Declare o corpo utilizando tipos padrão Python, graças ao Pydantic.

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool] = None


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

Declara el body usando las declaraciones de tipo estándares de Python gracias a Pydantic.

```Python hl_lines="2  7-10  23-25"
from fastapi import FastAPI
from pydantic import BaseModel
from typing import Union

app = FastAPI()


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


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

from typing import List, Union

import pytest
from fastapi import FastAPI
from fastapi.exceptions import FastAPIError, ResponseValidationError
from fastapi.responses import JSONResponse, Response
from fastapi.testclient import TestClient
from pydantic import BaseModel


class BaseUser(BaseModel):
    name: str


class User(BaseUser):
    surname: str


class DBUser(User):
    password_hash: str

 */
package okhttp3.containers

import assertk.assertThat
import assertk.assertions.contains
import assertk.assertions.isEmpty
import assertk.assertions.isNotEmpty
import java.io.ByteArrayOutputStream
import java.io.PrintStream
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors
import okhttp3.Dispatcher
import okhttp3.HttpUrl.Companion.toHttpUrl
import okhttp3.OkHttpClient
import okhttp3.Request

import org.dbflute.bhv.readable.EntityRowHandler;
import org.dbflute.cbean.ConditionBean;
import org.dbflute.cbean.result.ListResultBean;
import org.dbflute.cbean.result.PagingResultBean;
import org.dbflute.exception.IllegalBehaviorStateException;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.util.DfTypeUtil;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.delete.DeleteRequestBuilder;

from fastapi import FastAPI, Path
from typing_extensions import Annotated

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    q: str, item_id: Annotated[int, Path(title="The ID of the item to get")]
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.common.primitives.Doubles;
import com.google.common.testing.NullPointerTester;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.RoundingMode;

package com.google.common.collect.testing.google;

import static com.google.common.collect.testing.Helpers.assertEqualIgnoringOrder;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multimap;
import com.google.common.collect.testing.AbstractContainerTester;
import com.google.common.collect.testing.SampleElements;

package org.codelibs.fess.es.user.cbean.bs;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.codelibs.fess.es.user.allcommon.EsAbstractConditionBean;
import org.codelibs.fess.es.user.bsentity.dbmeta.UserDbm;
import org.codelibs.fess.es.user.cbean.UserCB;
import org.codelibs.fess.es.user.cbean.ca.UserCA;
import org.codelibs.fess.es.user.cbean.ca.bs.BsUserCA;
import org.codelibs.fess.es.user.cbean.cq.UserCQ;

package org.codelibs.fess.crawler.extractor.impl;

import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScheme;
import org.apache.http.auth.AuthSchemeProvider;