//// tab | Pydantic v2

У версії Pydantic 2 використовується атрибут `model_config`, який приймає `dict`, як описано в <a href="https://docs.pydantic.dev/latest/api/config/" class="external-link" target="_blank">документації Pydantic: Конфігурація</a>.

# CORS (Cross-Origin Resource Sharing) { #cors-cross-origin-resource-sharing }

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORS or "Cross-Origin Resource Sharing"</a> refers to the situations when a frontend running in a browser has JavaScript code that communicates with a backend, and the backend is in a different "origin" than the frontend.

## Origin { #origin }

 │                                                     │
 │  Serving at: http://127.0.0.1:8000                  │
 │                                                     │
 │  API docs: http://127.0.0.1:8000/docs               │
 │                                                     │
 │  Running in development mode, for production use:   │
 │                                                     │

      when (val protocol = sslSocket.applicationProtocol) {
        null, "" -> null
        else -> protocol
      }
    } catch (e: UnsupportedOperationException) {
      // https://docs.oracle.com/javase/9/docs/api/javax/net/ssl/SSLSocket.html#getApplicationProtocol--
      null
    }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? {
    // Not supported due to access checks on JDK 9+:

  /**
   * The HTTP <a
   * href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-Host">{@code
   * X-Forwarded-Host}</a> header field name.
   *
   * @since 20.0
   */
  public static final String X_FORWARDED_HOST = "X-Forwarded-Host";

  /**
   * The HTTP <a
   * href="https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/x-forwarded-headers.html#x-forwarded-port">{@code

      when (val protocol = sslSocket.applicationProtocol) {
        null, "" -> null
        else -> protocol
      }
    } catch (e: UnsupportedOperationException) {
      // https://docs.oracle.com/javase/9/docs/api/javax/net/ssl/SSLSocket.html#getApplicationProtocol--
      null
    }

  @SuppressLint("NewApi")
  override fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,

    * 📨 & 📨 🔜 🎨 `str` 💾 8️⃣6️⃣0️⃣1️⃣ 📁, 💖: `14:23:55.003`.
* `datetime.timedelta`:
    * 🐍 `datetime.timedelta`.
    * 📨 & 📨 🔜 🎨 `float` 🌐 🥈.
    * Pydantic ✔ 🎦 ⚫️ "💾 8️⃣6️⃣0️⃣1️⃣ 🕰 ➕ 🔢", <a href="https://docs.pydantic.dev/latest/concepts/serialization/#json_encoders" class="external-link" target="_blank">👀 🩺 🌅 ℹ</a>.
* `frozenset`:
    * 📨 &amp; 📨, 😥 🎏 `set`:
        * 📨, 📇 🔜 ✍, ❎ ❎ &amp; 🏭 ⚫️ `set`.

 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code
 * default} methods. Specifically, it forwards calls only for methods that existed <a
 * href="https://docs.oracle.com/javase/7/docs/api/java/util/Iterator.html">before {@code default}
 * methods were introduced</a>. For newer methods, like {@code forEachRemaining}, it inherits their

 │  Serving at: http://127.0.0.1:8000                  │
 │                                                     │
 │  API docs: http://127.0.0.1:8000/docs               │
 │                                                     │
 │  Running in development mode, for production use:   │
 │                                                     │
 │  fastapi run                                        │

Notice that the *path operations* define the models they use for request payload and response payload, using the models `Item` and `ResponseMessage`.

### API Docs { #api-docs }

If you go to `/docs`, you will see that it has the **schemas** for the data to be sent in requests and received in responses:

<img src="/img/tutorial/generate-clients/image01.png">