eth_gasPrice return values

[rodrigoherrerai]

Hi,

I have a couple of questions regarding eth_gasPrice.

1. For chains that support EIP-1559 what is the exact return value ?
2. For chains that do not support EIP-1559 what is the returned value ?

Thanks !

[zemse]

For chains that support EIP-1559 what is the exact return value ?

It gives: last block base fee + avg priority fee (while querying alchemy node it seemed to be 0.15930 gwei on mainnet, but avg priority fees on a etherscan chart say it's around 1-2 gwei usually).

For chains that do not support EIP-1559 what is the returned value ?

It gives a value suggested by the gas price oracle in the node. A standard eth node has a gas price oracle which is exposed over RPC under eth namespace. From geth docs:

GAS PRICE ORACLE OPTIONS:
  --gpo.blocks value                  Number of recent blocks to check for gas prices (default: 20)
  --gpo.percentile value              Suggested gas price is the given percentile of a set of recent transaction gas prices (default: 60)
  --gpo.maxprice value                Maximum transaction priority fee (or gasprice before London fork) to be recommended by gpo (default: 500000000000)
  --gpo.ignoreprice value             Gas price below which gpo will ignore transactions (default: 2)