object browser built into MinIO Server. Point a web browser running on the host machine to <http://127.0.0.1:9000> and log in with the
root credentials. You can use the Browser to create buckets, upload objects, and browse the contents of the MinIO server.

    You can probably skip this part.

There's an alternative way to define this logic to be executed during *startup* and during *shutdown*.

You can define event handlers (functions) that need to be executed before the application starts up, or when the application is shutting down.

These functions can be declared with `async def` or normal `def`.

### `startup` event

* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.
* The process can be **terminated** (or "killed") by you, or by the operating system. At that point, it stops running/being executed, and it can **no longer do things**.

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

These exceptions can be imported directly from `fastapi`:

```python

Some of the options you could use as a TLS Termination Proxy are:

* Traefik (that can also handle certificate renewals)
* Caddy (that can also handle certificate renewals)
* Nginx
* HAProxy

## Let's Encrypt

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

# Response Model - Return Type

You can declare the type used for the response by annotating the *path operation function* **return type**.

You can use **type annotations** the same way you would for input data in function **parameters**, you can use Pydantic models, lists, dictionaries, scalar values like integers, booleans, etc.

=== "Python 3.10+"

    ```Python hl_lines="16  21"
    {!> ../../../docs_src/response_model/tutorial001_01_py310.py!}
    ```

// And then call the program again
$ python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python
```

</div>

As environment variables can be set outside of the code, but can be read by the code, and don't have to be stored (committed to `git`) with the rest of the files, it's common to use them for configurations or settings.

		case objectlock.RetCompliance:
			// In compliance mode, a protected object version can't be overwritten
			// or deleted by any user, including the root user in your AWS account.
			// When an object is locked in compliance mode, its retention mode can't
			// be changed, and its retention period can't be shortened. Compliance mode
			// ensures that an object version can't be overwritten or deleted for the
			// duration of the retention period.

{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

You can think of `APIRouter` as a "mini `FastAPI`" class.

All the same options are supported.

All the same `parameters`, `responses`, `dependencies`, `tags`, etc.

!!! tip
    In this example, the variable is called `router`, but you can name it however you want.

# Middleware

You can add middleware to **FastAPI** applications.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.