So, with that type declaration, **FastAPI** gives you automatic request <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>.

## Data validation

```Python hl_lines="20-37  39-40"
{!../../../docs_src/path_operation_advanced_configuration/tutorial006.py!}
```

👉 🖼, 👥 🚫 📣 🙆 Pydantic 🏷. 👐, 📨 💪 🚫 <abbr title="converted from some plain format, like bytes, into Python objects">🎻</abbr> 🎻, ⚫️ ✍ 🔗 `bytes`, &amp; 🔢 `magic_data_reader()` 🔜 🈚 🎻 ⚫️ 🌌.

👐, 👥 💪 📣 📈 🔗 📨 💪.

### 🛃 🗄 🎚 🆎

⚙️ 👉 🎏 🎱, 👆 💪 ⚙️ Pydantic 🏷 🔬 🎻 🔗 👈 ⤴️ 🔌 🛃 🗄 🔗 📄 *➡ 🛠️*.

```

</div>

That would work for most of the cases. 😎

You could use that command for example to start your **FastAPI** app in a container, in a server, etc.

## ASGI Servers

Let's go a little deeper into the details.

FastAPI uses a standard for building Python web frameworks and servers called <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI is an ASGI web framework.

You can write <a href="https://en.wikipedia.org/wiki/Markdown" class="external-link" target="_blank">Markdown</a> in the docstring, it will be interpreted and displayed correctly (taking into account docstring indentation).

=== "Python 3.10+"

    ```Python hl_lines="17-25"
    {!> ../../../docs_src/path_operation_configuration/tutorial004_py310.py!}
    ```

=== "Python 3.9+"

     * @param {number} time - Timeout, in ms.
     */
    _wait(time) {
        return new Promise(resolve => setTimeout(resolve, time));
    }

    /**
     * Converts line data objects into line elements.
     *
     * @param {Object[]} lineData - Dynamically loaded lines.
     * @param {Object} line - Line data object.
     * @returns {Element[]} - Array of line elements.
     */

All the same process that applied for path parameters also applies for query parameters:

* Editor support (obviously)
* Data <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>
* Data validation
* Automatic documentation

## Defaults

As query parameters are not a fixed part of a path, they can be optional and can have default values.

          - starlette
          inherited_members: true
          members_order: source
          separate_signature: true
          unwrap_annotated: true
          filters:
          - '!^_'
          merge_init_into_class: true
          docstring_section_style: spacy
          signature_crossrefs: true
          show_symbol_type_heading: true
          show_symbol_type_toc: true
nav:
- FastAPI: index.md
- features.md
- Learn:

👫 🍕 📛, 👫 "🛎" 🎻.

✋️ 🕐❔ 👆 📣 👫 ⏮️ 🐍 🆎 (🖼 🔛, `int`), 👫 🗜 👈 🆎 & ✔ 🛡 ⚫️.

🌐 🎏 🛠️ 👈 ⚖ ➡ 🔢 ✔ 🔢 🔢:

* 👨‍🎨 🐕‍🦺 (🎲)
* 💽 <abbr title="converting the string that comes from an HTTP request into Python data">"✍"</abbr>
* 💽 🔬
* 🏧 🧾

## 🔢

🔢 🔢 🚫 🔧 🍕 ➡, 👫 💪 📦 &amp; 💪 ✔️ 🔢 💲.

🖼 🔛 👫 ✔️ 🔢 💲 `skip=0` &amp; `limit=10`.

, 🔜 📛:

```
http://127.0.0.1:8000/items/
```

class APIKeyQuery(APIKeyBase):
    """
    API key authentication using a query parameter.

    This defines the name of the query parameter that should be provided in the request
    with the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the query parameter automatically and provides it as the
    dependency result. But it doesn't define how to send that API key to the client.

    ## Usage

```JSON
{"item_id":3}
```

!!! check
    👀 👈 💲 👆 🔢 📨 (& 📨) `3`, 🐍 `int`, 🚫 🎻 `"3"`.

    , ⏮️ 👈 🆎 📄, **FastAPI** 🤝 👆 🏧 📨 <abbr title="converting the string that comes from an HTTP request into Python data">"✍"</abbr>.

## 💽 🔬

✋️ 🚥 👆 🚶 🖥 <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, 👆 🔜 👀 👌 🇺🇸🔍 ❌:

```JSON
{