Уже сейчас вы можете создавать приложения в продакшене, используя **FastAPI** (и скорее всего так и делаете), главное убедиться в том, что вы используете версию, которая корректно работает с вашим кодом.

## Закрепите вашу версию `fastapi` { #pin-your-fastapi-version }

Первым делом вам следует "закрепить" конкретную последнюю используемую версию **FastAPI**, которая корректно работает с вашим приложением.

# `APIRouter` class

Here's the reference information for the `APIRouter` class, with all its parameters, attributes and methods.

You can import the `APIRouter` class directly from `fastapi`:

```python
from fastapi import APIRouter
```

::: fastapi.APIRouter
    options:
        members:
            - websocket
            - include_router
            - get
            - put
            - post
            - delete

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


app = FastAPI()


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

from functools import lru_cache
from typing import Annotated

from fastapi import Depends, FastAPI

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: Annotated[config.Settings, Depends(get_settings)]):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,

from fastapi import FastAPI, HTTPException

app = FastAPI()

items = {"foo": "The Foo Wrestlers"}


@app.get("/items-header/{item_id}")
async def read_item_header(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "There goes my error"},
        )

from typing import Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(headers: CommonHeaders = Header(convert_underscores=False)):

/// tip

请注意， `name` 和 `price` 的自动补全，是通过其在`Item`模型(FastAPI)中的定义实现的。

///

如果发送的数据字段不符，你也会看到编辑器的错误提示:

<img src="/img/tutorial/generate-clients/image04.png">

响应(response)对象也拥有自动补全:

<img src="/img/tutorial/generate-clients/image05.png">

## 带有标签的 FastAPI 应用

在许多情况下，你的FastAPI应用程序会更复杂，你可能会使用标签来分隔不同组的*路径操作(path operations)*。

from collections.abc import AsyncGenerator, Generator
from functools import partial
from typing import Annotated

import pytest
from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


def function_dependency(value: str) -> str:
    return value


async def async_function_dependency(value: str) -> str:
    return value


def gen_dependency(value: str) -> Generator[str, None, None]:

from fastapi import Depends, FastAPI

app = FastAPI()


async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
    return {"q": q, "skip": skip, "limit": limit}


@app.get("/items/")
async def read_items(commons: dict = Depends(common_parameters)):
    return commons


@app.get("/users/")
async def read_users(commons: dict = Depends(common_parameters)):

from typing import Annotated, Union

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str
    save_data: bool
    if_modified_since: Union[str, None] = None
    traceparent: Union[str, None] = None
    x_tag: list[str] = []


@app.get("/items/")
async def read_items(
    headers: Annotated[CommonHeaders, Header(convert_underscores=False)],
):