feat(evm): add gas fee distribution mechanism

app/app.go

@@ -163,6 +163,8 @@ import (
 	"github.com/evmos/evmos/v12/x/ibc/transfer"
 	transferkeeper "github.com/evmos/evmos/v12/x/ibc/transfer/keeper"
 
+	v2 "github.com/evmos/evmos/v12/app/upgrades/v2"
+
 	// Force-load the tracer engines to trigger registration due to Go-Ethereum v1.10.15 changes
 	"github.com/ethereum/go-ethereum/core/vm"
 	_ "github.com/ethereum/go-ethereum/eth/tracers/js"
@@ -1077,7 +1079,7 @@ func (app *Evmos) EvmPrecompiled() {
 
 	// distribution precompile
 	precompiled[precompilesdistribution.GetAddress()] = func(ctx sdk.Context) vm.PrecompiledContract {
-		return precompilesdistribution.NewPrecompiledContract(ctx, app.DistrKeeper)
+		return precompilesdistribution.NewPrecompiledContract(ctx, app.DistrKeeper, app.EvmKeeper)
 	}
 
 	// gov precompile
@@ -1110,6 +1112,14 @@ func (app *Evmos) EvmPrecompiled() {
 }
 
 func (app *Evmos) setupUpgradeHandlers() {
+	// v2.0.0 upgrade handler
+	app.UpgradeKeeper.SetUpgradeHandler(
+		v2.UpgradeName,
+		v2.CreateUpgradeHandler(
+			app.mm, app.configurator, app.EvmKeeper,
+		),
+	)
+
 	// When a planned update height is reached, the old binary will panic
 	// writing on disk the height and name of the update that triggered it
 	// This will read that value, and execute the preparations for the upgrade.
@@ -1125,6 +1135,9 @@ func (app *Evmos) setupUpgradeHandlers() {
 	var storeUpgrades *storetypes.StoreUpgrades
 
 	switch upgradeInfo.Name {
+	case v2.UpgradeName:
+		// v2.0.0: No store upgrades needed.
+		// Gas fee distribution statistics use new key prefixes in existing EVM store.
 	}
 
 	if storeUpgrades != nil {

app/upgrades/v2/upgrades.go

@@ -0,0 +1,44 @@
+package v2
+
+import (
+	sdkmath "cosmossdk.io/math"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/module"
+	upgradetypes "github.com/cosmos/cosmos-sdk/x/upgrade/types"
+	evmkeeper "github.com/evmos/evmos/v12/x/evm/keeper"
+)
+
+const (
+	// UpgradeName is the shared upgrade plan name for mainnet
+	UpgradeName = "v2.0.0"
+	// UpgradeInfo defines the binaries that will be used for the upgrade
+	UpgradeInfo = `'{"binaries":{"darwin/arm64":"https://github.com/mud-chain/mud/releases/download/v2.0.0/mud_2.0.0_darwin_arm64.tar.gz","darwin/amd64":"https://github.com/mud-chain/mud/releases/download/v2.0.0/mud_2.0.0_darwin_amd64.tar.gz","linux/arm64":"https://github.com/mud-chain/mud/releases/download/v2.0.0/mud_2.0.0_linux_arm64.tar.gz","linux/amd64":"https://github.com/mud-chain/mud/releases/download/v2.0.0/mud_2.0.0_linux_amd64.tar.gz","windows/x86_64":"https://github.com/mud-chain/mud/releases/download/v2.0.0/mud_2.0.0_windows_x86_64.zip"}}'`
+)
+
+// CreateUpgradeHandler creates an SDK upgrade handler for v2.0.0
+//
+// This upgrade introduces gas fee distribution mechanism:
+// - 40% of gas fees are burned (sent to zero address)
+// - 40% distributed to validators
+// - 20% sent to core team address
+//
+// The upgrade initializes gas fee statistics tracking for these distributions.
+func CreateUpgradeHandler(
+	mm *module.Manager,
+	configurator module.Configurator,
+	evmKeeper *evmkeeper.Keeper,
+) upgradetypes.UpgradeHandler {
+	return func(ctx sdk.Context, _ upgradetypes.Plan, vm module.VersionMap) (module.VersionMap, error) {
+		logger := ctx.Logger().With("upgrade", UpgradeName)
+
+		// Initialize gas fee statistics
+		logger.Info("initializing gas fee distribution statistics")
+		evmKeeper.SetTotalBurnedFee(ctx, sdkmath.ZeroInt())
+		evmKeeper.SetTotalCoreTeamFee(ctx, sdkmath.ZeroInt())
+		evmKeeper.SetTotalValidatorFee(ctx, sdkmath.ZeroInt())
+
+		// Leave modules as-is to avoid running InitGenesis.
+		logger.Debug("running module migrations ...")
+		return mm.RunMigrations(ctx, configurator, vm)
+	}
+}

proto/ethermint/evm/v1/query.proto

@@ -74,6 +74,11 @@ service Query {
   rpc BaseFee(QueryBaseFeeRequest) returns (QueryBaseFeeResponse) {
     option (google.api.http).get = "/evmos/evm/v1/base_fee";
   }
+
+  // GasFeeStatistics queries the gas fee distribution statistics (total burned and project fees).
+  rpc GasFeeStatistics(QueryGasFeeStatisticsRequest) returns (QueryGasFeeStatisticsResponse) {
+    option (google.api.http).get = "/evmos/evm/v1/gas_fee_statistics";
+  }
 }
 
 // QueryAccountRequest is the request type for the Query/Account RPC method.
@@ -296,3 +301,17 @@ message QueryBaseFeeResponse {
   // base_fee is the EIP1559 base fee
   string base_fee = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int"];
 }
+
+// QueryGasFeeStatisticsRequest defines the request type for querying gas fee
+// distribution statistics.
+message QueryGasFeeStatisticsRequest {}
+
+// QueryGasFeeStatisticsResponse returns the gas fee distribution statistics.
+message QueryGasFeeStatisticsResponse {
+  // total_burned_fee is the total amount of gas fees that have been burned
+  string total_burned_fee = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false];
+  // total_core_team_fee is the total amount of gas fees sent to the core team address
+  string total_core_team_fee = 2 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false];
+  // total_validator_fee is the total amount of gas fees distributed to validators
+  string total_validator_fee = 3 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int", (gogoproto.nullable) = false];
+}

solidity/contracts/distribution/IDistribution.sol

@@ -12,6 +12,15 @@ struct DelegationDelegatorReward {
     DecCoin[] rewards;
 }
 
+/**
+ * @dev GasFeeStatistics represents the gas fee distribution statistics
+ */
+struct GasFeeStatistics {
+    uint256 totalBurnedFee;
+    uint256 totalCoreTeamFee;
+    uint256 totalValidatorFee;
+}
+
 
 /**
  * @dev Params defines the set of params for the distribution module.
@@ -147,6 +156,12 @@ interface IDistribution {
         address delegatorAddress
     ) external view returns (address withdrawAddress);
 
+    /**
+     * @dev gasFeeStatistics queries the gas fee distribution statistics.
+     * Returns total burned fees, total core team fees, and total validator fees.
+     */
+    function gasFeeStatistics() external view returns (GasFeeStatistics memory statistics);
+
     /**
      * @dev SetWithdrawAddress defines an Event emitted when a user change the withdraw address
      */

x/evm/keeper/gas_distribution.go

@@ -0,0 +1,109 @@
+package keeper
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/core"
+
+	errorsmod "cosmossdk.io/errors"
+	sdkmath "cosmossdk.io/math"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+)
+
+const (
+	// Gas fee distribution ratios (in percentage)
+	BurnRatio      = 40 // 40% burn (send to zero address)
+	ValidatorRatio = 40 // 40% to validators (kept in FeeCollector)
+	CoreTeamRatio  = 20 // 20% to core team
+
+	// Zero address for burning tokens
+	BurnAddress = "mud1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq4sx9vz"
+
+	// Core team address (hardcoded)
+	CoreTeamAddress = "mud1d58wfeq0re6awm7t3qynu6dz5cwk787phgl0f9"
+)
+
+// DistributeGasFee distributes the gas fee according to the configured ratios:
+// - 40% sent to zero address (burn)
+// - 40% to validators (kept in FeeCollector for distribution module)
+// - 20% to core team address
+func (k *Keeper) DistributeGasFee(ctx sdk.Context, msg core.Message, gasUsed uint64, denom string) error {
+	// Calculate the actual gas fee consumed
+	gasFee := new(big.Int).Mul(new(big.Int).SetUint64(gasUsed), msg.GasPrice())
+
+	// If gas fee is zero, nothing to distribute
+	if gasFee.Sign() <= 0 {
+		return nil
+	}
+
+	totalFee := sdkmath.NewIntFromBigInt(gasFee)
+
+	// Calculate distribution amounts
+	// burnAmount = totalFee * 40 / 100
+	burnAmount := totalFee.Mul(sdkmath.NewInt(BurnRatio)).Quo(sdkmath.NewInt(100))
+	// coreTeamAmount = totalFee * 20 / 100
+	coreTeamAmount := totalFee.Mul(sdkmath.NewInt(CoreTeamRatio)).Quo(sdkmath.NewInt(100))
+	// validatorAmount = totalFee - burnAmount - coreTeamAmount (remaining goes to validators)
+	validatorAmount := totalFee.Sub(burnAmount).Sub(coreTeamAmount)
+
+	// 1. Send 40% to zero address (burn)
+	if burnAmount.IsPositive() {
+		burnAddr, err := sdk.AccAddressFromBech32(BurnAddress)
+		if err != nil {
+			k.Logger(ctx).Error("invalid burn address", "address", BurnAddress, "error", err)
+		} else {
+			burnCoins := sdk.NewCoins(sdk.NewCoin(denom, burnAmount))
+			if err := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, authtypes.FeeCollectorName, burnAddr, burnCoins); err != nil {
+				return errorsmod.Wrapf(err, "failed to send gas fee to burn address: %s", burnCoins.String())
+			}
+
+			// Update burn statistics
+			k.AddTotalBurnedFee(ctx, burnAmount)
+
+			k.Logger(ctx).Debug("sent gas fee to burn address", "amount", burnAmount.String(), "denom", denom, "address", BurnAddress)
+		}
+	}
+
+	// 2. Send 20% to core team address
+	if coreTeamAmount.IsPositive() {
+		coreTeamAddr, err := sdk.AccAddressFromBech32(CoreTeamAddress)
+		if err != nil {
+			// If core team address is invalid, log error but don't fail the transaction
+			// The core team amount will remain in FeeCollector
+			k.Logger(ctx).Error("invalid core team address", "address", CoreTeamAddress, "error", err)
+		} else {
+			coreTeamCoins := sdk.NewCoins(sdk.NewCoin(denom, coreTeamAmount))
+			if err := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, authtypes.FeeCollectorName, coreTeamAddr, coreTeamCoins); err != nil {
+				return errorsmod.Wrapf(err, "failed to send gas fee to core team: %s", coreTeamCoins.String())
+			}
+
+			// Update core team fee statistics
+			k.AddTotalCoreTeamFee(ctx, coreTeamAmount)
+
+			k.Logger(ctx).Debug("sent gas fee to core team", "amount", coreTeamAmount.String(), "denom", denom, "address", CoreTeamAddress)
+		}
+	}
+
+	// 3. The remaining 40% stays in FeeCollector and will be distributed to validators
+	// by the distribution module at the end of each block
+	// Update validator fee statistics
+	if validatorAmount.IsPositive() {
+		k.AddTotalValidatorFee(ctx, validatorAmount)
+	}
+
+	// Emit event for gas fee distribution
+	ctx.EventManager().EmitEvent(
+		sdk.NewEvent(
+			"gas_fee_distribution",
+			sdk.NewAttribute("gas_used", sdkmath.NewIntFromUint64(gasUsed).String()),
+			sdk.NewAttribute("total_fee", totalFee.String()),
+			sdk.NewAttribute("burned", burnAmount.String()),
+			sdk.NewAttribute("core_team", coreTeamAmount.String()),
+			sdk.NewAttribute("validator", validatorAmount.String()),
+			sdk.NewAttribute("denom", denom),
+		),
+	)
+
+	return nil
+}