Day153 — get maxPriorityFeePerGas and maxFeePerGas

I did a project that involves getting the estimated gas for a EIP-1559 transaction so that it could proceed smoothly.

In the ethers.js library, it provides a method getFeeData() to get the estimated gas, which is maxPriorityFeePerGas and maxFeePerGas .

ethers.js/index.ts at 608864fc3f00390e1260048a157af00378a98e41 · ethers-io/ethers.js

but as you can see, the maxPriorityFeePerGas is hardcoded as 1500000000 wei (1.5 gwei). That is not ideal.

To get the maxPriorityFeePerGas, a custom rpc method is called

await provider.send("eth_maxPriorityFeePerGas", [])

referencing below in alchemy-web3

const fee = await web3.eth.getMaxPriorityFeePerGas();

alchemy-web3/eth_maxPriorityFeePerGas.ts at 25687f874adf8e1f29f1c2ef49dac923844a953e ·…

There is a easier way to do it. It is to use official api to get the gas estimation provided in different level.

Polygon Gas Station | Polygon Technology | Documentation