This decoupling of parts, and being a "microframework" that could be extended to cover exactly what is needed was a key feature that I wanted to keep.

Given the simplicity of Flask, it seemed like a good match for building APIs. The next thing to find was a "Django REST Framework" for Flask.

!!! check "Inspired **FastAPI** to"

This can be very useful for setting up **resources** that you need to use for the whole app, and that are **shared** among requests, and/or that you need to **clean up** afterwards. For example, a database connection pool, or loading a shared machine learning model.

## Use Case

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

* Then check that the tests **pass** after the PR. ✅

* Many PRs don't have tests, you can **remind** them to add tests, or you can even **suggest** some tests yourself. That's one of the things that consume most time and you can help a lot with that.

* Then also comment what you tried, that way I'll know that you checked it. 🤓

## Create a Pull Request

  - type: textarea
    attributes:
      label: 1. What are you trying to do?
    validations:
      required: true

  - type: textarea
    attributes:
      label: 2. What's the best code you can write to accomplish that without the new feature?
    validations:
      required: true

  - type: textarea
    attributes:
      label: 3. What would that same code look like if we added your feature?
    validations:

### FastAPI Data Filtering

Now, for FastAPI, it will see the return type and make sure that what you return includes **only** the fields that are declared in the type.

<div class="termy">

```console
$ pip install "fastapi[all]"

---> 100%
```

</div>

...that also includes `uvicorn`, that you can use as the server that runs your code.

!!! note
    You can also install it part by part.

    This is what you would probably do once you want to deploy your application to production:

    ```
    pip install fastapi
    ```

```

The `@app.get("/")` tells **FastAPI** that the function right below is in charge of handling requests that go to:

* the path `/`
* using a <abbr title="an HTTP GET method"><code>get</code> operation</abbr>

!!! info "`@decorator` Info"
    That `@something` syntax in Python is called a "decorator".

    You put it on top of a function. Like a pretty decorative hat (I guess that's where the term came from).

  // DriverName defines the name of the dynamic resource driver that is
  // used for allocation of a ResourceClaim that uses this class.
  //
  // Resource drivers have a unique name in forward domain order
  // (acme.example.com).
  optional string driverName = 2;

  // ParametersRef references an arbitrary separate object that may hold
  // parameters that will be used by the driver when allocating a

## Containers and Processes

A **container image** normally includes in its metadata the default program or command that should be run when the **container** is started and the parameters to be passed to that program. Very similar to what would be if it was in the command line.

When a **container** is started, it will run that command/program (although you can override it and make it run a different command/program).

You can see those schemas because they were declared with the models in the app.

That information is available in the app's **OpenAPI schema**, and then shown in the API docs (by Swagger UI).

And that same information from the models that is included in OpenAPI is what can be used to **generate the client code**.

### Generate a TypeScript Client

Now that we have the app with the models, we can generate the client code for the frontend.