* ✏ Fix typo in `docs/en/docs/tutorial/query-params-str-validations.md`. PR [#9272](https://github.com/tiangolo/fastapi/pull/9272) by [@nicornk](https://github.com/nicornk).
* ✏ Fix typo/bug in inline code example in `docs/en/docs/tutorial/query-params-str-validations.md`. PR [#9273](https://github.com/tiangolo/fastapi/pull/9273) by [@tim-habitat](https://github.com/tim-habitat).

    * Sprawdzi czy posiada wymagany atrybut `name`, który powinien być typu `str`.
    * Sprawdzi czy posiada wymagany atrybut `price`, który musi być typu `float`.
    * Sprawdzi czy posiada opcjonalny atrybut `is_offer`, który (jeżeli obecny) powinien być typu `bool`.
    * To wszystko będzie również działać dla głęboko zagnieżdżonych obiektów JSON.
* Automatycznie konwertuje z i do JSON.

When referring to the remote machine, it's common to call it **server**, but also **machine**, **VM** (virtual machine), **node**. Those all refer to some type of remote machine, normally running Linux, where you run programs.

## Install the Server Program

When you install FastAPI, it comes with a production server, Uvicorn, and you can start it with the `fastapi run` command.

* Validar que el `item_id` es del tipo `int` para requests de tipo `GET` y `PUT`.
    * Si no lo es, el cliente verá un mensaje de error útil y claro.
* Revisar si existe un query parameter opcional llamado `q` (cómo en `http://127.0.0.1:8000/items/foo?q=somequery`) para requests de tipo `GET`.
    * Como el parámetro `q` fue declarado con `= None` es opcional.

# Deployments Concepts

When deploying a **FastAPI** application, or actually, any type of web API, there are several concepts that you probably care about, and using them you can find the **most appropriate** way to **deploy your application**.

Some of the important concepts are:

* Security - HTTPS
* Running on startup
* Restarts
* Replication (the number of processes running)
* Memory
* Previous steps before starting

# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

### Tested

* 100% <abbr title="The amount of code that is automatically tested">test coverage</abbr>.
* 100% <abbr title="Python type annotations, with this your editor and external tools can give you better support">type annotated</abbr> code base.
* Used in production applications.

## Starlette features

          filters:
          - '!^_'
          merge_init_into_class: true
          docstring_section_style: spacy
          signature_crossrefs: true
          show_symbol_type_heading: true
          show_symbol_type_toc: true
nav:
- FastAPI: index.md
- features.md
- Learn:
  - learn/index.md
  - python-types.md
  - async.md
  - Tutorial - User Guide:
    - tutorial/index.md

**Código fonte**: <a href="https://github.com/tiangolo/fastapi" target="_blank">https://github.com/tiangolo/fastapi</a>

---

FastAPI é um moderno e rápido (alta performance) _framework web_ para construção de APIs com Python, baseado nos _type hints_ padrões do Python.

Os recursos chave são:

* **Rápido**: alta performance, equivalente a **NodeJS** e **Go** (graças ao Starlette e Pydantic). [Um dos frameworks mais rápidos disponíveis](#performance).

</div>

Open your browser at <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

You will see a simple page like:

<img src="/img/tutorial/websockets/image01.png">

You can type messages in the input box, and send them:

<img src="/img/tutorial/websockets/image02.png">

And your **FastAPI** application with WebSockets will respond back:

<img src="/img/tutorial/websockets/image03.png">