## The main `FastAPI` { #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` { #import-fastapi }

You import and create a `FastAPI` class as normally.

```console
$ pip install -r requirements.txt

---> 100%
```

</div>

It will install all the dependencies and your local FastAPI in your local environment.

### Using your local FastAPI

If you create a Python file that imports and uses FastAPI, and run it with the Python from your local environment, it will use your cloned local FastAPI source code.

          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and

### Cache the OpenAPI schema { #cache-the-openapi-schema }

You can use the property `.openapi_schema` as a "cache", to store your generated schema.

That way, your application won't have to generate the schema every time a user opens your API docs.

It will be generated only once, and then the same cached schema will be used for the next requests.

     this Public License, then Your rights under this Public License
     terminate automatically.

  b. Where Your right to use the Licensed Material has terminated under
     Section 6(a), it reinstates:

       1. automatically as of the date the violation is cured, provided
          it is cured within 30 days of Your discovery of the
          violation; or

 *     logger.info("Done with {0}", name);
 *   }
 * }, executor);
 * }
 *
 * <h3>How to get an instance</h3>
 *
 * <p>We encourage you to return {@code ListenableFuture} from your methods so that your users can
 * take advantage of the {@linkplain Futures utilities built atop the class}. The way that you will
 * create {@code ListenableFuture} instances depends on how you currently create {@code Future}
 * instances:

```
(You can paste links or attach files by dragging & dropping them below)
- Provide links to your updated versions of the above two colab notebooks.
- Provide links to your TensorFlow model and (optionally) TensorFlow Lite Model.
```

oh! she knows such a very little!  Besides, SHE'S she, and I'm I,
and--oh dear, how puzzling it all is!  I'll try if I know all the
things I used to know.  Let me see:  four times five is twelve,
and four times six is thirteen, and four times seven is--oh dear!
I shall never get to twenty at that rate!  However, the
Multiplication Table doesn't signify:  let's try Geography.

If you open the automatic API docs, your extension will show up at the bottom of the specific *path operation*.

<img src="/img/tutorial/path-operation-advanced-configuration/image01.png">

And if you see the resulting OpenAPI (at `/openapi.json` in your API), you will see your extension as part of the specific *path operation* too:

```JSON hl_lines="22"
{

```

### Build the Docker Image { #build-the-docker-image }

Now that all the files are in place, let's build the container image.

* Go to the project directory (in where your `Dockerfile` is, containing your `app` directory).
* Build your FastAPI image:

<div class="termy">

```console
$ docker build -t myimage .

---> 100%
```

</div>

/// tip