Get base fee to caculate the transaction fee

[haianh130799]

@ricmoo can you help me to estimate transaction fee on eip 1559 ?

[haianh130799]

https://ropsten.etherscan.io/tx/0x47e0f8c979f2d51fe244aed3110263371f96a766ca5351c4c044bcfb391d853e
How to estimate the gas price of transaction before i submit it ?

[ricmoo]

You probably want to use the provider.getFeeData.

The current defaults are to use twice the most recents block's baseFee and use 2.5 gwei for the priority fee.

In the future the priority fee will be based on additional properties queried from a node, but for now 2.5 gwei accounts for both uncle risk (+1 gwei) and for the majority (I believe TP90) of MEV risk (+1.5 gwei).

[haianh130799]

@ricmoo [Error: cannot estimate gas; transaction may fail or may require manual gas limit (error={"reason":"processing response error","code":"SERVER_ERROR","body":"{"jsonrpc":"2.0","id":103,"error":{"code":-32000,"message":"err: max fee per gas less than block base fee"] how can i detect extract error message instead of error cannot estimate gas ?

[zemse]

@haianh130799 you can try catching the error and chain it down with .error

try {
  await yourCall()
} catch (e) {
  console.lg(e.error) // or e.error.error
}

[haianh130799]

I want error max fee per gas less than block base fee