A practical tutorial for building a real-time AI chat feature in Node.js using OpenAI's streaming API and Server-Sent Events (SSE). Covers the full implementation: SSE headers and flushHeaders(), AbortController for cancelling disconnected streams, in-memory session management with TTL cleanup for multi-turn conversation context, and a browser frontend that reads the stream via fetch and ReadableStream. Includes production gaps to address before launch: context overflow handling, rate limiting, authentication, and Redis for multi-process session storage.
Table of contents
PrerequisitesThe Architecture Before Any CodeProject SetupWhy SSE and Not WebSocketsSession ManagementThe Streaming EndpointThe Complete server.jsBuilding the FrontendRunning ItProduction Gaps to Address Before LaunchConclusion238 Impressions