eth_gasPrice - Astar RPC Method

Returns the current gas price on Astar in wei.

Why Astar? Build on Polkadot's leading dApp hub supporting EVM, WASM, and upcoming PolkaVM environments with EVM + WASM + PolkaVM support, Build2Earn developer rewards, dApp Staking, and Soneium cross-layer integration.

When to Use This Method

The eth_gasPrice method serves these key scenarios for multi-chain dApp developers, DeFi builders, and teams leveraging Polkadot + Ethereum ecosystems:

• Set gas price for legacy transactions - Use the returned wei value as the gasPrice field in legacy (pre-EIP-1559) transactions on Astar
• Monitor network congestion - Track gas price fluctuations to determine the best time to submit transactions for lower fees
• Estimate transaction costs - Multiply gas price by estimated gas units to calculate the total cost before sending any transaction
• Build gas price oracles - Feed real-time gas price data into fee estimation UIs, automated trading bots, and wallet applications

Common Use Cases

1. Calculate Total Transaction Cost

Multiply the current gas price by the estimated gas for a transaction to determine the total cost in the native currency of Astar. This lets users see the expected fee before confirming any transaction.

import { JsonRpcProvider, formatUnits } from 'ethers';

const provider = new JsonRpcProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY');

async function calculateTransactionCost(gasLimit) {
  const gasPrice = await provider.send('eth_gasPrice', []);
  const costWei = BigInt(gasPrice) * BigInt(gasLimit);
  const costEth = formatUnits(costWei, 'ether');
  console.log(`Gas price: ${formatUnits(gasPrice, 'gwei')} Gwei`);
  console.log(`Estimated cost: ${costEth} ETH`);
  return costEth;
}

await calculateTransactionCost(21000);

2. Build Dynamic Gas Price Strategy

Adjust gas prices dynamically based on current network conditions. During peak congestion on Astar, multiply the base gas price by 1.2-1.5x for faster inclusion; during quiet periods, use the raw gas price for the most economical confirmation.

import { JsonRpcProvider, formatUnits } from 'ethers';

const provider = new JsonRpcProvider('https://api-astar.n.dwellir.com/YOUR_API_KEY');

async function getDynamicGasPrice(strategy = 'medium') {
  const baseGasPrice = BigInt(await provider.send('eth_gasPrice', []));
  const multipliers = { low: 1.0, medium: 1.2, high: 1.5 };

  const adjustedPrice = baseGasPrice * BigInt(Math.floor(multipliers[strategy] * 100)) / 100n;

  console.log(`Base gas price: ${formatUnits(baseGasPrice, 'gwei')} Gwei`);
  console.log(`Strategy (${strategy}): ${formatUnits(adjustedPrice, 'gwei')} Gwei`);
  return adjustedPrice;
}

await getDynamicGasPrice('medium');

3. Compare Gas Prices Across Chains

If your application supports multiple chains, compare gas prices to route transactions to the most cost-effective network. This is particularly useful for cross-chain bridges and multi-chain DeFi aggregators.

const chains = {
  ethereum: 'https://eth.dwellir.com',
  polygon: 'https://polygon.dwellir.com',
  arbitrum: 'https://arb.dwellir.com'
};

async function compareGasPrices() {
  const results = {};
  for (const [name, rpcUrl] of Object.entries(chains)) {
    const provider = new JsonRpcProvider(rpcUrl);
    const gasPrice = await provider.send('eth_gasPrice', []);
    results[name] = {
      wei: BigInt(gasPrice).toString(),
      gwei: Number(BigInt(gasPrice)) / 1e9
    };
  }

  const sorted = Object.entries(results).sort((a, b) => a[1].gwei - b[1].gwei);
  console.log('Cheapest chain:', sorted[0][0], '-', sorted[0][1].gwei, 'Gwei');
  return results;
}

compareGasPrices();

Best Practices

• Legacy gas price is a single number: for EIP-1559 transactions, prefer using eth_feeHistory combined with eth_maxPriorityFeePerGas instead
• The return value is in wei: divide by 1e9 to convert to gwei, which is the standard unit for gas price display
• Consider current network conditions on Astar: multiply by 1.2-1.5x for faster block inclusion during congestion
• Most modern chains use EIP-1559 exclusively: check if Astar supports dynamic fee transactions before relying on legacy gas price

Code Examples

Error Handling

Related Methods

• eth_maxPriorityFeePerGas - Get priority fee (EIP-1559)
• eth_feeHistory - Get historical fee data
• eth_estimateGas - Estimate gas needed