whatsmeow is a Go library that implements the WhatsApp multidevice protocol, providing direct access to the binary node serialization, WebSocket-based connection management, and Signal‑Protocol encryption that underpin WhatsApp’s messaging infrastructure. It maintains persistent, low-latency connections across multiple devices, handles session credentials independently for each device, and processes incoming events through an event‑driven dispatch system for messages, receipts, and presence updates.
The library differentiates itself through comprehensive client‑side state management: it caches contact and chat data locally, synchronizes group metadata and membership via delta updates from the server, and supports chunked, encrypted uploads of media files. This architecture enables real‑time group administration, media exchange, and automated message handling without requiring an intermediary service.