# Hooks

The fees module implements one transaction hook from the `x/evm` module in order to distribute fees between developers and validators.

### EVM Hook <a href="#evm-hook" id="evm-hook"></a>

A `PostTxProcessing` EVM hook executes custom logic after each successful EVM transaction. All fees paid by a user for transaction execution are sent to the `FeeCollector` module account during the `AnteHandler` execution before being distributed to developers and validators.

If the `x/feesplit` module is disabled or the EVM transaction targets an unregistered contract, the EVM hook returns `nil`, without performing any actions. In this case, 100% of the transaction fees remain in the `FeeCollector` module, to be distributed to the block proposer.

If the `x/feesplit` module is enabled and a EVM transaction targets a registered contract, the EVM hook sends a percentage of the transaction fees (paid by the user) to the withdraw address set for that contract, or to the contract deployer.

1. User submits EVM transaction (`MsgEthereumTx`) to a smart contract and transaction is executed successfully
2. Check if
   * fees module is enabled
   * smart contract is registered to receive fees
3. Calculate developer fees according to the `DeveloperShares` parameter. The initial transaction message includes the gas price paid by the user and the transaction receipt, which includes the gas used by the transaction.

```go
devFees := receipt.GasUsed * msg.GasPrice * params.DeveloperShares
```

&#x20; 4\. Transfer developer fee from the `FeeCollector` (Cosmos SDK `auth` module account) to the registered withdraw address for that contract. If there is no withdraw address, fees are sent to contract deployer's address.

&#x20; 5\. Distribute the remaining amount in the `FeeCollector` to validators according to the [SDK Distribution Scheme](https://docs.cosmos.network/main/modules/distribution/03_begin_block.html#the-distribution-scheme).