SignalR

Add real-time web functionality to apps with ease.

ASP.NET Core SignalR is an open-source library that simplifies adding real-time web functionality to .NET applications. It handles connection management automatically and intelligently negotiates the best transport method — WebSockets, Server-Sent Events, or long polling — based on client and server capabilities. Its Hubs API provides a high-level RPC-style abstraction over persistent connections, allowing servers to call methods on connected clients and vice versa. SignalR supports streaming results from server to client, automatic reconnection, and scale-out to thousands of concurrent connections using Redis, Azure Service Bus, or Azure SignalR Service as a backplane. With built-in authentication, message grouping, and client-side libraries for JavaScript and .NET, SignalR powers real-time dashboards, chat applications, live notifications, and collaborative editing in enterprise-scale .NET applications.