Aqui está um pouco dessa história.

## Alternativas

Eu tenho criado APIs com requisitos complexos por vários anos (Aprendizado de Máquina, sistemas distribuídos, tarefas assíncronas, banco de dados NoSQL etc.), liderando vários times de desenvolvedores.

Como parte disso, eu precisava investigar, testar e usar muitas alternativas.

A história do **FastAPI** é, em grande parte, a história de seus predecessores.

query_or_cookie_extractor(["query_or_cookie_extractor"])

read_query["/items/"]

query_extractor --> query_or_cookie_extractor --> read_query
```

## Using the same dependency multiple times

If one of your dependencies is declared multiple times for the same *path operation*, for example, multiple dependencies have a common sub-dependency, **FastAPI** will know to call that sub-dependency only once per request.

Usando essa combinação levou a criação de vários geradores Flask _full-stack_. Há muitas _stacks_ que eu (e vários times externos) estou utilizando até agora:

* <a href="https://github.com/tiangolo/full-stack" class="external-link" target="_blank">https://github.com/tiangolo/full-stack</a>

    So, it's important to put this **near the end** of the `Dockerfile`, to optimize the container image build times.

6. Set the **command** to run the `uvicorn` server.

    `CMD` takes a list of strings, each of these strings is what you would type in the command line separated by spaces.

### Restart After Crash

But in those cases with really bad errors that crash the running **process**, you would want an external component that is in charge of **restarting** the process, at least a couple of times...

!!! tip

But all this functionality of using asynchronous code with `async` and `await` is many times summarized as using "coroutines". It is comparable to the main key feature of Go, the "Goroutines".

## Conclusion

Let's see the same phrase from above:

* Then **comment** saying that you did that, that's how I will know you really checked it.

!!! info
    Unfortunately, I can't simply trust PRs that just have several approvals.

    Several times it has happened that there are PRs with 3, 5 or more approvals, probably because the description is appealing, but when I check the PRs, they are actually broken, have a bug, or don't solve the problem they claim to solve. 😅

<img src="/img/tutorial/bigger-applications/image01.png">

## Include the same router multiple times with different `prefix`

You can also use `.include_router()` multiple times with the *same* router using different prefixes.

This could be useful, for example, to expose the same API under different prefixes, e.g. `/api/v1` and `/api/latest`.

## Opiniões

"*[...] Estou usando **FastAPI** muito esses dias. [...] Estou na verdade planejando utilizar ele em todos os times de **serviços _Machine Learning_ na Microsoft**. Alguns deles estão sendo integrados no _core_ do produto **Windows** e alguns produtos **Office**.*"

        Generate the OpenAPI schema of the application. This is called by FastAPI
        internally.

        The first time it is called it stores the result in the attribute
        `app.openapi_schema`, and next times it is called, it just returns that same
        result. To avoid the cost of generating the schema every time.

        If you need to modify the generated OpenAPI schema, you could modify it.

        Read more in the