from fastapi import FastAPI, Request

app = FastAPI()


@app.get("/items/{item_id}")
def read_root(item_id: str, request: Request):
    client_host = request.client.host

## Zusatzfunktionen { #additional-features }

Das Haupt-[Tutorial – Benutzerhandbuch](../tutorial/index.md){.internal-link target=_blank} sollte ausreichen, um Ihnen einen Überblick über alle Hauptfunktionen von **FastAPI** zu geben.

In den nächsten Abschnitten sehen Sie weitere Optionen, Konfigurationen und zusätzliche Funktionen.

/// tip | Tipp

Die nächsten Abschnitte sind **nicht unbedingt „fortgeschritten“**.

## Recursos Adicionais { #additional-features }

O [Tutorial - Guia de Usuário](../tutorial/index.md){.internal-link target=_blank} deve ser o suficiente para dar a você um tour por todos os principais recursos do **FastAPI**.

Nas próximas seções você verá outras opções, configurações, e recursos adicionais.

/// tip | Dica

As próximas seções **não são necessáriamente "avançadas"**

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[list[str] | None, Query()] = None):
    query_items = {"q": q}

`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

///

* Un `client_secret` opcional (no lo necesitamos para nuestro ejemplo).

/// info | Información

`OAuth2PasswordRequestForm` no es una clase especial para **FastAPI** como lo es `OAuth2PasswordBearer`.

`OAuth2PasswordBearer` hace que **FastAPI** sepa que es un esquema de seguridad. Así que se añade de esa manera a OpenAPI.

from fastapi import FastAPI
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    openapi_url: str = "/openapi.json"


settings = Settings()

app = FastAPI(openapi_url=settings.openapi_url)


@app.get("/")
def root():

## テスト駆動開発のコース

このセクションの内容を補完するために脱初心者用コースを受けたい場合は、**TestDriven.io**による、<a href="https://testdriven.io/courses/tdd-fastapi/" class="external-link" target="_blank">Test-Driven Development with FastAPI and Docker</a>を確認するのがよいかもしれません。

* The path as parameters.
* Headers.
* Cookies.
* etc.

And by doing so, **FastAPI** is validating that data, converting it and generating documentation for your API automatically.

But there are situations where you might need to access the `Request` object directly.

## Details about the `Request` object { #details-about-the-request-object }

from decimal import Decimal

from dirty_equals import IsOneOf
from fastapi import FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel, condecimal

app = FastAPI()


class Item(BaseModel):
    name: str
    age: condecimal(gt=Decimal(0.0))  # type: ignore


@app.post("/items/")
def save_item_no_body(item: list[Item]):
    return {"item": item}