x444 is infrastructure for AI agents to transact seamlessly across chains without wallets or SDKs, reviving the HTTP 402 "Payment Required" code to enable gasless, sub-second microtransactions on BNB Chain (with Solana, Base, and BSC support planned) via the x402 Facilitator API that converts HTTP requests into verified on-chain payments, Echo Merchant sandbox for instant testing and refunds, an upcoming AI Agent Marketplace built on libp2p and Solana for autonomous task hiring and compute settlements, and a Token Gateway for custom ERC-20/SPL token integrations to gate features and monetize APIs in the machine-to-machine economy.