Feemarket
Note
XPLA Chain’s feemarket module inherits from Evmos’s feemarket module. This document is a stub and covers mainly important XPLA Chain-specific notes about how it is used.
The feemarket module which allows to define a global transaction fee for the network.
This module has been designed to support EIP1559 in cosmos-sdk.
The MempoolFeeDecorator in x/auth module needs to be overrided to the minimal-gas-prices.
This module will be used in the XPLA Chain.
Concepts
The transaction fee is calculated with
fee = gasPrice * gasLimit
where gasPrice is the price per gas and gasLimit describes the amount of gas required to perform the transaction.
The more complex operations a transaction requires, the higher the gasLimit (See Executing EVM bytecode).
To submit a transaction, the signer needs to specify the gasPrice.
gas than Ethereum.
What is called gasLimit on Ethereum is called gasWanted on Cosmos.
You might encounter both terminologies on XPLA Chain since it builds Ethereum on top of the SDK,
e.g. when using different wallets like Keplr for Cosmos and Metamask for Ethereum.Transitions
End block
The block_gas_used value is updated at the end of each block.
Block Gas Used
The total gas used by current block is stored in the KVStore at EndBlock.
It is initialized to block_gas defined in the genesis.
Parameters
The x/feemarket module contains the following parameters:
// Params defines the EVM module parameters
type Params struct {
// no_base_fee forces the EIP-1559 base fee to 0 (needed for 0 price calls)
NoBaseFee bool `protobuf:"varint,1,opt,name=no_base_fee,json=noBaseFee,proto3" json:"no_base_fee,omitempty"`
// base_fee_change_denominator bounds the amount the base fee can change
// between blocks.
BaseFeeChangeDenominator uint32 `protobuf:"varint,2,opt,name=base_fee_change_denominator,json=baseFeeChangeDenominator,proto3" json:"base_fee_change_denominator,omitempty"`
// elasticity_multiplier bounds the maximum gas limit an EIP-1559 block may
// have.
ElasticityMultiplier uint32 `protobuf:"varint,3,opt,name=elasticity_multiplier,json=elasticityMultiplier,proto3" json:"elasticity_multiplier,omitempty"`
// enable_height defines at which block height the base fee calculation is enabled.
EnableHeight int64 `protobuf:"varint,5,opt,name=enable_height,json=enableHeight,proto3" json:"enable_height,omitempty"`
// base_fee for EIP-1559 blocks.
BaseFee github_com_cosmos_cosmos_sdk_types.Int `protobuf:"bytes,6,opt,name=base_fee,json=baseFee,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Int" json:"base_fee"`
// min_gas_price defines the minimum gas price value for cosmos and eth transactions
MinGasPrice github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,7,opt,name=min_gas_price,json=minGasPrice,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"min_gas_price"`
// min_gas_multiplier bounds the minimum gas used to be charged
// to senders based on gas limit
MinGasMultiplier github_com_cosmos_cosmos_sdk_types.Dec `protobuf:"bytes,8,opt,name=min_gas_multiplier,json=minGasMultiplier,proto3,customtype=github.com/cosmos/cosmos-sdk/types.Dec" json:"min_gas_multiplier"`
}