/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

Make sure you evaluate if the **benefits** for your use case compensate the **drawbacks**. 🤓

///

## GraphQL Libraries

Here are some of the **GraphQL** libraries that have **ASGI** support. You could use them with **FastAPI**:

To keep the Groovy DSL ergonomic, we generate methods as necessary from the non-Groovy equivalents.

Doing this provides the following specific benefits:
- **Reduce the API surface** - We no longer need to maintain two methods.
- **Consistency** - All languages have consistent access to the same APIs and ergonomics in the DSL.

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

///

## Dependencies errors and return values

Again, just with that same Python type declaration, **FastAPI** gives you automatic, interactive documentation (integrating Swagger UI).

Notice that the path parameter is declared to be an integer.

///

## Standards-based benefits, alternative documentation

</pre>
```

</div>

It is **HIGHLY encouraged** that you write or copy the code, edit it and run it locally.

Using it in your editor is what really shows you the benefits of FastAPI, seeing how little code you have to write, all the type checks, autocompletion, etc.

---

## Install FastAPI

The first step is to install FastAPI.

It means that **FastAPI** was specifically tested with the editors used by 80% of the Python developers. And as most of the other editors tend to work similarly, all its benefits should work for virtually all editors.

That way I could find the best ways to reduce code duplication as much as possible, to have completion everywhere, type and error checks, etc.

    ikrt["Istio krt.Collection"]
    ikrt--"Builds on"-->ikc--"Builds on"-->ic--"Builds on"-->kcg
```

**`kube.Client`** is a fairly light wrapper around Kubernetes clients, but offers quite a few benefits.
Istio consumes _many_ different types of clients (at the time of writing, 7), as well as informers for each of these.
Additionally, we often need to convert to various different client forms for different libraries we integrate with.

     * fail. Use a custom [HostnameVerifier] to ignore such problems.
     *
     * Other TLS features are still used but provide no security benefits in absence of the above
     * gaps. For example, an insecure TLS connection is capable of negotiating HTTP/2 with ALPN and
     * it also has a regular-looking handshake.
     *

  }
}
```

After generating the new client, you would now have **clean method names**, with all the **autocompletion**, **inline errors**, etc:

<img src="/img/tutorial/generate-clients/image08.png">

## Benefits

When using the automatically generated clients you would get **autocompletion** for:

* Methods.
* Request payloads in the body, query parameters, etc.
* Response payloads.

To declare a **request** body, you use <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> models with all their power and benefits.

/// info

To send data, you should use one of: `POST` (the more common), `PUT`, `DELETE` or `PATCH`.