This package contains TypeScript definitions for SockJS, a JavaScript library that provides a fallback mechanism for WebSocket-like bidirectional communication. It enables real-time, cross-browser messaging by gracefully degrading to technologies like XHR streaming and long polling when native WebSockets are unavailable. Utilizing these definitions improves code completion, type safety, and overall development experience when incorporating SockJS into TypeScript projects. Maintainers of this package ensure it stays updated with the core SockJS library.