Monitor Prices

Three approaches to tracking TRON energy prices: REST API polling, WebSocket streaming, and the embeddable widget. Choose based on your latency needs and architecture.

When to Use Each Approach

Approach	Latency	Best For
REST polling	30-60s	Cron jobs, serverless functions, simple scripts
WebSocket	Real-time	Dashboards, trading bots, live applications
Price widget	60s	Website embeds, informational pages

Approach 1: REST API Polling

Call GET /api/v1/prices on a timer. The endpoint is public and rate-limited to 60 requests per minute. Prices update every 30 seconds on the server side, so polling more frequently than that provides no benefit.

Node.js polling examplejavascript

async function pollPrices() {
  const res = await fetch('https://merx.exchange/api/v1/prices')
  const data = await res.json()

  for (const provider of data.prices) {
    const cheapest = provider.energy_prices[0]
    console.log(provider.provider, cheapest.price_sun, 'SUN')
  }
}

// Poll every 30 seconds
setInterval(pollPrices, 30_000)
pollPrices()

Approach 2: WebSocket Streaming

Connect to wss://merx.exchange/ws for real-time price updates pushed by the server. No authentication required. You receive a message each time any provider price changes.

WebSocket clientjavascript

const ws = new WebSocket('wss://merx.exchange/ws')

ws.addEventListener('open', () => {
  // Optional: filter to specific providers
  ws.send(JSON.stringify({ subscribe: ['catfee', 'itrx'] }))
})

ws.addEventListener('message', (event) => {
  const price = JSON.parse(event.data)
  console.log(price.provider, price.energy_prices)
})

See the WebSocket reference for heartbeat handling and reconnection logic.

Approach 3: Price Widget

For websites that just need to display current prices, embed the widget with two lines of HTML. It auto-refreshes every 60 seconds.

Widget embedhtml

<div id="merx-prices"></div>
<script src="https://merx.exchange/widget.js"></script>

See the widget reference for customization options.

Example: Price Alert Bot

A practical example that monitors prices via WebSocket and sends a notification when the cheapest energy price drops below a threshold. This pattern is useful for buying energy at optimal prices.

Price alert bot (Node.js)javascript

const WebSocket = require('ws')

const THRESHOLD_SUN = 80
const ALERT_URL = 'https://hooks.slack.com/services/YOUR/WEBHOOK/URL'

function connect() {
  const ws = new WebSocket('wss://merx.exchange/ws')

  ws.on('message', async (raw) => {
    const price = JSON.parse(raw)
    const cheapest = price.energy_prices?.[0]

    if (cheapest && cheapest.price_sun < THRESHOLD_SUN) {
      const msg = [
        price.provider,
        ': ',
        cheapest.price_sun,
        ' SUN (below ',
        THRESHOLD_SUN,
        ')',
      ].join('')

      await fetch(ALERT_URL, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ text: msg }),
      })
    }
  })

  ws.on('close', () => {
    // Reconnect after 5 seconds
    setTimeout(connect, 5000)
  })
}

connect()

TIP

Combine price monitoring with the prices.best() SDK method to automatically place an order when the price hits your target.