Introduction

EthBFT is a thin BFT consensus adapter for Ethereum Execution Layer clients. CometBFT decides complete Ethereum execution payloads, and every validator asks an independent Geth node to validate the same state transition.

Status: v0.1.1 MVP. The default Docker network has one validator. The protocol path is designed for one dedicated EL per CometBFT validator, but the project is not yet a production multi-validator network.

Current protocol

• The proposer builds an Engine API V2 execution payload in PrepareProposal.
• A canonical RLP envelope and the exact ordered payload transactions become the CometBFT proposal.
• Validators reconstruct the payload and require engine_newPayloadV2 to return VALID in ProcessProposal.
• Only after CometBFT decides the proposal does EthBFT advance canonical EL forkchoice.
• The ABCI app hash commits to the EL block hash, state root, receipts root, and transaction root.
• Commit persists the CometBFT height to EL block mapping with an fsynced atomic state update.

MVP boundary

Protocol v1 supports a Shanghai-only private execution chain, Engine API V2, empty withdrawals, and non-blob Ethereum transactions. State sync, dynamic validators, mixed execution clients, and external light-client proofs remain future work.

See RFC 0001 for the complete target protocol and security model.