eth_feeHistory - Blast

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 a window of historical base fees, gas-used ratios, and requested priority-fee percentiles. It is the basis for building adaptive EIP-1559 fee strategies on GIWA Sepolia.

Parameters

Parameter	Type	Required	Description
blockCount	string	Yes	Number of blocks in the history window (hex, 1-1024)
newestBlock	string	Yes	Newest block of the range in hex, or "latest"/"pending"
rewardPercentiles	array	No	Ascending list of percentiles (0-100) for priority-fee sampling

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_feeHistory",
    "params": ["0x5", "latest", [10, 50, 90]],
    "id": "getblock.io"
}'

Axios

example.js

const axios = require('axios');

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'eth_feeHistory',
    params: ['0x5', 'latest', [10, 50, 90]],
    id: 'getblock.io'
}, {
    headers: { 'Content-Type': 'application/json' }
});

console.log(response.data.result);

Request

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'eth_feeHistory',
        'params': ['0x5', 'latest', [10, 50, 90]],
        'id': 'getblock.io'
    }
)

print(response.json())

Rust

example.rs

use reqwest::Client;
use serde_json::{json, Value};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "eth_feeHistory",
            "params": ["0x5", "latest", [10, 50, 90]],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "oldestBlock": "0x14b8a10",
        "baseFeePerGas": [
            "0x7",
            "0x8",
            "0x7",
            "0x7",
            "0x8",
            "0x7"
        ],
        "gasUsedRatio": [
            0.42,
            0.51,
            0.33,
            0.61,
            0.47
        ],
        "reward": [
            [
                "0x0",
                "0xf4240",
                "0x1e8480"
            ]
        ]
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	object	Fee history window (see fields below)

Result Object

Field	Type	Description
oldestBlock	string	Lowest block number of the returned range (hex)
baseFeePerGas	array	Base fee per gas for each block, plus the next block (hex)
gasUsedRatio	array	Ratio of gas used to gas limit per block (float 0-1)
reward	array	Per-block priority-fee samples at the requested percentiles (hex)

Use Cases

• Adaptive Fees: Pick a priority fee from a recent percentile distribution

• Congestion Signals: Read gasUsedRatio to detect busy periods

• Fee Charts: Render base-fee trends in a wallet or dashboard

• Retry Pricing: Bump fees on a stuck transaction using recent percentiles

Error Handling

Error Code	Message	Description
-32602	Invalid params	blockCount out of range or malformed percentile list
-32603	Internal error	The node failed to assemble the fee history

Web3 Integration

Ethers.js

ethers-example.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const history = await provider.send('eth_feeHistory', ['0x5', 'latest', [10, 50, 90]]);

Viem

viem-example.js

import { createPublicClient, http } from 'viem';

const client = createPublicClient({
  transport: http('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/')
});

const history = await client.getFeeHistory({ blockCount: 5, rewardPercentiles: [10, 50, 90] });