maxPriorityFeePerGas

MaxPriorityFeePerGas is a parameter of Ethereum transactions introduced with EIP-1559. It represents the maximum amount of tip per unit of gas that a sender is willing to pay to miners to prioritize their transaction. The value is expressed in gwei and works in conjunction with maxFeePerGas to govern transaction fees under the base fee/tip model.

In the EIP-1559 fee model, each transaction specifies both maxFeePerGas and maxPriorityFeePerGas. The baseFeePerGas is determined by network demand and is burned. The actual tip received by the miner is the minimum of maxPriorityFeePerGas and (maxFeePerGas minus baseFeePerGas). The total price per gas unit paid by the sender is baseFeePerGas plus that tip. If maxFeePerGas is less than baseFeePerGas, the transaction cannot be included.

The practical effect is that increasing maxPriorityFeePerGas can make a transaction more attractive to miners, potentially speeding up inclusion during congestion. Setting maxPriorityFeePerGas to zero removes the tip. Users balance cost and speed, often relying on wallet defaults or guidance to set an appropriate value.

Compatibility considerations: on networks or nodes that do not support EIP-1559, maxPriorityFeePerGas is ignored and legacy gasPrice is used instead. It is also important to note that baseFeePerGas is burned, while the tip portion represented by maxPriorityFeePerGas goes to the miner as an incentive.

---