You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies { #install-dependencies }

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `jinja2`:

      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Unauthorized request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: Page not found
      content:
        application/json:
          schema:

import java.beans.Introspector;
import java.util.Deque;

/**
 * Utility class for disposing of resources at the end of an application.
 * <p>
 * If there are resources that must be disposed of at the end of the application,
 * create a class that implements {@link Disposable} and register it with this class.
 * </p>
 *
 * @author koichik
 */
public abstract class DisposableUtil {

about just retrofitting monolithic applications onto modern container based compute environment. A cloud-native application is portable and resilient by design, and can scale horizontally by simply replicating. Modern orchestration platforms like Kubernetes, DC/OS make replicating and managing containers in huge clusters easier than ever.

While containers provide isolated application execution environment, orchestration platforms allow seamless scaling by helping replicate and manage containers....

	// Some standard content-types which we strictly dis-allow for compression.
	standardExcludeCompressContentTypes = []string{"video/*", "audio/*", "application/zip", "application/x-gzip", "application/x-zip-compressed", " application/x-compress", "application/x-spoon"}

	// AuthZ Plugin system.
	globalAuthZPlugin *polplugin.AuthZPlugin

	// Deployment ID - unique per deployment

And to communicate using WebSockets with your backend you would probably use your frontend's utilities.

Or you might have a native mobile application that communicates with your WebSocket backend directly, in native code.

Or you might have any other way to communicate with the WebSocket endpoint.

---

            mimeType = "text/html";
        } else if (response instanceof JsonResponse) {
            mimeType = "application/json";
        } else if (response instanceof XmlResponse) {
            mimeType = "text/xml";
        } else if (response instanceof StreamResponse) {
            mimeType = "application/octet-stream";
        } else {
            logger.debug("Unknown response: {}", response);
            return;

# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

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/// note | Технические детали

Команда `uvicorn main:app` обращается к:

* `main`: файл `main.py` (модуль Python).

<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

**ДУЖЕ радимо** написати або скопіювати код, відредагувати його та запустити локально.