Live Trades

Real-time trade execution data.

Channel: trades

Overview

The trades channel provides real-time trade executions for subscribed instruments. Each trade includes price, quantity, and timestamp information.

Connection

Connect to the WebSocket endpoint:

wss://marketdata.app.hello.trade/ws

Subscription Request

{
  "type": "subscribe",
  "channel": "trades",
  "symbols": ["BTC", "ETH"],
  "limit": 1
}

Field	Type	Required	Description
type	string	Yes	Must be "subscribe"
channel	string	Yes	Must be "trades"
symbols	string[]	Yes	List of instrument symbols
limit	Number	No	Number of recent trades to return on subscription (default: 1)

Unsubscription Request

{
  "type": "unsubscribe",
  "channel": "trades",
  "symbols": ["BTC"]
}

Response

{
  "type": "marketData",
  "channel": "trades",
  "data": {
    "symbol": "BTC",
    "price": "45000.50",
    "quantity": "0.5",
    "timestamp": 1705596400000
  }
}

Field	Type	Description
symbol	string	Instrument symbol
price	string	Trade execution price
quantity	string	Trade quantity. "0" marks the end of the snapshot; a negative value is a trade cancellation (see below)
timestamp	Number	Unix timestamp (milliseconds) of trade execution

Snapshot and Special Messages

On subscribe, each symbol first receives a snapshot of its most recent trades (up to limit), oldest first, followed by live trades as they occur.

End of snapshot

When the snapshot is complete, the last snapshot trade is sent again with quantity set to "0" — same price and timestamp. It is sent once per symbol per subscription and is not a trade.

{
  "type": "marketData",
  "channel": "trades",
  "data": {
    "symbol": "BTC",
    "price": "45000.50",
    "quantity": "0",
    "timestamp": 1705596400000
  }
}

If the instrument has no trades yet, the end-of-snapshot message has price "0", quantity "0" and timestamp 0.

Trade cancellations

A cancelled trade is sent with a negative quantity equal to the cancelled trade's quantity multiplied by -1. Subtract it from any volume you have accumulated for that trade.

Error Response

{
  "type": "error",
  "message": "Invalid subscription request",
  "code": 400
}

Unknown symbols are rejected with a 400 that names them. See Unknown symbols.

Notes

• Trades are sent in real-time as they occur

• Includes symbol, price, quantity, and timestamp information

• Treat quantity "0" as a snapshot boundary, not a trade, and negative quantity as a cancellation