Kalshi Market Daily Open Interest, 180-Day Window (by Market Ticker)

{
  "type": "object",
  "required": [
    "ticker",
    "time_range"
  ],
  "properties": {
    "ticker": {
      "type": "string",
      "minLength": 1,
      "description": "The Kalshi market ticker: the full uppercase code of one market (series, date and outcome joined by hyphens), not an event or series ticker."
    },
    "time_range": {
      "enum": [
        "180d"
      ],
      "type": "string",
      "description": "The window of history; only `180d` is offered: a window that starts 180 days before the call and can end weeks before today."
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "timestamp": {
            "type": "number",
            "description": "Unix seconds of the day the point is for (midnight UTC)."
          },
          "open_interest": {
            "type": "number",
            "description": "The market's open interest on that day."
          }
        }
      },
      "description": "One point per day, oldest first. The newest point can be weeks old, and a day can be missing."
    }
  },
  "description": "The market's daily open interest series."
}