Tether has announced the open-sourcing of its Wallet Development Kit (WDK), designed to provide secure, cross-chain, self-custody wallet infrastructure for humans, machines, and AI agents. The WDK supports multiple blockchain environments, including Bitcoin, Lightning, Ethereum, Arbitrum, Polygon, TON, and Solana. Developers can leverage this toolkit to build applications in payments, DeFi, prediction markets, gaming, and AI finance.