eth_feeHistory - Base

Example code for the eth_feeHistory JSON-RPC method. Complete guide on how to use eth_feeHistory JSON-RPC in GetBlock Web3 documentation.

The eth_feeHistory method returns historical gas information for EIP-1559 fee estimation. This method provides base fee history and reward percentiles to help calculate optimal transaction fees.

Parameters

Parameter	Type	Required	Description
blockCount	string	Yes	Number of blocks in the requested range (hex, max 1024)
newestBlock	string	Yes	Highest block of the range ("latest" or block number in hex)
rewardPercentiles	array	No	Array of percentile values (0-100) for priority fee sampling

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_feeHistory",
    "params": ["0xa", "latest", [25, 50, 75]],
    "id": "getblock.io"
}'

Axios (JavaScript)

Requests (Python)

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "oldestBlock": "0x12d6876",
        "baseFeePerGas": [
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100",
            "0x5f5e100"
        ],
        "gasUsedRatio": [
            0.0,
            0.1234,
            0.0567,
            0.0,
            0.2345,
            0.0,
            0.0,
            0.0891,
            0.0,
            0.0
        ],
        "reward": [
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"],
            ["0x0", "0x0", "0x0"]
        ]
    }
}

Response Parameters

Parameter	Type	Description
oldestBlock	string	Oldest block number in the returned range (hex)
baseFeePerGas	array	Array of base fees per gas (N+1 elements for N blocks)
gasUsedRatio	array	Array of gas used ratios (0 to 1) for each block
reward	array	Array of priority fee arrays at requested percentiles

Use Cases

1. Fee Estimation: Calculate optimal gas fees for transactions.

2. Gas Price Prediction: Forecast future base fees.

3. Network Analysis: analyze gas usage patterns.

4. UI Display: Show fee trends to users.

5. MEV Strategies: Optimize transaction priority fees.

Error Handling

Error Code	Message	Description
-32602	Invalid params	Invalid block count or percentiles
-32603	Internal error	Node internal failure

Web3 Integration

Ethers.js (v6)

const { ethers } = require('ethers');

const provider = new ethers.JsonRpcProvider('https://go.getblock.io/<ACCESS-TOKEN>/');

async function getFeeHistory() {
    // Get fee history for last 10 blocks
    const feeHistory = await provider.send('eth_feeHistory', ['0xa', 'latest', [25, 50, 75]]);
    
    console.log('Oldest Block:', parseInt(feeHistory.oldestBlock, 16));
    console.log('Base Fees:', feeHistory.baseFeePerGas.map(f => 
        ethers.formatUnits(f, 'gwei') + ' gwei'
    ));
    
    // Calculate suggested fees
    const latestBaseFee = BigInt(feeHistory.baseFeePerGas[feeHistory.baseFeePerGas.length - 1]);
    const suggestedMaxFee = latestBaseFee * 2n;
    
    console.log('Suggested Max Fee:', ethers.formatUnits(suggestedMaxFee, 'gwei'), 'gwei');
    
    return feeHistory;
}

// Using getFeeData (simpler)
async function getSimpleFeeData() {
    const feeData = await provider.getFeeData();
    console.log('Gas Price:', ethers.formatUnits(feeData.gasPrice, 'gwei'), 'gwei');
    console.log('Max Fee:', ethers.formatUnits(feeData.maxFeePerGas, 'gwei'), 'gwei');
    console.log('Priority Fee:', ethers.formatUnits(feeData.maxPriorityFeePerGas, 'gwei'), 'gwei');
    return feeData;
}

getFeeHistory();

Viem