reth-abci (Tiny Skeleton)

A minimal ABCI app to drive an Ethereum execution layer (Reth) from CometBFT. This repository is intentionally tiny and compile-friendly without Reth; enable the with-reth feature to wire real execution once you pin matching Reth crate versions.

Layout

reth-abci/
├─ Cargo.toml                # workspace
└─ crates/abci-node/
   ├─ Cargo.toml             # features + deps
   └─ src/
      ├─ main.rs             # boots ABCI server (tcp://127.0.0.1:26658)
      ├─ app.rs              # ABCI methods
      ├─ exec.rs             # RethCtx + block execution (feature-gated)
      └─ wire.rs             # tx decoding, apphash util (feature-gated)

Build & run (stub, no Reth)

This mode compiles everywhere so you can test CometBFT plumbing first.

cargo build -p abci-node
cargo run -p abci-node

Then point CometBFT at it:

# ~/.cometbft/config/config.toml
proxy_app = "tcp://127.0.0.1:26658"
create_empty_blocks = false
timeout_propose = "1s"
timeout_precommit = "1s"

Run CometBFT:

cometbft init
cometbft start

Enable real Reth integration

1. Check your Reth version:

   reth --version

2. Edit crates/abci-node/Cargo.toml to pin all reth* crates to the same minor.
3. Build with feature:

   cargo run -p abci-node --features with-reth

4. Fill TODOs in:
   • RethCtx::open() – open MDBX, load ChainSpec, init txpool
   • validate_tx_basic() – sig/nonce/balance checks
   • propose_block() – policy + pre-sim (optional)
   • apply_tx() – execute via reth-evm, update overlay/receipts
   • commit() – flush overlay, compute real stateRoot & receiptsRoot

Milestones

• ✅ ABCI plumbing with stubbed execution
• ☐ Real EVM execution via Reth
• ☐ EIP-1559 basefee at end_block
• ☐ Deterministic AppHash = keccak(stateRoot || receiptsRoot)
• ☐ Minimal eth JSON-RPC facade (balance, block, receipt)

License

MIT