Does anything change on getGasPrice( ) in Web3js after EIP-1559?

Question

Using getGasPrice in web3js returns the last few blocks median gas price. After EIP-1559, the fees system is divided into Base + Tip.

My question is, what is returned using getGasPrice after EIP1559? Is it the total average Base+Tip value or just one or the other?

Answer 1

what is returned using getGasPrice after EIP-1559 ? Is it the total average Base+Tip value or just one or the other?

Something similar to pre EIP-1559 for backward compatibility : The base fee + a gas tip estimation, this value is directly usable for legacy transactions.

You can see the go-ethereum implementation of the RPC here where the base fee is explicitely added to a gasTipCap estimation.

You can also see it for yourself by running the following web3 code on mainnet:

const gasPrice = await web3.eth.getGasPrice();
console.log(web3.utils.fromWei(gasPrice, "Gwei"));

// Displays : 30.38 at the time of writing
// Which at block 14448993 is around 25 Gwei of base fee + 5 Gwei of gas tip cap.

I hope that answers your question.

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For the error mentioned in the comments : given the code I linked, you may encounter an error as metioned in the comments if the current header cannot be accessed by your provider for any reason :

if head := s.b.CurrentHeader(); head.BaseFee != nil {
        tipcap.Add(tipcap, head.BaseFee)
    }

As it would bypass the addition of the baseFee and probably result in a gasPrice lower than the baseFee itself leading to the rejection of your tx. That's just an idea.