"value": {
                                            "name": "Baz",
                                            "price": "thirty five point four",
                                        },
                                    },
                                },
                            }
                        },
                        "required": True,

#### The time to answer helps the attackers

At that point, by noticing that the server took some microseconds longer to send the "Incorrect username or password" response, the attackers will know that they got _something_ right, some of the initial letters were right.

* ✏️ Fix typo in `fastapi/security/oauth2.py`. PR [#11368](https://github.com/tiangolo/fastapi/pull/11368) by [@shandongbinzhou](https://github.com/shandongbinzhou).
* 📝 Update links to Pydantic docs to point to new website. PR [#11328](https://github.com/tiangolo/fastapi/pull/11328) by [@alejsdev](https://github.com/alejsdev).

Probably the main use case for this is if you already have some autogenerated client code/SDKs and you don't want to update all the autogenerated client code/SDKs yet, you probably will want to do it at some point, but maybe not right now.

In that case, you can disable this feature in **FastAPI**, with the parameter `separate_input_output_schemas=False`.

!!! info

Instead of, for example, a `dict`, or something else, as it could break the application at some point later, making it a security risk.

We also verify that we have a user with that username, and if not, we raise that same exception we created before.

=== "Python 3.10+"

    ```Python hl_lines="46  116-127"

If you are helping a lot of people with their questions, you will become an official [FastAPI Expert](fastapi-people.md#fastapi-experts){.internal-link target=_blank}. 🎉

Just remember, the most important point is: try to be kind. People come with their frustrations and in many cases don't ask in the best way, but try as best as you can to be kind. 🤗

### Étape 2 : créer une "instance" `FastAPI`

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

Ici la variable `app` sera une "instance" de la classe `FastAPI`.

Ce sera le point principal d'interaction pour créer toute votre API.

Cette `app` est la même que celle à laquelle fait référence `uvicorn` dans la commande :

<div class="termy">

```console
$ uvicorn main:app --reload

Let's check back those deployment concepts from before:

* Security - HTTPS
* Running on startup
* Restarts
* **Replication (the number of processes running)**
* Memory
* Previous steps before starting

Up to this point, with all the tutorials in the docs, you have probably been running a **server program** like Uvicorn, running a **single process**.

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="3  77-79"
    {!> ../../../docs_src/security/tutorial003.py!}
    ```

### Check the password

At this point we have the user data from our database, but we haven't checked the password.

Let's put that data in the Pydantic `UserInDB` model first.

## A dependency with `yield` and `try`

If you use a `try` block in a dependency with `yield`, you'll receive any exception that was thrown when using the dependency.

For example, if some code at some point in the middle, in another dependency or in a *path operation*, made a database transaction "rollback" or create any other error, you will receive the exception in your dependency.