Dazu verwenden Sie `app.add_middleware()` (wie schon im Beispiel für CORS gesehen).

```Python
from fastapi import FastAPI
from unicorn import UnicornMiddleware

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

from typing import Optional

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: Optional[str] = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool

package jcifs;

import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.Iterator;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertSame;

import java.util.Arrays;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

 */

package gradlebuild.samples

import org.gradle.api.file.Directory
import org.gradle.buildinit.plugins.internal.CompositeProjectInitDescriptor
import org.gradle.buildinit.plugins.internal.InitSettings
import org.gradle.buildinit.plugins.internal.ProjectLayoutSetupRegistry
import org.gradle.buildinit.plugins.internal.modifiers.BuildInitDsl
import org.gradle.buildinit.plugins.internal.modifiers.BuildInitTestFramework

import functools

import pytest
from fastapi import (
    APIRouter,
    Depends,
    FastAPI,
    Header,
    WebSocket,
    WebSocketDisconnect,
    status,
)
from fastapi.middleware import Middleware
from fastapi.testclient import TestClient

router = APIRouter()
prefix_router = APIRouter()
native_prefix_route = APIRouter(prefix="/native")
app = FastAPI()


@app.websocket_route("/")

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Annotated[Item, Body(embed=True)]):
    results = {"item_id": item_id, "item": item}

from typing import Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")
async def read_items(filter_query: FilterParams = Query()):

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.CompatibleWith;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;

from typing import Any, Union

from fastapi import FastAPI
from pydantic import BaseModel, EmailStr

app = FastAPI()


class UserIn(BaseModel):
    username: str
    password: str
    email: EmailStr
    full_name: Union[str, None] = None


class UserOut(BaseModel):
    username: str
    email: EmailStr
    full_name: Union[str, None] = None


@app.post("/user/", response_model=UserOut)