Baileys is a TypeScript API client library used to interact with the WhatsApp Web API via WebSockets without requiring a browser. It functions as a real-time communication tool that handles bidirectional data exchange and event-based socket connections.
The project includes a dedicated toolkit for managing WhatsApp Business profiles and product catalogs, alongside a session manager that authenticates accounts using QR codes or pairing codes and persists session state to disk.
Its capabilities cover a wide range of messaging functions, including multi-type message transmission, chat history synchronization, and group membership management. It also provides tools for identity management, account privacy configuration, and the handling of media content through data streams.
The library is implemented as an asynchronous messaging framework using an event-emitter pattern to handle incoming messages and real-time socket events.