eth_feeHistory - Monad

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

This method returns historical gas information for a range of blocks, useful for EIP-1559 fee estimation.

Parameters

Parameter	Type	Required	Description
blockCount	string	Yes	Number of blocks to return (hex), max 1024.
newestBlock	string	Yes	Highest block number in hex, or "latest", "pending".
rewardPercentiles	array	No	Array of percentiles (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": ["0x5", "latest", [25, 50, 75]],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "oldestBlock": "0x1b0",
        "baseFeePerGas": [
            "0x7",
            "0x7",
            "0x7",
            "0x7",
            "0x7",
            "0x7"
        ],
        "gasUsedRatio": [
            0.25,
            0.30,
            0.28,
            0.35,
            0.22
        ],
        "reward": [
            ["0x3b9aca00", "0x3b9aca00", "0x3b9aca00"],
            ["0x3b9aca00", "0x3b9aca00", "0x3b9aca00"],
            ["0x3b9aca00", "0x3b9aca00", "0x3b9aca00"],
            ["0x3b9aca00", "0x3b9aca00", "0x3b9aca00"],
            ["0x3b9aca00", "0x3b9aca00", "0x3b9aca00"]
        ]
    }
}

Response Parameters

Field	Type	Description
oldestBlock	string	Lowest block number in the returned range (hex).
baseFeePerGas	array	Array of base fees per gas for each block (includes next block).
gasUsedRatio	array	Array of gas used ratios (0-1) for each block.
reward	array	2D array of priority fees at requested percentiles for each block.

Use Case

The eth_feeHistory method is essential for:

• EIP-1559 fee estimation

• Dynamic gas pricing algorithms

• Fee prediction for wallets

• Gas price analytics

• Transaction prioritization

• Cost optimization

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid ACCESS-TOKEN.
-32602	Invalid params	Invalid block count or percentiles.
-32000	Resource not found	Block not found.

Web3 Integration

Ethers.js

import { ethers } from 'ethers';

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

// Get fee data (uses feeHistory internally)
const feeData = await provider.getFeeData();
console.log('Base fee:', 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');

// Direct feeHistory call
const feeHistory = await provider.send('eth_feeHistory', ['0x5', 'latest', [25, 50, 75]]);
console.log('Base fees:', feeHistory.baseFeePerGas);

Viem