How do you implement streaming in a RAG system?

Stream the language model's output tokens as they are generated so users see the answer appear progressively instead of waiting for the full response. Most language model APIs including OpenAI and Anthropic support server-sent events for token streaming. Before streaming starts, you must complete retrieval and reranking, which adds baseline latency. Some systems also stream retrieval progress indicators so users see that work is happening. Streaming does not reduce total time to last token but dramatically improves perceived latency.