item_id = "ff97dd87-a4a5-4a12-b412-cde99f33e00e"
    data = {
        "start_datetime": "2018-12-22T14:00:00+00:00",
        "end_datetime": "2018-12-24T15:00:00+00:00",
        "repeat_at": "15:30:00",
        "process_after": 300,
    }
    expected_response = data.copy()
    expected_response.update(
        {
            "start_process": "2018-12-22T14:05:00+00:00",
            "duration": 176_100,

import time

from fastapi import FastAPI, Request

app = FastAPI()


@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)

<div class="termy">

```console
$ python ./scripts/docs.py live

<span style="color: green;">[INFO]</span> Serving on http://127.0.0.1:8008
<span style="color: green;">[INFO]</span> Start watching changes
<span style="color: green;">[INFO]</span> Start detecting changes
```

</div>

It will serve the documentation on `http://127.0.0.1:8008`.

That way, you can edit the documentation/source files and see the changes live.

    about: Ask a question or ask about a problem in GitHub Discussions.
    url: https://github.com/tiangolo/fastapi/discussions/categories/questions
  - name: Feature Request
    about: To suggest an idea or ask about a feature, please start with a question saying what you would like to achieve. There might be a way to do it already.
    url: https://github.com/tiangolo/fastapi/discussions/categories/questions
  - name: Show and tell

<font color="#4E9A06">INFO</font>:     Uvicorn running on <b>http://0.0.0.0:8000</b> (Press CTRL+C to quit)
```

</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.

<div class="termy">

```console
$ python ./scripts/docs.py live

<span style="color: green;">[INFO]</span> Serving on http://127.0.0.1:8008
<span style="color: green;">[INFO]</span> Start watching changes
<span style="color: green;">[INFO]</span> Start detecting changes
```

</div>

⚫️ 🔜 🍦 🧾 🔛 `http://127.0.0.1:8008`.

👈 🌌, 👆 💪 ✍ 🧾/ℹ 📁 &amp; 👀 🔀 🖖.

#### 🏎 ✳ (📦)

And then it will redirect its requests to your Uvicorn running on `http://127.0.0.1:8000`.

Now start Traefik:

<div class="termy">

```console
$ ./traefik --configFile=traefik.toml

INFO[0000] Configuration loaded from file: /home/user/awesomeapi/traefik.toml
```

</div>

And now start your app, using the `--root-path` option:

<div class="termy">

```console

    * Wenn Sie FastAPI nicht, und direkt Starlette (oder ein anderes Tool wie Sanic, Flask, Responder, usw.) verwenden würden, müssten Sie die gesamte Datenvalidierung und Serialisierung selbst implementieren. Ihre finale Anwendung...

Das einzig Neue ist `callbacks=invoices_callback_router.routes` als Argument für den *Pfadoperation-Dekorator*. Wir werden als Nächstes sehen, was das ist.

## Dokumentation des Callbacks

Der tatsächliche Callback-Code hängt stark von Ihrer eigenen API-Anwendung ab.

Und er wird wahrscheinlich von Anwendung zu Anwendung sehr unterschiedlich sein.

Es könnten nur eine oder zwei Codezeilen sein, wie zum Beispiel:

```Python

<img src="/img/deployment/https/https01.svg">

### TLS-Handshake-Start

Der Browser kommuniziert dann mit dieser IP-Adresse über **Port 443** (den HTTPS-Port).