BEP: 226
    Title: Enable EIP-1559 with base fee of 0
    Status: Pre-Draft
    Type: Standards
    Created: 2023-04-17

BEP-226: Enable EIP-1559 with base fee of 0

• BEP-226: Enable EIP-1559 with base fee of 0
  • 1. Summary
  • 2. Motivation
  • 3. Specification
  • 4. Backwards Compatibility
  • 5. License

1. Summary

This BEP introduces EIP-1559 headers and transactions to BSC but with base fee set to 0.

2. Motivation

To keep up to date with the latest developments in EVM blockchains it is important to keep the block and transaction structures up to date. New features (such as account abstraction) being introduced
to EVM chains already presuppose EIP-1559 type of block headers and transactions. Therefore, for compatibility reasons it is important that EIP-1559 constructs be enabled on BSC.

EIP-1559 was introduced in Ethereum to improve the gas fee pricing mechanism and to make the ETH token more deflationary, as the base fee would be burnt after a transaction was completed. In BSC there is already a burning mechanism in place (BEP-95) so there is no need to burn the base fee. Therefore the base fee will be set to 0, and will
not adjust based on network congestion like in the Ethereum EIP.

3. Specification

Essentially the same gas fee mechanism will be kept in place but the extra BaseFee field will be enabled in the header (which will be required to be 0). In addition, the GasTipCap (a.k.a. maxPriorityFeePerGas) and maxFeePerGas fields will be enabled by using a dynamic transaction type instead of the legacy transaction types. Since baseFee will be 0, maxPriorityFeePerGas = maxFeePerGas .

The code for EIP-1559 has already been merged from upstream go-ethereum codebase into BSC node codebase, but some custom modifications are still needed (to maintain a constant base fee of 0, and disable extra checks that keep track of the gas utilization over time ) and to ensure everything works correctly before a hard fork enabling this BEP on BSC network.

4. Backwards Compatibility

Legacy transactions will still work and be included in blocks. This is due to the fact that upgrading from legacy transactions to new transactions results in the legacy transaction's gas_price entirely being consumed either by the base_fee_per_gas and the priority_fee_per_gas.

5. License

Copyright and related rights waived via CC0.