### Normales **FastAPI**

Schreiben Sie zunächst wie gewohnt Ihre ganze **FastAPI**-Anwendung:

```Python hl_lines="1  4  7-9"
{!../../docs_src/extending_openapi/tutorial001.py!}
```

### Das OpenAPI-Schema generieren

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(default=None, min_length=3, max_length=50)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)] = ...):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310, needs_pydanticv1, needs_pydanticv2


@pytest.fixture(name="client")
def get_client():
    from docs_src.path_operation_configuration.tutorial005_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_query_params_str_validations(client: TestClient):

from fastapi import FastAPI, Query
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)] = "fixedquery"):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, File, UploadFile
from typing_extensions import Annotated

app = FastAPI()


@app.post("/files/")
async def create_file(file: Annotated[bytes, File()]):
    return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(file: UploadFile):

import time

from fastapi import FastAPI, Request

app = FastAPI()


@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.perf_counter()
    response = await call_next(request)
    process_time = time.perf_counter() - start_time
    response.headers["X-Process-Time"] = str(process_time)

{!../../docs_src/path_operation_configuration/tutorial001.py!}
```

そのステータスコードはレスポンスで使用され、OpenAPIスキーマに追加されます。

/// note | "技術詳細"

また、`from starlette import status`を使用することもできます。

**FastAPI** は開発者の利便性を考慮して、`fastapi.status`と同じ`starlette.status`を提供しています。しかし、これはStarletteから直接提供されています。

///

## タグ

`tags`パラメータを`str`の`list`（通常は１つの`str`）と一緒に渡すと、*path operation*にタグを追加できます:

```Python hl_lines="17  22  27"

import pytest
from dirty_equals import IsDict
from fastapi import FastAPI, Form
from fastapi.testclient import TestClient
from typing_extensions import Annotated

from .utils import needs_py310


def get_client():
    app = FastAPI()
    with pytest.warns(DeprecationWarning):

        @app.post("/items/")
        async def read_items(
            q: Annotated[str | None, Form(regex="^fixedquery$")] = None,
        ):

import typing

from fastapi import Body, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

media_type = "application/vnd.api+json"


# NOTE: These are not valid JSON:API resources
# but they are fine for testing requestBody with custom media_type
class Product(BaseModel):
    name: str
    price: float


class Shop(BaseModel):
    name: str


@app.post("/products")