You can read more about this in the [Advanced User Guide](../advanced/index.md){.internal-link target=_blank}.

## Details { #details }

The first `"/static"` refers to the sub-path this "sub-application" will be "mounted" on. So, any path that starts with `"/static"` will be handled by it.

```Python
contents = myfile.file.read()
```

/// note | `async` Technical Details

When you use the `async` methods, **FastAPI** runs the file methods in a threadpool and awaits for them.

///

/// note | Starlette Technical Details

{!../../docs_src/templates/static/styles.css!}
```

And because you are using `StaticFiles`, that CSS file would be served automatically by your **FastAPI** application at the URL `/static/styles.css`.

## More details { #more-details }

With `openapi_examples` added to `Body()` the `/docs` would look like:

<img src="/img/tutorial/body-fields/image02.png">

## Technical Details { #technical-details }

/// tip

If you are already using **FastAPI** version **0.99.0 or above**, you can probably **skip** these details.

They are more relevant for older versions, before OpenAPI 3.1.0 was available.

/// warning

You most probably don't need these technical details, you can skip this section and continue below.

These details are useful mainly if you were using a version of FastAPI prior to 0.106.0 and used resources from dependencies with `yield` in background tasks.

///

### Dependencies with `yield` and `except`, Technical Details { #dependencies-with-yield-and-except-technical-details }

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

#### More details { #more-details }

Let's say your file is named `myapp.py`.

If you run it with:

<div class="termy">

```console
$ python myapp.py
```

</div>

But there are situations where you might need to access the `Request` object directly.

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

| `license_info` | `dict` | The license information for the exposed API. It can contain several fields. <details><summary><code>license_info</code> fields</summary><table><thead><tr><th>Parameter</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><code>name</code></td><td><code>str</c...

Because of that, it's now recommended to instead use the `lifespan` as explained above.

## Technical Details { #technical-details }

Just a technical detail for the curious nerds. 🤓

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Або використайте <code>async def</code>...</summary>

Якщо ваш код використовує `async` / `await`, скористайтеся `async def`:

```Python hl_lines="9  14"
from typing import Union