evm/deployments/alternative-l2s/based-rollup

Based Rollup on Ethereum

Deploy a based rollup that uses Ethereum L1 for sequencing while settling on Lux.

Overview

Based rollups achieve maximum decentralization by:

• Using Ethereum L1 for transaction sequencing
• No centralized sequencer
• Settling state on Lux for cheaper execution
• MEV captured by Ethereum validators

Architecture

Ethereum L1 (Sequencing) → Based Rollup → Lux C-Chain (Settlement)

Components

1. Ethereum Contracts

   • Inbox: Accepts L2 transactions
   • Outbox: Processes withdrawals

2. Lux Contracts

   • StateCommitment: Stores L2 state roots
   • FraudVerifier: Handles fraud proofs
   • Bridge: Asset bridging

3. Services

   • Prover: Generates execution proofs
   • Relayer: Syncs between chains

Deployment

Deploy on Ethereum

cd contracts/ethereum
export ETH_RPC_URL=https://eth-mainnet.g.alchemy.com/<key>

# Deploy inbox
forge create --rpc-url $ETH_RPC_URL \
  --private-key $PRIVATE_KEY \
  src/Inbox.sol:Inbox \
  --constructor-args $LUX_COMMITMENT_CONTRACT

Deploy on Lux

cd contracts/lux
export LUX_RPC_URL=https://api.lux.network/rpc

# Deploy state commitment
forge create --rpc-url $LUX_RPC_URL \
  --private-key $PRIVATE_KEY \
  src/StateCommitment.sol:StateCommitment \
  --constructor-args $ETH_INBOX_ADDRESS

Start Services

# Start prover
npm run prover:start -- \
  --eth-rpc $ETH_RPC_URL \
  --lux-rpc $LUX_RPC_URL \
  --inbox $ETH_INBOX_ADDRESS \
  --commitment $LUX_COMMITMENT_ADDRESS

# Start relayer
npm run relayer:start -- \
  --source ethereum \
  --destination lux

Usage

Submit Transaction

// Send L2 transaction via Ethereum
const inbox = new ethers.Contract(INBOX_ADDRESS, INBOX_ABI, ethSigner);

const l2Tx = {
  to: "0x...",
  value: 0,
  data: "0x...",
  gasLimit: 1000000
};

await inbox.submitTransaction(l2Tx, { value: estimatedCost });

Read L2 State

// Query state from Lux
const commitment = new ethers.Contract(
  COMMITMENT_ADDRESS, 
  COMMITMENT_ABI, 
  luxProvider
);

const stateRoot = await commitment.stateRoots(blockNumber);

Benefits

1. Maximum Decentralization

   • No sequencer monopoly
   • Ethereum validators order transactions
   • Censorship resistance from Ethereum

2. Cost Efficiency

   • Settlement on Lux is cheaper
   • Users pay Ethereum gas + small Lux fee
   • Batch proofs amortize costs

3. Security

   • Ethereum ordering security
   • Lux economic security
   • Fraud proof protection

Trade-offs

• Higher latency (Ethereum block time)
• More complex architecture
• Requires monitoring two chains