## The main `FastAPI`

Now, let's see the module at `app/main.py`.

Here's where you import and use the class `FastAPI`.

This will be the main file in your application that ties everything together.

And as most of your logic will now live in its own specific module, the main file will be quite simple.

### Import `FastAPI`

    six_months_commenters = Counter()
    one_year_commenters = Counter()
    authors: Dict[str, Author] = {}

    now = datetime.now(tz=timezone.utc)
    one_month_ago = now - timedelta(days=30)
    three_months_ago = now - timedelta(days=90)
    six_months_ago = now - timedelta(days=180)
    one_year_ago = now - timedelta(days=365)

    for discussion in discussion_nodes:
        discussion_author_name = None

Using it led to the creation of several Flask full-stack generators. These are the main stacks I (and several external teams) have been using up to now:

* <a href="https://github.com/tiangolo/full-stack" class="external-link" target="_blank">https://github.com/tiangolo/full-stack</a>

    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

## Import Couchbase components

For now, don't pay attention to the rest, only the imports:

```Python hl_lines="3-5"
{!../../../docs_src/nosql_databases/tutorial001.py!}
```

## Define a constant to use as a "document type"

You will see the JSON response as:

```JSON
{"message": "Hello World"}
```

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

    {!> ../../../docs_src/response_model/tutorial002_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="18"
    {!> ../../../docs_src/response_model/tutorial002.py!}
    ```

Now, whenever a browser is creating a user with a password, the API will return the same password in the response.

In this case, it might not be a problem, because it's the same user sending the password.

To **learn the basics of HTTPS**, from a consumer perspective, check <a href="https://howhttps.works/" class="external-link" target="_blank">https://howhttps.works/</a>.

Now, from a **developer's perspective**, here are several things to keep in mind while thinking about HTTPS:

* For HTTPS, **the server** needs to **have "certificates"** generated by a **third party**.

<div class="termy">

```console
$ hypercorn main:app --worker-class trio
```

</div>

And that will start Hypercorn with your app using Trio as the backend.

Now you can use Trio internally in your app. Or even better, you can use AnyIO, to keep your code compatible with both Trio and asyncio. 🎉

## Deployment Concepts