From ed2512a5ec33d9d70f7a9ef2e5f9fe52d3b77ab2 Mon Sep 17 00:00:00 2001
From: Motov Yurii <109919500+YuriiMotov@users.noreply.github.com>
Date: Mon, 9 Feb 2026 17:31:57 +0100
Subject: [PATCH] =?utf8?q?=F0=9F=90=9B=20Fix=20`on=5Fstartup`=20and=20`on?=
 =?utf8?q?=5Fshutdown`=20parameters=20of=20`APIRouter`=20(#14873)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
---
 fastapi/routing.py          | 21 ++++++-------
 tests/test_router_events.py | 60 +++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 10 deletions(-)

diff --git a/fastapi/routing.py b/fastapi/routing.py
index 0b4d28873..16a89ef3e 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -952,16 +952,6 @@ class APIRouter(routing.Router):
             ),
         ] = Default(generate_unique_id),
     ) -> None:
-        # Handle on_startup/on_shutdown locally since Starlette removed support
-        # Ref: https://github.com/Kludex/starlette/pull/3117
-        # TODO: deprecate this once the lifespan (or alternative) interface is improved
-        self.on_startup: list[Callable[[], Any]] = (
-            [] if on_startup is None else list(on_startup)
-        )
-        self.on_shutdown: list[Callable[[], Any]] = (
-            [] if on_shutdown is None else list(on_shutdown)
-        )
-
         # Determine the lifespan context to use
         if lifespan is None:
             # Use the default lifespan that runs on_startup/on_shutdown handlers
@@ -985,6 +975,17 @@ class APIRouter(routing.Router):
             assert not prefix.endswith("/"), (
                 "A path prefix must not end with '/', as the routes will start with '/'"
             )
+
+        # Handle on_startup/on_shutdown locally since Starlette removed support
+        # Ref: https://github.com/Kludex/starlette/pull/3117
+        # TODO: deprecate this once the lifespan (or alternative) interface is improved
+        self.on_startup: list[Callable[[], Any]] = (
+            [] if on_startup is None else list(on_startup)
+        )
+        self.on_shutdown: list[Callable[[], Any]] = (
+            [] if on_shutdown is None else list(on_shutdown)
+        )
+
         self.prefix = prefix
         self.tags: list[Union[str, Enum]] = tags or []
         self.dependencies = list(dependencies or [])
diff --git a/tests/test_router_events.py b/tests/test_router_events.py
index 65f2f521c..a47d11913 100644
--- a/tests/test_router_events.py
+++ b/tests/test_router_events.py
@@ -317,3 +317,63 @@ def test_router_async_generator_lifespan(state: State) -> None:
         assert response.json() == {"message": "Hello World"}
     assert state.app_startup is True
     assert state.app_shutdown is True
+
+
+def test_startup_shutdown_handlers_as_parameters(state: State) -> None:
+    """Test that startup/shutdown handlers passed as parameters to FastAPI are called correctly."""
+
+    def app_startup() -> None:
+        state.app_startup = True
+
+    def app_shutdown() -> None:
+        state.app_shutdown = True
+
+    app = FastAPI(on_startup=[app_startup], on_shutdown=[app_shutdown])
+
+    @app.get("/")
+    def main() -> dict[str, str]:
+        return {"message": "Hello World"}
+
+    def router_startup() -> None:
+        state.router_startup = True
+
+    def router_shutdown() -> None:
+        state.router_shutdown = True
+
+    router = APIRouter(on_startup=[router_startup], on_shutdown=[router_shutdown])
+
+    def sub_router_startup() -> None:
+        state.sub_router_startup = True
+
+    def sub_router_shutdown() -> None:
+        state.sub_router_shutdown = True
+
+    sub_router = APIRouter(
+        on_startup=[sub_router_startup], on_shutdown=[sub_router_shutdown]
+    )
+
+    router.include_router(sub_router)
+    app.include_router(router)
+
+    assert state.app_startup is False
+    assert state.router_startup is False
+    assert state.sub_router_startup is False
+    assert state.app_shutdown is False
+    assert state.router_shutdown is False
+    assert state.sub_router_shutdown is False
+    with TestClient(app) as client:
+        assert state.app_startup is True
+        assert state.router_startup is True
+        assert state.sub_router_startup is True
+        assert state.app_shutdown is False
+        assert state.router_shutdown is False
+        assert state.sub_router_shutdown is False
+        response = client.get("/")
+        assert response.status_code == 200, response.text
+        assert response.json() == {"message": "Hello World"}
+    assert state.app_startup is True
+    assert state.router_startup is True
+    assert state.sub_router_startup is True
+    assert state.app_shutdown is True
+    assert state.router_shutdown is True
+    assert state.sub_router_shutdown is True
-- 
2.47.3