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

As **FastAPI** is actually **Starlette** underneath, with a layer of several tools on top, you can use Starlette's <a href="https://www.starlette.io/requests/" class="external-link" target="_blank">`Request`</a> object directly when you need to.

* Configure any required permissions and roles using dependencies.
* Never store plaintext passwords, only password hashes.
* Implement and use well-known cryptographic tools, like Passlib and JWT tokens, etc.
* Add more granular permission controls with OAuth2 scopes where needed.
* ...etc.

/// warning

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.
As these keys may not necessarily be part of the OpenAPI specification, some OpenAPI tools, for example [the OpenAPI validator](https://validator.swagger.io/), may not work with your generated schema.

///

## Recap { #recap }

import java.util.Collections.singletonMap
import java.util.Locale.US
import kotlin.text.Charsets.ISO_8859_1
import okhttp3.internal.unmodifiable

/**
 * An [RFC 7235][rfc_7235] challenge.
 *
 * [rfc_7235]: https://tools.ietf.org/html/rfc7235
 */
class Challenge(
  /** Returns the authentication scheme, like `Basic`. */
  @get:JvmName("scheme") val scheme: String,
  authParams: Map<String?, String>,
) {
  /**

 *   int result = 1;
 *   while ((response = response.priorResponse()) != null) {
 *     result++;
 *   }
 *   return result;
 * }
 * ```
 *
 * [1]: https://tools.ietf.org/html/rfc2817
 */
fun interface Authenticator {
  /**
   * Returns a request that includes a credential to satisfy an authentication challenge in
   * [response]. Returns null if the challenge cannot be satisfied.

{* ../../docs_src/websockets/tutorial002.py hl[66:77,76:91] *}

/// info

👉 *️⃣ ⚫️ 🚫 🤙 ⚒ 🔑 🤚 `HTTPException`, ↩️ 👥 🤚 `WebSocketException`.

👆 💪 ⚙️ 📪 📟 ⚪️➡️ <a href="https://tools.ietf.org/html/rfc6455#section-7.4.1" class="external-link" target="_blank">☑ 📟 🔬 🔧</a>.

///

### 🔄 *️⃣ ⏮️ 🔗

🚥 👆 📁 📛 `main.py`, 🏃 👆 🈸 ⏮️:

<div class="termy">

```console

                                        <la:message key="labels.elevate_word_link_details"/>
                                    </c:if>
                                </h3>
                                <div class="card-tools">
                                    <div class="btn-group">
                                        <la:link href="/admin/elevateword"
                                                 styleClass="btn btn-default btn-xs">

                                        <la:message key="labels.dict_mapping_link_edit"/>
                                    </c:if>
                                </h3>
                                <div class="card-tools">
                                    <div class="btn-group">
                                        <la:link href="/admin/dict"
                                                 styleClass="btn btn-default btn-xs">

                                        <la:message key="labels.dict_stemmeroverride_link_details"/>
                                    </c:if>
                                </h3>
                                <div class="card-tools">
                                    <div class="btn-group">
                                        <la:link href="/admin/dict"
                                                 styleClass="btn btn-default btn-xs">

# Templates { #templates }

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies { #install-dependencies }