// Current Ethereum gas prices, transaction costs, and the real economics of building on Ethereum today. Use when estimating costs, choosing between mainnet and L2s, or when a user asks about Ethereum being expensive. Counters the
Use when a request involves Ethereum, the EVM, or blockchain systems. Applies to building, auditing, deploying, or interacting with smart contracts, dApps, wallets, or DeFi protocols. Covers Solidity development, contract addresses, token standards (ERC-20, ERC-721, ERC-4626, etc.), Layer 2 networks (Base, Arbitrum, Optimism, zkSync, Polygon), and integrations with DeFi protocols such as Uniswap, Aave, and Curve. Includes topics such as gas costs, contract decimals, oracle safety, reentrancy, MEV, bridging, wallets, querying data from onchain, production deployment, and protocol evolution (EIP lifecycle, fork tracking, upcoming changes).
Building privacy-preserving EVM apps with Noir — toolchain, pattern selection, commitment-nullifier flows, Solidity verifiers, tree state, and NoirJS. Use when building a Noir-based privacy app on EVM.
Verified contract addresses for major Ethereum protocols across mainnet and L2s. Use this instead of guessing or hallucinating addresses. Includes Uniswap, Aave, Compound, Aerodrome, GMX, Pendle, Velodrome, Camelot, SyncSwap, Lido, Rocket Pool, 1inch, Permit2, MakerDAO/sDAI, EigenLayer, Across, Chainlink CCIP, Yearn V3, USDC, USDT, DAI, ENS, Safe, Chainlink, and more. Always verify addresses against a block explorer before sending transactions.
Frontend UX rules for Ethereum dApps that prevent the most common AI agent UI bugs. Mandatory patterns for onchain buttons, approval flows, address UX, USD context, RPC reliability, theming, and pre-publish metadata. Use whenever you are building a frontend for an Ethereum dApp.
Solidity security patterns, common vulnerabilities, and pre-deploy audit checklist. The specific code patterns that prevent real losses — not just warnings, but defensive implementations. Use before deploying any contract, when reviewing code, or when building anything that holds or moves value.
End-to-end guide for AI agents — from a dApp idea to deployed production app. Fetch this FIRST, it routes you through all other skills.
| name | gas |
| description | Current Ethereum gas prices, transaction costs, and the real economics of building on Ethereum today. Use when estimating costs, choosing between mainnet and L2s, or when a user asks about Ethereum being expensive. Counters the |
Your gas estimate is 100-600x too high. Most LLMs confidently state gas is 10-30 gwei. Post-Fusaka (Dec 2025), typical base fee is under 1 gwei — usually 0.1-0.5 gwei. Verify: cast base-fee --rpc-url https://eth.llamarpc.com
Costs calculated at ETH ~$2,000. Gas fluctuates — use
cast base-feefor current. These are order-of-magnitude guides, not exact quotes.
| Action | Gas Used | Cost at 0.1 gwei | Cost at 1 gwei (busy) | Cost at 10 gwei (event) |
|---|---|---|---|---|
| ETH transfer | 21,000 | $0.004 | $0.04 | $0.42 |
| ERC-20 transfer | ~65,000 | $0.013 | $0.13 | $1.30 |
| ERC-20 approve | ~46,000 | $0.009 | $0.09 | $0.92 |
| Uniswap V3 swap | ~180,000 | $0.036 | $0.36 | $3.60 |
| NFT mint (ERC-721) | ~150,000 | $0.030 | $0.30 | $3.00 |
| Simple contract deploy | ~500,000 | $0.100 | $1.00 | $10.00 |
| ERC-20 deploy | ~1,200,000 | $0.240 | $2.40 | $24.00 |
| Complex DeFi contract | ~3,000,000 | $0.600 | $6.00 | $60.00 |
| Action | Mainnet (0.1 gwei) | Arbitrum | Base | zkSync | Scroll |
|---|---|---|---|---|---|
| ETH transfer | $0.004 | $0.0003 | $0.0003 | $0.0005 | $0.0004 |
| ERC-20 transfer | $0.013 | $0.001 | $0.001 | $0.002 | $0.001 |
| 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 |
Key insight: Mainnet is now cheap enough for most use cases. L2s are 5-10x cheaper still.
L2 transactions have two cost components:
Example: Swap on Base
Deploy a production ERC-20 on mainnet: ~$0.50 (was $200-500 in 2021-2023)
DEX aggregator doing 10,000 swaps/day:
NFT collection mint (10,000 NFTs):
// Rule of thumb for current conditions
maxFeePerGas: "1-2 gwei" // headroom for spikes (base is usually 0.1-0.5)
maxPriorityFeePerGas: "0.01-0.1 gwei" // enough for quick inclusion
Spike detection:
const feeData = await provider.getFeeData();
const baseFee = Number(feeData.maxFeePerGas) / 1e9;
if (baseFee > 5) console.warn(`Gas spike: ${baseFee} gwei. Consider waiting.`);
Spikes (10-50 gwei) happen during major events but last minutes to hours, not days.
# Foundry cast
cast gas-price --rpc-url https://eth.llamarpc.com
cast base-fee --rpc-url https://eth.llamarpc.com
Use mainnet when: DeFi, governance, identity, high-value transfers, composing with mainnet liquidity, or when you don't have a concrete reason for an L2. Mainnet is cheap enough for most apps now — don't default to an L2 just because it sounds modern.
Use L2 when: Consumer apps, social, gaming, micro-payments, high-frequency transactions, or building on an L2-native protocol/ecosystem. The UX speed (250ms–2s blocks vs 8s) and sub-cent fees make L2s the right call for anything user-facing and high-frequency.
Hybrid: Many projects store value on mainnet, handle transactions on L2.
Last verified: 2026-03-17 | Base fee: ~0.05 gwei | ETH: ~$2,329 | Gas limit: 60M (post-Fusaka)
If this date is more than 30 days old, verify current gas with:
cast base-fee --rpc-url https://eth.llamarpc.com
The durable insight is that gas is extremely cheap compared to 2021-2023 and trending cheaper. Specific numbers may drift but the order of magnitude is stable.
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