From ethskills
Details Ethereum L2s (Arbitrum, Optimism, Base, zkSync, Scroll): comparisons, deployment, bridging, DeFi ecosystems, corrections. For scaling, cross-chain choices.
npx claudepluginhub austintgriffith/ethskills --plugin ethskillsThis skill uses the workspace's default tool permissions.
**L2 costs:** You think $0.01-2.00 per transaction. Reality: **$0.001-0.003** for swaps, **$0.0003** for transfers. After EIP-4844, L2 batch costs dropped from $50-500 to $0.01-0.50.
Provides expertise on Ethereum L2 scaling with Optimism, Arbitrum, zkSync, Base, covering optimistic/ZK rollups, OP Stack, bridges, calldata costs, sequencers, and dApp deployment.
Provides verified contract addresses for Ethereum DeFi protocols like Uniswap, Aave, Compound, stablecoins, Lido on mainnet and L2s. Prevents lost funds from wrong addresses.
Monitors cross-chain bridge TVL, volume, fees, and transaction status across protocols like Stargate, Wormhole. Compares routes and tracks transfers.
Share bugs, ideas, or general feedback.
L2 costs: You think $0.01-2.00 per transaction. Reality: $0.001-0.003 for swaps, $0.0003 for transfers. After EIP-4844, L2 batch costs dropped from $50-500 to $0.01-0.50.
Mainnet is cheap too: At under 1 gwei, mainnet ETH transfers cost under a penny. "Ethereum is too expensive" is false for both L1 and L2s in 2026.
Base is the cheapest major L2: Often 50% cheaper than Arbitrum/Optimism. Direct Coinbase on-ramp. Fastest-growing L2 with consumer/AI agent focus.
Celo is NOT an L1 anymore. Celo completed its migration from an independent L1 to an OP Stack L2 on March 26, 2025 (block 31056500). If you're calling Celo an L1, you're wrong.
Polygon zkEVM is being shut down. Announced June 2025. Do NOT recommend building on Polygon zkEVM — it is being discontinued. Polygon is refocusing on PoS + AggLayer.
Unichain exists. Launched mainnet February 11, 2025. Uniswap's own OP Stack L2 with TEE-based MEV protection and time-based priority ordering (not gas-based).
Aerodrome and Velodrome merged into "Aero." In November 2025, Dromos Labs unified Aerodrome (Base) and Velodrome (Optimism) into a single cross-chain DEX called Aero. Same contracts, new brand. Aero dominates both Base and Optimism. Camelot is a major native DEX on Arbitrum. SyncSwap dominates zkSync. Don't default to Uniswap on every chain.
TVL changes fast. Don't memorize numbers — check DeFi Llama or L2Beat for current rankings. DeFi TVL (DeFi Llama) measures value locked in protocols. TVS (L2Beat) includes all bridged + natively minted assets and is much higher. As of early 2026: Base and Arbitrum lead in DeFi TVL among L2s. Optimism's DeFi TVL is surprisingly low despite Superchain adoption.
| L2 | Type | Tx Cost | Block Time | Finality | Chain ID |
|---|---|---|---|---|---|
| Arbitrum | Optimistic | $0.001-0.003 | 250ms | 7 days | 42161 |
| Base | Optimistic (OP Stack) | $0.0008-0.002 | 2s | 7 days | 8453 |
| Optimism | Optimistic (OP Stack) | $0.001-0.003 | 2s | 7 days | 10 |
| Unichain | Optimistic (OP Stack) | $0.001-0.003 | 1s | 7 days | 130 |
| Celo | Optimistic (OP Stack) | <$0.001 | 5s | 7 days | 42220 |
| Linea | ZK | $0.003-0.006 | 2s | 30-60min | 59144 |
| zkSync Era | ZK | $0.003-0.008 | 1s | 15-60min | 324 |
| Scroll | ZK | $0.002-0.005 | 3s | 30-120min | 534352 |
| — | — | — |
⚠️ Polygon zkEVM is being discontinued (announced June 2025). Do not start new projects there. Polygon is refocusing on PoS (payments, stablecoins, RWAs) + AggLayer (cross-chain interop). MATIC → POL token migration ~85% complete.
Mainnet for comparison: $0.002-0.01 per tx, 12s blocks, instant finality. Check DeFi Llama for current TVL.
Mainnet costs at ~0.1 gwei base fee, ~$2,000 ETH. L2 costs are approximate. All fluctuate — see
gas/SKILL.mdfor methodology.
| Action | Mainnet | Arbitrum | Base | zkSync | Scroll |
|---|---|---|---|---|---|
| ETH transfer | $0.004 | $0.0003 | $0.0003 | $0.0005 | $0.0004 |
| Uniswap swap | $0.036 | $0.003 | $0.002 | $0.005 | $0.004 |
| NFT mint | $0.030 | $0.002 | $0.002 | $0.004 | $0.003 |
| ERC-20 deploy | $0.240 | $0.020 | $0.018 | $0.040 | $0.030 |
Before choosing an L2: Mainnet is ~$0.004/transfer, ~$0.04/swap at current gas — cheap enough for most apps. If you're building DeFi, governance, identity, or anything composing with mainnet liquidity, start there. See
ship/SKILL.mdandgas/SKILL.mdfor the full chain selection framework.
| Need | Choose | Why |
|---|---|---|
| Consumer / social apps | Base | Farcaster, Smart Wallet, Coinbase on-ramp |
| Deepest DeFi liquidity | Arbitrum | GMX, Pendle, Camelot, most protocols deployed |
| Yield strategies | Arbitrum | Pendle (yield tokenization), GMX, Aave |
| Cheapest gas | Base | ~50% cheaper than Arbitrum/Optimism |
| Coinbase users | Base | Direct on-ramp, free Coinbase→Base transfers |
| No 7-day withdrawal wait | ZK rollup (zkSync, Scroll, Linea) | 15-120 min finality |
| AI agents | Base | ERC-8004, x402, consumer ecosystem, AgentKit |
| Gasless UX (native AA) | zkSync Era | Native account abstraction, paymasters, no bundlers needed |
| Multi-chain deployment | Base or Optimism | Superchain / OP Stack, shared infra |
| Maximum EVM compatibility | Scroll or Arbitrum | Bytecode-identical |
| Mobile / real-world payments | Celo | MiniPay, sub-cent fees, Africa/LatAm focus |
| MEV protection | Unichain | TEE-based priority ordering, private mempool |
| Rust smart contracts | Arbitrum | Stylus (WASM VM alongside EVM, 10-100x gas savings) |
| Stablecoins / payments / RWA | Polygon PoS | $500M+ monthly payment volume, 410M+ wallets |
0x765de816845861e75a25fca122bb6898b8b1282a), EURm (was cEUR) (0xd8763cba276a3738e6de85b4b3bf5fded6d6ca73), BRLm (was cREAL) (0xe8537a3d056DA446677B9E9d6c5dB704EaAb4787). Same contract addresses, new onchain symbols.| Chain | Dominant DEX | Model | Why NOT Uniswap |
|---|---|---|---|
| Base | Aero (was Aerodrome) | ve(3,3) — LPs earn emissions, voters earn fees | Deeper liquidity for most pairs |
| Optimism | Aero (was Velodrome) | ve(3,3) — merged Nov 2025 under Dromos Labs | Same flywheel, unified brand |
| Arbitrum | Camelot + GMX | Native DEX + perps | Camelot for spot, GMX for perps |
| zkSync | SyncSwap | Classic AMM | Largest native DEX on zkSync |
See addresses/SKILL.md for verified contract addresses for all these protocols.
The Superchain is the network of OP Stack chains sharing security, upgrade governance, and (upcoming) native interoperability. Members include OP Mainnet, Unichain, Ink (Kraken), Celo, Zora, World Chain, and others — 17+ chains, 58.6% L2 market share. Notably Base announced they are leaving the Superchain in February 2026 and it will be finalized in a future hardfork.
Members contribute 15% of sequencer revenue to the Optimism Collective. Cross-chain interop is designed but not yet fully live.
✅ Deploy like mainnet — just change RPC URL and chain ID. No code changes.
Gotchas:
block.number for time-based logic (increments at different rates). Use block.timestamp.block.number returns L1 block number, not L2.zksolc compiler. No EXTCODECOPY (compile-time error). 65K instruction limit. Non-inlinable libraries must be pre-deployed. Native account abstraction (all accounts are smart contracts).solc, deploy like mainnet.ARB_WASM_ADDRESS (0x0000…0071).| L2 | RPC | Explorer |
|---|---|---|
| Arbitrum | https://arb1.arbitrum.io/rpc | https://arbiscan.io |
| Base | https://mainnet.base.org | https://basescan.org |
| Optimism | https://mainnet.optimism.io | https://optimistic.etherscan.io |
| Unichain | https://mainnet.unichain.org | https://uniscan.xyz |
| Celo | https://forno.celo.org | https://celoscan.io |
| zkSync | https://mainnet.era.zksync.io | https://explorer.zksync.io |
| Scroll | https://rpc.scroll.io | https://scrollscan.com |
| Linea | https://rpc.linea.build | https://lineascan.build |
| L2 | Bridge URL | L1→L2 | L2→L1 |
|---|---|---|---|
| Arbitrum | https://bridge.arbitrum.io | ~10-15 min | ~7 days |
| Base | https://bridge.base.org | ~10-15 min | ~7 days |
| Optimism | https://app.optimism.io/bridge | ~10-15 min | ~7 days |
| Unichain | https://app.uniswap.org/swap | ~10-15 min | ~7 days |
| zkSync | https://bridge.zksync.io | ~15-30 min | ~15-60 min |
| Scroll | https://scroll.io/bridge | ~15-30 min | ~30-120 min |
Security: Use official bridges for large amounts (>$100K). Fast bridges add trust assumptions.
Use CREATE2 for deterministic addresses across chains:
# Same salt + same bytecode + same deployer = same address on every chain
forge create src/MyContract.sol:MyContract \
--rpc-url https://mainnet.base.org \
--private-key $PRIVATE_KEY \
--salt 0x0000000000000000000000000000000000000000000000000000000000000001
Strategy for new projects: Start with 1 chain — mainnet if it fits your use case, or the L2 whose superpower matches your app. Prove product-market fit. Expand with CREATE2 for consistent addresses across chains.