You could also use it to generate code automatically, for clients that communicate with your API. For example, frontend, mobile or IoT applications.

## Recap, step by step

### Step 1: import `FastAPI`

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}
```

`FastAPI` is a Python class that provides all the functionality for your API.

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"sigs.k8s.io/controller-runtime/pkg/client"

	"istio.io/api/operator/v1alpha1"
	"istio.io/istio/istioctl/pkg/cli"
	"istio.io/istio/istioctl/pkg/clioptions"
	revtag "istio.io/istio/istioctl/pkg/tag"
	"istio.io/istio/istioctl/pkg/util"
	v1alpha12 "istio.io/istio/operator/pkg/apis/istio/v1alpha1"
	"istio.io/istio/operator/pkg/cache"
	"istio.io/istio/operator/pkg/helmreconciler"

<pre class="ebnf">
rune_lit         = "'" ( unicode_value | byte_value ) "'" .
unicode_value    = unicode_char | little_u_value | big_u_value | escaped_char .
byte_value       = octal_byte_value | hex_byte_value .
octal_byte_value = `\` octal_digit octal_digit octal_digit .
hex_byte_value   = `\` "x" hex_digit hex_digit .
little_u_value   = `\` "u" hex_digit hex_digit hex_digit hex_digit .

```Dockerfile
CMD ["fastapi", "run", "app/main.py", "--proxy-headers", "--port", "80"]
```

## Recap

Using container systems (e.g. with **Docker** and **Kubernetes**) it becomes fairly straightforward to handle all the **deployment concepts**:

* HTTPS
* Running on startup
* Restarts

* The alternative documentation will also reflect the new query parameter and body:

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Recap

In summary, you declare **once** the types of parameters, body, etc. as function parameters.

You do that with standard modern Python types.

	if targetUser == requestorUser || targetUser == requestorParentUser {
		isSvcAccForRequestor = true
	}

	// If we are creating svc account for request sender, ensure
	// that targetUser is a real user (i.e. not derived
	// credentials).
	if isSvcAccForRequestor {
		if requestorIsDerivedCredential {
			if requestorParentUser == "" {
				writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx,