WAHA is a server that exposes WhatsApp as a programmable REST API, enabling applications and AI agents to send and receive messages programmatically. It operates unlimited independent WhatsApp sessions from a single instance, each with its own connection state and message history, and can switch between underlying WhatsApp communication libraries by changing a single environment variable while preserving the same API interface.
The system distinguishes itself through its engine abstraction layer, which allows operators to swap the WhatsApp communication library without modifying integrations, and its Model Context Protocol (MCP) server capability that lets AI agents read and send WhatsApp messages programmatically. It provides scope-based access control to restrict which operations AI agents can perform, and supports horizontal scaling by distributing sessions across multiple server instances. The service runs in a Docker container, authenticates via QR code scanning, and forwards incoming messages to configured webhook URLs for real-time processing.
Beyond core messaging, WAHA handles session lifecycle management through REST calls, supports multimedia message sending, and provides monitoring endpoints for health checks, uptime reporting, and configuration exposure. It also offers presence management features including chat-level typing indicators and global online status control.