# Global Dependencies

For some types of applications you might want to add dependencies to the whole application.

Similar to the way you can [add `dependencies` to the *path operation decorators*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, you can add them to the `FastAPI` application.

In that case, they will be applied to all the *path operations* in the application:

=== "Python 3.9+"

    ```Python hl_lines="16"

# Including WSGI - Flask, Django, others

You can mount WSGI applications as you saw with [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}, [Behind a Proxy](behind-a-proxy.md){.internal-link target=_blank}.

For that, you can use the `WSGIMiddleware` and use it to wrap your WSGI application, for example, Flask, Django, etc.

## Using `WSGIMiddleware`

You need to import `WSGIMiddleware`.

* **Starlette**:
    * Will have the next best performance, after Uvicorn. In fact, Starlette uses Uvicorn to run. So, it probably can only get "slower" than Uvicorn by having to execute more code.
    * But it provides you the tools to build simple web applications, with routing based on paths, etc.
    * If you are comparing Starlette, compare it against Sanic, Flask, Django, etc. Web frameworks (or microframeworks).

* [Building Java Applications](https://docs.gradle.org/current/samples/sample_building_java_applications.html)
* [Building Java Libraries](https://docs.gradle.org/current/samples/sample_building_java_libraries.html)
* [Building Groovy Applications](https://docs.gradle.org/current/samples/sample_building_groovy_applications.html)

### Multiple Applications

In the same server (or servers), there could be **multiple applications**, for example, other API programs or a database.

* **Starlette** :
    * A les seconde meilleures performances après Uvicorn. Starlette utilise en réalité Uvicorn. De ce fait, il ne peut qu’être plus "lent" qu'Uvicorn car il requiert l'exécution de plus de code.
    * Cependant il nous apporte les outils pour construire une application web simple, avec un routage basé sur des chemins, etc.

Later, when reading about how to structure bigger applications ([Bigger Applications - Multiple Files](../../tutorial/bigger-applications.md){.internal-link target=_blank}), possibly with multiple files, you will learn how to declare a single `dependencies` parameter for a group of *path operations*.

## Global Dependencies

## HTTPX

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.

# 包含 WSGI - Flask，Django，其它

您可以挂载多个 WSGI 应用，正如您在 [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}, [Behind a Proxy](behind-a-proxy.md){.internal-link target=_blank} 中所看到的那样。

为此, 您可以使用 `WSGIMiddleware` 来包装你的 WSGI 应用，如：Flask，Django，等等。

## 使用 `WSGIMiddleware`

您需要导入 `WSGIMiddleware`。

然后使用该中间件包装 WSGI 应用（例如 Flask）。

之后将其挂载到某一个路径下。

```Python hl_lines="2-3  22"
{!../../../docs_src/wsgi/tutorial001.py!}
```

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns.Companion.SYSTEM

/**
 * A domain name service that resolves IP addresses for host names. Most applications will use the
 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,
 * or to force a specific known IP address.
 *