Rollup-as-a-Service setup (Conduit, Caldera, AltLayer)

Rollup-as-a-Service Setup (Conduit, Caldera, AltLayer)

Launching your own L2 in 2024 is no longer a task for 20 engineers over half a year. RaaS (Rollup-as-a-Service) platforms — Conduit, Caldera, AltLayer, Gelato Rollup-as-a-Service — lowered the entry barrier to hours of setup. But this doesn't mean there's nothing to configure: stack choice, sequencer parameters, DA layer, bridge configuration, fee token, gas limits — all require conscious decisions.

Technology stack selection

All modern RaaS platforms are built on one of three frameworks:

For most gaming and NFT projects — OP Stack via Conduit: simplest, greatest tooling compatibility (Foundry, Hardhat, Etherscan support via Blockscout).

For financial apps needing ZK-finality — Polygon CDK or zkSync ZK Stack.

Conduit: OP Stack rollup setup

Conduit is the most popular OP Stack platform. Deployment process:

1. Chain parameter configuration

Key parameters to set on creation:

# Example Conduit chain configuration
chain:
  name: "MyAppChain"
  chain_id: 42069          # unique, no conflicts on chainlist.org
  block_time: 2            # seconds, OP Stack standard
  gas_limit: 30000000      # like Ethereum mainnet

sequencer:
  fee_token: ETH           # or custom ERC-20
  base_fee_recipient: "0x..."  # where base fees go
  l1_fee_recipient: "0x..."    # where L1 data fees go

data_availability:
  type: ethereum           # or celestia, eigenda
  l1_chain: mainnet        # or sepolia for testnet

genesis:
  l2_output_oracle_starting_block_number: 0
  fund_dev_accounts: false # testnet only

2. Bridge configuration

Standard OP Stack bridge (OptimismPortal + L1CrossDomainMessenger) deploys automatically with Conduit. Critical to understand limitations:

• L1→L2 deposit: ~1-2 minutes
• L2→L1 withdrawal: 7 days (challenge period for fraud proofs)

7 days is unacceptable for UX. Standard solution — integrate liquidity bridge on top of native bridge: Across Protocol, Hop Protocol, Socket. They provide withdrawals in minutes through liquidity providers who assume wait risk.

3. Custom gas token

OP Stack supports using an ERC-20 token instead of ETH as gas token. Requires setting CustomGasToken in genesis configuration:

// In genesis config for custom gas token
const genesisConfig = {
    gasPayingToken: {
        addr: ERC20_TOKEN_ADDRESS,  // L1 token address
        decimals: 18,
    }
}

Important limits: custom gas token must be ERC-20 without rebasing/fee-on-transfer mechanics. USDC, WETH work. Standard ERC-20 works. stETH doesn't.

Caldera: multi-stack and customization

Caldera supports OP Stack, Arbitrum Orbit, and ZK Stack in a single interface. Adds enterprise features:

Mach (fast finality) — Caldera-specific technology for OP Stack chain, reducing effective finality from 7 days to minutes via attestation network similar to EigenLayer AVS.

Rollup configuration via API — useful for IaC approach:

# Create rollup via Caldera API
curl -X POST https://api.caldera.xyz/v1/rollups \
  -H "Authorization: Bearer $CALDERA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "my-appchain",
    "stack": "op-stack",
    "network": "mainnet",
    "chainId": 42069,
    "config": {
      "blockTime": 2,
      "gasLimit": "30000000",
      "dataAvailability": "ethereum",
      "gasToken": "ETH"
    }
  }'

AltLayer: re-staked rollups and flash rollups

AltLayer builds on EigenLayer re-staking infrastructure. Key feature — Restaked Rollups: validators/sequencers backed by restaked ETH, providing additional security guarantees without separate token economics.

Flash Layer — temporary rollups for specific events (NFT drop, game tournament, high-load drop). Deploys for hours, then liquidates. State can settle back to L1 or persistent L2.

Data Availability: Ethereum vs Celestia vs EigenDA

DA layer choice is one of the key architectural decisions:

Ethereum calldata / EIP-4844 blobs — most secure option. After EIP-4844 (Dencun upgrade), blob DA cost dropped 10-100x. Standard choice for production.

Celestia — separate DA layer with lower cost and higher throughput. Requires trust in Celestia network (separate validator set). Good for high-load apps where DA cost is critical.

EigenDA — DA via EigenLayer operators (re-staked ETH). Compromise between Ethereum security and Celestia cost.

DA cost (approximate):
Ethereum blobs: ~$0.001-0.01 / KB
EigenDA:        ~$0.0001 / KB  
Celestia:       ~$0.00001 / KB

Post-deployment: what to configure

After RaaS platform deploys, it creates basic infrastructure. Additionally needed:

Blockscout / Explorer: all platforms offer built-in explorer, but for custom branding — self-hosted Blockscout. Configuration is minimal: specify RPC URL and chain ID.

Monitoring: RPC endpoint uptime, sequencer lag (gap between L1 head and L2), bridge pending withdrawals. Grafana + Prometheus, metrics exported by most RaaS platforms.

Testnet faucet: simple service, important for developer onboarding.

Multicall3 deploy: address 0xcA11bde05977b3631167028862bE2a173976CA11 — standard on most networks, but may not exist on fresh rollup. Deploy — one transaction.

Chainlist.org registration: for public chains — submit to ethereum-lists/chains repository.

Typical timeline: 1-2 days for deploy and basic setup, plus 3-5 days for custom bridge UI integration, explorer, monitoring, and testing.