What it is
Baileys is an unofficial TypeScript and JavaScript library that connects to WhatsApp through the same WebSocket protocol the WhatsApp Web client uses, without running a browser. Developers building chat integrations, notification senders, or personal bots on Node.js, Bun, or Deno use it to log in with a linked device, send and receive messages, and handle media and groups. It is not affiliated with WhatsApp, and the maintainers discourage spam and bulk messaging.