from fastapi import FastAPI, Response, status app = FastAPI() tasks = {"foo": "Listen to the Bar Fighters"} @app.put("/get-or-create-task/{task_id}", status_code=200) def get_or_create_task(task_id: str, response: Response): if task_id not in tasks: tasks[task_id] = "This didn't exist before" response.status_code = status.HTTP_201_CREATED return tasks[task_id]