Fix SSE handling

app.py

@@ -604,15 +604,41 @@ async def generate_text(request: Request):
     headers = {"Authorization": f"Bearer {API_KEY}"}
 
     if stream:
+        body["stream"] = True
+    
         async def event_generator():
-            async with httpx.AsyncClient(timeout=None) as client:
-                async with client.stream("POST", url, json=body, headers=headers) as r:
-                    async for chunk in r.aiter_raw():
-                        yield chunk
+            try:
+                async with httpx.AsyncClient(timeout=None) as client:
+                    async with client.stream(
+                        "POST",
+                        url,
+                        json=body,
+                        headers=headers,
+                    ) as r:
+                        content_type = r.headers.get(
+                            "content-type", "text/event-stream"
+                        )
+    
+                        async for line in r.aiter_lines():
+                            if line == "":
+                                yield "\n"
+                                continue
+    
+                            yield line + "\n"
+    
+            except asyncio.CancelledError:
+                return
+            except Exception as e:
+                yield f"data: {{\"error\": \"{str(e)}\"}}\n\n"
     
         return StreamingResponse(
             event_generator(),
             media_type="text/event-stream",
+            headers={
+                "Cache-Control": "no-cache",
+                "Connection": "keep-alive",
+                "X-Accel-Buffering": "no",  # critical for nginx
+            },
         )
     else:
         async with httpx.AsyncClient(timeout=None) as client: