Blockchain and Web3 MCP servers give AI assistants access to on-chain data, DeFi protocol APIs, NFT marketplaces, and cryptocurrency price feeds — letting developers and researchers query wallet balances, trace transactions, and monitor smart contract events through conversation. They are used by Web3 developers to inspect contract state, by traders to automate data gathering, and by researchers to analyse on-chain activity. Most servers in this category are read-only by default, meaning they fetch data rather than sign or submit transactions.