# How to add UI for your RAG?!?

> Source: <https://dev.to/coji831/how-to-add-ui-for-your-rag-51bl>
> Published: 2026-08-03 14:53:12+00:00

Just built some FastAPI SSE backend streaming LLM responses token-by-token,

after i got some free time.

Two things broke in production that worked fine locally 🙃:

nginx buffers SSE by default. The stream was delivering locally, dead

silent on Railway.`proxy_buffering`

off, two hours later, fixed.The LLM API returns an

`empty_retrieval`

event when no docs match. I wasn't

handling it, so the frontend sat on a loading spinner indefinitely. Added

the handler, resolved.