0600"
          },
          "title": {
            "description": "Human-readable question title.",
            "type": "string",
            "nullable": true,
            "example": "BTC above 78,213 on May 4 at 06:00 UTC?"
          },
          "underlying": {
            "description": "Underlying asset for price-binary questions.",
            "type": "string",
            "nullable": true,
            "example": "BTC"
          },
          "updated_at": {
            "type": "string",
            "format": "date-time",
            "nullable": true
          }
        },
        "additionalProperties": true
      }
    },
    "meta": {
      "description": "Response metadata",
      "type": "object",
      "properties": {
        "count": {
          "description": "Number of records returned",
          "type": "integer"
        },
        "next_cursor": {
          "description": "Cursor for pagination (timestamp). Use this value as the `cursor` parameter to fetch the next page of results.",
          "type": "string",
          "nullable": true
        },
        "request_id": {
          "description": "Unique request ID for support",
          "type": "string",
          "format": "uuid"
        }
      }
    },
    "success": {
      "type": "boolean",
      "example": true
    }
  }
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "listHip4Questions response 400",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}

{
  "code": 400,
  "error": "Invalid request parameters"
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "listHip4Questions response 401",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}

{
  "code": 401,
  "error": "Missing or invalid API key. Provide X-API-Key header."
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "listHip4Questions response 429",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}

{
  "code": 429,
  "error": "Rate limit exceeded"
}