We will be using getFeeHistory to get the data of the previous blocks and then we will use that data to get the estimated gas fee for a transaction to be included.
We will use this logic to get the estimated gas fees
Top 1 %ile of the transactions to get slow gas fee
Top 50 %ile of the transactions to get average gas fee
Top 99 %ile of the transactions to get fast gas fee
Demo Code :
web3.eth
.getFeeHistory(4, "pending", [25, 50, 75])
.then((result) => {
console.log(result);
});
// gives 4 blocks and their transaction dataO/P :
{
baseFeePerGas: [
'0x1ca4585f75',
'0x20088ba00f',
'0x1f69bc3768',
'0x1dcf8fe9b1',
'0x1c0df207ce'
],
gasUsedRatio: [
0.9736275666666667,
0.4225367666666667,
0.29597783333333333,
0.2643383
],
oldestBlock: '0x84e95a',
reward: [
[ '0x362845373', '0x3eefd5de7', '0x4729167a3' ],
[ '0x59682f00', '0x59682f00', '0x9502f900' ],
[ '0x59682f00', '0x59682f00', '0xdf736f7f' ],
[ '0x40a406d8', '0x59682f00', '0x59682f00' ]
]
}I wrote a formatter to format the above data into more readable form so the above data is represented as :
[
{
block_number: 8710493,
baseFeePerGas: 128036366769,
gasUsedRatio: 0.3185674666666667,
priorityFeePerGasPercentiles: [ 1084491480, 1500000000, 1500000000 ]
},
{
block_number: 8710494,
baseFeePerGas: 122228876174,
gasUsedRatio: 0.46493013333333333,
priorityFeePerGasPercentiles: [ 1331000000, 1500000000, 1500000000 ]
},
{
block_number: 8710495,
baseFeePerGas: 121157238577,
gasUsedRatio: 0.397112,
priorityFeePerGasPercentiles: [ 1500000000, 1500000000, 5000000000 ]
},
{
block_number: 8710496,
baseFeePerGas: 118040832087,
gasUsedRatio: 0.9201721666666667,
priorityFeePerGasPercentiles: [ 1500000000, 1500000000, 2500000000 ]
}
]Now after writing the logic our final output is :
web3.eth
.getFeeHistory(historicalBlocks, "pending", [1, 50, 99])
.then((result) => {
const res = formatResult(result, historicalBlocks);
const slow = calcAverage(
res.map((block) => block.priorityFeePerGasPercentiles[0])
);
const average = calcAverage(
res.map((block) => block.priorityFeePerGasPercentiles[1])
);
const fast = calcAverage(
res.map((block) => block.priorityFeePerGasPercentiles[2])
);
// Getting the latest block
web3.eth.getBlock("pending").then((block) => {
const baseFeeOfLatestBlock = Number(block.baseFeePerGas);
console.log(`Gas Estimation (Block Number : ${Number(block.number)}) :
slow 🐌 : ${slow + baseFeeOfLatestBlock}
average 🚩 : ${average + baseFeeOfLatestBlock}
fast ⚡ : ${fast + baseFeeOfLatestBlock}`);
});
});Gas Estimation (Block Number : 8710534) :
slow 🐌 : 160758582325
average 🚩 : 161582842530
fast ⚡ : 455478648655
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent