Mientras estás en la fila, estás inactivo 😴, esperando tu turno, sin hacer nada muy "productivo". Pero la fila es rápida porque el cajero solo está tomando los pedidos (no preparándolos), así que está bien.

Pendant que vous faites la queue, vous être simplement inactif 😴, attendant votre tour, ne faisant rien de "productif". Mais la queue est rapide car le serveur 💁 prend seulement les commandes (et ne les prépare pas), donc tout va bien.

For production you would use `fastapi run` instead. 🚀

Internally, **FastAPI CLI** uses <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a>, a high-performance, production-ready, ASGI server. 😎

## `fastapi dev` { #fastapi-dev }

Running `fastapi dev` initiates development mode.

 │                                                     │
 │  API docs: http://127.0.0.1:8000/docs               │
 │                                                     │
 │  Running in development mode, for production use:   │
 │                                                     │
 │  fastapi run                                        │
 │                                                     │

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets client { #websockets-client }

### In production { #in-production }

In your production system, you probably have a frontend created with a modern framework like React, Vue.js or Angular.

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

Imagine you are the computer / program 🤖 in that story.

While you are at the line, you are just idle 😴, waiting for your turn, not doing anything very "productive". But the line is fast because the cashier is only taking the orders (not preparing them), so that's fine.

# About FastAPI versions { #about-fastapi-versions }

**FastAPI** is already being used in production in many applications and systems. And the test coverage is kept at 100%. But its development is still moving quickly.

New features are added frequently, bugs are fixed regularly, and the code is still continuously improving.

## About security, APIs, and docs { #about-security-apis-and-docs }

Hiding your documentation user interfaces in production *shouldn't* be the way to protect your API.

That doesn't add any extra security to your API, the *path operations* will still be available where they are.

If there's a security flaw in your code, it will still exist.

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:solid">main.py</u>

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting production server 🚀

             Searching for package file structure from directories
             with <font color="#3465A4">__init__.py</font> files

    - 🤖 An automatically generated frontend client.
    - 🧪 [Playwright](https://playwright.dev) for End-to-End testing.
    - 🦇 Dark mode support.
- 🐋 [Docker Compose](https://www.docker.com) for development and production.
- 🔒 Secure password hashing by default.
- 🔑 JWT token authentication.
- 📫 Email based password recovery.
- ✅ Tests with [Pytest](https://pytest.org).