<div class="termy">

    ```console
    $ pip install hypercorn

    ---> 100%
    ```

    </div>

    ...or any other ASGI server.

## Run the Server Program

If you installed an ASGI server manually, you would normally need to pass an import string in a special format for it to import your FastAPI application:

=== "Uvicorn"

    <div class="termy">

    ```console

    # TODO: remove after upgrading python-jose to a version that explicitly supports Python 3.12
    # also, if it won't receive an update, consider replacing python-jose with some alternative
    # related issues:
    #   - https://github.com/mpdavis/python-jose/issues/332
    #   - https://github.com/mpdavis/python-jose/issues/334

=== "Python 3.10+ non-Annotated"

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

    ```Python hl_lines="66-67  79"
    {!> ../../../docs_src/websockets/tutorial002_py310.py!}
    ```

=== "Python 3.8+ non-Annotated"

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

    ```Python hl_lines="68-69  81"
    {!> ../../../docs_src/websockets/tutorial002.py!}

### Just Modern Python

It's all based on standard **Python type** declarations (thanks to Pydantic). No new syntax to learn. Just standard modern Python.

If you need a 2 minute refresher of how to use Python types (even if you don't use FastAPI), check the short tutorial: [Python Types](python-types.md){.internal-link target=_blank}.

You write standard Python with types:

```Python
from datetime import date

In this case, it's the `str`:

```Python
"{$callback_url}/invoices/{$request.body.id}"
```

So, if your API user (the external developer) sends a request to *your API* to:

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

with a JSON body of:

```JSON
{

  mkdocstrings:
    handlers:
      python:
        options:
          extensions:
          - griffe_typingdoc
          show_root_heading: true
          show_if_no_docstring: true
          preload_modules:
          - httpx
          - starlette
          inherited_members: true
          members_order: source
          separate_signature: true
          unwrap_annotated: true

        ] = None,
        auto_error: Annotated[
            bool,
            Doc(
                """
                By default, if the query parameter is not provided, `APIKeyQuery` will
                automatically cancel the request and send the client an error.

                If `auto_error` is set to `False`, when the query parameter is not
                available, instead of erroring out, the dependency result will be

And the rest will be handled by **FastAPI**.

If you run it and go to <a href="http://localhost:8000/v1/" class="external-link" target="_blank">http://localhost:8000/v1/</a> you will see the response from Flask:

```txt
Hello, World from Flask!
```

{% if sponsors %}

{% if sponsors.gold %}

### 金牌赞助商

{% for sponsor in sponsors.gold -%}
<a href="{{ sponsor.url }}" target="_blank" title="{{ sponsor.title }}"><img src="{{ sponsor.img }}" style="border-radius:15px"></a>
{% endfor %}
{% endif %}

{% if sponsors.silver %}

### 银牌赞助商

{% for sponsor in sponsors.silver -%}

<div class="termy">

```console
$ pip install fastapi

---> 100%
```

</div>

!!! note
    When you install with `pip install fastapi` it comes with some default optional standard dependencies.

    If you don't want to have those optional dependencies, you can instead install `pip install fastapi-slim`.

## Advanced User Guide

There is also an **Advanced User Guide** that you can read later after this **Tutorial - User guide**.