The **socket.io-adapter** repository provides the default in‑memory adapter used by Socket.IO to coordinate events across multiple server instances. It implements the core publish/subscribe logic that lets Socket.IO rooms and namespaces work when the server runs in a single process, and serves as a reference implementation for custom adapters (e.g., Redis or NATS) in real‑time web applications. It’s intended for Socket.IO developers and anyone building or extending real‑time, bidirectional communication services.