RektoMeter — Pyth Network Price Feeds Integration

pyth-price-feeds.js

/**
 * RektoMeter — Pyth Network Price Feeds Integration
 * https://rektometer.click
 *
 * This gist shows how to fetch real-time crypto prices
 * from Pyth Network's Hermes API for a portfolio tracker.
 */

// Step 1: Fetch all available crypto feeds from Pyth
async function getAllCryptoFeeds() {
  const res = await fetch(
    'https://hermes.pyth.network/v2/price_feeds?asset_type=crypto'
  );
  const data = await res.json();

  // Filter for USD pairs only and map to usable format
  return data
    .filter(f => 
      f.attributes?.base && 
      f.attributes?.quote_currency === 'USD'
    )
    .map(f => ({
      id:      f.id,
      symbol:  f.attributes.base,
      display: `${f.attributes.base}/USD`,
    }))
    .sort((a, b) => a.symbol.localeCompare(b.symbol));
}

// Step 2: Fetch live prices for multiple assets at once
async function getLivePrices(feedIds) {
  const params = new URLSearchParams();
  feedIds.forEach(id => params.append('ids[]', id));

  const res = await fetch(
    `https://hermes.pyth.network/v2/updates/price/latest?${params}`
  );

  if (!res.ok) throw new Error(`Pyth API error: ${res.status}`);

  const data = await res.json();

  // Parse prices using expo to get actual USD value
  const prices = {};
  data.parsed.forEach(item => {
    prices[item.id] = parseFloat(item.price.price) 
      * Math.pow(10, item.price.expo);
  });

  return prices;
}

// Step 3: Calculate P&L for a position
function calculatePnL(qty, buyPrice, currentPrice) {
  const modalCost     = qty * buyPrice;
  const currentValue  = qty * currentPrice;
  const unrealizedPnl = currentValue - modalCost;
  const unrealizedPct = modalCost > 0 
    ? (unrealizedPnl / modalCost) * 100 
    : 0;

  return { modalCost, currentValue, unrealizedPnl, unrealizedPct };
}

// Example usage
async function main() {
  // Get all available crypto feeds
  const feeds = await getAllCryptoFeeds();
  console.log(`Found ${feeds.length} crypto feeds on Pyth`);

  // Find BTC and ETH feed IDs
  const btc = feeds.find(f => f.symbol === 'BTC');
  const eth = feeds.find(f => f.symbol === 'ETH');

  // Fetch live prices
  const prices = await getLivePrices([btc.id, eth.id]);

  const btcPrice = prices[btc.id];
  const ethPrice = prices[eth.id];

  console.log(`BTC/USD: $${btcPrice.toLocaleString()}`);
  console.log(`ETH/USD: $${ethPrice.toLocaleString()}`);

  // Calculate P&L example
  // Bought 1 BTC at $70,000
  const pnl = calculatePnL(1, 70000, btcPrice);
  console.log(`Unrealized P&L: $${pnl.unrealizedPnl.toFixed(2)}`);
  console.log(`ROI: ${pnl.unrealizedPct.toFixed(2)}%`);
}

main().catch(console.error);