# OpenAPI-Callbacks { #openapi-callbacks }

Sie könnten eine API mit einer *Pfadoperation* erstellen, die einen <abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr> an eine *externe API* auslösen könnte, welche von jemand anderem erstellt wurde (wahrscheinlich derselbe Entwickler, der Ihre API *verwenden* würde).

            status_code=HTTP_401_UNAUTHORIZED,
            detail="Not authenticated",
            headers={"WWW-Authenticate": "Bearer"},
        )

    async def __call__(self, request: Request) -> str | None:
        authorization = request.headers.get("Authorization")
        if not authorization:
            if self.auto_error:
                raise self.make_not_authenticated_error()
            else:

        /**
         * Sets the URL for this request data.
         *
         * @param url the URL string to be set
         * @return the current RequestDataContext instance for method chaining
         */
        public RequestDataContext url(final String url) {
            data.setUrl(url);
            return this;
        }

        /**
         * Sets the weight for the request data.
         *

func (api objectAPIHandlers) DeleteBucketWebsiteHandler(w http.ResponseWriter, r *http.Request) {
	writeSuccessResponseHeadersOnly(w)
}

// GetBucketCorsHandler - GET bucket cors, a dummy api
func (api objectAPIHandlers) GetBucketCorsHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "GetBucketCors")

	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

from __future__ import annotations

from typing import Annotated

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

from .utils import needs_py310


class Dep:
    def __call__(self, request: Request):
        return "test"


@needs_py310
def test_stringified_annotations():
    app = FastAPI()

    client = TestClient(app)

    @app.get("/test/")

from fastapi import FastAPI, Request
from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from pydantic import BaseModel

app = FastAPI()


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=422,

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse


class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name


app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,

# Request Parameters

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python

# Configuration for probot-stale - https://github.com/probot/stale

# Number of days of inactivity before an Issue or Pull Request becomes stale
daysUntilStale: 30

# Number of days of inactivity before an Issue or Pull Request with the stale label is closed.
# Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.
daysUntilClose: 15

        return LaRequestUtil.getOptionalRequest().map(request -> {
            String query = (String) request.getAttribute(key);
            if (query == null) {
                final StringBuilder buf = new StringBuilder(100);
                final Enumeration<String> names = request.getParameterNames();
                while (names.hasMoreElements()) {
                    final String name = names.nextElement();