eth-tools

name	eth-tools
description	Ethereum development tools for contract exploration and testing. Use when inspecting Gnars DAO contracts, checking auction/treasury state, testing transactions locally, or scripting onchain reads via cast/anvil/viem. Covers Foundry cast commands, abi.ninja, Blockscout MCP, RPC providers, block explorers, and fork testing.

Ethereum Development Tools

What You Probably Got Wrong

Blockscout MCP server exists: https://mcp.blockscout.com/mcp — gives AI agents structured blockchain data via Model Context Protocol.

abi.ninja is essential: https://abi.ninja — paste any verified contract address, get a UI to call any function. Zero setup. Supports mainnet + all major L2s. Perfect for contract exploration.

Foundry is the default for new projects in 2026. Not Hardhat. 10-100x faster tests, Solidity-native testing, built-in fuzzing.

Tool Discovery Pattern for AI Agents

When an agent needs to interact with Ethereum:

1. Read operations: Blockscout MCP, Etherscan API, or cast call
2. Write operations: Foundry cast send or viem
3. Contract exploration: abi.ninja (browser) or cast interface (CLI)
4. Testing: Fork mainnet/Base with anvil, test locally
5. Deployment: forge create or forge script
6. Verification: forge verify-contract or Etherscan API

Essential Foundry cast Commands

# Read contract state
cast call 0xAddr "balanceOf(address)(uint256)" 0xWallet --rpc-url $RPC

# Read with named function
cast call 0xAddr "totalSupply()(uint256)" --rpc-url $RPC

# Send transaction
cast send 0xAddr "transfer(address,uint256)" 0xTo 1000000 \
  --private-key $KEY --rpc-url $RPC

# Gas price / base fee
cast gas-price --rpc-url $RPC
cast base-fee --rpc-url $RPC

# Decode calldata
cast 4byte-decode 0xa9059cbb...

# ENS resolution
cast resolve-name vitalik.eth --rpc-url $RPC

# Get contract ABI from Etherscan/Basescan
cast interface 0xAddr --etherscan-api-key $KEY --chain base

# Check ETH balance
cast balance 0xAddr --rpc-url $RPC

# Convert units
cast to-wei 1.5 ether    # -> 1500000000000000000
cast from-wei 1500000000000000000  # -> 1.5

# Block info
cast block latest --rpc-url $RPC
cast block-number --rpc-url $RPC

# Get logs/events
cast logs --address 0xAddr --from-block 12345 --to-block latest --rpc-url $RPC

Gnars DAO Contract Exploration Examples

# Base RPC
export BASE_RPC="https://mainnet.base.org"

# Check current auction
cast call 0x494eaa55ecf6310658b8fc004b0888dcb698097f \
  "auction()(uint256,uint256,address,uint256,uint256,bool)" \
  --rpc-url $BASE_RPC

# Check token total supply
cast call 0x880fb3cf5c6cc2d7dfc13a993e839a9411200c17 \
  "totalSupply()(uint256)" --rpc-url $BASE_RPC

# Check treasury ETH balance
cast balance 0x72ad986ebac0246d2b3c565ab2a1ce3a14ce6f88 --rpc-url $BASE_RPC

# Check a proposal
cast call 0x3dd4e53a232b7b715c9ae455f4e732465ed71b4c \
  "getProposal(bytes32)" PROPOSAL_ID --rpc-url $BASE_RPC

# Check voting power
cast call 0x880fb3cf5c6cc2d7dfc13a993e839a9411200c17 \
  "getVotes(address)(uint256)" 0xVOTER_ADDRESS --rpc-url $BASE_RPC

Fork Testing with Anvil

Fork Base locally to test against real contracts with fake ETH:

# Fork Base at latest block
anvil --fork-url https://mainnet.base.org

# Fork at specific block (reproducible)
anvil --fork-url https://mainnet.base.org --fork-block-number 12345678

# Now test against real contracts at http://localhost:8545
# Anvil gives you 10 funded accounts with 10,000 ETH each

Use cases for Gnars DAO:

• Test bidding on auctions without spending real ETH
• Simulate proposal creation and voting
• Debug contract interactions locally
• Verify frontend data fetching against forked state

Blockscout MCP Server

URL: https://mcp.blockscout.com/mcp

A Model Context Protocol server for structured blockchain data:

• Transaction, address, contract queries
• Token info and balances
• Smart contract interaction helpers
• Multi-chain support

abi.ninja

URL: https://abi.ninja

Paste any contract address, interact with all functions. Multi-chain. Zero setup.

Quick exploration of Gnars contracts:

1. Go to https://abi.ninja
2. Select Base network
3. Paste contract address (e.g., 0x494eaa55ecf6310658b8fc004b0888dcb698097f for Auction)
4. Call any read function directly in browser

RPC Providers

Free (testing/development):

• https://mainnet.base.org — Base public RPC
• https://eth.llamarpc.com — Ethereum mainnet, no key
• https://rpc.ankr.com/eth — Ankr free tier

Paid (production):

• Alchemy — generous free tier (300M CU/month)
• Infura — established, MetaMask default
• QuickNode — performance-focused

Community: rpc.buidlguidl.com

Block Explorers

Network	Explorer	API
Base	https://basescan.org	Etherscan-compatible
Mainnet	https://etherscan.io	https://api.etherscan.io
Arbitrum	https://arbiscan.io	Etherscan-compatible
Optimism	https://optimistic.etherscan.io	Etherscan-compatible

Viem Quick Reference (Used in This Project)

import { createPublicClient, http } from 'viem';
import { base } from 'viem/chains';

const client = createPublicClient({
  chain: base,
  transport: http('https://mainnet.base.org'),
});

// Read contract
const totalSupply = await client.readContract({
  address: '0x880fb3cf5c6cc2d7dfc13a993e839a9411200c17',
  abi: tokenAbi,
  functionName: 'totalSupply',
});

// Multicall (batch reads in one RPC call)
const results = await client.multicall({
  contracts: [
    { address: tokenAddr, abi: erc721Abi, functionName: 'totalSupply' },
    { address: auctionAddr, abi: auctionAbi, functionName: 'auction' },
    { address: treasuryAddr, abi: treasuryAbi, functionName: 'delay' },
  ],
});

// Watch for events (real-time)
const unwatch = client.watchContractEvent({
  address: auctionAddr,
  abi: auctionAbi,
  eventName: 'AuctionBid',
  onLogs: (logs) => console.(, logs),
});

What Changed in 2025-2026

• Foundry became default over Hardhat for new projects
• Viem gaining on ethers.js (smaller, better TypeScript)
• MCP servers emerged for agent-blockchain interaction
• Deprecated: Truffle (use Foundry/Hardhat), Goerli/Rinkeby (use Sepolia)

Source: https://ethskills.com/tools/SKILL.md