eth_feeHistory | Plasma RPC Docs

Get historical gas fee data on Plasma including base fees and priority fee percentiles. Essential for gas price prediction, fee estimation UIs, and network congestion monitoring.

Returns historical gas fee data on Plasma, including base fees per gas and priority fee percentiles for a range of recent blocks. This data is essential for building accurate fee estimation algorithms for EIP-1559 transactions.

Why Plasma? Build on an EVM Layer 1 for stablecoin payments with PlasmaBFT consensus and Reth execution with 1 second blocks, XPL gas, full EVM JSON-RPC, and debug plus txpool on Dwellir.

When to Use This Method

The eth_feeHistory method serves these key scenarios for payment app developers, wallet teams, and teams shipping Solidity contracts for dollar transfers:

Calculate optimal EIP-1559 fee parameters - Derive maxPriorityFeePerGas from reward percentiles and maxFeePerGas from base fee trends for stablecoin transfers, payment apps, and wallets that need 1 second confirmation
Analyze fee market trends - Inspect historical base fees and gas utilization ratios to forecast fee direction and time transactions for lower costs
Build intelligent gas pricing strategies - Create automated fee estimation that adapts to network congestion on Plasma without manual intervention
Predict future base fees - Use the trailing baseFeePerGas value (index blockCount in the array) to anticipate the next block's base fee using EIP-1559 elasticity math

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

Derive maxPriorityFeePerGas from reward percentile data and set maxFeePerGas with a safety margin above the predicted next base fee. This approach gives you fee parameters tuned to real network conditions on Plasma.

JavaScript

import { JsonRpcProvider, formatUnits } from 'ethers';

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

async function getEIP1559Fees(blockCount = 10) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + blockCount.toString(16),
    'latest',
    [50, 90]
  ]);

  const nextBaseFee = BigInt(feeHistory.baseFeePerGas[blockCount]);
  const rewards50th = feeHistory.reward.map(r => BigInt(r[0]));
  const rewards90th = feeHistory.reward.map(r => BigInt(r[1]));

  const avg50th = rewards50th.reduce((s, r) => s + r, 0n) / BigInt(blockCount);
  const avg90th = rewards90th.reduce((s, r) => s + r, 0n) / BigInt(blockCount);

  return {
    medium: {
      maxPriorityFeePerGas: avg50th,
      maxFeePerGas: nextBaseFee * 2n + avg50th
    },
    fast: {
      maxPriorityFeePerGas: avg90th,
      maxFeePerGas: nextBaseFee * 2n + avg90th
    }
  };
}

const fees = await getEIP1559Fees();
console.log('Medium priority fee:', formatUnits(fees.medium.maxPriorityFeePerGas, 'gwei'), 'Gwei');
console.log('Fast priority fee:', formatUnits(fees.fast.maxPriorityFeePerGas, 'gwei'), 'Gwei');

2. Build Fee Estimation UI

Display recent base fee trends and provide low/medium/high fee estimates to end users. This pattern powers gas estimation widgets in wallets and dApp interfaces.

JavaScript

import { JsonRpcProvider, formatUnits } from 'ethers';

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

async function getFeeEstimateUI(blockRange = 20) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + blockRange.toString(16),
    'latest',
    [10, 50, 90]
  ]);

  const baseFees = feeHistory.baseFeePerGas.map(f => Number(BigInt(f)) / 1e9);
  const rewardAvgs = [0, 1, 2].map(idx => {
    const fees = feeHistory.reward.map(r => Number(BigInt(r[idx])) / 1e9);
    return fees.reduce((s, f) => s + f, 0) / fees.length;
  });

  const nextBaseFee = baseFees[baseFees.length - 1];

  return {
    currentBaseFee: nextBaseFee,
    baseFeeTrend: baseFees.slice(-5),
    fees: {
      low: { maxPriority: rewardAvgs[0], max: nextBaseFee + rewardAvgs[0] },
      medium: { maxPriority: rewardAvgs[1], max: nextBaseFee * 2 + rewardAvgs[1] },
      high: { maxPriority: rewardAvgs[2], max: nextBaseFee * 3 + rewardAvgs[2] }
    }
  };
}

const estimate = await getFeeEstimateUI();
console.log('Base fee:', estimate.currentBaseFee, 'Gwei');
console.log('Low:', estimate.fees.low);
console.log('Medium:', estimate.fees.medium);
console.log('High:', estimate.fees.high);

3. Implement Adaptive Gas Pricing

Build a pricing engine that automatically adjusts fee parameters based on real-time network congestion. When gas utilization ratios spike above 80%, the system shifts to higher priority fees to maintain inclusion speed.

JavaScript

import { JsonRpcProvider } from 'ethers';

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

async function adaptiveFeeParams(window = 10) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + window.toString(16),
    'latest',
    [25, 50, 75, 90]
  ]);

  const recentUtilization = feeHistory.gasUsedRatio.slice(-3);
  const avgUtilization = recentUtilization.reduce((s, r) => s + r, 0) / recentUtilization.length;
  const baseFeePerGas = BigInt(feeHistory.baseFeePerGas[window]);

  let priorityFeePercentile;
  let baseFeeMultiplier;

  if (avgUtilization > 0.8) {
    priorityFeePercentile = 3;
    baseFeeMultiplier = 3;
    console.log('High congestion detected, using premium fees');
  } else if (avgUtilization > 0.5) {
    priorityFeePercentile = 2;
    baseFeeMultiplier = 2;
    console.log('Moderate congestion, using standard fees');
  } else {
    priorityFeePercentile = 1;
    baseFeeMultiplier = 2;
    console.log('Low congestion, using economy fees');
  }

  const maxPriorityFeePerGas = feeHistory.reward.reduce(
    (sum, r) => sum + BigInt(r[priorityFeePercentile]), 0n
  ) / BigInt(window);

  return {
    maxPriorityFeePerGas,
    maxFeePerGas: baseFeePerGas * BigInt(baseFeeMultiplier) + maxPriorityFeePerGas,
    congestionLevel: avgUtilization > 0.8 ? 'high' : avgUtilization > 0.5 ? 'moderate' : 'low'
  };
}

const params = await adaptiveFeeParams();
console.log('Adaptive fee params:', params);

Best Practices

Use 5-20 blocks of history for accurate fee estimation: fewer blocks miss recent trends, more blocks dilute signal with stale data
Calculate maxPriorityFeePerGas from reward percentiles: use the 50th percentile for normal confirmation and the 90th for fast inclusion
Multiply baseFeePerGas by 2x as a safety margin for maxFeePerGas: this covers a 12.5% base fee increase per full block over 6 consecutive blocks
Cache fee history results with a short TTL of 12 seconds (roughly one block on Plasma) to balance freshness with API call efficiency
Fall back to eth_gasPrice if eth_feeHistory returns a "method not found" error, indicating the node does not support EIP-1559

JSON-RPC request

{
  "jsonrpc": "2.0",
  "method": "eth_feeHistory",
  "params": ["0x5", "latest", [25, 50, 75]],
  "id": 1
}

Code Examples

Error Handling

Common errors and solutions:

Error Code	Description	Solution
-32602	Invalid params	Ensure `blockCount` is 1-1024, `rewardPercentiles` is sorted ascending, and values are 0-100
-32601	Method not found	The node may not support EIP-1559: fall back to `eth_gasPrice`
-32603	Internal error	Retry with exponential backoff
-32005	Rate limit exceeded	Reduce `blockCount` or implement caching
-32000	Block range unavailable	Requested blocks may be pruned: use a smaller range or more recent `newestBlock`

JavaScript

async function safeFeeHistory(provider, blockCount = 10, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await provider.send('eth_feeHistory', [
        '0x' + blockCount.toString(16),
        'latest',
        [25, 50, 75]
      ]);
    } catch (error) {
      if (error.code === -32602 && blockCount > 1) {
        // Reduce block count and retry
        blockCount = Math.max(1, Math.floor(blockCount / 2));
        continue;
      }
      if (error.code === -32005) {
        await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
        continue;
      }
      if (i === maxRetries - 1) throw error;
      await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
    }
  }
}

eth_gasPrice - Get the current legacy gas price
eth_maxPriorityFeePerGas - Get the suggested priority fee for EIP-1559 transactions
eth_estimateGas - Estimate gas units required for a transaction
eth_getBlockByNumber - Get block details including baseFeePerGas

Why Plasma? Build on an EVM Layer 1 for stablecoin payments with PlasmaBFT consensus and Reth execution with 1 second blocks, XPL gas, full EVM JSON-RPC, and debug plus txpool on Dwellir.

When to Use This Method

The eth_feeHistory method serves these key scenarios for payment app developers, wallet teams, and teams shipping Solidity contracts for dollar transfers:

Calculate optimal EIP-1559 fee parameters - Derive maxPriorityFeePerGas from reward percentiles and maxFeePerGas from base fee trends for stablecoin transfers, payment apps, and wallets that need 1 second confirmation
Analyze fee market trends - Inspect historical base fees and gas utilization ratios to forecast fee direction and time transactions for lower costs
Build intelligent gas pricing strategies - Create automated fee estimation that adapts to network congestion on Plasma without manual intervention
Predict future base fees - Use the trailing baseFeePerGas value (index blockCount in the array) to anticipate the next block's base fee using EIP-1559 elasticity math

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

JavaScript

import { JsonRpcProvider, formatUnits } from 'ethers';

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

async function getEIP1559Fees(blockCount = 10) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + blockCount.toString(16),
    'latest',
    [50, 90]
  ]);

  const nextBaseFee = BigInt(feeHistory.baseFeePerGas[blockCount]);
  const rewards50th = feeHistory.reward.map(r => BigInt(r[0]));
  const rewards90th = feeHistory.reward.map(r => BigInt(r[1]));

  const avg50th = rewards50th.reduce((s, r) => s + r, 0n) / BigInt(blockCount);
  const avg90th = rewards90th.reduce((s, r) => s + r, 0n) / BigInt(blockCount);

  return {
    medium: {
      maxPriorityFeePerGas: avg50th,
      maxFeePerGas: nextBaseFee * 2n + avg50th
    },
    fast: {
      maxPriorityFeePerGas: avg90th,
      maxFeePerGas: nextBaseFee * 2n + avg90th
    }
  };
}

const fees = await getEIP1559Fees();
console.log('Medium priority fee:', formatUnits(fees.medium.maxPriorityFeePerGas, 'gwei'), 'Gwei');
console.log('Fast priority fee:', formatUnits(fees.fast.maxPriorityFeePerGas, 'gwei'), 'Gwei');

2. Build Fee Estimation UI

Display recent base fee trends and provide low/medium/high fee estimates to end users. This pattern powers gas estimation widgets in wallets and dApp interfaces.

JavaScript

import { JsonRpcProvider, formatUnits } from 'ethers';

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

async function getFeeEstimateUI(blockRange = 20) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + blockRange.toString(16),
    'latest',
    [10, 50, 90]
  ]);

  const baseFees = feeHistory.baseFeePerGas.map(f => Number(BigInt(f)) / 1e9);
  const rewardAvgs = [0, 1, 2].map(idx => {
    const fees = feeHistory.reward.map(r => Number(BigInt(r[idx])) / 1e9);
    return fees.reduce((s, f) => s + f, 0) / fees.length;
  });

  const nextBaseFee = baseFees[baseFees.length - 1];

  return {
    currentBaseFee: nextBaseFee,
    baseFeeTrend: baseFees.slice(-5),
    fees: {
      low: { maxPriority: rewardAvgs[0], max: nextBaseFee + rewardAvgs[0] },
      medium: { maxPriority: rewardAvgs[1], max: nextBaseFee * 2 + rewardAvgs[1] },
      high: { maxPriority: rewardAvgs[2], max: nextBaseFee * 3 + rewardAvgs[2] }
    }
  };
}

const estimate = await getFeeEstimateUI();
console.log('Base fee:', estimate.currentBaseFee, 'Gwei');
console.log('Low:', estimate.fees.low);
console.log('Medium:', estimate.fees.medium);
console.log('High:', estimate.fees.high);

3. Implement Adaptive Gas Pricing

JavaScript

import { JsonRpcProvider } from 'ethers';

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

async function adaptiveFeeParams(window = 10) {
  const feeHistory = await provider.send('eth_feeHistory', [
    '0x' + window.toString(16),
    'latest',
    [25, 50, 75, 90]
  ]);

  const recentUtilization = feeHistory.gasUsedRatio.slice(-3);
  const avgUtilization = recentUtilization.reduce((s, r) => s + r, 0) / recentUtilization.length;
  const baseFeePerGas = BigInt(feeHistory.baseFeePerGas[window]);

  let priorityFeePercentile;
  let baseFeeMultiplier;

  if (avgUtilization > 0.8) {
    priorityFeePercentile = 3;
    baseFeeMultiplier = 3;
    console.log('High congestion detected, using premium fees');
  } else if (avgUtilization > 0.5) {
    priorityFeePercentile = 2;
    baseFeeMultiplier = 2;
    console.log('Moderate congestion, using standard fees');
  } else {
    priorityFeePercentile = 1;
    baseFeeMultiplier = 2;
    console.log('Low congestion, using economy fees');
  }

  const maxPriorityFeePerGas = feeHistory.reward.reduce(
    (sum, r) => sum + BigInt(r[priorityFeePercentile]), 0n
  ) / BigInt(window);

  return {
    maxPriorityFeePerGas,
    maxFeePerGas: baseFeePerGas * BigInt(baseFeeMultiplier) + maxPriorityFeePerGas,
    congestionLevel: avgUtilization > 0.8 ? 'high' : avgUtilization > 0.5 ? 'moderate' : 'low'
  };
}

const params = await adaptiveFeeParams();
console.log('Adaptive fee params:', params);

Best Practices

Use 5-20 blocks of history for accurate fee estimation: fewer blocks miss recent trends, more blocks dilute signal with stale data
Calculate maxPriorityFeePerGas from reward percentiles: use the 50th percentile for normal confirmation and the 90th for fast inclusion
Multiply baseFeePerGas by 2x as a safety margin for maxFeePerGas: this covers a 12.5% base fee increase per full block over 6 consecutive blocks
Cache fee history results with a short TTL of 12 seconds (roughly one block on Plasma) to balance freshness with API call efficiency
Fall back to eth_gasPrice if eth_feeHistory returns a "method not found" error, indicating the node does not support EIP-1559

JSON-RPC request

{
  "jsonrpc": "2.0",
  "method": "eth_feeHistory",
  "params": ["0x5", "latest", [25, 50, 75]],
  "id": 1
}

Code Examples

Error Handling

Common errors and solutions:

Error Code	Description	Solution
-32602	Invalid params	Ensure `blockCount` is 1-1024, `rewardPercentiles` is sorted ascending, and values are 0-100
-32601	Method not found	The node may not support EIP-1559: fall back to `eth_gasPrice`
-32603	Internal error	Retry with exponential backoff
-32005	Rate limit exceeded	Reduce `blockCount` or implement caching
-32000	Block range unavailable	Requested blocks may be pruned: use a smaller range or more recent `newestBlock`

JavaScript

async function safeFeeHistory(provider, blockCount = 10, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await provider.send('eth_feeHistory', [
        '0x' + blockCount.toString(16),
        'latest',
        [25, 50, 75]
      ]);
    } catch (error) {
      if (error.code === -32602 && blockCount > 1) {
        // Reduce block count and retry
        blockCount = Math.max(1, Math.floor(blockCount / 2));
        continue;
      }
      if (error.code === -32005) {
        await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
        continue;
      }
      if (i === maxRetries - 1) throw error;
      await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
    }
  }
}

eth_gasPrice - Get the current legacy gas price
eth_maxPriorityFeePerGas - Get the suggested priority fee for EIP-1559 transactions
eth_estimateGas - Estimate gas units required for a transaction
eth_getBlockByNumber - Get block details including baseFeePerGas

eth_feeHistory - Plasma RPC Method

When to Use This Method

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

2. Build Fee Estimation UI

3. Implement Adaptive Gas Pricing

Best Practices

Code Examples

Error Handling

On this page

eth_feeHistory - Plasma RPC Method

When to Use This Method

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

2. Build Fee Estimation UI

3. Implement Adaptive Gas Pricing

Best Practices

Code Examples

Error Handling

On this page

eth_feeHistory - Plasma RPC Method

When to Use This MethodCopy Anchor Link

Common Use CasesCopy Anchor Link

1. Calculate Optimal EIP-1559 Fee ParametersCopy Anchor Link

2. Build Fee Estimation UICopy Anchor Link

3. Implement Adaptive Gas PricingCopy Anchor Link

Best PracticesCopy Anchor Link

Code ExamplesCopy Anchor Link

Error HandlingCopy Anchor Link

Related MethodsCopy Anchor Link

On this page

eth_feeHistory - Plasma RPC Method

When to Use This MethodCopy Anchor Link

Common Use CasesCopy Anchor Link

1. Calculate Optimal EIP-1559 Fee ParametersCopy Anchor Link

2. Build Fee Estimation UICopy Anchor Link

3. Implement Adaptive Gas PricingCopy Anchor Link

Best PracticesCopy Anchor Link

Code ExamplesCopy Anchor Link

Error HandlingCopy Anchor Link

Related MethodsCopy Anchor Link

On this page

When to Use This Method

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

2. Build Fee Estimation UI

3. Implement Adaptive Gas Pricing

Best Practices

Code Examples

Error Handling

Related Methods

When to Use This Method

Common Use Cases

1. Calculate Optimal EIP-1559 Fee Parameters

2. Build Fee Estimation UI

3. Implement Adaptive Gas Pricing

Best Practices

Code Examples

Error Handling

Related Methods