Aedes is a barebone MQTT broker library for Node.js, supporting MQTT 3.1 and 3.1.1. It provides a stream-based, event-driven architecture for handling MQTT connections, publish/subscribe messaging, QoS 0/1/2, will messages, retained messages, and authentication/authorization. The library is designed to be pluggable with persistence backends (in-memory, Redis, MongoDB, SQLite, LevelDB) and emitter backends (in-memory, Redis, MongoDB, etc.) for clustering and high availability. Aedes is the successor to Mosca, focusing on performance and stability. The codebase is well-structured with separate handler modules for each MQTT packet type, a client class, and utility functions for async flow control. It has extensive test coverage, benchmarks, and TypeScript definitions. Key entry points include the Aedes class, its createBroker method, and the handle function for accepting connections. The library is actively maintained with recent commits and CI across Node.js 20, 22, and 24. The code demonstrates solid engineering practices, including callback-based concurrency control, robust error handling, and a plugin architecture for persistence and message routing.