parameters: Optional[list[Union[Parameter, Reference]]] = None
    requestBody: Optional[Union[RequestBody, Reference]] = None
    # Using Any for Specification Extensions
    responses: Optional[dict[str, Union[Response, Any]]] = None
    callbacks: Optional[dict[str, Union[dict[str, "PathItem"], Reference]]] = None
    deprecated: Optional[bool] = None
    security: Optional[list[dict[str, list[str]]]] = None

Por exemplo, você pode querer retornar uma *response* em *plain text* ao invés de um JSON para os seguintes erros:

{* ../../docs_src/handling_errors/tutorial004_py39.py hl[3:4,9:11,25] *}

/// note | Detalhes Técnicos

Você pode usar `from starlette.responses import PlainTextResponse`.

    app.post("/endpoint2")(passthrough(passthrough(forwardref_method)))
    with client:
        response = client.post("/endpoint", json={"input": {"x": 0}})
        response2 = client.post("/endpoint2", json={"input": {"x": 0}})

### Add some custom `tags`, `responses`, and `dependencies` { #add-some-custom-tags-responses-and-dependencies }

We are not adding the prefix `/items` nor the `tags=["items"]` to each *path operation* because we added them to the `APIRouter`.

But we can still add _more_ `tags` that will be applied to a specific *path operation*, and also some extra `responses` specific to that *path operation*:

def test_query(client: TestClient):
    response = client.post("/graphql", json={"query": "{ user { name, age } }"})
    assert response.status_code == 200
    assert response.json() == {"data": {"user": {"name": "Patrick", "age": 100}}}


def test_openapi(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {
        "info": {

O middleware responde a dois tipos específicos de solicitação HTTP...

### Requisições CORS pré-voo (preflight) { #cors-preflight-requests }

Estas são quaisquer solicitações `OPTIONS` com cabeçalhos `Origin` e `Access-Control-Request-Method`.

    client = TestClient(app)
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert b"<form" in response.content


def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {

		if rec.Code != testCase.expectedRespStatus {
			t.Errorf("Test %d: %s: Expected the response status to be `%d`, but instead found `%d`", i+1, instanceType, testCase.expectedRespStatus, rec.Code)
		}

		// Verify response the V2 signed HTTP request.
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		recV2 := httptest.NewRecorder()

def test_create_item(client: TestClient) -> None:
    response = client.post("/items/", json={"name": "Foo"})
    assert response.status_code == 200, response.text
    assert response.json() == {"name": "Foo", "description": None}


def test_read_items(client: TestClient) -> None:
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [
        {
            "name": "Portal Gun",

## `GZipMiddleware` { #gzipmiddleware }

Verarbeitet GZip-Responses für alle Requests, die `"gzip"` im `Accept-Encoding`-Header enthalten.

Diese Middleware verarbeitet sowohl Standard- als auch Streaming-Responses.