Server-Sent Events (SSE) is a standard HTTP protocol that enables servers to push data to clients over a single, long-lived connection. In the context of AI chat applications, SSE is the backbone of the 'streaming' or 'typewriter' effect where responses appear word by word. This article breaks down the core concepts of SSE, its design rationale, protocol specifications, and provides a minimal working demo for both frontend and backend. For developers building AI-powered chat interfaces, mastering SSE is crucial for delivering a smooth, real-time user experience. The protocol is simpler than WebSockets for unidirectional data flow and is natively supported by modern browsers. The article also discusses common pitfalls and best practices for handling streaming data in production environments.
This article explains Server-Sent Events (SSE) as the mechanism behind AI streaming chat responses. It covers the protocol, implementation in both frontend and backend, and provides a runnable demo. Understanding SSE is essential for developers building real-time AI interfaces.