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eth_maxPriorityFeePerGas - BSC RPC Method

Get the suggested priority fee (tip) per gas for EIP-1559 transactions on Binance Smart Chain. Essential for gas estimation, fee optimization, and time-sensitive transaction pricing.

Returns the current suggested priority fee (tip) per gas in wei on Binance Smart Chain. This is the amount paid directly to validators to incentivize faster transaction inclusion in EIP-1559 compatible blocks.

Why BSC? Build on the third-largest blockchain by market cap with $12B+ TVL and 37%+ DEX market share with sub-$0.10 fees, 2.6M daily active users, full EVM compatibility, and direct Binance integration.

When to Use This Method

eth_maxPriorityFeePerGas is essential for DeFi developers, trading platform builders, and teams seeking Binance ecosystem access:

  • EIP-1559 Transaction Building — Get the recommended tip to include in maxPriorityFeePerGas when constructing type-2 transactions on BSC
  • Fee Optimization — Balance transaction speed against cost by adjusting the priority fee relative to the suggested value
  • Time-Sensitive Transactions — Increase the tip above the suggested value for DEX swaps, liquidations, or other latency-sensitive operations on high-frequency DeFi (PancakeSwap), NFT marketplaces, and GameFi applications
  • Gas Price Estimation — Combine with baseFeePerGas from the latest block to calculate the total maxFeePerGas for accurate fee estimation

Code Examples

Common Use Cases

1. Build an EIP-1559 Transaction

Construct a properly priced type-2 transaction on BSC:

JavaScript
import { JsonRpcProvider, Wallet, parseEther } from 'ethers';

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

async function buildEIP1559Transaction(privateKey, to, valueEth) {
  const wallet = new Wallet(privateKey, provider);

  // Get current fee data
  const feeData = await provider.getFeeData();
  const latestBlock = await provider.getBlock('latest');
  const baseFee = latestBlock.baseFeePerGas;

  // Set maxPriorityFeePerGas from the suggestion
  const maxPriorityFeePerGas = feeData.maxPriorityFeePerGas;

  // maxFeePerGas = 2 * baseFee + maxPriorityFeePerGas (buffer for base fee increases)
  const maxFeePerGas = baseFee * 2n + maxPriorityFeePerGas;

  const tx = await wallet.sendTransaction({
    to,
    value: parseEther(valueEth),
    type: 2,
    maxPriorityFeePerGas,
    maxFeePerGas
  });

  console.log('Sent with priority fee:', Number(maxPriorityFeePerGas) / 1e9, 'Gwei');
  return tx;
}

2. Dynamic Fee Strategy

Adjust priority fees based on transaction urgency:

JavaScript
async function getFeeByUrgency(provider, urgency = 'standard') {
  const feeData = await provider.getFeeData();
  const basePriorityFee = feeData.maxPriorityFeePerGas;

  const multipliers = {
    low: 0.8,       // Willing to wait
    standard: 1.0,  // Normal speed
    fast: 1.5,      // Faster inclusion
    urgent: 2.0     // Next-block target
  };

  const multiplier = multipliers[urgency] || 1.0;
  const adjustedFee = BigInt(Math.ceil(Number(basePriorityFee) * multiplier));

  const block = await provider.getBlock('latest');
  const maxFeePerGas = block.baseFeePerGas * 2n + adjustedFee;

  return {
    maxPriorityFeePerGas: adjustedFee,
    maxFeePerGas
  };
}

// Usage
const fees = await getFeeByUrgency(provider, 'fast');
console.log('Priority fee:', Number(fees.maxPriorityFeePerGas) / 1e9, 'Gwei');
console.log('Max fee:', Number(fees.maxFeePerGas) / 1e9, 'Gwei');

3. Priority Fee Monitor

Track priority fee changes over time on BSC:

JavaScript
async function monitorPriorityFee(provider, interval = 12000) {
  let previousFee = null;

  setInterval(async () => {
    const feeData = await provider.getFeeData();
    const currentFee = feeData.maxPriorityFeePerGas;
    const feeGwei = Number(currentFee) / 1e9;

    if (previousFee !== null) {
      const change = Number(currentFee - previousFee) / Number(previousFee) * 100;
      const direction = change > 0 ? 'UP' : change < 0 ? 'DOWN' : 'STABLE';
      console.log(`Priority fee: ${feeGwei.toFixed(4)} Gwei (${direction} ${Math.abs(change).toFixed(1)}%)`);
    } else {
      console.log(`Priority fee: ${feeGwei.toFixed(4)} Gwei`);
    }

    previousFee = currentFee;
  }, interval);
}

Error Handling

Common errors and solutions:

Error CodeDescriptionSolution
-32601Method not foundThe node may not support EIP-1559 — fall back to eth_gasPrice
-32603Internal errorRetry with exponential backoff
-32005Rate limit exceededImplement rate limiting and caching client-side
JavaScript
async function getSafePriorityFee(provider, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      const feeData = await provider.getFeeData();
      if (feeData.maxPriorityFeePerGas !== null) {
        return feeData.maxPriorityFeePerGas;
      }
      // Fallback: derive from legacy gas price
      const gasPrice = await provider.send('eth_gasPrice', []);
      return BigInt(gasPrice);
    } catch (error) {
      if (error.code === -32601) {
        // EIP-1559 not supported — use legacy gas price
        const gasPrice = await provider.send('eth_gasPrice', []);
        return BigInt(gasPrice);
      }
      if (i === maxRetries - 1) throw error;
      await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
    }
  }
}