epic: Gas Price Equilibrium

[eugypalu]

Kakarot version

Description

In the current design, we:

• relay transactions for users (execute_from_outside feature)
  • relayers pay the Starknet fee associated with their Kakarot transaction
• charge users in Kakarot Core EVM wrt to consumed EVM gas and signed gas price (base fee and max priority fee)

Problem

We need to find a way to balance relayers operational costs and user EVM fees

Non-exhaustive ideas and options:

1. In legacy transactions, there is only one concept of fee: gas price. We could use the gas price parameter to make sure the user pays (user fee := gasUsed* gasPrice) for the Starknet costs. Note that we know in advance the expected Starknet cost as well as the EVM gas a specific transaction consumes.
   TL;DR: Force legacy transactions on Kakarot & set gasPrice := starknet_total_estimated_fee/EVM_gas
2. We are able to observe dynamically Kakarot transactions on Starknet public and compute the average relayer cost per transaction as well as the average EVM gas used. And then, dynamically set the baseFee of Kakarot: baseFee := average_relayer_cost_per_transaction/average_EVM_gas

• Charge gas according to actual resources consumed #1328
• relayers-observer lambda function #1527
• fee-balancer lambda function #1528
• Set up CloudWatch alarms