🐛 fix(chat.py): add support for running celery tasks for building vertices and fallback to local build if celery task fails

src/backend/langflow/api/v1/chat.py

@@ -123,7 +123,10 @@ async def stream_build(flow_id: str):
                         "log": f"Building node {vertex.vertex_type}",
                     }
                     yield str(StreamData(event="log", data=log_dict))
-                    vertex.build()
+                    if vertex.is_task:
+                        vertex = try_running_celery_task(vertex)
+                    else:
+                        vertex.build()
                     params = vertex._built_object_repr()
                     valid = True
                     logger.debug(f"Building node {str(vertex.vertex_type)}")
@@ -179,3 +182,20 @@ async def stream_build(flow_id: str):
     except Exception as exc:
         logger.error(f"Error streaming build: {exc}")
         raise HTTPException(status_code=500, detail=str(exc))
+
+
+def try_running_celery_task(vertex):
+    # Try running the task in celery
+    # and set the task_id to the local vertex
+    # if it fails, run the task locally
+    try:
+        from langflow.worker import build_vertex
+
+        task = build_vertex.delay(vertex)
+        vertex.task_id = task.id
+    except Exception as exc:
+        logger.exception(exc)
+        logger.error("Error running task in celery, running locally")
+        vertex.task_id = None
+        vertex.build()
+    return vertex