Sync fastapi docs from b5ca1324 on 2025-12-07

fastapi/background.py

@@ -0,0 +1,60 @@
+from typing import Any, Callable
+
+from annotated_doc import Doc
+from starlette.background import BackgroundTasks as StarletteBackgroundTasks
+from typing_extensions import Annotated, ParamSpec
+
+P = ParamSpec("P")
+
+
+class BackgroundTasks(StarletteBackgroundTasks):
+    """
+    A collection of background tasks that will be called after a response has been
+    sent to the client.
+
+    Read more about it in the
+    [FastAPI docs for Background Tasks](https://fastapi.tiangolo.com/tutorial/background-tasks/).
+
+    ## Example
+
+    ```python
+    from fastapi import BackgroundTasks, FastAPI
+
+    app = FastAPI()
+
+
+    def write_notification(email: str, message=""):
+        with open("log.txt", mode="w") as email_file:
+            content = f"notification for {email}: {message}"
+            email_file.write(content)
+
+
+    @app.post("/send-notification/{email}")
+    async def send_notification(email: str, background_tasks: BackgroundTasks):
+        background_tasks.add_task(write_notification, email, message="some notification")
+        return {"message": "Notification sent in the background"}
+    ```
+    """
+
+    def add_task(
+        self,
+        func: Annotated[
+            Callable[P, Any],
+            Doc(
+                """
+                The function to call after the response is sent.
+
+                It can be a regular `def` function or an `async def` function.
+                """
+            ),
+        ],
+        *args: P.args,
+        **kwargs: P.kwargs,
+    ) -> None:
+        """
+        Add a function to be called in the background after the response is sent.
+
+        Read more about it in the
+        [FastAPI docs for Background Tasks](https://fastapi.tiangolo.com/tutorial/background-tasks/).
+        """
+        return super().add_task(func, *args, **kwargs)