{
  "type": "post",
  "id": 1,
  "request": {
    "type": "placeOrder",
    "payload": {
      "address": "0x...",
      "accountIndex": 0,
      "marketId": 0,
      "orderSide": "BUY",
      "orderType": "LIMIT",
      "timeInForce": "GTC",
      "quantity": "0.01",
      "price": "50000"
    },
    "apiKey": "<64-hex-public-key>",
    "timestamp": "1712345678000",
    "signature": "<128-hex-signature>"
  }
}