fix prod grouped chunks with nginx and server config

Author: ahmedkhaleel2004

backend/app/routers/generate.py

@@ -346,7 +346,6 @@ async def event_generator():
                     reasoning_effort="medium",
                 ):
                     explanation += chunk
-                    print("sending explanation chunk", chunk)
                     yield f"data: {json.dumps({'status': 'explanation_chunk', 'chunk': chunk})}\n\n"
 
                 if "BAD_INSTRUCTIONS" in explanation:
@@ -416,6 +415,14 @@ async def event_generator():
             except Exception as e:
                 yield f"data: {json.dumps({'error': str(e)})}\n\n"
 
-        return StreamingResponse(event_generator(), media_type="text/event-stream")
+        return StreamingResponse(
+            event_generator(),
+            media_type="text/event-stream",
+            headers={
+                "X-Accel-Buffering": "no",  # Hint to Nginx
+                "Cache-Control": "no-cache",
+                "Connection": "keep-alive",
+            },
+        )
     except Exception as e:
         return {"error": str(e)}

backend/entrypoint.sh

@@ -7,7 +7,13 @@ if [ "$ENVIRONMENT" = "development" ]; then
     exec uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload
 elif [ "$ENVIRONMENT" = "production" ]; then
     echo "Starting in production mode with multiple workers..."
-    exec uvicorn app.main:app --host 0.0.0.0 --port 8000 --timeout-keep-alive 300 --workers 2
+    exec uvicorn app.main:app \
+        --host 0.0.0.0 \
+        --port 8000 \
+        --timeout-keep-alive 300 \
+        --workers 2 \
+        --loop uvloop \
+        --http httptools
 else
     echo "ENVIRONMENT must be set to either 'development' or 'production'"
     exit 1

backend/nginx/api.conf

@@ -15,6 +15,14 @@ server {
         proxy_pass http://127.0.0.1:8000;
         include proxy_params;
         proxy_redirect off;
+
+        # Disable buffering for SSE
+        proxy_buffering off;
+        proxy_cache off;
+        
+        # Required headers for SSE
+        proxy_set_header Connection '';
+        proxy_http_version 1.1;
     }
 
     # Return 444 for everything else (no response, just close connection)

src/hooks/useDiagram.ts

@@ -125,7 +125,6 @@ export function useDiagram(username: string, repo: string) {
                         }));
                         break;
                       case "explanation_chunk":
-                        console.log("received explanation chunk:", data.chunk);
                         if (data.chunk) {
                           explanation += data.chunk;
                           setState((prev) => ({ ...prev, explanation }));