}
            },
            "/level1/level2/default5": {
                "get": {
                    "tags": ["level1a", "level1b", "level2a", "level2b"],
                    "summary": "Path5 Default Router4 Default",
                    "operationId": "path5_default_router4_default_level1_level2_default5_get",
                    "parameters": [
                        {

@app.get("/items/{item_id}")
def main(
    item_id: int = Path(default=..., gt=0),
    query: str = Query(default=..., max_length=10),
    session: str = Cookie(default=..., min_length=3),
    x_trace: str = Header(default=..., title="Tracing header"),
):
    return {"message": "Hello World"}
```

...all these parameters are required because the default value is `...` (Ellipsis).