Building AI Agents That Interact With Blockchain: A Deep Technical Guide Using LangChain (opens in new tab)

Most tutorials on AI agents stop at chat interfaces and RAG pipelines. This one doesn't. This guide walks through building a production-grade AI agent that can read on-chain data, interact with smart contracts, and execute DeFi operations — using LangChain's agent framework, ethers.js, and a set of custom tools you'll write from scratch. By the end, you'll have an agent that can: Query wallet balances and token holdings Read state from any smart contract via ABI Simulate and execute token swa...