Morph Reth

Overview

Morph Reth is the next-generation execution client for Morph, a decentralized Layer 2 scaling solution for Ethereum. Built on the modular Reth SDK, it provides high-performance block execution with Morph-specific features.

Key Features

• L1 Message Support: Seamless bridging of assets and messages from Ethereum L1 to Morph L2
• Morph Transaction: Morph EVM+ transaction enabling alternative token fees, reference key indexing, and memo attachment
• Morph Hardforks: Full support for Morph's upgrade schedule (Bernoulli, Curie, Morph203, Viridian, Emerald, Jade)
• Custom Engine API: L2-specific Engine API for sequencer block building and validation
• L1 Fee Validation: Transaction pool with L1 data fee affordability checks

Supported Networks

Network	Chain ID	Type
Morph Mainnet	2818	Production
Morph Hoodi	2910	Testnet

Architecture

Morph Reth is designed as a modular extension of Reth, following the SDK pattern:

morph-reth/
├── bin/
│   └── morph-reth/      # Main CLI binary
└── crates/
    ├── chainspec/        # Morph chain specification and hardfork definitions
    ├── consensus/        # L2 block validation (header, body, L1 messages)
    ├── engine-api/       # Custom L2 Engine API (assemble/validate/import blocks)
    ├── evm/              # EVM configuration and block execution
    ├── node/             # Node assembly with component builders
    ├── payload/
    │   ├── builder/      # Block building logic
    │   └── types/        # Engine API types (MorphExecutionData, etc.)
    ├── primitives/       # Core types (transactions, receipts)
    ├── revm/             # L1 fee calculation, token fee logic
    ├── rpc/              # RPC implementation and type conversions
    └── txpool/           # Transaction pool with L1 fee validation

Crates

Crate	Description
morph-reth	Main CLI binary — Morph L2 Execution Layer Client
morph-chainspec	Chain specification with Morph hardfork definitions
morph-consensus	Consensus validation for L2 blocks
morph-engine-api	Custom L2 Engine API for sequencer interaction
morph-evm	EVM configuration and receipt builder
morph-node	Node implementation with modular component builders
morph-payload-types	Engine API payload types
morph-payload-builder	Block building implementation
morph-primitives	Transaction and receipt types
morph-revm	L1 fee and token fee calculations
morph-rpc	RPC implementation and type conversions
morph-txpool	Transaction pool with L1 fee and MorphTx validation

Getting Started

Prerequisites

• Rust 1.88 or later
• Cargo

Building from Source

git clone https://github.com/morph-l2/morph-reth.git
cd morph-reth
cargo build --release

Running the Node

Morph Reth is a sequencer-driven L2 execution client. It does not sync blocks via P2P — blocks are delivered through the custom L2 Engine API by an external sequencer or derivation pipeline.

# Generate a JWT secret for Engine API authentication
openssl rand -hex 32 > jwt.hex

# Run on Morph mainnet
./target/release/morph-reth node \
  --chain mainnet \
  --http \
  --authrpc.jwtsecret jwt.hex

# Run on Hoodi testnet
./target/release/morph-reth node \
  --chain hoodi \
  --http \
  --authrpc.jwtsecret jwt.hex

# Run with a custom genesis file
./target/release/morph-reth node \
  --chain /path/to/genesis.json \
  --http \
  --authrpc.jwtsecret jwt.hex

Note: The node requires a sequencer or derivation pipeline to call the Engine API (engine_assembleL2Block, engine_newL2Block, etc.) for block production and import. See Morph Documentation for full deployment guides.

Morph-Specific CLI Flags

Flag	Default	Description
--morph.max-tx-payload-bytes	122880 (120KB)	Maximum transaction payload bytes per block
--morph.max-tx-per-block	None (unlimited)	Maximum number of transactions per block
--morph.geth-rpc-url	None	Geth RPC URL for cross-validating MPT state root via morph_diskRoot

Running Tests

# Run all tests
cargo test --all

# Run tests for a specific crate
cargo test -p morph-consensus

Development

# Format code
cargo +nightly fmt --all

# Run clippy
cargo clippy --all --all-targets -- -D warnings

# Check documentation
cargo doc --no-deps --document-private-items

Morph L2 Specifics

Transaction Types

Morph supports the following transaction types:

Type	ID	Description
Legacy	0x00	Standard legacy transactions
EIP-2930	0x01	Access list transactions
EIP-1559	0x02	Dynamic fee transactions
EIP-7702	0x04	Delegate EOA execution to smart contract code
L1 Message	0x7e	L1-to-L2 deposit messages
Morph Transaction	0x7f	Morph EVM+ transaction with enhanced features

L1 Messages

L1 messages are special deposit transactions that originate from Ethereum L1:

• Must appear at the beginning of each block
• Must have strictly sequential queue_index values
• Gas is prepaid on L1, so no L2 gas fee is charged
• Cannot be sent via the mempool (sequencer only)

Morph Transaction

Morph Transaction (0x7f) is Morph's EVM+ transaction type, extending standard EVM transactions for better user experience and enterprise integration:

Feature	Description
Alternative Fee Tokens	Pay gas in stablecoins (USDT, USDC) or other ERC-20 tokens — no ETH required
Transaction Reference	Tag transactions with a 32-byte key for order tracking and payment reconciliation
Memo Field	Attach notes or invoice numbers (up to 64 bytes) for auditing and record-keeping

Hardforks

Bernoulli and Curie use block-based activation; Morph203, Viridian, Emerald, and Jade use timestamp-based activation.

Hardfork	Activation	Description
Bernoulli	Block	Initial L2 launch with disabled ripemd160 and blake2f precompiles
Curie	Block	EIP-1559 fee market activation with blob-based L1 data fee
Morph203	Timestamp	Re-enable ripemd160 and blake2f precompiles
Viridian	Timestamp	EIP-7702 EOA delegation support
Emerald	Timestamp	BLS12-381 and P256verify precompiles
Jade	Timestamp	MPT state root validation, MorphTx V1 with reference and memo fields

Engine API

Morph provides a custom L2 Engine API (different from the standard Ethereum Engine API) for sequencer interaction:

Method	Description
engine_assembleL2Block	Build a new block with given transactions
engine_validateL2Block	Validate a block without importing
engine_newL2Block	Import and finalize a block
engine_newSafeL2Block	Import a safe block from derivation

Contributing

See CONTRIBUTING.md for guidelines on how to contribute.

License

Licensed under either of:

• Apache License, Version 2.0
• MIT License

at your option.

Links

• Morph Website
• Morph Documentation
• Morph GitHub
• Reth Documentation