## Adding ASGI middlewares

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

In general, ASGI middlewares are classes that expect to receive an ASGI app as the first argument.

## ASGI Servers

Let's go a little deeper into the details.

FastAPI uses a standard for building Python web frameworks and servers called <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI is an ASGI web framework.

* <a href="https://tartiflette.io/" class="external-link" target="_blank">Tartiflette</a>
    * With <a href="https://tartiflette.github.io/tartiflette-asgi/" class="external-link" target="_blank">Tartiflette ASGI</a> to provide ASGI integration
* <a href="https://graphene-python.org/" class="external-link" target="_blank">Graphene</a>

import strawberry
from fastapi import FastAPI
from strawberry.asgi import GraphQL


@strawberry.type
class User:
    name: str
    age: int


@strawberry.type
class Query:
    @strawberry.field
    def user(self) -> User:
        return User(name="Patrick", age=100)


schema = strawberry.Schema(query=Query)


graphql_app = GraphQL(schema)

app = FastAPI()
app.add_route("/graphql", graphql_app)

!!! note "Technical Details"
    ASGI is a new "standard" being developed by Django core team members. It is still not a "Python standard" (a PEP), although they are in the process of doing that.

    Nevertheless, it is already being used as a "standard" by several tools. This greatly improves interoperability, as you could switch Uvicorn for any other ASGI server (like Daphne or Hypercorn), or you could add ASGI compatible tools, like `python-socketio`.

## 구니콘과 유비콘 워커

**Gunicorn**은 **WSGI 표준**을 주로 사용하는 애플리케이션 서버입니다. 이것은 구니콘이 플라스크와 쟝고와 같은 애플리케이션을 제공할 수 있다는 것을 의미합니다. 구니콘 자체는 최신 **<a href="https://asgi.readthedocs.io/en/latest/" class="external-link" target="_blank">ASGI 표준</a>**을 사용하기 때문에 FastAPI와 호환되지 않습니다.

하지만 구니콘은 **프로세스 관리자**역할을 하고 사용자에게 특정 **워커 프로세스 클래스**를 알려줍니다. 그런 다음 구니콘은 해당 클래스를 사용하여 하나 이상의 **워커 프로세스**를 시작합니다.

그리고 **유비콘**은 **구니콘과 호환되는 워커 클래스**가 있습니다.

!!! note "Technical Details"
    The ASGI specification defines a `root_path` for this use case.

    And the `--root-path` command line option provides that `root_path`.

### Checking the current `root_path`

You can get the current `root_path` used by your application for each request, it is part of the `scope` dictionary (that's part of the ASGI spec).

Es gibt 3 Hauptalternativen:

* <a href="https://www.uvicorn.org/" class="external-link" target="_blank">Uvicorn</a>: ein hochperformanter ASGI-Server.
* <a href="https://pgjones.gitlab.io/hypercorn/" class="external-link" target="_blank">Hypercorn</a>: ein ASGI-Server, der unter anderem mit HTTP/2 und Trio kompatibel ist.

Die Hierarchie ist wie folgt:

* **Uvicorn**: ein ASGI-Server
    * **Starlette**: (verwendet Uvicorn) ein Web-Mikroframework
        * **FastAPI**: (verwendet Starlette) ein API-Mikroframework mit mehreren zusätzlichen Funktionen zum Erstellen von APIs, mit Datenvalidierung, usw.

Чем проще проблема, которую решает инструмент, тем выше его производительность. И большинство тестов не проверяют дополнительные функции, предоставляемые инструментом.

Иерархия инструментов имеет следующий вид:

* **Uvicorn**: ASGI-сервер
    * **Starlette** (использует Uvicorn): веб-микрофреймворк
        * **FastAPI** (использует Starlette): API-микрофреймворк с дополнительными функциями для создания API, с валидацией данных и т.д.

* **Uvicorn**: