Dissecting Open WebUI's FastAPI Architecture: SSE Streaming and Multi-Provider Routing When evaluating Open WebUI ( https://github.com/open-webui/open-webui ) for a self-hosted AI gateway project, I needed to understand how it handles concurrent LLM provider connections and server-sent event (SSE) streaming without blocking the event loop. Here's what I found digging through the codebase and running integration tests. The Multi-Provider Abstraction Layer Open WebUI acts a...