# Alias


@app.get("/required-alias")
async def read_required_alias(p: Annotated[str, Header(alias="p_alias")]):
    return {"p": p}


class HeaderModelRequiredAlias(BaseModel):
    p: str = Field(alias="p_alias")


@app.get("/model-required-alias")
async def read_model_required_alias(p: Annotated[HeaderModelRequiredAlias, Header()]):
    return {"p": p.p}


@pytest.mark.parametrize(

    ## Example

    ```python
    from typing import Annotated

    from fastapi import Depends, FastAPI
    from fastapi.security import OAuth2PasswordRequestForm

    app = FastAPI()


    @app.post("/login")
    def login(form_data: Annotated[OAuth2PasswordRequestForm, Depends()]):
        data = {}
        data["scopes"] = []

            return func

        return decorator

    def include_router(
        self,
        router: Annotated["APIRouter", Doc("The `APIRouter` to include.")],
        *,
        prefix: Annotated[str, Doc("An optional path prefix for the router.")] = "",
        tags: Annotated[
            list[str | Enum] | None,
            Doc(
                """

from typing import Annotated

import pytest
from fastapi import APIRouter, FastAPI, Query
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

app = FastAPI()


@app.get("/default")
async def default(foo: Annotated[str, Query()] = "foo"):
    return {"foo": foo}


@app.get("/required")
async def required(foo: Annotated[str, Query(min_length=1)]):
    return {"foo": foo}


@app.get("/multiple")

            return func

        return decorator

    def include_router(
        self,
        router: Annotated[routing.APIRouter, Doc("The `APIRouter` to include.")],
        *,
        prefix: Annotated[str, Doc("An optional path prefix for the router.")] = "",
        tags: Annotated[
            list[str | Enum] | None,
            Doc(
                """

from typing import Annotated

import pytest
from fastapi import FastAPI, File, UploadFile
from fastapi.testclient import TestClient

from .utils import get_body_model_name

app = FastAPI()

# =====================================================================================
# Without aliases


@app.post("/optional-list-bytes")
async def read_optional_list_bytes(p: Annotated[list[bytes] | None, File()] = None):

Make sure you [Upgrade the FastAPI version](../deployment/versions.md#upgrading-the-fastapi-versions) to at least 0.95.1 before using `Annotated`.

///

## Use `Annotated` in the type for the `q` parameter { #use-annotated-in-the-type-for-the-q-parameter }

위 코드에서 `CommonQueryParams`를 두 번 작성하는 방식에 주목하세요:

//// tab | Python 3.10+

```Python
commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]
```

////

//// tab | Python 3.10+ Annotated 미사용

/// tip | 팁

가능하다면 `Annotated` 버전을 사용하는 것을 권장합니다.

///

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

////

from typing import Annotated

from fastapi import Body, FastAPI, status
from fastapi.responses import JSONResponse

app = FastAPI()

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Annotated[str | None, Body()] = None,
    size: Annotated[int | None, Body()] = None,
):
    if item_id in items:

## `Path`のインポート { #import-path }

まず初めに、`fastapi`から`Path`をインポートし、`Annotated`もインポートします:

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[1,3] *}

/// info | 情報

FastAPI はバージョン 0.95.0 で`Annotated`のサポートを追加し（そして推奨し始めました）。

古いバージョンの場合、`Annotated`を使おうとするとエラーになります。

`Annotated`を使用する前に、FastAPI のバージョンを少なくとも 0.95.1 まで[アップグレードしてください](../deployment/versions.md#upgrading-the-fastapi-versions)。