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. This is cutting-edge infra as of Feb 2026.

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 agent-driven contract exploration.

x402 has production SDKs: @x402/fetch (TS), x402 (Python), github.com/coinbase/x402/go — production-ready libraries for HTTP payments.

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

Blockscout MCP Server

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

A Model Context Protocol server giving AI agents structured blockchain data:

• Transaction, address, contract queries
• Token info and balances
• Smart contract interaction helpers
• Multi-chain support
• Standardized interface optimized for LLM consumption

Why this matters: Instead of scraping Etherscan or making raw API calls, agents get structured, type-safe blockchain data via MCP.

abi.ninja

URL: https://abi.ninja — Paste any contract address → interact with all functions. Multi-chain. Zero setup.

x402 SDKs (HTTP Payments)

TypeScript:

npm install @x402/core @x402/evm @x402/fetch @x402/express

import { x402Fetch } from '@x402/fetch';
import { createWallet } from '@x402/evm';

const wallet = createWallet(privateKey);
const response = await x402Fetch('https://api.example.com/data', {
  wallet,
  preferredNetwork: 'eip155:8453' // Base
});

Python: pip install x402 Go: go get github.com/coinbase/x402/go Docs: https://www.x402.org | https://github.com/coinbase/x402

Scaffold-ETH 2

• Setup: npx create-eth@latest
• What: Full-stack Ethereum toolkit: Solidity + Next.js + Foundry
• Key feature: Auto-generates TypeScript types from contracts. Scaffold hooks make contract interaction trivial.
• Deploy to IPFS: yarn ipfs (BuidlGuidl IPFS)
• UI Components: https://ui.scaffoldeth.io/
• Docs: https://docs.scaffoldeth.io/

Choosing Your Stack (2026)

Need	Tool
Rapid prototyping / full dApps	Scaffold-ETH 2
Contract-focused dev	Foundry (forge + cast + anvil)
Quick contract interaction	abi.ninja (browser) or cast (CLI)
React frontends	wagmi + viem (or SE2 which wraps these)
Agent blockchain reads	Blockscout MCP
Agent payments	x402 SDKs

Essential Foundry cast Commands

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

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

# Gas price
cast gas-price --rpc-url $RPC

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

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

# Fork mainnet locally
anvil --fork-url $RPC

RPC Providers

Free (testing):

• https://eth.llamarpc.com — LlamaNodes, no key
• https://rpc.ankr.com/eth — Ankr, free tier

Paid (production):

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

Community: rpc.buidlguidl.com

Block Explorers

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

MCP Servers for Agents

Model Context Protocol — standard for giving AI agents structured access to external systems.

1. Blockscout MCP — multi-chain blockchain data (primary)
2. eth-mcp — community Ethereum RPC via MCP
3. Custom MCP wrappers emerging for DeFi protocols, ENS, wallets

MCP servers are composable — agents can use multiple together.

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
• x402 SDKs went production-ready
• ERC-8004 tooling emerging (agent registration/discovery)
• Deprecated: Truffle (use Foundry/Hardhat), Goerli/Rinkeby (use Sepolia)

Testing Essentials

Fork mainnet locally:

anvil --fork-url https://eth.llamarpc.com
# Now test against real contracts with fake ETH at http://localhost:8545

Primary testnet: Sepolia (Chain ID: 11155111). Goerli and Rinkeby are deprecated.