"antlr",
          "base-diagnostics",
          "file-watching",
          "ide",
          "ide-native",
          "kotlin-dsl",
          "platform-base",
          "plugins-application",
          "plugins-java-library",
          "software-diagnostics",
          "test-kit"
        ],
        "parallelizationMethod": {
          "name": "TestDistribution"
        }
      },

                            "content": {
                                "application/json": {
                                    "schema": {},
                                }
                            },
                        },
                        "422": {
                            "content": {
                                "application/json": {
                                    "schema": {

app = FastAPI()

router = APIRouter()


class ContentSizeLimitMiddleware:
    """Content size limiting middleware for ASGI applications
    Args:
      app (ASGI application): ASGI application
      max_content_size (optional): the maximum content size allowed in bytes, None for no limit
    """

    def __init__(self, app: APIRouter, max_content_size: Optional[int] = None):
        self.app = app

Vous pouvez connecter le <abbr title="En anglais: debugger">débogueur</abbr> dans votre éditeur, par exemple avec Visual Studio Code ou PyCharm.

## Faites appel à `uvicorn`

Dans votre application FastAPI, importez et exécutez directement `uvicorn` :

{* ../../docs_src/debugging/tutorial001.py hl[1,15] *}

### À propos de `__name__ == "__main__"`

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

                    "responses": {
                        "404": {
                            "description": "The item was not found",
                            "content": {
                                "application/json": {
                                    "schema": {"$ref": "#/components/schemas/Message"}
                                }
                            },
                        },
                        "200": {

                            "content": {
                                "application/json": {"schema": {}},
                            },
                            "description": "Successful Response",
                        },
                        "422": {
                            "content": {
                                "application/json": {
                                    "schema": {

# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

   *
   * @since 20.0
   */
  public static final MediaType THREE_GPP2_VIDEO = createConstant(VIDEO_TYPE, "3gpp2");

  /* application types */
  /**
   * As described in <a href="http://www.ietf.org/rfc/rfc3023.txt">RFC 3023</a>, this constant
   * ({@code application/xml}) is used for XML documents that are "unreadable by casual users."
   * {@link #XML_UTF_8} is provided for documents that may be read by users.
   *