Evolution API is a production-grade, multi-tenant WhatsApp API gateway built with Node.js, TypeScript, and Express. It manages independent WhatsApp instances via Baileys (WhatsApp Web), Meta Business API, and its own Evolution API channel, providing REST endpoints for messaging, chat management, groups, labels, and media. The system integrates deeply with chatbot platforms (Typebot, OpenAI, Dify, Flowise, N8N, EvoAI, EvolutionBot) and event systems (Webhook, WebSocket, RabbitMQ, SQS, NATS, Kafka, Pusher), and includes storage via S3/MinIO and CRM sync with Chatwoot. The architecture follows a modular controller-service pattern with Prisma ORM (supporting MySQL and PostgreSQL), Redis caching, and centralized configuration. It is actively maintained with frequent updates, extensive migrations, and CI/CD pipelines.