Gas Statistics

Subscribe to real-time gas price and PPU (Price Per Unit) statistics per shard. This data helps optimize transaction timing and gas price selection for faster confirmation.

Subscribe

ws.send(JSON.stringify({
  action: 'subscribe',
  topic: 'gasStats'
}));

Response

Upon subscription, you immediately receive current statistics, followed by updates every 50ms:

{
  "type": "gasStats",
  "data": {
    "shards": [
      {
        "shardId": 0,
        "gasPrice": {
          "min": 1000000000,
          "max": 1500000000,
          "avg": 1200000000
        },
        "ppu": {
          "min": 1000000000,
          "max": 2000000000,
          "avg": 1400000000
        },
        "txCount": 145,
        "lastUpdated": 1704067200000
      },
      {
        "shardId": 1,
        "gasPrice": {
          "min": 1000000000,
          "max": 1800000000,
          "avg": 1350000000
        },
        "ppu": {
          "min": 1000000000,
          "max": 2500000000,
          "avg": 1600000000
        },
        "txCount": 178,
        "lastUpdated": 1704067200000
      },
      {
        "shardId": 2,
        "gasPrice": {
          "min": 1000000000,
          "max": 1200000000,
          "avg": 1100000000
        },
        "ppu": {
          "min": 1000000000,
          "max": 1500000000,
          "avg": 1200000000
        },
        "txCount": 92,
        "lastUpdated": 1704067200000
      }
    ],
    "timestamp": 1704067200000
  }
}

Response Fields

Root Object

Field	Type	Description
type	string	Always "gasStats"
data	object	Gas statistics container
data.shards	array	Per-shard statistics
data.timestamp	number	Unix timestamp in milliseconds

Shard Statistics

Field	Type	Description
shardId	number	Shard identifier (0, 1, 2)
gasPrice	object	Gas price statistics in atomic units
ppu	object	Price Per Unit statistics
txCount	number	Transactions in the time window
lastUpdated	number	Last update timestamp

Metric Statistics

Each metric (gasPrice, ppu) contains:

Field	Type	Description
min	number	Minimum value in window
max	number	Maximum value in window
avg	number	Average value in window

Understanding Gas Statistics

Gas Price

The gas price is the amount of EGLD (in atomic units) paid per unit of gas. The minimum network gas price is 1,000,000,000 (1 Gwei).

PPU (Price Per Unit)

PPU represents the effective cost of transaction processing, calculated as:

PPU = (gasLimit × gasPrice) / gasLimit = gasPrice

For transactions with data, PPU accounts for the additional cost per byte.

Shard Selection

MultiversX has 3 execution shards (0, 1, 2) plus a metachain. Use gas statistics to:

1. Identify congested shards - Higher avg gas prices indicate congestion

2. Optimize timing - Wait for lower gas prices during off-peak times

3. Set competitive gas prices - Use avg or slightly above for faster confirmation

Example: Dynamic Gas Pricing

class GasOptimizer {
  constructor(wsUrl) {
    this.ws = new WebSocket(wsUrl);
    this.gasStats = null;
    
    this.ws.onmessage = (event) => {
      const msg = JSON.parse(event.data);
      if (msg.type === 'gasStats') {
        this.gasStats = msg.data;
      }
    };
    
    this.ws.onopen = () => {
      this.ws.send(JSON.stringify({
        action: 'subscribe',
        topic: 'gasStats'
      }));
    };
  }

  getRecommendedGasPrice(senderAddress) {
    if (!this.gasStats) {
      return 1000000000; // Default minimum
    }

    // Determine sender's shard from address
    const shard = this.getShardFromAddress(senderAddress);
    const shardStats = this.gasStats.shards.find(s => s.shardId === shard);
    
    if (!shardStats || shardStats.txCount === 0) {
      return 1000000000; // Shard is empty, use minimum
    }

    // Use average + 10% for competitive pricing
    return Math.ceil(shardStats.gasPrice.avg * 1.1);
  }

  isShardCongested(shardId) {
    if (!this.gasStats) return false;
    
    const shardStats = this.gasStats.shards.find(s => s.shardId === shardId);
    if (!shardStats) return false;

    // Consider congested if avg is 50% above minimum
    return shardStats.gasPrice.avg > 1500000000;
  }

  getShardFromAddress(address) {
    // Simplified shard calculation
    const bytes = Buffer.from(address.slice(4), 'hex');
    return bytes[bytes.length - 1] % 3;
  }
}

// Usage
const optimizer = new GasOptimizer('wss://relayer.xoxno.com/ws');

// Wait for connection and initial stats
setTimeout(() => {
  const gasPrice = optimizer.getRecommendedGasPrice(userAddress);
  console.log(`Recommended gas price: ${gasPrice}`);
}, 1000);

Example: Gas Price Monitor UI

function formatGasPrice(atomic) {
  return (atomic / 1e9).toFixed(2) + ' Gwei';
}

function updateGasUI(stats) {
  stats.shards.forEach(shard => {
    const element = document.getElementById(`shard-${shard.shardId}`);
    if (element) {
      element.innerHTML = `
        <div class="shard-stats">
          <h4>Shard ${shard.shardId}</h4>
          <p>Min: ${formatGasPrice(shard.gasPrice.min)}</p>
          <p>Avg: ${formatGasPrice(shard.gasPrice.avg)}</p>
          <p>Max: ${formatGasPrice(shard.gasPrice.max)}</p>
          <p>Transactions: ${shard.txCount}</p>
        </div>
      `;
    }
  });
}

// Connect and subscribe
const ws = new WebSocket('wss://relayer.xoxno.com/ws');

ws.onopen = () => {
  ws.send(JSON.stringify({
    action: 'subscribe',
    topic: 'gasStats'
  }));
};

ws.onmessage = (event) => {
  const msg = JSON.parse(event.data);
  if (msg.type === 'gasStats') {
    updateGasUI(msg.data);
  }
};

Default Values

When a shard has no recent transactions, default values are returned:

Metric	Default Value	Meaning
gasPrice.min/max/avg	1,000,000,000	Minimum network gas price
ppu.min/max/avg	1,000,000,000	Minimum PPU
txCount	0	No transactions in window

These defaults indicate an empty shard with full capacity available.

Unsubscribe

ws.send(JSON.stringify({
  action: 'unsubscribe',
  topic: 'gasStats'
}));

Gas statistics are computed over a 1-minute sliding window. The data reflects recent mempool activity, not historical blockchain data.

Related Topics

• Account Subscriptions - Monitor address changes

• Transaction Broadcasting - Submit transactions

• Troubleshooting - WebSocket connection issues