Coinbase Developer Platform has launched a new SQL API powered by the x402 protocol, allowing AI agents to access on-chain data on Base without the need for API keys or account registration. This innovative service enables AI agents to query indexed data such as blocks, transactions, token transfers, and decoded events, with each query costing a fixed fee of $0.10, payable instantly via USDC. The x402 protocol facilitates seamless payment by issuing a 402 error response to indicate the payment requirement. AI agents can then sign a USDC payment proof to immediately receive the query results. This development streamlines the process for AI agents to access blockchain data, enhancing efficiency and reducing the need for human intervention.