Candle Updates

ws.send() wss://api.synthetix.io/v1/ws/subscriptions

{
  "id": "sub-1",
  "method": "subscribe",
  "params": {
    "type": "candles",
    "symbol": "BTC-USDT",
    "interval": "1m"
  }
}

{
  "method": "candle_update",
  "data": {
    "symbol": "BTC-USDT",
    "timeframe": "1m",
    "open_price": "50000.00",
    "high_price": "50125.50",
    "low_price": "49875.00",
    "close_price": "50050.25",
    "volume": "12.5",
    "open_time": "2025-01-01T00:00:00Z",
    "close_time": "2025-01-01T00:00:59.999Z",
    "quote_volume": "625125.75",
    "trade_count": 145
  }
}

{
  "method": "candle_update",
  "data": {
    "symbol": "BTC-USDT",
    "timeframe": "1m",
    "open_price": "50050.25",
    "high_price": "50075.00",
    "low_price": "50025.00",
    "close_price": "50060.50",
    "volume": "3.2",
    "open_time": "2025-01-01T00:01:00Z",
    "close_time": "2025-01-01T00:01:59.999Z",
    "quote_volume": "160193.60",
    "trade_count": 42
  }
}

// First authenticate with EIP-712 signature
const domain = {
  name: "Synthetix",
  version: "1",
  chainId: 1,
  verifyingContract: "0x0000000000000000000000000000000000000000"
};
 
// Subscribe to candle updates after authentication
const subscription = {
  id: "sub-1",
  method: "subscribe",
  params: {
    type: "candles",
    symbol: "BTC-USDT",
    timeframe: "1m"
  }
};
 
ws.send(JSON.stringify(subscription));
 
// Handle candle update messages
ws.onmessage = (event) => {
  const message = JSON.parse(event.data);
 
  if (message.method === "candle_update") {
    // WebSocket candles use snake_case field names
    const { symbol, timeframe, open_price, high_price, low_price, close_price } = message.data;
    console.log(`${symbol} ${timeframe} candle: O=${open_price} H=${high_price} L=${low_price} C=${close_price}`);
    
    // Update chart with new candle data
    updateCandlestickChart(message.data);
  }
};
 
function updateCandlestickChart(candleData) {
  // Destructure using actual snake_case field names
  const { 
    open_time,     // RFC3339 string
    open_price, 
    high_price, 
    low_price, 
    close_price, 
    volume 
  } = candleData;
 
  // Parse timestamp from RFC3339 string
  const timestamp = new Date(open_time).getTime();
 
  // Add/update candle in chart
  chart.updateCandle({
    time: timestamp / 1000,  // TradingView expects seconds
    open: parseFloat(open_price),
    high: parseFloat(high_price),
    low: parseFloat(low_price),
    close: parseFloat(close_price),
    volume: parseFloat(volume)
  });
}

// Subscribe to multiple timeframes
const subscriptions = [
  {
    id: "sub-1m",
    method: "subscribe",
    params: { type: "candles", symbol: "BTC-USDT", interval: "1m" }
  },
  {
    id: "sub-5m",
    method: "subscribe",
    params: { type: "candles", symbol: "BTC-USDT", interval: "5m" }
  },
  {
    id: "sub-1h",
    method: "subscribe",
    params: { type: "candles", symbol: "BTC-USDT", interval: "1h" }
  }
];
 
subscriptions.forEach(sub => ws.send(JSON.stringify(sub)));

{
  "id": "sub-1",
  "status": 400,
  "result": null,
  "error": {
    "code": 400,
    "message": "Invalid interval: 2m not supported"
  }
}